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Open-File Report 2010–XX

U.S. Department of the Interior
U.S. Geological Survey

U.S. Department of the Interior
Ken Salazar, Secretary

U.S. Geological Survey
Marsha McNutt, Director

U.S. Geological Survey, Reston, Virginia 2010
Revised and reprinted: 2010

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                                                            Table of Contents
ABSTRACT .................................................................................................................................................... 12
INTRODUCTION .......................................................................................................................................... 12
RESPONSIBILITIES ..................................................................................................................................... 13
   FLWSC Associate Center Director for Data ................................................................................. 13

   FLWSC Chief of Hydrologic Record Section (Data Section Chief) of the Fort Lauderdale, Fort

   Myers, Orlando, Tallahassee and Tampa Offices.......................................................................... 14

   FLWSC Surface-Water Specialists ............................................................................................... 14

   Surface-Water Coordinator and Database Supervisor (Field Operations and Data Management

   Units) ............................................................................................................................................. 15

   Surface-Water Coordinator and Database Unit Team Leaders ..................................................... 16

      Functions of Team Leaders ........................................................................................................ 17

      Differences between Team Leaders and Supervisors ................................................................ 18

   Senior Hydrographers .................................................................................................................... 19

   Project Chiefs ................................................................................................................................ 20

   Field Hydrographers ...................................................................................................................... 20

   Surface-Water Database Administrator ......................................................................................... 20

   FLWSC Safety Officer .................................................................................................................. 21

COLLECTION OF STAGE AND STREAMFLOW DATA ......................................................................... 21
   Gage Installation and Maintenance ............................................................................................... 22

   Measurement of Stage ................................................................................................................... 23

   Measurement of Velocity .............................................................................................................. 25

      Velocity Gage Installation Considerations................................................................................. 26

      Velocity Data Processing ........................................................................................................... 27

   Measurement of Hydraulic Structure Parameters .......................................................................... 27

   Gage Documents ........................................................................................................................... 28

   Levels ............................................................................................................................................ 29

   Site Documentation ....................................................................................................................... 32

      Station Descriptions ................................................................................................................... 32

      Documenting the Establishment of New Surface-Water Stations ............................................. 33

      Station Identification Number Assignment ................................................................................ 35

      Downstream Order Station Number........................................................................................... 35

      Latitude-Longitude Sequence Number ...................................................................................... 36

   Photographs ................................................................................................................................... 36

Direct Measurements ...................................................................................................................................... 36
   Acoustic Wading Measurements ................................................................................................... 37

   Acoustic Doppler Current Profilers ............................................................................................... 37

   Discharge Measurements in General ............................................................................................. 37

   Field Notes..................................................................................................................................... 39

   Acceptable Equipment ................................................................................................................... 40

      Price AA and Pygmy Current Meters ........................................................................................ 40

      Flume Measurements ................................................................................................................. 43

   Measurement Checking ................................................................................................................. 43

   Hydroacoustic Measurements ....................................................................................................... 44

      FlowTracker ............................................................................................................................... 44

   Acoustic Doppler Current Profiler ................................................................................................ 44

      Training ...................................................................................................................................... 45

      Data Processing .......................................................................................................................... 47

      Alternative Equipment ............................................................................................................... 47

      Other Direct Methods of Measuring Discharge ......................................................................... 48

Indirect Measurements .................................................................................................................................... 48
   Peaks above Base .......................................................................................................................... 49

      Peak Flow Files .......................................................................................................................... 50

   Crest-Stage Indicator Gages .......................................................................................................... 51

   Artificial Controls .......................................................................................................................... 52

   Flood Conditions ........................................................................................................................... 52

   Low-Flow Conditions .................................................................................................................... 54

   Weather Conditions ....................................................................................................................... 55

PROCESSING AND ANALYSIS OF STREAMFLOW DATA ................................................................... 55
   Processing of Real-Time Streamflow Data ................................................................................... 55

      NWIS Web Presentation Format ................................................................................................ 56

      Review of Real-Time Streamflow Data ..................................................................................... 57

      Error Handling ........................................................................................................................... 57

   Measurements and Field Notes...................................................................................................... 58

   Continuous Record ........................................................................................................................ 58

   Records and Computation ............................................................................................................. 59

      Procedures for Working and Checking Records ........................................................................ 60

      Discharge Surrogates ................................................................................................................. 60

      Levels ......................................................................................................................................... 60

      Rating ......................................................................................................................................... 61

      Datum corrections, gage-height corrections, and shifts ............................................................. 63

      Hydrographs ............................................................................................................................... 63

      Hydra .......................................................................................................................................... 64

      Station Analysis ......................................................................................................................... 65

      Furnished records ....................................................................................................................... 66

      Manuscript and Annual Data Report .......................................................................................... 66

   Crest-Stage Indicator Gages .......................................................................................................... 68

OFFICE SETTING ......................................................................................................................................... 68

   Work plan ...................................................................................................................................... 69

   File Folders for Surface-Water Stations ........................................................................................ 69

   Field-Trip Folders .......................................................................................................................... 69

   Levels ............................................................................................................................................ 70

   Benchmark Elevation .................................................................................................................... 70

   Station Descriptions....................................................................................................................... 70

   Discontinued Stations .................................................................................................................... 70

Map Files ........................................................................................................................................................ 71
   Archiving ....................................................................................................................................... 71

   Communication of New Methods and Current Procedures ........................................................... 71

COLLECTION OF SEDIMENT DATA ........................................................................................................ 72
   Sampling Procedures ..................................................................................................................... 72

   Field Notes..................................................................................................................................... 72

   Equipment...................................................................................................................................... 73

   Sample Handling and Storage ....................................................................................................... 73

   High-flow Conditions .................................................................................................................... 74

   Cold-Weather Conditions .............................................................................................................. 74

   Site Documentation ....................................................................................................................... 74

PROCESSING AND ANALYSIS OF SEDIMENT DATA .......................................................................... 74
   Sediment Station Analysis ............................................................................................................. 74

   Sediment Analysis Results ............................................................................................................ 75

   Sediment Data Storage .................................................................................................................. 75

DATABASE MANAGEMENT ..................................................................................................................... 75
PUBLICATION OF SURFACE-WATER DATA ......................................................................................... 76
   Publication Policy .......................................................................................................................... 76

   Types of Publications .................................................................................................................... 76

   Review Process .............................................................................................................................. 77

SAFETY ......................................................................................................................................................... 78
TRAINING ..................................................................................................................................................... 78
SUMMARY .................................................................................................................................................... 79
   Appendix 1 - Selected Office of Surface-Water and Water Resources Division/Discipline

   Memorandum Cited ....................................................................................................................... 81

   Appendix 1a. OSW 83.07--Availability of hydraulics programs for Prime computers--

   September 9, 1983 ......................................................................................................................... 82

   Appendix 1b. OSW 85.17--Policy on Providing Low-Flow Information-- September 20, 1985 . 84

   Appendix 1c. OSW 87.05--Bridge Waterways Analysis: Research Report.-- March 6, 1987 .... 86

   Appendix 1d. OSW 88.07--Guidelines for the Operation of a Crest-Stage Program-- April 14,

   1988 ............................................................................................................................................... 87

   Appendix 1e. OSW 89.07--Policy to Ensure the Accurate Performance of Current Meters--

   June 2, 1989 ................................................................................................................................... 89

   Appendix 1f. OSW 89.08--Policy Statement on Stage Accuracy-- June 2, 1989 ......................... 91

   Appendix 1g. OSW 92.09--Adjustment of Discharge Measurements Made at a Distance from

   the Gaging Station during Periods of Changing Stage and Discharge--June 17, 1992 ................. 92

   Appendix 1h. OSW 92.10--Guidelines for Identifying and Evaluating Peak Discharge Errors--

   July 2, 1992 ................................................................................................................................... 96

   Appendix 1i. OSW 92.11--Flow Process Recognition for Floods in Mountain Streams-- July

   21, 1992 ....................................................................................................................................... 100

   Appendix 1j. OSW 93.07--Policy Statement on Stage Accuracy-- December 4, 1992 .............. 103

   Appendix 1k. OSW 93.12--Techniques of Water-Resources Investigations (TWRI) Book 3,

   Chapter A19--Clarification of Leveling Procedure-- February 4, 1993 ...................................... 105

   Appendix 1l. OSW 2002.02--Policy and Technical Guidance on Discharge Measurements

   using Acoustic Doppler Current Profilers-- December 7, 2001 .................................................. 106

Appendix 1m. OSW 2002.03--Release of WinRiver Software (version 10.03) for Computing

Streamflow from Acoustic Profiler Data--December 7, 2001 ..................................................... 110

Appendix 1n. OSW 2003.04--Release of WinRiver Software version 10.05 for Computing

Streamflow from Acoustic Profiler Data—May 19, 2003 .......................................................... 116

Appendix 1o. OSW 2004.04--Policy on the use of the FlowTracker for discharge

measurements.--June 2, 2004 ...................................................................................................... 126

Appendix 1p. OSW 96.05-- Policy Concerning Accuracy of Stage Data.—February 5, 1996 .. 133

Appendix 1q. OSW 90.10-- Frequency of Levels at Streamflow Gaging Stations.—February

28, 1990 ....................................................................................................................................... 135

Appendix 1r. WRD 77.83--Retention of Original Water Records--March 30. 1977 .................. 136

Appendix 1s. WRD 92.59--Policy for Management and Retention of Hydrologic Data of the

U.S. Geological Survey ............................................................................................................... 138

Appendix 1t. WRD 95.19--Policy for Making Provisional Water-Resource Data Available on

the Internet--March 10, 1995 ....................................................................................................... 140

Appendix 1u. WRD 97.17--Disseminating Real-time Streamflow Data through the World

Wide Web-- April 11, 1997 ......................................................................................................... 142

Appendix 1v. WRD 99.34--Quality Assurance Measures for Serving Real-time Water Data on

the World Wide Web--February 28, 2000 ................................................................................... 144

Appendix-1w OSW 2006.01--Collection, Quality Assurance, and Presentation of Precipitation

Data--December 28, 2005............................................................................................................ 146

Appendix – 1 y OSW 2005.08 -- Policy and Guidance for Archiving Electronic Discharge

Measurement Data ....................................................................................................................... 171

 Appendix 1z – OSW 2007.01 – SonTek/YSI FlowTracker firmware version 3.10 and software

 version 2.11 upgrades and additional policy on the use of FlowTrackers for discharge

 measurements. ............................................................................................................................. 175

 Appendix 2a – Index velocity station installation form. ............................................................. 186

 Appendix 2b – Index velocity station field form. ........................................................................ 187

 Appendix 3a. – Florida WSC electronic file archive directory structure. ................................... 188

 Appendix 3b. Florida Water Science Center electronic file naming conventions....................... 189


 1. Map showing location of Florida Water Science Center ........................................................... 12
 2. Diagram showing variables in estimating flow disturbance ...................................................... 27
 3. Station levels at Little Charley Bowlegs Creek ......................................................................... 29
 4. Assembly drawing of Price AA current meter ........................................................................... 40
 5. SonTek FlowTracker ................................................................................................................. 44
 6. Two acoustic Doppler current profilers commonly used by the USGS to measure streamflow45
 7. Crest-stage gage......................................................................................................................... 51
 8. Compound weir at Sixmile Creek phosphate-mine outfall ....................................................... 52
 9. Flood inundation at Buckhorn Creek ........................................................................................ 53
 10. Hurricane—Potential for wide-spread flooding ...................................................................... 54
 11. Low-flow conditions along the Peace River ........................................................................... 54
 12. Example of a stage-discharge rating curve .............................................................................. 62
 13. Streamflow hydrographs of gaging stations in the upper Peace River basin .......................... 64
 14. US DH-48 and US D-74 sediment samplers ........................................................................... 73


  ADAPS - Automated Data Processing System
  ADCP - Acoustic Doppler Current Profilers
  ADVM - Acoustic Doppler velocity meter
  ADR - Analog-to-Digital Recorders
  CAP - Computer Program used to Compute Peak Discharge at Culverts
  CD - Compact Disk
  CRP - Continuous Record Processing
  CSG - Crest-Stage Gage
  DCP - Data Collection Platforms
  EDL - Electronic Data Loggers
  FLWSC - Florida Water Science Center
  FRC - Federal Records Center
  GIS - Geographic Information System
  GPS - Global Positioning System
  HEC-RAS - Hydrologic Engineer Center-River Analysis System
  HIF - Hydrologic Instrumentation Facility
  HYDRA – Plotting and editing program within ADAPS
  IT - Information Technology
  JHA - Job Hazard Analysis
  LRGS - Local Receiving Ground Station
  NAWQA - National Water-Quality Assessment Program
  NCALC - Computer Program used to Compute Manning‘s n Value
  NWIS - National Water Information System
  NWIS Web - National Water Information System Web
  OSW - Office of Surface Water, USGS
  PDF - Portable Document Format
  PZF - Point-of-Zero Flow (also known as gage-height of zero flow)
  QA - Quality Assurance
  SAC - Computer Program used to Compute Peak Discharge with the
          Slope-Area Method
  TWRI - Techniques of Water Resources Investigations
  USGS – United States Geological Survey
  WSPRO - Water-Surface Profile Computation Model
  WebCASS - USGS Occupational, Safety, Health and Environmental (OSHE) Management System

Surface-Water Quality-Assurance Plan for
the Florida Water Science Center, U.S. Geological Survey
By J.L. Pearman, R.L. Kane, S.A. Tomlinson, M.R. Dickman, E.P. Simonds, K.B. Overton, P.R.
Messer, E.C. Price, A. Nazarian, and V.A. Levesque

   Abstract                                          levels for resources planning and
        The U.S. Geological Survey (USGS)
   Florida Water Science Center (FLWSC)                    The purpose of the Florida Water
   Offices, located in Tallahassee, Tampa,           Science Center comprehensive Surface-
   Orlando, Fort Lauderdale, and Fort Myers          Water Quality-Assurance Plan (SW/QA
   have developed a state-wide Surface-Water         Plan) is to document the standards, policies,
   Quality-Assurance Plan (fig. 1). This plan        and procedures used by the USGS in the
   documents the standards, policies, and            FLWSC for activities related to the
   procedures used by the Florida Water              collection, processing, storage, analysis, and
   Science Centers for activities related to the     publication of surface-water data. This plan
   collection, processing, storage, analysis, and    identifies responsibilities for ensuring that
   publication of surface-water data. This plan      stated policies and procedures are carried
   serves as a standardized comprehensive            out. The plan also serves as a guide for all
   guide for all USGS Florida personnel              personnel involved in surface-water
   involved in surface-water data activities.        activities and as a resource for identifying
   This is a living document that will change as     memorandums, publications, and other
   the needs, technology, and requirements of        literature that describe in more detail asso-
   the USGS change. Regular updates to this          ciated techniques and requirements.
   Plan represent an integral part of the quality-
   assurance process. Direct oversight and
   responsibility by the employee(s) involved
   in surface-water data activities, combined
   with team approaches in all work efforts,
   assure high-quality data, analyses, reviews,
   and reports for cooperating agencies and the

        The U.S. Geological Survey was
   established by an act of Congress on
   March 3, 1879, to provide a permanent
   Federal agency to conduct the systematic
   and scientific ―classification of the public
   lands, and examination of the geologic
   structure, mineral resources, and products of
   the national domain.‖ Surface-water
   activities in Florida are part of the USGS        Figure 1. Location of Florida Water Science
   overall mission of appraising the Nation's
   water resources. Surface-water information,       Center offices.
   including streamflow, stage, and sediment
   data, is used at the Federal, State, and local

      Specific types of surface-water data        with the FLWSC Director (Schroder and
addressed by this plan include the collection     Shampine, 1992, p. 7). The FLWSC
of stage, streamflow, sediment, and basin         Director has delegated that responsibility to
characteristics data along with the               the FLWSC Associate Center Director for
processing and publication of this                Data who is responsible for future updates
information. In addition, issues related to the   and revisions of the SW/QA Plan. Project
management of the computer database,              chiefs involved in the collection of surface-
employee safety, and training are presented.      water data are required to prepare a SW/QA
Although procedures and products of               plan as part of their proposal and work plan
interpretive projects are subject to the          that conforms to the policies and procedures
criteria presented in this report, individual     outlined in this plan (Shampine and others,
interpretive projects are required to have a      1992, p.2).
separate and complete SW/QA plan.
                                                       The following is a list of the titles and
     The Florida SW/QA Plan is reviewed           responsibilities of personnel involved in the
and revised at least once every three years in    collection, processing, storage, analysis, or
order that responsibilities and methodologies     publication of surface-water data.
are kept current and in order that the
ongoing procedural improvements can be
effectively documented.

                                                  Manage and direct the FLWSC program,
                                                  including all surface-water activities.
     Quality assurance (QA) is required to
actively maintain and improve high-quality        1. Ensure that surface-water activities meet
                                                      the needs of the Federal Government,
standards for surface-water data, as well as
                                                      the FLWSC, State and local agencies,
other data, and remains key to the integrity
of the USGS. Clear delineations of                    other cooperating agencies, and the
responsibility sometimes become difficult to          general public.
                                                  2. Ensure that all aspects of this SW/QA
determine because of varying levels of
expertise and duties in an office, combined           Plan are understood and followed by
with numerous types of gaging activities and          Data Section personnel throughout the
                                                      State. This is accomplished by the
instruments. While the FLWSC Associate
Center Director for Data takes responsibility         Associate Center Director for Data‘s
for overseeing the entire program, which              direct involvement or through clearly
                                                      stated delegation of this responsibility to
includes surface-water data-collection and
analysis, ultimately the person having the            the Data Chiefs located in the five
most impact on the quality assurance of the           offices in Florida.
collected data is the field person who            3. Provide final resolution of any conflicts
                                                      or disputes related to surface-water
collects the data. Errors and deficiencies can
occur when individuals fail to carry out their        activities within the office.
responsibilities. Clear and specific              4. Keep personnel briefed on procedural
                                                      and technical communications from
statements of responsibilities promote an
understanding of each person's duties in the          Region and Headquarters.
overall process of assuring surface-water         5. Ensure that all publications and other
                                                      technical communications released by
data quality.
                                                      the FLWSC are accurate and are in
     Responsibilities are assigned to                 accord with USGS policy.
personnel by position title. The                  6. Implementing USGS and FLWSC safety
responsibility for the preparation of,                policies.
implementation of, and adherence to the QA        7. Has the overall responsibility to ensure
policies described in the SW/QA Plan is               that the FLWSC is adequately prepared

   to respond immediately in the event of a           communicate the contents of those work
   flood.                                             plans to personnel in the Hydrologic
8. Perform or facilitate periodic reviews of          Records Section.
   all surface-water programs.                  7.    Ensure that records for all surface-water
9. In the event of a major flood:                     data stations are computed correctly and
        a. Notify the appropriate Regional            checked and that all records are
            and Headquarters officials of             reviewed either semi-annually or
            the nature and extent of the              annually.
            flood in accordance with WRD        8.    Ensure that any identified deficiencies
            Memo 90.22, dated February 6,             associated in the collection, analysis, or
            1990 (See FLWSC flood plan).              publication of surface-water data are
        b. Request assistance from other              corrected and ensure that improved
            USGS offices if deemed                    methods are instituted.
            necessary.                          9.    Ensure that all personnel in the FLWSC
                                                      involved in the collection, analyses, and
FLWSC Chief of Hydrologic Record                      publication of surface-water data receive
Section (Data Section Chief) of the Fort              a copy of the SW/QA Plan and that they
Lauderdale, Fort Myers, Orlando,                      are familiar with its contents.
Tallahassee and Tampa Offices                   10.   Serve as the Flood Coordinator of their
                                                      respective office.
Advise the Associate Center Director for        11.   Ensure that all personnel are aware of
Data on all matters related to surface-water          and operate in accordance with safety
networks and data-collection in the FLWSC.            policies established by the USGS and
1. Manage the data-collection program of              the -FLWSC as implemented by the
    their respective office by serving as the         FLWSC director.
    principle contact between cooperators       12.   Ensure that the surface-water databases
    and the USGS.                                     are properly maintained and updated.
2. Manage the office data section budget to     13.   Implement USGS and FLWSC safety
    assure the data-collection program                policies.
    operates in a fiscally responsible
    manner.                                     FLWSC Surface-Water Specialists
3. Implement the FLWSC SW/QA Plan in            (position has not been filled)
    the Hydrologic Data Program and
    coordinate quality-assurance activities     1. Maintain technical proficiency in and
    between the Data Section, Hydrologic           awareness of new developments in the
    Studies program, and other programs of         field of surface-water hydrology;
    the FLWSC.                                     reading appropriate journals, conferring
4. Ensure the surface-water data collection        with colleagues and staff; reviewing
    and analysis activities associated with        technical advances in monitoring and
    the FLWSC surface-water gaging                 interpretation; and communicating new
    network conform to the goals and               methods and technologies to FLWSC
    policies of the USGS, the Office of            personnel.
    Surface Water (OSW), and the FLWSC.         2. Develop or assist in writing project
5. With the Associate Center Director for          proposals that address specific
    Data, coordinate SW/QA issues with             hydrologic investigations involving
    FLWSC, Regional, and Headquarters              Cooperator, FLWSC, Regional, or
    staff specialists.                             USGS thrust programs.
6. Develop the work plans designed to           3. Provide technical review of project
    accomplish the goals of collecting,            proposals and, when necessary and
    processing, analyzing, and storing             mutually agreed upon, proposals from
    FLWSC surface-water data; publishing           other FLWSC offices in order to provide
    the data in the Annual Data Report; and

      an independent appraisal at the initial            for the FLWSC Director and other
      stage of project development.                      appropriate staff.
4.    Provide technical review of reports          14.   Meet either face-to-face or via
      (entire report or selected portions)               conference call periodically as necessary
      before transmittal to Region, or                   with other members of the FLWSC
      delegates such review after consultation           Specialist Committee. The team leader
      with the appropriate Section Chief.                will provide quarterly reports of team
5.    Maintain archives for surface-water                activities and accomplishments to the
      records and publications in accordance             FLWSC Director and the Associate
      with Regional and Bureau policies.                 Directors.
6.    Advise management on training needs          15.   Review a cross-section of data annually
      for personnel. Organize or perform                 prior to publication. Review should
      training.                                          cover an appropriate representative
7.    Assist Associate Center Director for               sample subset of stations per year to
      Data and the Data Chiefs with                      insure that the QA plans are being
      maintaining the SW/QA plan.                        properly implemented. (The review
8.    Participate in progress, quarterly, and            should also cover data descriptors, daily
      technical reviews of surface-water                 value inventory, and NWIS Web.)
      projects, as requested by the Associate      16.   Ensure that correct technical procedures
      Center Director for Data or to maintain            are used in the collection and use of
      the quality of program.                            surface-water data.
9.    Assist other Florida FLWSC specialists,      17.   Provide technical assistance to data
      when necessary and mutually agreed                 collection activities.
      upon, to take advantage of each              18.   Provide technical assistance in data
      specialist‘s areas of expertise.                   analysis and interpretation for surface-
10.   Serve on committees and working                    water hydrologic investigations.
      groups within FLWSC, Region, Bureau,         19.   Review hydrologic conditions
      and external to the USGS as time and               statements for the Annual Data Reports.
      resources allow. Promotes good working       20.   Check all indirect measurements and
      relations with the public and all                  ensure that correct procedures are
      cooperating agencies.                              followed.
11.   Serve on the FLWSC specialist                21.   Review the FLWSC Flood Activities
      committee as an advisor to the Director,           and Flood Plan.
      Associate Directors, Project Chiefs,         22.   Oversee the maintenance of the official
      Data Chief, and all members of FLWSC               drainage area map files.
      staff on scientific programs,
      methodologies, plans and execution of        Surface-Water Coordinator and Database
      NWIS database activities.                    Supervisor (Field Operations and Data
12.   Represent FLWSC at meetings with             Management Units)
      cooperators, the public, and other
      agencies on scientific and database          1. Ensure that personnel in the Data
      activities. Coordinate database activities      Section or studies unit follow the
      with local, State, and Federal agencies,        FLWSC SW/QA Plan.
      local universities, and private industry.    2. In consultation with the Data Chief and
      Provide technical advice and                    Surface-Water Specialist, implement
      consultation on NWIS programs and               procedures to improve surface-water
      use.                                            data collection methods when needed.
13.   Interpret, apply, and disseminate water      3. Coordinate SW/QA activities between
      discipline technical memoranda                  personnel in the unit and staff within
      pertaining to science issues and NWIS           other units in the Hydrologic Records
      databases and summarize implications            Section and other staff within the

4. Provide input to the Data Chief on           15. Maintain scripts and procedures used to
    SW/QA procedures used by personnel in           store and decode electronic data logger
    the unit and others in the FLWSC.               data files.
5. Review a cross-section of data annually      16. Ensure that data is DECODED
    prior to publication. Review should             accurately and in a timely manner.
    cover an appropriate representative         17. Ensure that the publication of the
    sample subset of stations per year to           Annual Data Report adheres to policies
    insure that the QA plans are being              established by the USGS and is
    properly implemented. (The review               completed by established deadlines.
    should also cover data descriptors, daily   18. Ensure that DAMFLO programs are
    value inventory, and NWIS Web.)                 maintained and training provided when
6. Maintain archives for the hydrologic             needed.
    records from the Hydrologic Records         19. Ensure that the DECODES database,
    Section in accordance with Regional and         programs and configurations are
    Bureau policies.                                maintained.
7. Advise management on training needs          20. Ensure that instrumentation and
    for personnel. Organize or perform              construction needs of the Hydrologic
    training.                                       Records section are addressed.
8. Assist the Associate Center Director for     21. Ensure that stage-discharge stations for
    Data and the office Data Chiefs with            the Hydrologic Records Section are
    maintaining the Florida FLWSC                   reviewed.
    SW/QA plans.                                22. Provide guidance and training in the
9. Develop the work plans for the unit,             area of data collection, analyses, and
    designed to accomplish the work of              publication of stage-discharge stations.
    collecting, processing, analyzing, and      23. Ensure proper gage construction and
    storing surface-water data; publish the         selection of recording equipment.
    data in the Annual Data Report; and
    communicate the contents of those work      Surface-Water Coordinator and Database
    plans to personnel in the Hydrologic        Unit Team Leaders
    Records Section.
10. Ensure that records for all surface-water   Leaders are responsible to their supervisors
    data stations are computed correctly and    for ensuring that the work assignments of
    checked and that all records are            the other personnel of the team are carried
    reviewed either semi-annually or            out by performing a range of duties such as:
11. Ensure that supervised personnel are        1. Distribute and balance the workload
    aware of and operate in accordance with        among personnel in accordance with
    safety policies established by the USGS        established work flow or job
    and the FLWSC.                                 specialization, assure timely
12. Implement USGS, and FLWSC safety               accomplishment of the assigned
    policies.                                      workload, and assure that each
13. Data Management Unit supervisor                employee has enough work to keep
    serves as their respective office‘s NWIS       busy;
    Automated Data Processing System            2. Keep in touch with the status and
    (ADAPS) database administrator                 progress of work, and make day-to-day
    (DBA), ensuring that the NWIS ADAPS            adjustments in accordance with
    database is properly maintained and            established priorities, obtaining
    updated.                                       assistance from the supervisor on
14. Maintain scripts that retrieve reformat        problems that may arise, such as
    and store electronic data from other           backlogs which cannot be disposed of
    cooperative agencies.                          promptly;

3. Estimate and report on expected time of         supportive duties and responsibilities. Team
    completion of work, and maintain               leaders utilize a variety of coordination,
    records of work accomplishments and            coaching, facilitating, consensus-building,
    time expended and prepare production           and planning techniques. These various
    reports as requested;                          work methods, coupled with knowledge,
4. Instruct personnel in specific tasks and        skills and abilities, are alternatives to
    job techniques and make available              traditional supervision that enable the team
    written instructions, reference materials      to deliver improved quality and quantity,
    and supplies;                                  along with timely services and products to
5. Give on-the-job-training to new                 their customers. Team leaders perform all of
    personnel in accordance with                   the first seven functions: coaching,
    established procedures and practices;          facilitating, and mentoring duties and a total
6. Maintain a current knowledge and                of 14 of the 20 duties listed below:
    answer questions of other personnel on
    procedures, policies, directives, etc. and     1. Ensure that the organization‘s strategic
    obtain needed information or decisions            plan, mission, vision, and values are
    from supervisor on problems that arise;           communicated to the team and
7. Check on work-in-progress or spot                  integrated into the teams strategies,
    check work not requiring review (e. g.,           goals, objectives, work plans and work
    filing or direct services) and review             products, and services.
    completed work to see that supervisor's        2. Articulate and communicate to the team
    instruction on work sequence,                     the assignment, project, problem to be
    procedures, methods and deadlines have            solved, actionable events, milestones,
    been met;                                         and/or program issues under review, and
8. Amend or reject work not meeting                   deadlines and time frames for
    established standards, refer to supervisor        completion.
    questions or matters not covered by            3. Coach the team in the selection and
    standards and problems in meeting                 application of appropriate problem
    performance standards;                            solving methods and techniques, provide
9. Monitor working conditions such as                 advice on work methods, practices and
    seating, ventilation, lighting, safety, etc;      procedures, and assist the team and/or
10. Approve leave for a few hours or for              individual members in identifying the
    emergencies;                                      parameters of a viable solution.
11. Inform personnel of available services         4. Lead the team in: identifying,
    and employee activities;                          distributing, and balancing workload
12. Resolve simple, informal complaints of            and tasks among personnel in
    personnel and refer others to supervisor;         accordance with established work flow,
13. Report to supervisor on performance,              skill level and/or occupational
    progress, and training needs of                   specialization; making adjustments to
    personnel, and on behavior problems;              accomplish the workload in accordance
    and                                               with established priorities to ensure
14. Provide information to supervisor as              timely accomplishment of assigned team
    requested concerning promotions,                  tasks; and ensuring that each employee
    reassignment, recognition of                      has an integral role in developing the
    performance, and personnel needs.                 final team product.
                                                   5. Train or arrange for the training of team
Functions of Team Leaders                             members in methods and techniques of
                                                      team building and working in teams to
     Team Leaders are responsible to their            accomplish tasks or projects, and
supervisors or managers for assuring that the         provide or arrange for specific
work of their assigned team is carried out by         administrative or technical training
performing a range of coordination and

      necessary for accomplishment of                   ensure that all team members are aware
      individual and team tasks.                        of and participate in planning for
6.    Monitor and report on the status and              achievement of team goals and
      progress of work, checking on work-in-            objectives.
      progress and reviewing completed work       14.   Research, learn and apply a wide range
      to see that the supervisor‘s instructions         of qualitative and/or quantitative
      on work priorities, methods, deadlines,           methods to identify, assess, analyze and
      and quality have been met.                        improve team effectiveness, efficiency
7.    Serve as coach, facilitator and/or                and work products.
      negotiator in coordinating team             15.   Lead the team in assessing its strengths
      initiatives and in consensus building             and weaknesses and provide leadership
      activities among team members.                    to the team in exploring alternatives and
8.    Maintain program and administrative               determining what improvements can be
      reference materials, project files and            made (e.g., in work methods, processes
      relevant back-ground documents and                and procedures).
      make available policies, procedures and     16.   Approve emergency leave for up to
      written instructions from the supervisor;         three days; eight hours or less for
      maintain current knowledge to answer              medical appointments; and/or other
      questions from team members on                    types of leave as delegated by
      procedures, policies, directives, etc.            management.
9.    Prepare reports and maintain records of     17.   Resolve simple, informal complaints of
      work accomplishments and                          personnel and refer others, such as
      administrative information, as required,          formal grievances and appeals, to the
      and coordinate the preparation,                   supervisor or an appropriate
      presentation and communication of                 management official.
      work-related information to the             18.   Communicate team consensus and
      supervisor.                                       recommendations to the supervisor on
10.   Represent the team in dealings with the           actions affecting team and individual
      supervisor or manager for the purpose of          awards, rewards and recognition.
      obtaining resources (e.g., computer         19.   Inform personnel of available employee
      hardware and software, use of overtime            benefits, services and work related
      or compensatory time), and securing               activities.
      needed information or decisions from        20.   Intercede with the supervisor on behalf
      the supervisor on major work problems             of the team to inform the supervisor of
      and issues that arise.                            performance management
11.   Report to the supervisor periodically on          issues/problems and to
      team and individual work                          recommend/request related actions, such
      accomplishments, problems, progress in            as: assignments, reassignments,
      mastering tasks and work processes, and           promotions, tour of duty changes, peer
      individual and team training needs.               reviews and performance appraisals.
12.   Represent the team consensus and
      convey the team‘s findings and
      recommendations in meetings and             Differences between Team Leaders and
      dealings with other team leaders,           Supervisors
      program officials, and the public and
      other customers on issues related to or          The chart below lists examples of the
      that have an impact on the team‘s           more significant differences between team
      objectives, work products and/or tasks.     leaders and supervisors. These examples are
13.   Estimate and report to the team on          not intended to be all-inclusive:
      progress in meeting established
      milestones and deadlines for completion
      of assignments, projects and tasks, and

 TEAM                 SUPERVISORS:             3. Ensure the proper service and
 LEADERS:                                          maintenance of gage instrumentation
 Explain team         Set team goals,              and structures.
 goals and            select team leaders,     4. Ensure that correct procedures are
 objectives to        assign team                  followed for discharge measurements
 assigned team        members and                  and levels.
 members and          administratively and     5. Helps to maintain the FLWSC Flood
 assist team in       technically direct the       Plan.
 organizing to        work of subordinates     6. Assist the Data Chief in the review of
 accomplish work                                   computed records.
 Coach, facilitate,   Plan, assign, review     7. Provide training in data collection,
 solve work           and accept, amend            analysis procedures, and instrumentation
 problems and         or reject work done          to less experienced personnel in the
 participate in the   by teams and                 Hydrologic Records Section and as
 work of the team     subordinates                 needed to staff from the Hydrologic
 Provide              Assign performance           Studies Section.
 information to       ratings, approve         8. Ensure that the collection and analysis
 the supervisor on    awards and take              of surface-water data are done
 performance of       performance-based            accurately with minimal loss of data.
 the team and         corrective actions       9. Review 10 percent of area records on a
 individuals                                       rotating basis so that different records
 Communicate          Make work                    are reviewed each year, including at
 assignments,         assignments, set or          least one record computed by each
 milestones and       negotiate deadlines          person assigned to their unit.
 deadlines to the     and completion           10. Ensure that data for sites assigned to
 team and             dates                        review, are collected, computed,
 individuals based                                 checked, and reviewed in a timely
 on supervisor‘s                                   manner so that the data are available in
 instructions                                      final form one month ahead of the
                                                   Annual Data Report publication
 Observe training     Schedule and
                                                   deadline of April 1.
 needs and relay      approve funding for
                                               11. Ensure that they communicate to their
 training needs       team and individual
                                                   supervisor on how field visitations are
 and requests to      training
                                                   scheduled to allow for adequate
                                                   numbers of measurements to promote
 Inform               Counsel personnel            the accurate computation of streamflow
 supervisor of        on behavior and              records.
 attendance and       initiate disciplinary    12. Scan hydrographer‘s field notes after
 behavioral           actions if required          each trip and formal review at least two
 problems                                          field trips per person in each water year
 Relay requests       Allocate resources to        using the standard review forms to
 for resources and    teams                        ensure that proper methods are used for
 supplies                                          data collection and those field trips are
                                                   completed in a timely manner. The
                                                   review forms from the formal reviews
Senior Hydrographers                               will be stored in the yearly computations
1. Oversee the day-to-day operation of the     13. Inspect vehicles yearly to ensure proper
   Hydrologic Records Section if Data              equipment is carried and maintained and
   Chief is not present.                           that the vehicle is in good condition. A
2. Ensure the proper gage construction and         copy of the inspection should be filed
   selection of recording equipment.               with the supervisor and hydrographer.

14. Perform their job in accordance with             appropriate reference marks in
    safety policies established by the               accordance with USGS surveying
    USGS and the FLWSC as                            procedures.
    implemented by the FLWSC                     9. Regularly review - on a daily basis,
    Director.                                        when in the office - real-time data
                                                     displayed on the USGS real-time data
                                                     website to detect potential
Project Chiefs
                                                     equipment/programming problems or
(Studies or Data Section)
                                                     unusual hydrologic conditions.
                                                 10. Perform their duties in accordance
1. Prepare a SW/QA plan for individual
   projects and submit the completed plan           with safety policies established by
   to the Section Chief and the FLWSC               the USGS and the FLWSC as
   Surface-Water Specialist for review              implemented by the FLWSC
   (Shampine and others, 1992, p. 2).               Director.
2. Ensure that the collection, processing,
   storage, analysis, and publication of         Surface-Water Database Administrator
   surface-water data associated with the
   project meet all standards of policy and      1. Ensure that all new FLWSC site files are
   procedure presented in this report and           created properly in the NWIS and
   the project surface-water quality-               Ground-Water Site Inventory (GWSI)
   assurance plan.                                  database following establishment of
3. Ensure that all surface-water data               advanced station descriptions and/or
   associated with the project are stored in        establishment of GWSI forms.
   the NWIS database.                            2. Assist FLWSC personnel throughout the
4. Perform their job in accordance with             State in the proper use and application
   safety policies established by the USGS          of the NWIS ADAPS database.
   and FLWSC, as implemented by the              3. Ensure that the DECODES database,
   FLWSC Director.                                  associated software and configurations
                                                    for telemetry equipment and data
Field Hydrographers                                 loggers is maintained properly for the
                                                    FLWSC network.
1. Follow guidelines and procedures              4. Check the function of ADAPS, remote
   outlined in the FLWSC SW/QA Plan for             data-access software, and the internet
   all surface-water data-collection                data-presentation programs each day
   activities.                                      when present in the office; correcting
2. Ensure that streamflow-gaging stations           problems or alerting the proper
   operate in a manner resulting in minimal         individuals of problems that need
   loss of stage record.                            correction.
3. Make discharge measurements of                5. Review the creation of new data
   various types correctly and accurately.          descriptors in ADAPS to ensure
4. Install, service, and repair instruments at      correctness and adherence to policy
   streamflow-gaging stations.                      guidelines.
5. Store all retrieved data into the NWIS        6. Maintain scripts, guidelines and control
   ADAPS database.                                  files used to automatically process
6. Develop ratings, compute discharge               electronic data logger (EDL) data files,
   records, and update or create station            and remote data files received from
   descriptions and analyses in a timely            cooperators.
   manner.                                       7. Provide training in the functionality and
7. Assist in construction of streamflow-            design of the NWIS ADAPS database.
   gaging stations.
8. Survey station levels, establish and
   periodically confirm elevations of

FLWSC Safety Officer                             COLLECTION OF STAGE AND
                                                 STREAMFLOW DATA
1. Assist the FLWSC Director and
    Associate Directors in implementing          Planning and resource management require
    USGS and FLWSC safety policies.              reliable surface-water data because many
2. Coordinate, advise, and support               anthropogenic activities, including industry,
    managers and supervisors with the            agriculture, energy production, waste
    program implementation and                   disposal, and recreation, link closely to
    compliance with regards to OSHA, and         streamflow and water availability. A
    USGS safety and health standards.            primary component of operating
3. Participate as a member in the Florida        streamflow-gaging stations (referred to as
    Safety Committee.                            ―gaging stations‖ in this report) and
4. Ensure inspections are completed              conducting other water-resource studies
    annually and corrective actions are          includes the collection of stage and
    documented in USGS Occupational,             discharge data.
    Safety, Health and Environmental
    (OSHE) Management System –                         The objective of operating a gaging
    WebCASS.                                     station is to obtain a continuous record of
5. Track facilities corrective actions           stage and discharge at the site (Carter and
    through final abatement using                Davidian, 1968, p. 1). Some stations
    WebCASS.                                     monitored by the FLWSC collect continuous
6. Investigate allegations of reprisal,          stage data only. The same criteria used to
    reports of unsafe and unhealthful            collect stage at streamflow stations applies
    conditions, and accidents/incidents          to stage-only stations as well unless
    reports. Reports not resolved at the local   otherwise specified. A continuous record of
    level are forwarded to the Regional          stage is obtained by installing instruments
    Safety Officer, or Safety Officer, as        that sense and record water-surface
    appropriate for resolution.                  elevation in the stream.
7. Review office accident information to               At some gaging stations in the FLWSC
    determine accuracy, and ensure that          study areas, continuous record of stream
    appropriate action is taken to correct       velocity or hydraulic structure parameters
    deficiencies.                                (gate opening, pump revolutions per minute
8. Recommend safety policy changes to            (RPM)) are obtained when stage alone is not
    the FLWSC Safety Officers in each            sufficient to compute streamflow.
    office.                                            A continuous record of velocity is
9. Coordinate and assist managers and            obtained by installing instruments that
    supervisors in the identification of field   measure and record the velocity in a selected
    training resources and develop and           portion of the stream‘s area known as the
    implement general/specialized safety         index-velocity. This index-velocity is then
    and health training to meet field needs.     related to mean velocity of the stream by
10. Coordinate the development and               means of ratings.
    maintenance of field organization safety           A continuous record of hydraulic
    promotional and incentive programs.          parameters at a variety of water control
11. Maintain safety training logs.               structures is obtained by measurement of
                                                 upstream water-level elevation, downstream
                                                 water-level elevation, and either gate
                                                 opening height or pump RPM rate.
                                                 Discharge measurements are made at
                                                 periodic intervals to define or verify the
                                                 stage-discharge relation, index-velocity –
                                                 mean-velocity relation, or hydraulic

structure relation and to define the time and     unit and team leaders and senior
magnitude of variations in that relation.         hydrographers. The process of site selection
                                                  includes discussion with cooperators on the
     All personnel involved in the collection     purpose of the gage, and understanding
and computation of stage and streamflow are       hydraulic conditions at the proposed site
provided training in data collection,             including, but not limited to, horizontal and
analysis, and publication procedures.             vertical velocity distribution, proximity to a
Hydrographers are informed of and follow          water control structure, and inflow or
the procedures and guidelines established by      outflow that might affect the mean channel
the USGS and FLWSC offices. The highest           velocity. The responsibility for ensuring
priority in any field activity is employee        proper documentation of agreements with
safety.                                           property owners is held by the Data Chief.
                                                  Approval of site design is also the
Gage Installation and Maintenance                 responsibility of the Data Chief. Gage
                                                  construction is accomplished by the
      Proper installation and maintenance of      construction staff or by an approved outside
gaging stations are critical activities for       contractor. Inspection and approval of the
ensuring quality in streamflow-data               completed installation is the responsibility
collection and analysis. Effective and correct    of the Data Chief.
site selection, proper design and
construction, and regular maintenance of a              A program of careful inspection and
gage can make the difference between              maintenance of gages promotes the
efficient and accurate determination of           collection of reliable and accurate data.
drainage-basin discharge and time-con-            Allowing the equipment and structures to
suming, poor estimations of flow.                 fall into disrepair can result in unreliable
                                                  data and safety problems. It is a FLWSC
      Proposed sites for installation of gaging   policy that a visual safety inspection is
stations are selected with the intent to meet     performed at sites by field personnel during
the purpose of each specific gage.                each site visit.
Additionally, sites are selected with the
intent of achieving, to the greatest extent             It is the responsibility of the field
possible, ideal conditions. Criteria that         hydrographer to correct deficiencies
describe the ideal gaging-station site are        immediately. If corrections cannot be made
listed in Rantz and others (1982, p. 5). Rantz    a supervisor must be informed so
lists nine criteria for an ideal gaging station   preparations can be made to address the
and three are listed here;                        problem. This may involve a senior
      1. Unchanging natural controls that         hydrographer addressing the deficiencies, or
promote a stable stage-discharge relation,        assigning the task to the construction
      2. A satisfactory reach for measuring       personnel if major repairs are required that
discharge throughout the range of stage, and      are beyond the experience of the field
      3. The means for efficient access to the    hydrographer. It is also the responsibility of
gage and measuring location.                      the field hydrographer to ensure that gages
       Other aspects of controls considered       and gage shelters are kept in good repair. To
by personnel when planning gaging station         ensure these responsibilities are carried out,
installations include those discussed in          a supervisor, safety officer, or field
Kennedy (1984, p. 2).                             hydrographer will visit each gage annually
                                                  and fill out a Hydrologic Gaging Station
      The individual responsible for selecting    Safety Checklist. Any deficiency found by
sites for new gaging stations is the Chief of     the supervisor, safety officer, or
the Hydrologic Records Section, hereafter         hydrographer is to be addressed as soon as
simply referred to as the Data Chief, with        possible. It is the responsibility of the field
advice from the Surface-Water Specialist,         hydrographer to fill out a problem report

form and follow up as necessary to ensure        sites in the FLWSC must comply with OSW
problems at the site are addressed. The          standards.
problem report form is to be given to their
supervisor, who forwards it to the Data                In general, operation of gaging stations
Chief for prioritization. It is then submitted   for the purpose of determining daily
to the head of the construction team for         discharge includes the goal of collecting
scheduling and completion.                       stage data at the accuracy of + or - 0.01 ft or
                                                 0.2 percent, whichever is less restrictive for
      Although the responsibility to maintain    the stage being measured ( memos 89.08,
gages belongs to the field hydrographer, it is   93.07, 96.05, app. A1 f, j, and p).
the responsibility of the senior                       Upward-looking acoustic beams for the
hydrographers to provide guidance and            primary measurement of stage are used at
assistance on attaining the appropriate level    some FLWSC gaging stations. Morlock and
of maintenance. It is also the responsibility    others (2002, p. 46) described the Nortek
of all field hydrographers in the FLWSC          EZQ as being on average within 0.01 ft of
offices to maintain the gages; individuals       the encoder stage, but the accuracy of
may be called upon to repair gages that are      acoustic stage sensors integral with some
not their primary responsibility. When an        models of acoustic velocity sensors have not
individual hydrographer fails to adequately      been assessed formally by the USGS. Based
maintain their respective gages, it is the       on the Morlock report and informal studies
responsibility of the senior hydrographer to     conducted at the Fort Lauderdale FLWSC,
provide specific instruction to that             the acoustic stage can be within OSW
individual or, if appropriate, present the       guidelines for the measurement of stage,
problem to the supervisors and the Data          however, the accuracy needs to be verified
Chief who initiates corrective actions. It is    at each station because velocity sensor
the collective responsibility of all members     misalignment can adversely affect the
of the Hydrologic Records Section, hereafter     uplooking acoustic stage accuracy.
simply referred to as the Data Section, to             The types of instrumentation installed
collect accurate stream and measurement          at any specific gage shelter operated by the
data.                                            FLWSC offices depend on a number of
                                                 factors. These factors include the needs of
Measurement of Stage                             the cooperating agency, terrain—including
                                                 slope and aspect, configuration of the stream
      Many types of instruments are available    and its banks, and the expected range in
for measuring the water level, or stage, at      stage. Additional factors may include, the
gaging stations. There are non-recording         ability to install a stilling well, or size of
gages (Rantz and others, 1982, p. 24) and        stilling well, the ability to install a recording
recording gages (Rantz and others, 1982, p.      device and shelter at any particular site, and
32). Because the usage in which the stage        whether the site will be using satellite
data may be applied cannot be predicted, it      telemetry or not.
is Office of Surface Water (OSW) policy                Types of continuous water-level
that surface-water stage records at stream       recorders operated by personnel in the
sites are collected using instruments and        FLWSC offices primarily include various
procedures that provide sufficient accuracy      manufactures of electronic data loggers
to support computation of discharge from a       (EDLs) and Data Collection Platforms
stage-discharge relation, unless greater         (DCPs) connected to stage sensors. In rare
accuracy is required (OSW memo. 93.07,           situations partner agencies sometimes use
app. 1j). At a velocity-index site, stage is     analog-to-digital recorders (ADRs) and
used to determine stream cross-sectional         strip-chart recorders as backups for the
area by means of a stage-area relation. The      EDLs in USGS gages. Sensors used to
measurement of stage for all surface-water       monitor stage include float and tape
                                                 assemblages driving shaft encoders,

submersible and non-submersible pressure          as a tape indicator (TI) gage, is a non-
transducers, and radar units. For                 recording gage used to set the principal
instantaneous observation of stage,               gage. The main purpose of the inside
instruments used include steel tapes, staff       reference gage is to furnish periodic
gages, wire-weight gages, and electric-tape       independent water-surface elevations to
gages. The Data Chief or project chief, in        monitor the accuracy of the primary gage,
consultation with the cooperating agency          and other gages (Kennedy, 1983, p. 10). The
and employee to be assigned the station,          primary gage records the continuous or near-
determine which type of water-level               continuous record of surface-water
recorders and sensors will be installed and       elevations. For example, primary gage
operated at each gaging station. Some of the      readings are calibrated by performing down-
types of water-level recorders operated by        to-water (DTW) measurements from a
personnel in the FLWSC offices include, but       known measuring point (MP) inside the
are not limited to; Handar/Vaisala 436B           stilling well. An outside reference gage (OS)
encoders, Sutron 8400 recorders and               reading is also obtained by reading an
encoder, Design Analysis recorders and            outside staff gage or wire-weight gage
satellite transmitters, Campbell Scientific       independent of the stilling well or gage
recorders and satellite transmitters, Sutron      platform. If no outside staff gage or wire-
SAT II recorders and transmitters, YSI            weight gage is available, down to water
pressure sensors, SonTek/YSI Argonaut- SL         measurements are taken from a known
ADVM (Acoustic Doppler Velocity Meter)            reference mark (RM) to the stream water-
with uplooking beam, and SonTek/YSI               level surface to obtain an independent stage
Argonaut-SW ADVM with uplooking beam,             measurement. At a station with a pressure
Design Analysis radar gage, OTT radar gage,       transducer (both submersible and non-
Sutron bubbler systems, and Design                submersible), the transducer (the primary
Analysis bubbler systems.                         gage) is checked against a wire-weight gage
                                                  (WW), OS gage (the reference gages), or
      The responsibility for determining          crest-stage indicator gage (CSI). The same
what type of water-level recorders is             is true for radar gage installations as no IG
operated at each gaging station is held by the    exists as a reference gage.
Data Chief. Most surface-water gages used
to compute stage/water level or discharge               Personnel servicing the gage are
record stage at 15-min to 60-min intervals        responsible for comparing inside and outside
with the rate of stage rise or fall determining   readings during each site visit to determine
the time interval. It is the responsibility of    if the outside water level is being
the field hydrographer to ensure that new         represented correctly by the gages. Small
equipment has been installed correctly and        differences are sometimes seen when it is
proper maintenance or replacement, if             very windy or the stream is rapidly
appropriate, of gage instrumentation is           changing. Care should be taken when
preformed.                                        adjusting the gage during these times as
                                                  large errors can occur. If a large unexpected
      Accurate stage measurement requires         difference is found between the IG and OS
not only accurate instrumentation but also        gages, it is possible that the stilling-well
proper installation and continual monitoring      intakes (if present) are not working properly
of all system components to ensure the            or the MP elevation has shifted. It is also
accuracy does not deteriorate with time           possible the OS gage has been damaged.
(OSW memo 93.07, (app. 1j). Personnel             The stilling well and base should be
observe reference and primary gages to            carefully inspected for signs of damage. The
ensure that gage-house instruments                OS gage should be carefully examined to
accurately record the water levels of the         determine if it is vertically aligned and
body of water being investigated. The inside      steadfast. Any problems found should be
reference gage (IG), which is also referred to    thoroughly documented on the field sheets

and a supervisor contacted so that corrective     only. The hydrographer who inspects the
actions can be taken at the earliest              gage is responsible for ensuring that the
opportunity. Levels should be run as soon as      peak-stage indicator clips are read and reset
possible to determine the stage in the stream.    during each site visit. The readings and
     Differences between the recorder stage       associated times are written on the field note
(primary gage) and reference gage may be          sheet.
the result of the float-tape skipping splines,          Many gages in the FLWSC have small
pressure transducer drift or slipping, or the     diameter stilling wells that utilize floats,
ADVM stage sensor elevation changing.             float tapes, or counterweights that are too
Make sure the stage sensor is secure and not      light in weight to make the indicator clips
easily moved. Added care should be taken to       work properly.
ensure that gages with shaft encoders are               Secondary methods of data verification
level, because during rapidly changing water      are valuable tools in the quality-assurance of
levels an increased potential may occur           data. In Florida, low channel gradients keep
where the tape will start skipping splines.       flows near peak or low levels for several
Resetting the data recorder value during          days, which facilitate checking the accuracy
rapidly changing conditions should be done        of a peak or low. A method sometimes used
by securing the tape at a fixed level and         by FLWSC offices to provide a more
using the TI to reset the recorder.               independent verification of peak- and low-
                                                  flows at various sites is the CSI. At some
      The field hydrographer is responsible       gages, cooperators maintain independent
for ensuring that instrumentation installed at    backup recorders, which help assure a
gaging stations is properly serviced and          complete and accurate stage record at the
calibrated. The unit supervisor is responsible    gage. For example, a gaging station with a
for ensuring that personnel correctly carry       stilling well might contain two float-tape
out this duty by reviewing the data, field        systems, one for the primary EDL and one
inspection forms, and other supporting            for a back-up recorder. Special emphasis
documentation written and collected by the        should be placed on a thorough inspection
field hydrographer. When deficiencies are         when the field hydrographer visits a station
found, proper procedure is discussed and a        after a peak and finds that the primary
senior hydrographer may be asked to               recorder has malfunctioned. Special
accompany the hydrographer on the next            attention should be given to checking for
field trip. Hydrographers should carry            and locating outside high-water marks
equipment for most minor repairs and when         (HWM) and for any of those that are in the
deficiencies are identified, the hydrographer     stilling well.
at the site is responsible for correcting the
problem, if possible. Spare dataloggers and       Measurement of Velocity
satellite transmitters should be carried by the
field hydrographer to ensure the gage can be            Due to unique and complex flow
returned to operation with as little missing      conditions that exist in many parts of
data as possible. For major repairs a             Florida, such as water-control structures,
supervisor should be contacted and the            low-gradient flow, backwater, tidal
construction crew assigned to make repairs.       influences, and control changes due to
Individuals who have questions related to         seasonal vegetation growth, determination
the calibration and maintenance of water-         of discharge may not be accurately obtained
level recorders should contact their              by conventional stage/discharge methods. At
supervisor or any senior hydrographer.            these locations, the USGS has installed
          At stilling wells where data            index velocity measuring instruments
recorders are driven by a float with steel        (Morlock and others, 2002, p.2), where
tape, peak-indicator clips can be attached to     discharge is computed based on index-to-
the steel tape to identify or confirm             measured-mean velocity and stage-area
maximum stages at stage-discharge sites           relations. Approximately 30 % of FLWSC

continuous record discharge gages are             selection criteria are; the stream cross-
computed using this methodology.                  section should have uniform horizontal and
                                                  vertical flow distributions and parallel flow
      The selected type of velocity               lines. The flow characteristics can be
instrumentation at any given gaging station       measured using ADCPs during field
operated by FLWSC offices is dependent on         reconnaissance.
site condition, such as the potential for weed         For horizontally mounted systems (SL),
growth, the width, or depth of the cross-         the distance from the acoustic beam path to
section that is required to adequately define     the nearest boundary (water surface or
the mean velocity. Some of the types of           channel bed) must be considered. Boundary
velocity meters operated by FLWSC                 interference can be prevented or reduced
include: the Accusonic 7300 and Affra             with the proper use of signal amplitude
Acoustic Velocity Meters (AVMs),                  checks (beam checks) at the time of
SonTek/YSI Argonaut-SL (Side Looker)              installation. The maximum sample volume
ADVM, SonTek/YSI Argonaut-SW ADVM,                range should be programmed so that the
and SonTek/YSI Argonaut-XR ADVM.                  acoustic beams are not affected by surface,
These velocity meters can either be               bottom, or in-channel boundaries in the
connected to data-loggers equipped with           measured stream cross-section. The SL
satellite telemetry or to instruments where       ADVM will have less range in shallow than
data are only recorded internally. Sites with     in deep rivers and streams (Morlock and
velocity meters installed record data at no       others, 2002, p.8). In-channel boundaries
greater than 15-min intervals for tidal           may include bridge piers, channel-bed
stations and up to 60-min interval at other       outcrops, vegetation and/or the opposite
sites with the rate of change determining the     bank. These boundaries should be avoided
time interval.                                    by ending the sample volume at a distance
                                                  before the boundary where there is no effect
     The responsibility for determining what      on the acoustic signal. Avoiding boundaries
type of velocity meter is installed at a given    does not necessarily mean that the velocity
gage is held by the office Data Chief after       data will be accurate. Additional
consultation with the senior hydrographer,        considerations as to flow structure needs to
acoustic specialist, or project chief. A senior   be considered.
hydrographer with acoustic experience is               Because ADVMs must be mounted to
responsible for ensuring the new equipment        structures in the water, the flow disturbance
has been properly installed and configured. .     created by the structure must also be
The hydrographer servicing the station is         considered in determining sample volume
responsible for proper maintenance or             beginning and ending locations. The
replacement, if appropriate. The unit             beginning and ending of the sample volume
supervisor and field hydrographer are             should be located outside the region of
responsible for ensuring that the velocity        disturbed flow. The following equation
data being recorded at the site is accurate,      derived from Hughes and Brighton (1991),
reliable, and adequately monitors all             can be used to estimate the extent of flow
conditions that can occur at the site. If there   disturbance near bridge piers (Morlock and
are any questions as to the validity of the       others, 2002, p.9):
velocity data, a senior hydrographer with
acoustic experience should be consulted.                              b =c(dx)0.5,
Velocity Gage Installation Considerations
         Sites should be selected based on             b is the lateral distance from the pier
the criteria described in the section Gage        center line to the approximate edge of the
Installation and Maintenance. An index            wake-turbulence zone,
velocity site installation form is provided in
Appendix 2a. Additional index velocity site            d is the width of the pier,

                                                 a minimum on an annual basis. This
     x is the distance to the upstream face      documentation must include: the sample
of the pier,                                     volume start and end distances (ranges),
                                                 measured water temperature, water
     c is a factor accounting for pier shape:    temperature as reported by the ADVM,
                                                 boundary locations in the cross-section,
c = 0.62 for circular or round-nosed piers;      serial number of the unit as well as multiple
c = 0.81for rectangular piers.                   velocity cell information for blanking
                                                 distance, cell size, and number of cells..
                                                 During each site visit, internally recorded
                                                 data should be retrieved, beam check
                                                 diagnostics (minimum 30 pings) must be
                                                 recorded, internal clock time should be
                                                 recorded and verified (and corrected if
                                                 necessary), and temperature and salinity
                                                 should be measured and recorded during
                                                 each site visit. An index velocity site visit
                                                 field sheet is provided in Appendix 2b.

                                                 Velocity Data Processing

                                                      It is a FLWSC policy that all personnel
                                                 responsible for index-velocity stations attend
                                                 the OSW training course SW1319
                                                 Streamflow Record Computation using
                                                 ADVMs and Index Velocity Methods..
                                                 FLWSC offices use the methods and
                                                 procedures outlined in that class for the
Figure 2. Diagram showing variables for          processing of velocity data. Additional
estimating flow disturbance distance.            information can be obtained from Water-
                                                 Resources Investigations Report 01-4157,
Flow disturbance is estimated using the          Feasibility of Acoustic Doppler Velocity
preceding equation, however, the accurate        Meters for the Production of Discharge
determination of flow disturbance is             Records from U.S. Geological Survey
accomplished by analyzing the multiple cell      Streamflow-gaging Stations (Morlock and
velocity data. Multiple-cell velocity data are   others, 2002) and Scientific Investigations
compared with one another and an increase        Report 2005-5004, Computation of
in standard deviation of the velocity data       Discharge Using the Index-Velocity Method
(noisy data) can indicate that the ADVM is       in Tidally Affected Areas (Ruhl and
measuring in disturbed flow. The ADVM            Simpson, 2005)..
configuration should then be modified to
prevent measuring in a region of disturbed       Measurement of Hydraulic Structure
flow.                                            Parameters

Routine Maintenance                                   Some FLWSC offices may be required
                                                 to compute discharge at hydraulic structures,
       It is FLWSC policy that specific          such as, water-control gates (i.e. tainter,
procedures be followed for the operation of      sluice, and lock and sector), gated culverts,
index-velocity stations. Site specific           and pump complexes. Measurement of the
equipment configurations must be                 upstream (headwater) and downstream (tail
documented and archived at the time of           water) stage elevations is necessary for these
installation, after equipment changes, and as    computations. This stage measurement is

accomplished in the same way as described         1. Current station description which
previously in the Measurement of Stage               includes:
section. Care must be taken in the placement               a. reference mark (RM) elevation,
of the intake lines and general guidelines are             b. discharge measurement
given by Bos (1976, p. 58). The upstream                       location,
stage intakes should avoid the area of draw-               c. job hazard analysis (JHA) form,
down in front of the structure, yet be close                   and
enough so that energy loss is negligible. The              d. velocity meter configuration
recommendation is three to four times the                      including mounting elevation
upstream depth from the structure. The                         and horizontal location from
downstream stage should be measured                            known reference locations, and
immediately downstream of the deceleration        2. Field inspection summary form for the
transition where normal channel velocities           current water year, which is updated
occur (Bos, 1976, p. 61). The gate opening           every time the gage is inspected. This
can be measured by potentiometers that are           form lists the inspection activity and any
attached to the horizontal gate ram or               repairs that were done at the site. This
vertical gate rod or by sensors on the gate          form is required to be changed yearly so
that transmit the gate opening by telemetry          it is available for review at the end of
to a database. Also inclinometers can be             the year.
installed on tainter gates to measure the         3. Miscellaneous field forms.
angle and subsequently convert the angle to       4. Current rating table of stage/discharge
a vertical gate opening.                             relation.
      Pump complexes require the same             5. Index-velocity rating (if applicable).
upstream and downstream measurement at            6. Log updated by field personnel upon
the structure, along with specific pump data.        each site visit describing control
The revolutions per minute (RPM) of the              conditions and listing gage readings,
pump, as well as, the time duration that the         measurement values, gage-house
pump was in operation, are required. This            maintenance, and equipment
data is recorded manually or by sensors on           maintenance.
the motor. This data may be received to a         7. Gage house calendar with Julian dates.
FLWSC office from cooperators at                  8. Information related to extreme events,
established intervals by file transfer protocol      including the potential for channel
(FTP) procedures.                                    storage between the gage and measuring
      Ensuring that the upstream stage,              section during flood conditions.
downstream stage, and gate height or
pumping rate data being recorded at the site            Each gage is a representation to the
is reasonable is the responsibility of the        public of the USGS and therefore should be
hydrographer servicing the site. If there are     kept neat and well maintained. A green
any questions as to the validity of these data    USGS visual identity sticker should be
a senior hydrographer may be consulted.           affixed to each station where it is visible to
                                                  the public. The area should be kept as neat
Gage Documents                                    as possible in regard to weeds and small
                                                  brush removal. It is the responsibility of the
     It is FLWSC policy that certain              employee assigned the station to exchange
documents are placed in each gage house for       outdated material with updated gage
the purpose of keeping an on-site record of       documents as needed. When field personnel
observations, equipment maintenance,              visit a gage and identify a need to update
structural maintenance, and other                 one or more of the documents, the needed
information helpful to field personnel.           information will be replaced on the next
Documents maintained at each gage house           visit to that gage. Individuals having
can include:                                      questions related to what documents should
                                                  be kept in a gage shelter, when existing

documents should be replaced with newer             indicate a 0.015 ft or more vertical change.
documents, or appropriate methods of                Level notes should be checked on site before
appending logs or plotting measurements             the reset is made. When gages are reset,
should contact the senior hydrographer.             field personnel document the reset by
                                                    writing the ―found‖ and ―left‖ gage readings
Levels                                              on a miscellaneous note sheet (Form 9-
                                                    275D) or level note sheet (Form 9-276).
         The various gages (i.e. EDL, TI,           Outside water-surface elevation and the
OS, and CSI) at a gaging station are set to         associated time are determined each time
measure the elevation of a water surface            levels are run at a gaging station and are
above a selected level reference surface            written on the level note sheet.
called the gage datum. The gage's
supporting structures--stilling wells,
backings, shelters, bridges, and other
structures--tend to settle or rise as a result of
earth movement, static or dynamic loads,
vibration, or battering by floodwaters and
flood-borne debris. Vertical movement of a
structure makes the attached gages read too
high or too low and, if the errors go
undetected, may lead to increased
uncertainties in streamflow records. Lev-
eling, a procedure by which surveying
instruments are used to determine the
differences in elevation between points is
used to set the gages and to check them from        Figure 3. Station levels at Little Charley
time-to-time for vertical movement                  Bowlegs Creek.
(Kennedy, 1990, p. 1). Levels are run
periodically to all bench marks (BM),                    When levels are run, each mark must
reference marks (RM), reference points              have two independent shots, requiring a
(RP), and gages at each station for the             minimum of two instrument setups to
purpose of determining if any datum                 complete a circuit. The level loop must close
changes have occurred (Rantz and others,            to the starting elevation within 0.003 ft times
1982, p. 545). It is FLWSC policy that              the square root of the number of turning
levels are run at newly installed gaging            points (Kennedy, 1990, p.4) or the level run
stations at the time of construction. Outside       is considered to be invalid and the circuit is
staff gage (OS) and inside gage (IG)                run again. Even if there are more than 25
comparisons are evaluated to ensure the             turning points, the level loop must close
stability of the measuring point and staff          within no more than 0.015 ft or the level run
gage. If discrepancies are found, a new             is considered invalid and the circuit is run
complete set of levels are done.                    again. It is the responsibility of the field
         Levels are run to established gaging       party chief to ensure that all field level notes
stations once every three years if the station      are checked before departing the site. Levels
has been proven stable. If the station has          and inspection sheets are given to the
unresolved gage-reading differences, is             assigned site hydrographer within one week
movement prone, or has been proven                  of completion. The level information is
unstable, a complete new set of levels              entered in the level-summary form by the
should be performed annually. In all                responsible site hydrographer. The
instances where there is a gage-height              hydrographer assigned to work the station
discrepancy that cannot be explained by             records checks to see that the level
other means, levels should be run. Gages are        information has been entered onto the level-
reset to agree with levels when the levels          summary form.

      Levels are run by use of field methods     office in the designated file cabinet after
and documentation methods described in           copies are made for the computation folder.
Kennedy (1990) and in the North Carolina         Level information must be updated in the
method techniques manuals. At the time of        station description as well. Ensuring that
this QA plan update a new method which is        levels are run properly and that all level
a combination of the Kennedy and North           notes are completed accurately and
Carolina methods is being finalized and will     completely is the responsibility of the unit
be distributed by OSW to all the science         supervisor. Ensuring that levels are run at
centers in the upcoming year. Level proce-       the appropriate frequency is the
dures followed by the FLWSC personnel            responsibility of the Data Chief and unit
pertaining to circuit closure, instrument        supervisors.
reset, and repeated use of turning points are          A summary of uniform procedures
described in Kennedy (1990), OSW memo            established for the collection and recording
93.12 (app. 1k, in the North Carolina            of differential leveling data at gaging
method manual, and in Water-Resources            stations are as follows:
Investigations Report 03-4002 Levels at          1. Every gaging station will have at least
Streamflow Gaging Stations—A CD-ROM                   one complete level circuit every three
Based Training Class (Nolan and others,               years unless noted that the frequency
2003).                                                can be greater. If either the gage or the
      The level instruments are kept in proper        reference marks (RM) or the reference
adjustment by ensuring accuracy through the           points (RP) are found to be unstable,
use of collimation tests as described in              then annual or more frequent circuits
Kennedy (1990, p. 12). Adjustment tests are           will be run. (Every effort should be
done periodically on each instrument (Zeiss-          made to establish a stable RM and RP).
type levels). A two-peg test is typically             At a new station, run levels when
performed once at least once a year. A                establishing the gage, with another
fixed-scale test is performed before the start        complete circuit the next year. If there
of every level run, or if multiple trips are          are no significant discrepancies, go to
being run, at the start of each week of use.          the three-year cycle (Kennedy, 1990, p.
However, if the accuracy of a particular              14, and OSW memorandum 90.10 app.
instrument becomes suspect for any reason,            1q)
a collimation test is performed immediately.     2. Levels are run by use of field methods
      The ―newer‖ Sokia-type electronic               and documentation methods described
instruments which read a rod that is bar-             by the Kennedy (1990) and the North
coded require different checks than the older         Carolina methods. Level procedures
Zeiss-type instruments. These should be               followed by FLWSC personnel
done as per the manufacturer specifications           pertaining to circuit closure, instrument
with further information coming out in the            reset, and repeated use of turning points
forthcoming updated level manual. Results             are described by Kennedy (1990) and in
of the tests are entered into the FLWSC               OSW memo 93.12 (app. 1k). The level
office electronic Excel file for that                 instruments are kept in proper
instrument. A copy of the most recent                 adjustment by the peg test described by
collimation test must be kept with the                Kennedy (1990, p. 13).
instrument. If an instrument is found to be in   3. A two-peg test will be performed at least
error, level runs that involved the erroneous         once per week while doing leveling, and
instrument are examined and actions are               as necessary, whenever there is reason
taken to correct any errors or the level runs         to doubt instrument performance. The
are determined to be invalid and the level            error found with the test should not
procedures are repeated. Adjustments to the           exceed 0.003 ft in 100 ft of distance.
instrument, if any, are performed by the         4. Every level circuit will be run as a
senior hydrographer. Levels notes must be             closed loop. This means that the starting
filed immediately after returning to the              point of a level circuit must also be the

      finishing point. There must be at least             notes are completed correctly is the
      one turning point in the level network.             responsibility of the chief of field party.
      For a station where all marks and gages       11.   Field notes are as important as the actual
      may be shot from a single set-up, shoot             leveling techniques. They constitute an
      the last mark in the run, set a turning             official, permanent record of the survey
      point, shoot the turning point, move the            and must be in a format that is easily
      instrument, and shoot all points again              interpreted by a reviewer or anyone
      starting with the turning point elevation.          familiar with the type of work done. All
      The rod person will use a rod level, and            field notes must be recorded in the field
      rod readings should be recorded to 0.001            at the time of the survey. Notes from
      ft.                                                 memory are not acceptable. Notes
5.    When running the level circuit, the                 should be complete and should contain
      elevations of all RM, outside staffs,               all necessary information. A good
      inside staffs, wire weights, RP, orifice            sketch of the site is helpful in
      tips, water surface, and if possible, the           interpreting the notes at a later date.
      point-of-zero flow will be determined.              While there is no specifically correct
6.    The low-water section of the primary                format for level notes, standard methods
      reference gage will be reset if it is in            are outlined in various surveying
      error by more than 0.015 ft with respect            textbooks, and good examples of level
      to the base RM. Other gage sections                 notes using USGS notepaper, Form 9-
      may be in error by as much as 0.03 ft               276, are shown by Kennedy (1990).
      before resetting is mandatory.                12.   All active gages will have a
7.    There should be a minimum of 3 RM at                chronological summary sheet of all level
      each gage: 1) near the gage, 2) above               circuits at the station. This summary is
      major peak gage heights, and 3) at a                kept in the permanent records file.
      location beyond the reach of a                13.   Due to inherent errors, a wire-weight
      catastrophic flood (provides a point                gage may not read accurately at low
      from which the original gage station can            water if it is set to the check bar (CB)
      be reestablished in the event that the              elevation. Errors in low-water readings
      station and/or nearby RM are                        can amount to several hundredths when
      destroyed). Reference marks should                  the CB is set to read the same as the CB
      never be renumbered, nor should a lost              elevation. The correct CB reading is to
      or destroyed RM number ever be used                 be determined using the method outlined
      again. If a lost RM is recovered, the               by Kennedy (1990).
      original number is to be used.                14.   At pressure transducer gaging stations,
8.    Rod length will be checked with a steel             keeping ―on datum‖ is a matter of
      ruler or new condition steel tape (no               checking and maintaining the outside
      kinks or bends). This is not required for           staff gage by levels. The outside staff
      each circuit, but should be done when a             should not be the only reference gage.
      two-peg test is made, or whenever rod               An RP should be established over the
      damage is suspected.                                water and read and compared with the
9.    A 25-ft fiberglass telescoping rod will             staff gage each time. After checking the
      not be used for gaging station levels. It           staff gage, the procedure is to read the
      is not sufficiently accurate.                       gage counter, dial, or read out, record it
10.   It is the responsibility of the Data Chief,         in notes, and set the gage indicator to
      senior hydrographer, and project chief to           read the same as the staff gage. If the
      ensure that level notes are checked. The            reference staff gage is susceptible to
      level information is entered on the level           damage, it should be checked by levels
      summary form by the hydrographer in                 annually or more often if conditions
      charge of the field party. Ensuring that            warrant. All adjoining staff plates
      levels are run correctly and that all level         should be checked with steel rules at the
                                                          time of leveling.

15. If a bench mark (BM) is reasonably           reviewed for completeness and accuracy as
    close (3 mi or less), an effort should be    part of the end-of-year review process by the
    made to tie the gage into the National       field hydrographer responsible for the site.
    Geodetic Vertical Datum 1929                 Station descriptions are updated as required,
    (NGVD29) or North American Vertical          and reviewed for completeness every year.
    Datum 1988 (NAVD 88). It is preferable       The station description is updated any time
    to tie into NAVD88 as the water              levels are run, type of equipment is changed,
    management districts (FLWSC major            new features are installed at the site, and at
    cooperator) is in the process of changing    the end of the year if new extreme
    all sites to the NAVD 88 datum. Begin        conditions occurred. It is the responsibility
    at the ―base‖ RM at the gage, using the      of the hydrographer responsible for the
    gage datum elevation, and run a closed       station to ensure that station descriptions are
    loop to the BM. Double-rodded leveling       updated as described.
    may be used if proper procedures are               Station descriptions outline specific
    followed. If double-rodding is used, it is   types of information in a consistent format
    critical that the fore sights and back       (Kennedy, 1983, p. 2). The station
    sights are balanced, and that the level is   description includes information such as the
    in good adjustment.                          location of the station, date of establishment,
                                                 drainage area above the site, description of
Site Documentation                               the gages, history of activities at the station,
                                                 reference and benchmarks, equipment,
     Site documentation requires thorough        observer, photographs, channel and control
qualitative and quantitative information         characteristics, floods, point-of-zero-flow
describing each gaging station. This             (PZF), the Job Hazard Analysis (JHA), site
documentation, in the form of a station          maps, and road/driving logs to the site.
description, station sketch, and photographs,    Other items personnel should include are
provides a permanent record of site              detail on discharge measurements and cross-
characteristics, structures, equipment,          sections, extreme stage and discharge,
instrumentation, altitudes, location, and        regulations and diversions, cooperative
changes in conditions at each site. These        agencies, local observers, and other site-
documents also provide a history of past         specific information (Kennedy, 1983, p. 3-
flood events, nearby construction, or any        5). Drainage areas determined using
unusual occurrences at the site. Information     Geographic Information System (GIS)
pertaining to where these forms of               methods need to be checked against the
documentation are maintained is discussed        original drainage area maps for consistency
in the section of this report entitled Office    and accuracy. The scale, resolution, and
Setting.                                         method of measurement (LIDAR, photo-
                                                 interpretation, etc) of the digital elevation
Station Descriptions                             model (DEM) data used in the GIS analysis
                                                 as compared to the basin boundary
      A station description is prepared for      topographic map should be considered when
each gaging station and becomes part of the      determining which is the correct source. The
permanent record for each station. It is         most accurate data source should be used to
FLWSC policy that a working station              delineate drainage-basin boundaries. It
description is written within an 8-week          should be considered that the water
period that the site was established and a       management districts possibly have more
final description written no later than when     up-to-date and current information than that
the first-year station records are worked.       of FLWSC files as an update of drainage
The field hydrographer assigned to a station     areas in Florida has not been done.
is responsible for ensuring that station
descriptions are prepared correctly and in a          The hydrographer maintains paper
timely manner.. Station descriptions are         copies of the station description in the

station folder and field folder, at the gage        the conditions at a proposed streamflow
site, as well as an electronic copy in the          gage site. It will provide a summary
USGS Site Information Management                    evaluation of the site, including
System (SIMS). For new sites, personnel             potential problems. Much of the data
work together to obtain latitude, longitude,        included on the form will be beneficial
and drainage area information from the most         when the actual station description is
current USGS topographic maps or DEM,               written. After this form is completed in
after determining the accuracy of the               the field, it should be transmitted to the
selected data source. Latitude and longitude        Data Chief for review.
should be verified with Global Positioning       2. Once the site location has been
System (GPS) readings in the field. The             finalized, a copy of the Advance Station
horizontal datum (NAD 27 or NAD 83) and             Description Form should be prepared
vertical datum (NGVD 29 or NAVD 88) of              and forwarded, along with a site location
the site must be established. Across the State      sketch, to the Data Chief for approval.
of Florida, the NAVD 88 vertical elevation          Information from the Field Form should
datum can average approximately 1.0 ft              be entered on a copy of the Advance
(ranges from -0.2 ft to -1.8 ft) or more            Station Description Form. This form
higher than the NGVD 29 datum. Historical           should contain as much of the following
information from a variety of sources, such         as possible:
as, Annual Data Reports, investigative or               a. Station number--if the station
open-file reports, or USGS and other-agency                  is being reestablished, give the
files should be included when available.                     previously assigned station
      The downstream order station number                    number. For new stations, or if
for the new site is established by preparing                 the number is in question, leave
an Advanced Station Description (ASD) and                    the number blank and it will be
submitting it to the FLWSC Data Base                         determined by the FLWSC Data
Administrator (DBA) for determination. The                   Base Administrator (DBA). Be
latitude-longitude location for the new site                 sure to provide all necessary
should be the location of the outside staff                  information in the downstream
(OS) or over the gaged stream in order to                    order information section
accurately assign the downstream order                       including known active and
number. It should be determined from a                       discontinued station numbers on
GPS and read at least to tenths of a second                  the stream which will aid in the
to ensure the locator is on the stream and not               determination of the final
on land.                                                     downstream order number.
                                                             Pages 50-51 of Novak (1985)
Documenting the Establishment of New                         give criteria for determining
Surface-Water Stations                                       equivalence of record.
                                                        b. Station name--if the station is
      In the process of establishing a new                   being reestablished, give
surface-water data-collection station or                     previously assigned name. For
reestablishing an old station, the following                 new stations, refer to Novak
steps should be taken to make a record of                    (1985, pages 37-39) for
site evaluation and to insure assignment of a                selection of station name
correct downstream order number, entry into                  protocols.
the FLWSC Master and Active Station Lists,              c. Location--include
and creation of the necessary National Water                 latitude/longitude, quarter
Information System (NWIS) files.                             sections, township/range,
                                                             county, hydrologic unit code,
1. Field or project personnel should                         name and scale of topographic
   complete a Gaging Station                                 map, and description in the
   Reconnaissance Checklist to document                      format exactly as it will be

     published in the Annual Data               water-quality, periodic- or
     Report; refer to Novak (1985).             daily-sediment data, etc.
d.   Date established--show the            i.   Publication status--indicates
     date of first record published by          Annual Data Report, open-file,
     the USGS that is equivalent to             project report, or not published.
     present record. If the site is new,   j.   Cooperator/financing details--
     indicate date of first record to be        indicate cooperator name and
     published. Use whole months.               funding, such as cooperative
e.   Drainage area--if no drainage              funding, OFA, etc.
     area is given, indicate whether it    k.   Project account number--
     needs to be determined by the              indicate the 5-digit account
     FLWSC DBA, does not need to                number after the 4-digit
     be determined, or whether it is            FLWSC code, i.e. 2550-001TP.
     indeterminate (not defined). If       l.   Justification--describe the
     some of the drainage boundaries            purpose of this new site, such as
     of the site are not clearly                local Water Management
     defined on topographic maps,               District, rainfall/ runoff study,
     the field or project office should         minimum flows and levels,
     furnish a map indicating where             project monitoring, etc.
     the uncertain boundaries should       m.   Remarks--include anything that
     be drawn. The originating                  will provide more information
     individual need not outline the            on this site, such as previous
     entire basin unless it cannot be           records collected at this site, site
     determined from the                        previously operated by another
     topographic map.                           agency, etc.
f.   Elevation of gage--give the           n.   Date station map plot sent--
     physical elevation of the gage             copy of the section of the
     site. For streamflow stations,             topographic map with the
     use the approximate point-of-              station location clearly marked.
     zero-flow (PZF) in the stream              This must be sent to the
     channel. In most cases, this               FLWSC DBA for the drainage
     value is not the same as the               area to be determined. Include a
     datum of the gage.                         paper copy of the completed
g.   Equipment and data-                        Advance Station Description
     collection--indicate types of              with the map. If it is a
     data-collection devices (satellite         reestablished station, include a
     telemetry data-collection                  copy of the most recent station
     platform (DCP) or electronic               description. Indicate the date the
     data logger (EDL), index                   material was sent.
     velocity system, periods and          o.   Downstream order
     ranges of stage for which data             information--list any stations
     will be collected, recording               immediately upstream and
     intervals (5, 15, 30, 60 min, etc.,        downstream from new gage site,
     or variable), data formats (i.e.           including discontinued stations
     real numbers with decimal                  if known. Use the Advance
     points from DCP and EDL), and              Station Description forms for
     the names and codes of the                 standard downstream order
     parameters recorded.                       stations and other stations only
h.   Supplemental records--list                 identified by latitude and
     other data to be collected on a            longitude. Both types of stations
     recurring schedule, but not                will use the same Advance
     continuously recorded, such as

            Station Description form                for processing and storage of the data
            discussed herein.                       collected at the site.
                                                9. The Data Chief will confirm that the
3. The FLWSC DBA will assign a station              new station is in the center's Active
   number and determine the drainage area,          List of surface-water sites and update
   as necessary. NOTE: Drainage areas               any preliminary information as
   will not be determined until an Advance          necessary.
   Station Description has been provided.
   Novak (1985, pages 43-46), provides          Station Identification Number Assignment
   guidelines for the determination of
   drainage area. For any sites that include
                                                      The station identification number is a
   drainage area located in the State, but
                                                mandatory entry to the station header file in
   outside of the FLWSC operational
                                                the NWIS database. Each station for which
   boundaries, the FLWSC DBA will still
                                                data are entered in NWIS must have a single
   determine station number selection and
                                                station identification number, unique to that
   drainage area. If necessary contact with
                                                one site. The number should never be
   adjacent states will be done to ensure the
                                                assigned to another site, except when the
   accuracy of the drainage area and
                                                relocation of a site does not significantly
   downstream order number.
                                                change the drainage area of the basin
4. The database administrator (DBA) will
                                                upstream, and streamflow at the new site is
   update the FLWSC Master List. All
                                                equivalent to the old site. Should a station be
   established sites that have relevance to
                                                destroyed or removed from service, its
   determination of station numbers or
                                                unique number will continue to be
   drainage area within the FLWSC
                                                associated in the historical files with the data
   operational boundaries will be included
                                                from the discontinued site. In the event of
   in the Master List of surface-water sites.
                                                an incorrect entry, corrections will be made
5. The DBA will establish the NWIS Site
                                                by the DBA.
   File for any new site which will be
   processing and/or storing data in the
                                                      All FLWSC offices are required to
   NWIS systems. Sites not using these
                                                develop station identification numbers that
   databases will not be entered into the
                                                conform to the current USGS criteria. A
   Site File. Specific justification and
                                                station identification number may be an
   approval of the Associate Center
                                                eight to twelve-digit downstream order num-
   Director for data and the Data Chief of
                                                ber or may be composed of latitude,
   the office where the site is located are
                                                longitude, and a two-digit sequence number
   required for data processing and storage
                                                (a total of 15 digits).
   outside of the NWIS systems.
6. The Data Base Administrator (DBA)
                                                Downstream Order Station Number
   will make any necessary additions or
   corrections to the Advance Station
   Description (i.e. station number,                  The eight to twelve-digit downstream
   drainage area) and send the final            order number must be used for on-stream
   description to the office Data Chief,        sites where records are systematically
   originating project chief, the DBA, and      collected on a long-term monitoring basis.
   surface-water specialist.                    Examples of sites that meet these criteria
7. The DBA will put a copy of the final         are: 1) standard surface-water stations, 2)
   Advance Station Description in the           water-quality sites, 3) partial-record
   primary file folder.                         (surface-water and water-quality) stations,
8. The DBA will use the Advance Station         and 4) spring-flow stations where discharge
   Description to make all necessary            measurements are made.
   entries into the NWIS system to allow
                                                     Station numbers for sites are assigned
                                                by the designated FLWSC DBA and are

based on the Advance Station Description.          Photographs
When a downstream order number is used,
the number must contain eight to twelve                 Photographs should be made of newly
digits, thus, any preceding or following           installed and existing gage shelters, station
zeros must be included, such as 02301000.          controls, upstream and downstream channel
If a new site is located between two existing      conditions, reference marks, flood damage,
eight-digit station numbers without a space        indirect measurement sites, vandalism, and
between them then a 10-digit number can be         anything that may help explain anomalous
assigned that will place the station in the        data or other important circumstances to
proper downstream order. Punctuation, such         document activity and conditions at the
as periods or dashes, must not be used in the      gaging station. Field personnel should carry
number.                                            either a disposable or digital camera to make
                                                   photographic documentation as needed. On
Latitude-Longitude Sequence Number                 the back of each photographic print included
                                                   with the station folder should be marked
      A latitude-longitude sequence number         with a permanent-ink marker to document
is used primarily for non-stream sites;            the station number, station name, date, gage
however, they may be assigned to stream            height, and any other information needed to
sites where there is difficulty in assigning a     interpret the photograph. Digital
meaningful downstream order number, or             photographs taken at gages serviced by each
when data are obtained intermittently on a         of the FLWSC offices should have a digital
short-term monitoring basis. Examples of           data archive directory for each gage.
the sites that meet these criteria are: 1)         Photograph files should be named to
wells, 2) water-quality grab sample sites, 3)      document the event, location, viewpoint
surface-water sites where miscellaneous            (upstream, downstream, etc), and gage
measurements are made, 4) large open-water         involved. Hard-copy prints or CDs of digital
sites (i.e. lakes, reservoirs, and bays), and 5)   photographs for the current year are placed
sites located at distributaries on streams at      in the primary folder, while older
coastal locations where upstream and               photographs are placed in the station folder,
downstream become somewhat meaningless.            or in the historic station files for
                                                   documentation. Photographs should be
     If a latitude and longitude sequence          made on a periodic basis to maintain a
number to the second are used, a two-digit         record of possible changes in the low-water
sequence must be appended to differentiate         control and document other important
between stations or parameters (i.e. stage,        information at the site.
rainfall, conductivity) with the same latitude
and longitude. The latitude and longitude          Direct Measurements
numbers are joined by adding a zero. The
format of a latitude-longitude identifier is:           Direct measurements of discharge are
                                                   made with a number of approved methods
      Latitude Longitude Number.                   by the USGS. Historically, the USGS has
      Example 274847081561101 (01 first            relied predominately on the Price AA and
site or parameter, 02 second site or               pygmy mechanical current meters for
parameter, 03 third site or parameter, etc.)       making direct discharge measurements for
       where, ddmmssdddmmssnn                      over a century. The Price current meters
d=degrees, m=minutes, s=seconds, and               measure stream velocity based on the
n=sequence number                                  number of rotations that the bucket-wheel
      Station identification number                makes over a specific number of seconds.
assignments are made only by the DBA.              The Price current meters were used either
                                                   attached to a top-setting wading rod or
                                                   suspended by cable from a crane. A current
                                                   meter measurement is the summation of the

products of the subsection areas of the        validation of FlowTracker velocity
stream cross section and their respective      measurement accuracy. Each FlowTracker
average velocities (Rantz and others, 1982,    used by FLWSC personnel will be tested as
p. 80). Procedures used for current meter      described in OSW memorandum 2010.02
measurements are described in Rantz and        (appendix 1x). As with all FLWSC
others, 1982, p. 139; Carter and Davidian,     operations, safety is always the highest
1968, p. 7, and Buchanan and Somers, 1969,     priority in any measurement and OSW
p. 1.                                          memo 99.32 is always followed.

                                                     One of the most common methods used
      Technological advancements in            at FLWSC offices for making moderate-to-
streamflow measurement equipment,              high-flow measurements is the acoustic
however, has largely replaced the Price        Doppler current profiler (ADCP). The
current meters with the wading-type            USGS ADCP- QA plan is available as a
acoustic Doppler velocity meters (ADV) at      separate report; U.S. Geological Survey
the USGS. The hand-held SonTek/YSI             Scientific Investigations Report 2005-5183
FlowTracker is an ADV meter approved for       Quality Assurance Plan for Discharge
use in making USGS and FLWSC wading-           Measurements Using Acoustic Doppler
type measurements. Other brands (such as       Current Profilers, (Oberg, Morlock, and
OTT) utilizing similar technology are          Caldwell, 2005) and was announced in
coming on the market in the upcoming           OSW memo 2006.02. Proper operation and
years. The methods used to make a              collection of ADCP measurements are
FlowTracker measurement are similar to         specified in the U.S. Geological Survey
that of a Price current meter; both            Techniques and Methods 3A-22 Measuring
measurements are waded at a tagline across     Discharge with Acoustic Doppler Current
a stream (perpendicular to the flow), where    Profilers from a Moving Boat, Mueller and
point-velocity measurements are typically      Wagner, 2009. Guidance for archiving
taken at 0.2, 0.6, or 0.8 depths. Additional   electronic discharge measurements are
requirements for acoustic wading               described in OSW memo 2005.08 (app. 1z).
measurements are; an independent water               All hydrographers that use ADCPs for
temperature measurement must be made and       discharge measurements are required to be
documented prior to making the                 familiar with the guidelines and methods
measurement, and 0.2 and 0.8 depth velocity    specified in these reports. It is important that
measurements are the minimum number of         all acoustic operators have knowledge of all
velocity measurements required for depths      the appropriate OSW memos and are aware
equal to or greater than 1.5 feet. Field       of the latest methods required for accurate
procedures for ADV use and quality             discharge measurements.
assurance plan are given in OSW memo
2004.04 (app. 1n) and OSW memo 2007.01
SonTek/YSI FlowTracker firmware version
3.10 and software version upgrades and              The most important decision a
additional policy on the use of FlowTrackers   hydrographer makes is the location of the
for discharge measurements (app. 1y).          section where a discharge measurement is to
Guidance for archiving electronic discharge    be made. The section is what determines the
measurements are described in OSW memo         accuracy of the measurement and every
2005.08, Policy and guidance for archiving     effort should be made to obtain the
electronic discharge measurement data          discharge measurement from the best
(app. 1z). The SonTek/YSI FlowTrackers         available cross-section. Generally wading
are required to participate in the USGS wide   measurements with a FlowTracker or Price
FlowTracker validation program for the         current meter will give the best and

repeatable results and should be made at a      downgrade the measurement accuracy
location in relative proximity to the gage.     accordingly.
Wading measurements are quicker to make
and the checking process is much less time      Number of measurement subsections.--
consuming than those made with the ADCP.        The spacing of observation verticals in the
      When personnel make measurements of       measurement section can affect the accuracy
stream discharge, attempts are made to          of the measurement (Rantz and others, 1982,
minimize errors. Sources of errors are          p. 179). The criteria are that observations of
identified in Sauer and Meyer (1992). These     depth and velocity be made at a minimum of
include random errors such as depth errors      about 30 verticals, which are normally
associated with soft, uneven, or mobile         necessary so that no more than 5 percent of
streambeds, or uncertainties in mean            the total flow is measured in any one
velocity associated with vertical velocity      vertical. Even under the worst conditions the
distribution errors and pulsation errors.       discharge computed for each vertical should
These errors also include systematic errors,    not exceed 10 percent of the total discharge,
or bias, associated with improperly cali-       and ideally not exceed more than 5 percent
brated equipment or the improper use of         (Rantz and others, 1982, p. 140). Exceptions
such equipment. Field trips are rotated to      to this policy are allowed in circumstances
different personnel approximately every one     where accuracy would be sacrificed if this
to three years to help minimize some of         number of verticals were maintained, such
these errors. FLWSC policies related to the     as for measurements during rapidly
measurement of discharge by use of the          changing stage (Rantz and others, 1982, p.
current-meter method, in accordance with        174). Fewer verticals than are ideal are
USGS policies, include the following:           sometimes used for very narrow streams
      Depth criteria for Price AA and           (about 12-ft-wide for an AA meter and
pygmy meter selection.--Hydrographers           about 5-ft-wide for a pygmy meter).
select the type of current meter to be used     Measurement of discharge is essentially a
for each discharge measurement on the basis     sampling process, and the accuracy of
of criteria presented in the OSW Memo           sampling results typically decreases
89.07 (app. 1e). Meters are used with           markedly when the number of samples is
caution when a measurement must be made         less than 25. It is the FLWSC policy that
in conditions outside of the ranges presented   USGS and OSW techniques and guidelines
in that memorandum. Any deviation from          are followed when discharge measurements
those criteria is noted and the measurement     are made using any selected method of
accuracy is downgraded accordingly. It is       measurement. These methods include
recommended that a change of meters is not      ADCP, float, or volumetric techniques, tidal,
made during a measurement in response to        and methods involving portable weirs and
the occurrence of a couple of subsections in    flumes.
a single measurement cross section that
exceed the stated ranges of depth and                 Computation of mean gage height.--
velocity. Generally, a Price AA meter should    FLWSC hydrographers will use procedures
be used at depths greater that 1.5 ft, and a    for the computation of mean gage height
Price pygmy meter for depths below 1.5 ft.      during a discharge measurement presented
However, there are also velocity                in Rantz and others (1982, p. 170). Mean
considerations. On the reverse side of the      gage height is one of the coordinates used in
pygmy meter rating table details all the        describing the stage-discharge relation at a
specific information. Personnel should use      streamflow-gaging site.
current meters with caution when a
measurement must be made in conditions               Check measurements.--A second
outside of the ranges of the method             discharge measurement is made for the
presented in OSW Memo 89.07; and                purpose of checking a first discharge
                                                measurement when the measurement differs

from the rating and the recent trend, by more     Field Notes
than 10 percent unless a change in the                  A necessary component of surface-
control is documented. The results are            water data collection and analysis includes a
considered suspect if the measurement does        thorough documentation of field
not plot within rating limits – that is, within   observations and data-collection activities.
the range of either good, fair, or poor– and      Field notes should be as neat and legible as
there are no conditions to justify the results.   possible in order for personnel to be able to
An example of when a check measurement            read the notes without error. To ensure that
is not needed would be when a measurement         clear, thorough, and systematic notations are
plots to the negative side of the rating while    made during field observations, field
there is backwater caused by debris lodged        personnel record streamflow measurements
on the control, and the results conform to        on standardized USGS discharge
expectations. If, however, a measurement is       measurement notes (Form 9-275 series). If
an outlier and no logical explanation is          these forms are not available, any substitute
apparent, then a check measurement must be        can be used, even a regular sheet of paper,
made. When check measurements are made,           as long as the field person includes all the
the potential for systemic errors are             necessary information in the notes. Field
minimized by using methods described in           notes are considered original legal
Rantz and others (1982, p. 346). These            documents, and thus, personnel should not
methods include:                                  erase original observations once written on
      1) using another cross-section location     the note sheet. Instead, they should make
for wading or ADCP measurements,                  corrections to original data by crossing the
      2) using a different meter,                 value out, then writing the correct value.
      3) using verticals offset from the          Some examples of original data on a
locations of the original verticals used for a    discharge measurement note sheet include
bridge measurement,                               gage readings, depths, measurement
     4) spin testing meters, and                  stations, and wheel-bucket revolutions and
     5) other suggestions listed in Rantz and     time notations. Personnel can erase derived
others (pg 346-347).                              or computed data, such as computed widths,
                                                  velocities, sections, total discharge, and
      Corrections for storage.--Rantz and         mean gage height.
others (1982, p. 177) and OSW Memo 92.09
(app. 1g) discuss corrections for storage              The minimum information that should
applied to measured discharges for the            be included by hydrographers on the
purpose of defining stage-discharge               measurement note sheet includes:
relations. These corrections involve an           1) Initials and last name of all field-party
adjustment to the measured discharge based        members,
on the channel surface area and average rate      2) Date and times associated with gage
of change in stage in the reach between the       readings and other observations,
gage and point of measurement. Storage            3) Station name and number,
corrections generally apply only if the           4) Control and channel conditions,
discharge measurement is made at some             5) Outside and inside (if applicable) staff
distance from the gaging station cross            gage or wire-weight gage readings,
section.                                          6) Readings from the data recorder,
                                                  7) Condition of the battery, voltage
     Questions.--Hydrographers who have           regulator, and solar panel,
questions concerning the appropriate              8) Type of instrument used for any
procedures for making stage and discharge         discharge measurements,
measurements should address their questions       9) Any observed high water marks (HWM),
to their immediate supervisor or the office       10) Crest-stage indicator gage (CSI)
Data Chief.                                       readings,
                                                  11) Point-of-zero-flow (PZF) estimates, and

12) Any other pertinent information              Acceptable Equipment
regarding unusual gage or streamflow
conditions.                                            Equipment used by the FLWSC offices
      Points-of-zero-flow should be              for the measurement of surface-water
collected at wadeable streams whenever           discharge has been approved by the USGS
feasible and included on the Form 9-027, as      and the OSW through use and testing. An
well as, the measurement notes.                  array of acceptable equipment for measuring
Mathematics for PZF estimates, reference-        discharge includes current meters, timers,
point elevations, and similar calculations       wading rods, bridge cranes, tag lines, and
should be shown on the measurement note          other types of measurement equipment
sheet.                                           (Rantz and others, 1982, p. 82; and Smoot
     Hydrographers are required to               and Novak, 1968). Although an official list
document notations associated with               of acceptable equipment is not available,
miscellaneous surface-water data-collection      Buchanan and Somers (1969), Carter and
activities on miscellaneous note forms           Davidian (1968), and Edwards and Glysson
(Form 9-275D) or any other sheet of paper        (1988) discuss the equipment used by the
so long as the necessary information is          USGS.
included. The minimum information on all
miscellaneous notes include;                          Historically, the USGS has relied on
     1) station name and number or location      the Price AA and pygmy mechanical current
     2) initials and last name of field-party    meters for making direct discharge
          members,                               measurements for over a century. Methods
     3) date and time associated with            followed by hydrographers for inspecting,
          observations,                          repairing, and cleaning these meters are
     4) purpose of the site visit, and           described in Smoot and Novak (1968, p. 9),
     5) gage-height readings or other            Rantz and others (1982, p. 93), and
          information.                           Buchanan and Somers (1969, p. 7).

      Besides 9-275 series forms of discharge
measurement notes, other types of field
notes used in the FLWSC offices include
crest-stage indicator gage notes (T-9335),
level notes (9-276), and a field inspection
sheet for data loggers. A variety of pertinent
station and conditions information, readings,
observations, and calculations are required
in filling out these notes.
      Generally, discharge measurements
made during field site visits are calculated
onsite after the measurement is made. This       Figure 4. Assembly drawing of Price AA
allows check measurements to be made             current meter.
without having to make another station visit.
During floods or other emergency situations,
hydrographers should calculate discharge         Price AA and Pygmy Current Meters
measurements as soon as possible and phone
results into the office for informational             The ultimate responsibility for the good
purposes. This is particularly important         condition and accuracy of a current meter
during major floods so that discharges           rests with field personnel who use it (OSW
FLWSC personnel present to the public and        memo 89.07, app.1e). A timed spin test
cooperators through NWISWeb other                made a few minutes before a measurement
media outlets reflect the most current and       does not ensure that the meter will not
accurate data possible.                          become damaged or fouled during the

measurement. Field personnel must assess          second trip, provided that the seven-work-
apparent changes in velocity or visually          day rule is not violated.
inspect the meter periodically during the
measurement to ensure that the meter                    Timed spin tests are conducted at least
continues to remain in proper operating           once per year on spare meters that are
condition. FLWSC personnel follow the care        carried in field trucks to serve as backup
and maintenance of vertical-axis current          equipment, whether they are used or not.
meters as described in the OSW memo               Provided that spare meters have been
99.06. The procedures include, but are not        appropriately cleaned and stored, according
limited to the following steps:                   to procedures described in OSW memo
      1) after a day of use in the field, the     99.06, a timed spin test is not required of a
pivot and contact-chamber cap are removed         spare meter immediately prior to its use
to clean and lightly oil the upper and lower      (especially if the use of the spare meter is
bearing surfaces;                                 required in a rushed, time-sensitive
      2) the bearing surfaces, especially the     situation). It is required that FLWSC
pivot point, are examined for wear or             hydrographers perform a timed spin test
damage;                                           prior to making a discharge measurement
      3) after cleaning, the meter cups are       with a spare meter, or perform a timed spin
spun to ensure that the rotation motion does      test for the spare meter as soon after the
not have a ―wobble‖ and that the cups do not      measurement as is practical so there is
come to an abrupt stop (a timed spin test is      documentation that the measurement was
not required at the end of the day); and          made with a meter that was in good working
      4) the general condition of the meter is    order. If a Price AA meter does not spin for
examined to ensure that the cups, tail fins, or   at least 2 minutes and 40 seconds the meter
other parts are not bent or damaged.              is not to be used for discharge
     Any needed repairs are made and              measurements. If a pygmy meter does not
significant problems are documented in the        spin for at least 45 seconds it is not to be
spin-test log book.                               used for discharge measurements. When
                                                  timed spin tests are made in the field, the
                                                  test results are written on the associated
                                                  measurement note sheet. Upon returning to
      It is the USGS policy that timed spin       the office, that same information is entered
tests are carried out and documented as           into the spin-test log for that particular
described in Smoot and Novak (1968, p. 10).       instrument.
The goal of the spin tests are to ensure that
streamflow measurements are made with                   When deficiencies are identified, it is
meters that are in good working order, and        the responsibility of the senior hydrographer
to provide historical documentation that the      to correct the situation by instructing
meters were in good working order at the          hydrographers on the appropriate spin-test
time of the field measurements. For vertical-     policy. Spin-test results are documented in a
axis meters that are used during a field trip,    log that is maintained for each instrument.
timed spin tests are conducted prior to the       These logs are kept in filed vehicles with the
beginning of the field trip. If a field trip      meter. This log is part of the archived data
extends to more than one week, an                 of WRD (OSW memo 89.07 (app. 1e).
additional timed spin test is conducted so        Repairs are made to meters when
that no measurements are made beyond              deficiencies are identified through the spin
seven working days of the most recent spin        test or inspection. Review of this log by a
test. If one field trip ends one week, and a      supervisor is required annually. If
second field trip begins the following week,      deficiencies are observed during this review
a single timed spin test can serve as the test    of the log, the hydrographer responsible for
to follow the first trip and to precede the       the meter is informed through oral

communication and the problem is corrected                i)  Other pertinent information
immediately.                                                  regarding equipment and
      In addition to the timed spin tests                j) Meter type and meter number,
performed prior to field trips, field personnel          k) Streamflow location for
are required to inspect the meter before and                  measurement,
after each measurement to see that the meter             l) Stage readings and times before,
is in good condition, that the cups spin                      during, and after measurement,
freely, and the cups do not come to an                   m) Time measurement started and
abrupt stop. Descriptive notations are made                   ended, with intermediate times,
at the appropriate location on the field-note                 and
sheet concerning the meter condition, such               n) Bank of stream that
as "OK" or "free" or other such comments.                     measurement was started from.
To ensure that field personnel carry out their    2. Miscellaneous Field Notes
responsibilities in maintaining the                  Form 9-275-D
equipment they use, the equipment is                     a) Used for almost any type of
inspected annually by another hydrographer                    documentation of field
not responsible for the meter. If deficiencies                observations, maps, data, etc.,
are identified they must be corrected by the                  and
hydrographer responsible for the meter as                b) Include party, date, time, station
soon as possible. It is the responsibility of                 name, and number, and
the supervisor to determine if the deficiency                 observations.
affected the quality of data collected when       3. Crest-Stage Notes
the defective equipment was in use, and if               a) For crest-stage gage inspections
so, to determine the best course of action in                 and service,
correcting or voiding that data.                         b) Include party, date, time, station
                                                              number, station name, and
     Form 9-275 Series station inspection                c) Include stick readings, quality
and measurement, miscellaneous, crest-                        of marks, high-water marks, and
stage, and level notes should include the                     other observations.
following:                                        4. Level Notes - Form 9-276 for running
                                                     levels at streams
1. Discharge Measurement Notes                           a) Include station number, party,
   Form 9-275 I series (dependent on                          date, time, and level readings
   instrument used)                                           and calculations
        a) Date and party,                               b) Instrument number of
        b) Name of stream and USGS                            equipment used
           station number,                               c) Date of last peg test.
        c) Outside and inside (stilling
           well) stage readings,
        d) Data logger or DCP stages and
           times,                                 INFORMATION ON ALL NOTES
        e) Readings and times for all other       SHOULD BE WRITTEN AS
           sensors,                               COMPLETELY AND LEGIBLY AS
        f) Control and flow conditions,           POSSIBLE. ASK YOURSELF IF
        g) Observed high-water marks and          SOMEONE ELSE COULD
           maximum/minimum clip                   UNDERSTAND THE NOTES
           readings,                              COMPLETELY IN 10 YEARS TIME--
        h) Condition of battery and               THE ANSWER SHOULD BE ―YES.‖
           nitrogen tank (if applicable),

Flume Measurements                              fail to remedy documented deficiencies will
                                                be subject to disciplinary action, including
      When making a flume measurement, be       removal for serious and continued problems
sure to record the identification number of     (WRD Memo 98.10).
the HIF flume in the measurements notes.        1. Each trained hydrographer making
The care of flumes is very important, as             discharge measurements is solely
dents and misalignment can severely affect           responsible for completely and
the flume rating. For proper use of flumes,          accurately filling out the 'front sheet',
refer to Kilpatrick and Schneider (1983).            and the computational accuracy of the
These portable devices are applied                   measurement.
according to methods described by               2. Each person immediately upon
Buchanan and Somers (1969, p. 57) and                completion of a measurement
Rantz and others (1982, p. 263).                     computation is expected to:
                                                          a) Scan the measurement for
Measurement Checking                                           obvious errors in velocity,
         The degree of review and checking                     depth, partial areas, and partial
of field note sheets depends on the                            discharges.
experience of the hydrographer. For the new               b) Scan for misplaced decimal
hydrographer, either a fellow hydrographer                     points.
or the senior technical person needs to check             c) Check the sum of partial widths
every measurement or field note right after                    against total width.
the site visit to ensure that all required                d) Re-compute the sum of partial
information and observations are made and                      areas and discharges.
noted correctly, and that discharge             3. For personnel with less than 12 months
measurements are being completed                     experience, a 100 percent review of
according to standards and are correctly             computational accuracy, and 'front sheet'
computed. Experienced hydrographers with             data will be made. After 12 months,
demonstrated competence generally need               partial checking should be done by the
only periodic reviews of the measurements            Team Leader until competency is
and field notes. However, most FLWSC                 demonstrated.
offices do check all measurements prior to      4. For personnel that have demonstrated
entry into the database. With Continuous             competency to the satisfaction of the
Record Processing (CRP) it is more                   Team Leader, routine checking of their
important to make certain that shifts and            work is not required. Random spot
corrections are being applied based on               checks are recommended.
checked information. In the event of unusual    5. If a measurement, when compared to the
conditions, however, the measurement                 rating, is more than 10 percent off the
should be thoroughly reviewed and checked.           existing trend, a check of that
Reviewers finding deficiencies in the                measurement is recommended. This
content, accuracy, clarity, or thoroughness          does not apply to channels that normally
of field notes notify the hydrographer of            shift a large amount. For those channels,
these facts by communicating USGS                    each gage should have limits for the
standards and requirements directly with             acceptable percentage off, agreed to by
them. Reviewers who find continued                   the field hydrographer and their
deficiencies in a hydrographer‘s                     supervisor, and based on personal
measurement notes should notify the senior           knowledge of the site that would require
hydrographer, Data Chief, or project chief,          a complete review. It is becoming more
who will then review USGS measurement                important that measurements be checked
notes standards with the hydrographer.               and entered into SiteVisit as soon as
Clear, accurate, and thorough field notes are        possible upon completion of the field
crucial to the quality assurance of surface-         trip. With Continuous Record
water data. Hydrographers that consistently          Processing (CRP) it is critical that shift

    applications be done with checked
    measurements. This will ensure that the
    data is more reliable and less apt to have
    to be revised or altered at a later date.

Hydroacoustic Measurements

      The development of hydroacoustic
technology allows the collection of surface-
water discharge data with equipment other        Figure 5. SonTek FlowTracker
than mechanical current meters. To
demonstrate the quality of surface-water
data collected with hydroacoustic                Acoustic Doppler Current Profiler
equipment, a thorough documentation of
procedures and observations must be main-        Acoustic Doppler current profiler (ADCP)
tained. Hydroacoustic equipment used by          technology has been evolving since the first
this office includes the SonTek/YSI              systems were introduced in the early 1990s
FlowTracker ADV and acoustic Doppler             and new procedures and methods will
current profilers. The responsibility for        evolve as well. Training personnel and
ensuring that hydroacoustic equipment is         encouraging communication with experts in
utilized correctly and for ensuring that         this technology will help assure that ADCP
documentation is comprehensive and is            measurements are collected and processed
stored correctly is held by the acoustic         consistently and correctly to USGS
specialist within each office and will follow    standards of accuracy. The USGS has
OSW recommendations.                             documented approved ADCP procedures in
                                                 the following publications: Measuring
FlowTracker                                      discharge with acoustic Doppler current
                                                 profilers from a moving boat, USGS
     The SonTek/YSI FlowTracker acoustic         Techniques and Methods 3A-22, Mueller
Doppler velocimeter (ADV) has largely            and Wagner, 2009, and
replaced the Price AA and pygmy current          Quality-Assurance Plan for Discharge
meters used by FLWSC personnel for               Measurements Using Acoustic Doppler
measuring surface-water discharge in             Current Profilers, Scientific Investigations
wading conditions. The USGS methods and          Report 2005-5183, Oberg, Morlock, and
quality assurance procedures for streamflow      Caldwell , 2005. The OSW has a
measurements with the FlowTracker are            Hydroacoustics Section, which maintains a
outlined in OSW memo 2004-04 (app. 1o),          web page including information on quality
Policy on the use of the FlowTracker for         assurance procedures for ADCP
discharge measurements, and OSW memo             measurements at:
2007.01 SonTek/YSI FlowTracker firmware          http://hydroacoustics.usgs.gov/index.shtml.
version 3.10 and software version upgrades             The ADCP is used to measure
and additional policy on the use of              velocities and compute discharge in a wide
FlowTrackers for discharge measurements          range of hydrologic conditions. The ADCP
(app. 1z). Guidance for archiving electronic     measures three-dimensional velocities
discharge measurements are described in          throughout the water column as opposed to
OSW memo 2005.08 Policy and guidance             point velocity measurements made by
for archiving electronic discharge               conventional Price current meter methods.
measurement data (app. 1y).                      This instrument can be deployed from a
                                                 manned boat or an unmanned platform.

                                                  in a logical sequence from office preparation
                                                  to reviewing the data including how to
                                                  determine and correct for moving bed flow
                                                           The following paragraph is an
                                                  excerpt from the Foreword in the report
                                                  Measuring Discharge with Acoustic Doppler
                                                  Current Profilers from a Moving Boat:
                                                           ―This report contains the most
                                                  current information and guidance regarding
Figure 6. Two acoustic Doppler current            acoustic Doppler current profilers (ADCPs)
profilers commonly used by the USGS to            used by the USGS at the time of publication.
measure streamflow. (Left photograph by K.        The development of new and improved
Oberg, USGS and right photograph by               ADCPs is ongoing, as are the research and
SonTek/YSI.)                                      practical field experience with existing and
                                                  new ADCPs, which likely will lead to
Training                                          changes in the guidance on the application
                                                  of ADCPs over time and revisions to this
       Due to the complexity of the principles    document. The user is encouraged to log
of operation of the ADCP and the                  onto the USGS Office of Surface Water
collection/processing software, personnel         Web site [http://hydroacoustics.usgs.gov]
are required to complete the OSW training         for the latest revisions to this document and
class SW 1321 Streamflow measurements             technical memorandums that may be issued
using ADCPs and are encouraged to                 prior to revisions to ensure that the best
complete the second class in the series           techniques are communicated for use in
SW2441 Intermediate streamflow                    collecting and processing ADCP discharge
measurements using ADCPs after                    measurements.‖
approximately one year of ADCP
measurements. Acoustic instruments and                  All ADCP measurements are to be
their related software packages are               collected using the most recent OSW
continually being updated, and techniques         approved software provided on the USGS
and methods are still evolving. It is required    hydroacoustics website. The discharge
that users must keep up-to-date with current      measurement data will be stored under the
OSW policies and procedures by:                   station directory, the measurement sub-
        1) subscribing to the acoustics mailing   directory, in a sub-directory that specifies
list, (this can be done on the USGS               the measurement number or measurement
hydroacoustics website)                           series numbers. The measurement files will
        2) reviewing the OSW Hydroacoustic        be named with a filename reflecting the
Web pages (http://hydroacoustics.usgs.gov),       station number, the date of the measurement.
and                                               For example, discharge measurement
 3) attending USGS refresher classes or           number 271 and related data are collected at
workshops.                                        the St Johns River near Melbourne, FL
                                                  (02232000) on January 12, 2010. The
All trained ADCP hydrographers should be          filename of the measurement is entered in
completely familiar with, understand, and         the manufacturers software with the
follow the procedures and requirements            filename comprised of the station number
specified in the USGS report; Measuring           and the date of the measurement, in this case
discharge with acoustic Doppler current           02232000_20100112
profilers from a moving boat, USGS                (stationnumber_YYYYmmdd).
Techniques and Methods 3A-22, Mueller                   The measurement data will be
and Wagner, 2009. The report describes the        transferred to the office server within 48
current (2009) ADCP measurement process           hours of returning to the office and stored in

a sub-directory of the current water year,         1982) outlines proper measurement site
Station Number, Measurements, and finally          selection guidelines, and these guidelines are
in a sub-directory that specifies the              supplemented in the two reports; U.S.
measurement number (271 in this example).          Geological Survey Scientific Investigations
If the measurements are a series such as at a      Report 2005-5183 Quality Assurance Plan
tidally affected site, the Measurements sub-       for Discharge Measurements Using Acoustic
directory will be the beginning and ending         Doppler Current Profilers (pgs 6 – 8),
number of the discharge series (Example:           (Oberg, Morlock, and Caldwell, 2005), and
271_283). A flow chart of the directory            U.S. Geological Survey Techniques and
structure and file naming conventions for          Methods 3A-22 Measuring Discharge with
electronic data archival are presented in          Acoustic Doppler Current Profilers from a
Appendix 3.                                        Moving Boat (pgs 3 – 8), (Mueller and
      Acoustic Profiler Discharge                  Wagner, 2009) pgs. 3 – 8. These guidelines,
Measurement note sheet form No. 9-275-I            coupled with the knowledge of the acoustic
will be used when collecting ADCP data.            instrument capabilities and limitations, can
The most up-to-date ADCP measurement               avert many problems and allow the
field sheet (9-275-I) can be downloaded            measurement of accurate discharge.
from the USGS hydroacoustics web site
under the Moving Boat Deployment/Tech                    Once the measurement cross section is
Tips page;                                         selected, a moving bed test must be
http://hydroacoustics.usgs.gov/movingboat/         conducted prior to every measurement. The
mbd_techtips.shtml). The saved file can be         moving bed test consists of holding the boat
printed on regular or waterproof paper in          stationary for 5 to 10 minutes (depending on
each office. For long duration multiple            deployment method) while recording flow
measurements (i.e. tidal measurements) it is       data. A moving bed is present if data
recommended that the second page of the            indicate an apparent upstream (or up-flow)
field note sheet be copied and appended to         trend of the stationary boat. When a moving
the front sheet of the field form, so there will   bed is encountered, an attempt to find a
be at least one front sheet and perhaps            more acceptable location should be made. If
multiple pages for more than ten transects.        a site cannot be located that does not have
The note sheet will be completed as outlined       moving bed conditions, a Differential Global
in U.S. Geological Survey Scientific               Positioning System (DGPS) capable of sub-
Investigations Report 2005-5183 Quality            meter accuracy should be used as the
Assurance Plan for Discharge                       reference for the ADCP. If a DGPS system
Measurements Using Acoustic Doppler                is not available, there are other methods of
Current Profilers, (pg 19 and figure 11)           documenting and correcting discharge for a
(Oberg, Morlock, and Caldwell, 2005) and           moving bed flow condition. Procedures and
U.S. Geological Survey Techniques and              software for correcting discharge in moving
Methods 3A-22 Measuring Discharge with             bed conditions have been developed when
Acoustic Doppler Current Profilers from a          DGPS is not available or DGPS use is not
Moving Boat, (Mueller and Wagner, 2009             possible. The Loop Correction (LC) and
(pg 24 and figure 12).                             Stationary Moving Bed Analysis (SMBA)
      All of the fields on the note sheet          software programs have been written and
should be filled in with correct information.      approved by OSW and should be used as
If a particular field does not apply to that       described in the report; U.S. Geological
measurement, the user should record a dash         Survey Techniques and Methods 3A-22
(-) or N/A.                                        Measuring Discharge with Acoustic Doppler
                                                   Current Profilers from a Moving Boat
      When making ADCP discharge                   (Appendix B), (Mueller and Wagner, 2009)
measurements (as for any measurement),
site selection should be carefully considered.         The draft of the ADCP transducers
Water Supply Paper 2175 (Rantz and others,         must be measured prior to each discharge

measurement. This is accomplished by              as individual measurements. If conditions
measuring from the center of the transducers      permit, it is preferable to get pairs of
to the water surface. The ADCP should be          transects in reciprocal courses. If less than
accurately measured and marked with               four transects are used as a measurement, a
graduated tape or other permanent marking.        description of the varying conditions must
A direct reading of the water surface on the      be noted.
graduated tape or permanent marks is the
preferred method for measuring the                Data Processing
transducer depth. When measuring the
transducer depth solidly attached to a                  After returning to the office, the data
manned boat, it is important to ensure that       must be transferred to the network within 48
the depth is measured accurately and reflects     hours. All data should be named using the
the actual transducer depth when the boat is      file naming convention discussed in the
under way and both the boat operator and          previous section. Each year, a new water-
ADCP operator are in position to avoid            year directory will be created. Each station
potential errors from changes in transducer       will have a directory identified by the station
draft caused by changes to boat pitch and         number within the water year directory. A
roll. Both water temperature and salinity         separate directory for each measurement
should also be measured and recorded prior        number or measurement number series will
to and during the discharge measurement.          be created under the Measurements
                                                  directory within each station number
     The ADCP must be configured                  directory (see previous section for
correctly for the site conditions. Proper         examples). All ADCP data, including raw
configuration will be accomplished by using       files, configuration files, self test files,
the Configuration Wizard, a utility program       Discharge Measurement Wizard, and
provided with the ADCP software WinRiver          corrected discharge (if applicable) files will
II (OSW Technical Memorandum 2002.03              be stored in the Measurement Number
and 2003.04 (app. 1m and 1n).                     directory.

      Due to depth limitations, the ADCP               All ADCP measurements must be
cannot measure near-bank discharge. The           processed following the procedures
discharge in the unmeasured areas near the        presented in U.S. Geological Survey
banks is estimated in the software. In order      Techniques and Methods 3A-22 Measuring
to compute the near-bank discharge, the user      Discharge with Acoustic Doppler Current
is required to accurately measure the             Profilers from a Moving Boat (pgs 26-32
distance from the ADCP to the shore using         and Appendix F), (Mueller and Wagner,
either a laser rangefinder, tagline, measuring    2009). After processing, the file must be
tape, or optical range-finder. These distances    locked using the file lock feature in the
should be entered into the software and on        manufacturer software if applicable (OSW
the note sheet for each transect. The bank        memo 2003.04, app. 1n). All processed
geometry (triangular, rectangular, or other)      measurements must then be checked by a
should also be recorded.                          second party. The party responsible for
                                                  checking an ADCP measurement will follow
      A final discharge number is considered      the same outline mentioned above.
to be the average of four transects (two pairs
of transects in reciprocal headings). If any of
the four transects differ by more than five       Alternative Equipment
percent from the mean discharge, another set
of four transects should be made, and the              The FLWSC offices may cooperate or
average of all eight will be the total            contract work with another agency that uses
discharge. Under rapidly varying flow             alternative equipment, such as the Swoffer
conditions, individual transects may be used      current meters. Quality-assurance programs

between alternative meters and Price meters
will be developed between the USGS and                 FLWSC personnel follow data-
the other agency or contractor to assess          collection and computation procedures
whether the alternative meter can be              presented in Benson and Dalrymple (1967).
approved. Such a program would entail             This report includes policies and procedures
testing both types of meters under controlled     related to site selection, field survey,
and field conditions under an array of stream     identification of high-water marks, the
discharges to validate or invalidate use of       selection of roughness coefficients,
the alternative meter. In addition, the other     computations, and the written summary. The
agency or contractor must provide the USGS        FLWSC personnel also follow procedures
with the procedures that they use for             for measurement of peak discharge by
ensuring proper calibration of their current      indirect methods presented in Rantz and
meters.                                           others (1982, p. 273).

Other Direct Methods of Measuring                      In addition to the general procedures
Discharge                                         presented in Benson and Dalrymple (1967),
                                                  the FLWSC personnel follow guidelines
     The USGS OSW techniques and                  presented in other reports that describe
methods are followed when discharge               specific types of indirect measurements
measurements are made with any selected           suited to specific types of flow conditions.
method of measurement. These methods              The slope-area method is described in
include: the tracer-dilution method,              Barnes (1967) and Dalrymple and Benson
volumetric methods, and use of portable           (1967). The USGS uses the Manning
weirs and flumes (Rantz and others, 1982;         equation in application of the slope-area
Buchanan and Somers, 1969; and Kilpatrick         method. Procedures used for selecting the
and Schneider, 1983).                             roughness coefficient are described in
                                                  Arcement and Schneider (1989). The
Indirect Measurements                             computer-based tool, program C374,
                                                  available to assist in computations of peak
      In Florida, floods often last several       discharge using the slope-area method is
days to weeks because of relatively low           discussed in OSW memo 83.07, (app. 1a).
gradients in terrain and stream channels.
Thus, FLWSC offices have historically                   Procedures for the determination of
relied on obtaining peak discharges by direct     peak discharge through culverts, based on a
measurement. However, in some situations,         classification system which delineates six
especially extreme floods on smaller urban        types of flow, is described in Bodhaine
drainages, it is impossible or impractical to     (1982). The computer-based tool, program
measure peak discharges by means of a             A526, available to assist in computations of
current meter or ADCP. There may not be           peak discharge at culverts, is discussed in
sufficient warning for personnel to reach the     OSW memo 83.07 (app. 1a). At sites where
site to make a direct measurement, or             open-channel width contractions occur, such
physical access to the site during the event      as flow through a bridge structure, peak
may not be feasible. A peak discharge             discharge can be measured using methods
determined by indirect methods becomes, in        described in Matthai (1967) and using the
many situations, the best available means of      Water-Surface Profile Computation model
defining the upper portions of the stage-         (WSPRO) (Shearman, 1990) and the Corps
discharge relation at a site (Rantz and others,   of Engineers HEC-RAS step-backwater one-
1982, p. 334). Because the results may be         dimensional model. More recent programs
unreliable, USGS generally does not accept        for indirect measurement computation are
extrapolation of a stage-discharge relation,      the Slope-Area Method (SAC), OFR 94-360,
or rating, beyond twice the measured              and the Culvert Analysis Program (CAP),
discharge at a gaging station.                    WRIR 98-4166, by Janice Fulford, and the

NCALC program was used to compute               providing proper training. The Data
Manning‘s n-value from a known discharge,       Chief/Surface-Water Specialist refers
water surface profile, and cross-section        questionable and difficult indirect
properties. Debris-flow conditions, which       measurements to other Florida office
are most common in small mountainous            Surface-Water Specialists, or to the
basins, are discussed in OSW memo 92.11         Regional Surface-Water Specialist for
(app.1i).                                       resolution.

      Determinations of water-surface                The senior technical person and/or Data
profiles along a stream channel in              Chief determine when and where indirect
association with selected discharges are        measurements are made. Generally, an
made when studies are conducted that            indirect measurement should be performed
involve delineations of flood plains or when    when the estimated discharge is more than
extensions are made to stage-discharge          twice the highest direct measurement made
relations at streamflow sites. Personnel are    at the site. For quality assurance, validation,
required to follow the procedures associated    and training purposes, a few indirect
with step-backwater methods described in        measurements should be made annually.
Davidian (1984). The computer-based tool
used for assisting in the computations of             The employee should identify and flag
water-surface profiles using step-backwater     high-water marks as soon as possible after
methods, WSPRO, is discussed in OSW             the flood, and after obtaining permission
memo 87.05 (app.1c).                            from property owners. Because the quality
                                                and clarity of high-water marks are best just
      General guidelines that are followed by   after a flood, personnel traveling in the field
FLWSC personnel when making indirect            need flagging equipment such as nails and
measurements include those discussed in         plastic markers, spray paint, paint sticks, and
OSW memo 92.10 (app. 1h) in Shearman            brightly-colored flagging tape in their field
(1990). Violation of any one of the general     vehicles.
guidelines does not necessarily invalidate an
indirect measurement (OSW Memo 92.10,                After the computation of each indirect
app. 1h), but should be cause for careful       measurement, the section or project chief,
scrutiny and analysis. Criteria that might      Data Chief, or surface-water specialist
invalidate an indirect measurement include      checks graphs, field notes and data, plotted
possible presence of a 1) hydraulic jump, 2)    profiles, maps, calculations or computer
a discontinuous water-surface slope, 3)         output, and written analyses associated with
inadequate fall between cross sections, or 4)   the measurement. A single labeled folder
evidence of bed changes between the time of     organizes the information, which is then
the flood and the indirect measurement.         included with the primary folder for use in
                                                computing or reviewing the record. Historic
     In all indirect measurements, the          indirect measurements become part of the
computations should be documented with all      archived indirect measurement files.
plots as shown in the USGS Techniques of        FLWSC personnel maintain and update the
Water-Resources Investigations (TWRI)           peak-flow data files, including computer
reports and should include the field notes,     database files (OSW Memo 92.10, app. 1h).
photos, and a formal summary page. The          The section or project chief ensures that
Data Chief or project chief reviews indirect    appropriate indirect-measurement results are
measurements to ensure that they are being      entered correctly into the peak-flow files.
performed properly. If deficiencies are
found during the review, actions taken to       Peaks above Base
remedy the situations include discussing the
deficiencies with the person or persons             The USGS criteria for selecting peaks
completing the indirect measurement or          above base (PAB) for publishing in the

Annual Data Report are the same as those           discharge data and associated gage heights.
published in the preparation guide of Water        It contains one or more peaks for each sta-
Resources Data Reports (Novak, 1985). A            tion per year. The file is organized by
series of peaks occurring, for example, on         agency, station, and water year. To maintain
February 14, 16, 18, 19, and 21 do not             uniformity of peak-flow data entered into
constitute independent events even though          NWIS, the following set of basic procedures
they are independent by the criteria given in      have been established for use:
the preparation guide (Novak, 1985). Select
a base for peak above base that will be            1. Year the peaks for each of the FLWSC
exceeded on the average three times a year.             streamflow stations will be entered into
                                                        a computer file for verification and
      A peak should not be published unless             further processing.
the discharge at the trough, between it and        2. To avoid missed peaks, primary
the adjacent higher peak, goes down to 75               computations or peak discharge forms
percent or less of the lower peak and                   should be used to determine all peaks
remains that low for at least 48 hours. For             above base. As a cross check, the DBA
example: if two consecutive PAB are 2,000               will check input files against the Annual
  3               3
ft /s and 1,500 ft /s, they are independent             Data Report.
only if there are 48 hours of flow less than       3. The detailed format for entering peaks is
1120 ft /s, between the two.                            shown in WATSTORE, Vol. 4, Chapter
                                                        I, Instructions for Peak Flow File. For
Peak Flow Files                                         further clarification, FLWSC personnel
                                                        may add specific codes for qualifying
      The responsibility of maintaining the             discharge shown below:
accuracy of the peak-flow data files,                     Code 4: Discharge is a maximum daily
including computer database files, lies            mean--Applies only if there is no
within the FLWSC Offices (OSW memo                 instantaneous peak available. This code
92.10, app. 1h). It is the responsibility of the   should be applied to any daily value in the
Data Chief or their designate to ensure that       peak file.
appropriate indirect-measurement results are             Code 5: Discharge is an estimate --
entered into the peak-flow files. It is also       Should be used for any peak that is
their responsibility to ensure that the peak-      estimated by methods such as hydrographic
flow files are correct. The surface-water          comparison, flood routing, or drainage area
specialist may perform various types of            relations. Standard indirect methods are
reviews of peak-file data, including but not       considered to be measurements.
limited to:                                               Code 6: Discharge affected by dam
                                                   failure -- Should be applied whenever a
1. Graphical analysis of peak discharge            significant portion of the flow is affected by
   versus drainage area, by storm, within          the failure. Fifteen percent would be a
   hydrologic regional bounds.                     significant amount.
2. Graphical analysis of maximum peak                    Code 7: Discharge affected, but to an
   discharge versus drainage area, within          unknown degree, by regulation or diversion
   regional hydrologic bounds or for the           -- If total regulation and storage in the basin
   entire FLWSC office defined study area.         are undetermined and/or if total diversion
                                                   into or out of the basin is ungaged, use this
For further discussion on the update and           code.
review of the peak-flow files, refer to the               Code 8: Discharge affected by
Data-base Management section in the                regulation or diversion -- Use this code if the
SW/QA Plan.                                        total usable storage capacity, in acre-ft,
     The peak flow file is a National Water        divided by drainage area, in square miles, is
Information System (NWIS) database                 greater than 103. This should also be used if
containing instantaneous maximum stream            diversions exceed 10 percent of peak flow.

      Code 9: Discharge due to snowmelt,          computation of annual peaks at crest-stage
hurricane, ice jam or debris dam breakup, or      gages (OSW memo 88.07, app. 1d).
debris flow -- If a natural event, use Code 9;         Procedures followed by this office in
if an artificial structure fails, use Code 3.     the operation of crest-stage gages are
                                                  presented in Rantz and others (1982, p. 9,
     Generally, the office will be coding         77, 78). One or more gages are maintained
peaks for one water year at a time. However,      at each selected site where peak elevations
in case of additions, revisions, or corrections   are required on a stream. Upstream and
to previous years in the Peak File, the Data      downstream gages are maintained at culverts
Chief or field operations chief will be           or other structures where water-surface
responsible for verifying the data.               elevations are required to compute flow
     As explained in WATSTORE VOL. 4,             through the structure and to establish the
the ―2 and 3 cards‖ (the ENT and maximum          type of flow that occurred.
peak of year cards) are essential for entering          Except at sites where crest-stage gages
data for each station, and the ―4 card‖           are used only to confirm or determine peak
(partial or secondary peak card) is optional.     stages, stage-discharge relations are
Only ONE ―2 card‖ is necessary per station
EVEN IF coding more than one water year.

     When the base flow for peaks is newly
determined, revised, or dropped, it must be
given a discharge qualification code of ―D‖
and the change made in the site file. Failure
to do so may result in the secondary (partial)
peaks being dropped from the Peak File.
Coding errors such as incorrect dates will
not only affect the current water year but
could alter previous year's peaks as well.

     Policies and procedures for
computation of peak discharges at crest-
stage gages and associated documentation
are presented in this report in the section
Processing and Analysis of Streamflow
                                                  Figure 7. Crest-stage gage.
                                                  developed in association with the rating
Crest-Stage Indicator Gages
                                                  based on direct or indirect high-water
                                                  measurements. Direct or indirect
     Crest-stage Indicator gages (CSI) are        measurements are obtained yearly to verify
used as tools throughout the USGS for             or adjust the rating. Levels are run to the
determining peak stages at otherwise              gage every three years or as soon as possible
ungaged sites, confirming peak stages at          after significant changes in the gage
selected sites where recording gages are          occurred because of damage to the gage,
located, confirming peak stages where             reconstruction, or other such situation.
pressure transducers are used, and                When extremely high peaks occur, an
determining peak stages along selected            outside high-water mark to confirm the gage
stream reaches or other locations, such as        reading is found when possible, is described
upstream and downstream from bridges and          on the note sheet, and is flagged by a
culverts. The OSW requires quality-               durable indicator so that the elevation of the
assurance procedures comparable to those          high-water mark can be determined the next
used at continuous-record stations for the        time levels are run. Field observations are
operation of crest-stage gages and for the        written on crest-stage inspection sheets. All

field notes are required to include, at mini-     structures, it is FLWSC policy that stage-
mum, initials and last name of field              discharge relations are determined by
personnel, date, time of observation, and         making current-meter or ADCP
distance from the measuring point to the          measurements throughout the range of stage
flood mark.                                       or relying on the design rating when
                                                  measurements cannot be made. Portable
      The senior hydrographer is responsible      weir plates and flumes may be used by
for ensuring that correct data-collection         personnel in situations that include flows too
procedures are followed by field personnel.       small to be measured with a current meter.
This responsibility is carried out by             For very small flows volumetric measure-
examining all note sheets. When a                 ments are encouraged. These portable
deficiency in data-collection activities is       devices are used according to methods
identified, the problem is remedied by one-       described in Buchanan and Somers (1969, p.
on-one training by the senior hydrographer        57) and Rantz and others (1982, p. 263).
and/or Data Chief if needed. Policies and
procedures for computation of peak                      The Data Chief or project chief ensures
discharges at crest-stage gages and               the correct design and installation of
associated documentation are presented in         artificial controls appropriate for the gaging
this report in the section Processing and         site and that they use correct methods to
Analysis of Stage and Streamflow Data.            install and operate the control. When
                                                  installing an artificial control, personnel
Artificial Controls                               should take into account the criteria for
                                                  selecting the various types of controls,
     Artificial controls, including broad-        principles governing their design, and the
crested weirs, thin-plate weirs, and flumes,      attributes considered to be desirable in such
are built in stream channels for the purpose      structures (Carter and Davidian, 1968, p. 3;
of simplifying the procedure of obtaining         Rantz and others, 1982, p. 15 and 348; and
accurate records of discharge (Rantz and          Kilpatrick and Schneider, 1983, p. 2 and
others, 1982, p. 12). Such structures serve to    44).
stabilize and constrict the channel at a
section, reducing the variability of the stage-        When field inspections of artificial
discharge relation.                               controls are performed, specific information
                                                  pertaining to control conditions are written
                                                  on the field note sheets for the purpose of
                                                  assisting in analysis of the surface-water
                                                  data. These notes include comments
                                                  concerning scour or fill of the streambed
                                                  immediately upstream from the control,
                                                  debris on the control, and any damage to the
                                                  structure. Regular maintenance at artificial
                                                  controls include cleaning the controls and
                                                  approach sections each visit or as needed.
                                                  Any changes such as cleaning should be
                                                  noted on the field data sheet. When
                                                  problems are encountered by field personnel
                                                  pertaining to artificial controls the senior
Figure 8. Compound weir at Sixmile Creek          hydrographer should be contacted before
phosphate-mine outfall.                           leaving the site, if possible.
     Artificial controls are used at some         Flood Conditions
gaging stations maintained by FLWSC
personnel. In situations where artificial
controls are installed as permanent

      Flood conditions present problems that       is the responsibility of the Data Chief to
otherwise do not occur on a regular basis.         ensure that individuals that receive a copy of
These problems can include difficulties in         the plan are fully versed on the content of
gaining access to a streamflow gage or             the flood plan.
measuring site because roads and bridges are
flooded, closed, or destroyed. Debris carried            During a flood, coordination of flood
in the streamflow can damage equipment             activities is conducted by the Data Chief,
and present dangers to those collecting the        who serves as the office flood coordinator.
data. Rapidly changing stage or the presence       For personnel that are not already in the
of conditions requiring measurements to be         field, their first responsibility during flood
made at locations some distance away from          conditions is to call the flood coordinator
the gage can create problems in associating        before driving to the office. For personnel
a gage height to a measured discharge.             that are already in the field, their first
                                                   responsibility during flood conditions is to
                                                   call the flood coordinator. Personnel who
                                                   arrive at a gaging station to find evidence
                                                   that a flood has occurred are responsible for
                                                   first calling the flood coordinator if cellular
                                                   phone coverage is available, making a
                                                   discharge measurement then proceeding to
                                                   find and document high-water marks. The
                                                   office uses methods discussed in Rantz and
                                                   others (1982, p. 60) for determining peak
                                                   stage at gaging stations.

                                                   FLWSC personnel follow policies and
                                                   procedures stated in a number of
Figure 9. Flooding inundation at Buckhorn          publications and memorandums when
Creek.                                             collecting surface-water data during floods.
                                                   Techniques for current-meter measurements
      Each of the FLWSC offices maintains a        of flood flow are presented in Rantz and
comprehensive flood plan so that high-             others (1982, p. 159 to 170). Procedures for
priority surface-water data associated with        identifying high-water marks for indirect
flood conditions are collected correctly and       discharge measurements are presented in
in a timely manner. The flood plan describes       Benson and Dalrymple (1967, p. 11).
responsibilities before, during, and after a             Adjustments applied to make measured
flood, informational-reporting procedures,         flow hydraulically comparable with
and field-activity priorities. The flood plan      recorded gage height when discharge
serves as a central reference for emergency        measurements are made a distance from the
communications, telephone numbers for key          gaging station are presented in OSW memo
cooperator contacts, and codes for accessing       92.09 (app. 1g) and in Buchanan and
streamflow gages equipped with telemetry.          Somers (1969, p. 54). It is the responsibility
                                                   of all personnel who have questions about
     It is the responsibility of the flood         particular policies or procedures related to
coordinator (Data Chief) and senior                flood activities, or who recognize their need
hydrographer to ensure that the flood plan         for further training in any aspect of flood-
includes all appropriate and updated infor-        data collection, to address their questions to
mation. The flood plan is reviewed every           the Data Chief.
three years or after each major flood by the
surface-water specialist. A copy of the flood           Review of office activities related to
plan is provided to all data section               floods is the responsibility of the Associate
personnel. Each individual that receives a         Center Director for Data. This review
copy of the plan keeps it in their field box. It

includes verifying that guidelines and           available (OSW memo 85.17, app. 1b). The
priorities spelled out in the flood plan are     designated low-flow wading measurement
followed and that the guidelines                 location must be documented in the station
appropriately address requirements for           description.
obtaining flood information in a safe and
thorough manner. When deficiencies are
identified by the reviewer, the problem is
remedied by written communication to the
Data Chief, who is expected to correct the

                                                 Figure 11. Low-flow conditions along the
                                                 Peace River.

                                                       In many situations, low flows are
                                                 associated with factors that reduce the
                                                 accuracy of discharge measurements. These
                                                 factors include algae growth that impedes
                                                 the free movement of the current meter
Figure 10. Hurricane—potential for wide-         bucket wheel and the larger percentages of
spread flooding.                                 the flow moving in the narrow spaces
                                                 between cobbles. When natural conditions
Low-Flow Conditions                              are in the range considered by the field
                                                 personnel to be undependable, the cross
      Streamflow conditions encountered by       section is physically improved for
personnel during periods of low-flow             measurement by removal of debris or large
conditions are typically quite different from    cobbles, construction of dikes to reduce the
those encountered during periods of medium       amount of non-flowing water, or other such
and high flow. In Florida, seasonal low-flow     efforts (Buchanan and Somers, 1969, p. 39).
conditions may differ regionally across the      After modification of the cross section, the
State due to prevailing climate conditions.      flow is allowed to stabilize before the
North Florida experiences low-flow               discharge measurement is initiated. If the
conditions typically in the late summer and      modification affects the stage at the gage
fall, whereas, in central and south Florida,     notes are to be made on both the
this condition occurs in the spring (March to    measurement and recorder note sheet.
May).                                                  It is the responsibility of the
      Low-flow discharge measurements are        hydrographer assigned to the operation of a
made to: 1) define or confirm the lower          gage to keep on top of the flow conditions of
portions of stage-discharge relations for        his/her site and that of the Data Chief to
gaging stations, 2) as part of seepage runs to   remind them. Due to the instability of low-
identify channel gains or losses, and 3) to      water controls (especially in central and
help in the interpretation of other associated   south Florida) it is critical to make ―extra‖
data. Additionally, low-flow measurements        discharge measurements during the lower
are made to define the relation between low-     flow conditions. These measurements help
flow characteristics in one basin with those     to improve the accuracy of the daily
of a nearby basin for which more data are

discharge record immensely and greatly aids       of stage-discharge relations, adjustment and
in the applications of shifts on the rating.      application of those relations, and systematic
      FLWSC policy requires that point-of-        documentation of the methods and decisions
zero-flow (PZF) measurements be made by           that were applied. Streamflow records are
field personnel during periods of low flow.       computed and published for each gaging
Where there is a clearly defined control, the     station annually (Rantz and others, 1982, p.
PZF determination is made by finding the          544). Data collected and analyzed for
deepest point in the shallowest cross-section     different projects may be published in a
that is always downstream of the gage.            variety of reports such as Scientific
      The senior hydrographer is responsible      Investigations Report (SIR), Data-Series
for ensuring that personnel use appropriate       Report (DSR), or Open-File Report (OFR).
equipment and procedures during periods of
low flow. Determination that appropriate               This section of the SW/QA Plan
procedures are used for data-collection           includes descriptions of procedures and
activities during low-flow conditions is          policies pertaining to the processing and
accomplished by an immediate review of all        analysis of data associated with the
drought-related data by the Data Chief. The       computation of streamflow data, including
Data Chief is responsible for answering           real-time streamflow data. The procedures
questions from FLWSC personnel pertaining         followed by the FLWSC personnel coincide
to data collection during periods of low          with those described in Rantz and others
flow.                                             (1982), Kennedy (1983), and Saur (2002).

Weather Conditions                                Processing of Real-Time Streamflow Data

     Surface-water activities at FLWSC                  A necessary and critical element in
offices may occasionally include making           maintaining accurate streamflow records on
streamflow-discharge measurements during          a real-time basis is the need for rating
cold weather conditions. Cold temperatures        analysis and shift application as soon as
can create difficulties in collecting data. The   practicable after a discharge measurement
highest priority in collecting streamflow         has been made. The FLWSC office policy is
data during winter periods is employee            that rating analyses and shift applications
safety.                                           will be performed using the following proce-
     A more frequent weather associated           dures for data disseminated on the NWIS
problem is that of the summer high heat and       Web Interface
humidity. FLWSC personnel have to                 (http://fl.waterdata.usgs.gov/nwis/rt).
always be cognizant of keeping themselves
properly hydrated, using sunscreen, and                It is the policy of the FLWSC that real-
pacing themselves in an effort to prevent         time data presented on the NWISWeb pages
heatstroke.                                       are considered to be provisional and subject
     Another weather problem in Florida is        to revision. Website users are warned of the
that of lightning strikes. All personnel must     inherent limitations of provisional data by
take preventive measures when these events        providing them with prominent clickable
occur (generally during the summer) and           headings that link to a page which provides
seek shelter. Do not remain in a metal boat.      a detailed explanation of the meaning of the
Go to shore and seek shelter.                     term provisional data. It is a goal of each
                                                  FLWSC office to process, check, and
PROCESSING AND ANALYSIS OF                        finalize all surface-water records by April 1
STREAMFLOW DATA                                   of the following water year.
                                                       In practice, the Hydrologic Data
     The computation of streamflow records        Section at each of the FLWSC offices has
involves the analysis of field observations       completed a large portion of the records for
and field measurements, the determination         the streamflow network (including the

provisional application of shifts, gage-height   estimates provided by the National Weather
corrections, and datum corrections) within       Service, are used to help estimate the time of
one-to-three months of the most recent field     the peak and when field personnel are
trip. In addition, some FLWSC offices have       deployed to perform a high-flow
agreements with specific cooperators to          measurement. It is the responsibility of the
work records for selected stations on a          flood coordinator to direct the deployment
monthly basis. The records for those stations    of field personnel for the purpose of
are worked and up-to-date by the last day of     obtaining field measurements and for the
the next month, then they are checked,           repair of any failed equipment. It is also the
updated, and reviewed along with the             responsibility of the field personnel to call
remaining Hydrologic Data Section stations       and report measurement data to the flood
by April 1 of the following water year.          coordinator, along with other pertinent field
Although streamflow records are worked           information. The flood measurements are
during the year as time permits, at this time    used to update station ratings, shifts, and
it is not the policy of the FLWSC to present     other aspects of real-time discharge
all real-time discharge computations to          computations. Stage and discharge data
website users as final and up-to-date.           collected during flood events are very
      With added emphasis on Continuous          important information used by water
Record Processing (CRP) this will change         managers to help define potential flood
somewhat as more and more stations are           hazard risks to both life and property. Every
finalized at an earlier date than the April 1    attempt is made to make those updates the
date in the past. Most stations currently        same day that the measurements are
operated by the Hydrologic Data Section          reported.
offices throughout the State are available
real-time on the web. Daily data (historical)    NWIS Web Presentation Format
for most stations is available on the
NWISWeb from the beginning of the                      Real-time data for all the Florida
period-of-continuous-record to the               FLWSC offices are centrally served from
completion of the most resent field trip.        computers located at the FLWSC Fort
      During times of flooding, the use of       Lauderdale office. The National Water
real-time data is an integral part of            Information System Web (NWIS Web)
improving and maintaining the stage-             software is used to conform to National
discharge ratings used for computing             USGS standards. Links to real-time
streamflow records. All FLWSC office             streamflow data are displayed prominently
Flood Plans specify procedures and               on each of the FLWSC offices Home Pages.
responsibilities during floods. Each office      The FLWSC webpage, which shows an
maintains its own Flood Plan for personnel       interactive map of all real-time Florida
to use during flood conditions. The Data         stations and county delineations, can be
Chief for each FLWSC office serves as the        viewed by typing http://fl.water.usgs.gov/.
flood coordinator for that office. It is the     Any modifications to the FLWSC office
responsibility of each flood coordinator to      webpage, whether it be the addition or
declare a flood emergency based on the           deletion of web links, the posting of USGS
criteria spelled out in the flood plan. The      publications, or the addition of new web
plan includes a list of level one priority       pages, are approved and executed by the
stations and a list of level two priority        office webmaster. It is the responsibility of
stations for which high-water measurements       the webmaster to ensure that all FLWSC
are needed to provide definition for the         web pages conform to USGS web and
upper portion of the station ratings. The list   publication policies. It is the FLWSC
identifies where measurements are needed         Director who holds the ultimate
above specific gage heights for each site.       responsibility to approve the content of all
Real-time stage and discharge data on the        pages posted on the website.
web, along with projected streamflow crest

Review of Real-Time Streamflow Data               overall records computation process for the
                                                  streamflow network.
      Real-time streamflow data that are
disseminated on the public web page must          Error Handling
be reviewed frequently to ensure their
quality and to prevent the distribution of               There are two general types of errors
erroneous information. FLWSC personnel            associated with streamflow data that are
utilize both automated and manual review          delivered by the real-time system and
procedures to meet this objective.                disseminated on the Internet. The first are
      Automated procedures that have been         persistent-type problems usually associated
implemented by the FLWSC offices include          with some type of equipment failure,
the setting of minimum and maximum                whether in data collection or transmission.
threshold values for stage, temperature,          Because of the nature of the problem they
discharge, and other parameters and their         generally occur on a continuing basis for
rates of change. If exceeded, these settings      more than a single recording interval. The
will initiate warnings of potential errors that   second are the intermittent-type problems,
will be delivered via electronic mail to the      which are often the result of a data
appropriate FLWSC personnel thru                  transmission error. These often show up as
NWISWeb. The GWSI (ground water) and              either a zero or an unreasonably large value.
ADAPS (surface water) database                    It is the policy of the Florida FLWSC offices
administrators are the personnel designated       that intermittent-type errors, such as
to receive and act upon these messages.           extremely large gage-height data
                                                  transmission errors, are identified as soon as
      In addition to the automated                is reasonably possible, and the erroneous
procedures, Water-Resources Division              data are either deleted or corrected as soon
(WRD) Technical Memorandum 99.34 (app.            as is reasonably possible. For example,
1v) requires frequent and on-going                when a data transmission error is identified
screening and review of web data, including       by a senior hydrographer during the daily
at least daily review of hydrographs during       visual check of the real-time data, actions
normal hours of operation. The FLWSC              are taken immediately by that individual or
policy requires that all web pages containing     other assigned hydrographer to delete or
real-time streamflow data are reviewed            correct the value and update the real-time
regularly for accuracy and/or missing data.       website to reflect the corrected data.
      The real-time streamflow data for each             In regard to persistent-type problems, it
office are scanned visually each work day         is FLWSC office policy not to estimate
by a senior hydrographer or their designate.      corrected discharges; however, web users
The primary goal of the visual check is to        are warned about the provisional nature of
identify stations that have failed to transmit    the discharges. When real-time data shown
the real-time data, and to identify real-time     on the web for a particular station is clearly
data that appear to be in some way                in error, resulting from the malfunction of
erroneous. The hydrographer to whom the           equipment, vandalism at the site, or other
gage is assigned also has the responsibility      similar problems, it is the responsibility of
of checking his/her sites each day they are in    the unit supervisors or Data Chief of to
the office and not in the field. When             decide when data for the site are removed
problems are identified, the senior               from the web page. After repairs have been
hydrographer can make the situation known         made to the gaging station and the data are
to the unit supervisors who initiate the          determined to be accurate, it is the
actions necessary to correct specific             responsibility of the unit supervisors or Data
problems. Another goal of the visual check        Chief to decide when posting of the real-
is to identify high water, backwater, or other    time data on the Web is to resume.
pertinent conditions so that special
measurements can be made to improve the

Data Qualification Statements                    computation for each gaging station.
                                                 Measurements and field notes that contain
         WRD Technical Memorandum                original data are required to be stored
95.19 (app. 1t) requires that streamflow data    indefinitely (Hubbard, 1992). Measurements
made available on the web should be con-         and other field notes for the water year that
sidered provisional until the formal review      is currently being computed are filed in the
process has been completed. To ensure that       current-year file. Measurements and notes
everyone who accesses data from the web          for previous water years are stored in the
are aware of this, data qualification            designated file in each office.
statements must be included at key locations
with a clickable heading Provisional Data              It is FLWSC policy that all
Subject to Revision on all real-time data        measurements are scan checked as a
pages. The following data qualification          minimum and completely checked if the
statement                                        scan reveals a possible error. However, with
(http://waterdata.usgs.gov/fl/nwis/help/?pro     the implementation of Continuous Record
visional l) is used by FLWSC offices:            Processing (CRP) most discharge
                                                 measurements are checked prior to entry
      Recent data provided by the USGS in        into the Site Visit database. The
Florida -- including stream discharge and        measurements are checked by reviewing the
stage, ground-water elevation, precipitation,    mathematics and other items listed in
and components from water-quality                Kennedy (1983, p. 7), then entered into the
monitors--are preliminary and have not           state-wide NWIS computer database
received final approval. Most data relayed       residing at the FLWSC Ft. Lauderdale
by satellite or other telemetry have received    office. The ADCP computation and
little or no review. Inaccuracies in the data    checking procedures are available as a
may be present because of instrument             separate report (refer to the section:
malfunctions or physical changes at the          Hydroacoustic Measurements). Upon the
measurement site. Subsequent review may          completion of the record computation, a 9-
result in significant revisions to the data.     207 form (Discharge Measurement
                                                 Summary Sheet) is retrieved and filed in the
     Data users are cautioned to consider        9-207 folders.
carefully the provisional nature of the
information before using it for decisions that
concern personal or public safety or the         Continuous Record
conduct of business that involves substantial
monetary or operational consequences.                 Surface-water gage-height data are
Information concerning the accuracy and          collected as continuous record (hourly, 30-
appropriate uses of these data or concerning     minute, 15-minute, 6-minute, or 5-minute
other hydrologic data may be obtained from       unit values) in the form of electronic
the station manager, whose name is shown         transmissions via satellite, values recorded
on the single station data summary pages, or     in electronic data loggers, values recorded
from the USGS surface-water specialist in        internally by velocity meters, or values
Florida care of the webmaster email alias        recorded by a cooperator and transmitted to
gsw_NWISWeb_Maintainer@usgs.gov.                 the FLWSC offices via FTP protocol.
                                                 Streamflow records are computed by:
Measurements and Field Notes
                                                 1. Converting gage-height record to
     Gage-height and discharge information,         discharge record through application of
control conditions, and other field                 stage-discharge relations,
observations written by personnel onto the       2. Converting index-velocity to mean
measurement note sheets and other field             channel velocity through application of
note sheets form the basis for records              index-velocity ratings. The mean

   channel velocity is then multiplied by         Records and Computation
   area obtained through a stage-area
   relation,                                            The responsibility for working the
3. Calibrating relations between upstream,        record of each station is designated to a
   downstream, and gate opening at gated          specific hydrographer by the unit
   water control structures, and                  supervisors with input from the Data Chief.
4. Calibrating relations between upstream,        Each field hydrographer is responsible for
   downstream, and pumpage rates at               data collection, troubleshooting if necessary,
   pump complexes.                                rating analysis (with help from senior
                                                  hydrographers when necessary), record
Ensuring the accuracy of gage-height,             computation, station analysis, station
velocity, and auxiliary record is, therefore, a   description updates, and final publication.
necessary component of ensuring the               The ADCP measurements may be
accuracy of computed discharges.                  performed by a team, and the hydrographer
                                                  responsible for the site might not necessarily
     Gage-height record is assembled for the      be on the team performing discharge
period of analysis in as complete a manner        measurements. However, the field
as possible. Periods of inaccurate gage-          hydrographer is responsible for making sure
height data are identified then corrected (see    the discharge measurements are included in
the section Datum corrections, gage-height        the station analysis and entered on the rating
corrections, and shifts) or deleted as            for that site. For a limited number of
appropriate. Detailed guidelines for editing      stations, provisional discharge maybe
and computing stage data is discussed in          provided to the cooperator on a monthly or
appendix I. Items included in the assembly        quarterly basis. All other stations are
of gage-height record and procedures for          presented as final discharge in the Annual
processing the data are discussed in              Data Report published by April 1 of the
Kennedy (1983, p. 6), and Rantz and others        following year.
(1982, p. 560 and p. 587).
                                                       Records are reviewed at a minimum
      Data transmitted by satellite are entered   once a year by another person besides the
into ADAPS by automated processes. Data           hydrographer who computed the record or
that are downloaded from electronic data          more often if a supervisor feels it is
loggers (EDL) need to be put onto the             necessary. The station may be reviewed by
network immediately following a field trip.       someone outside of that FLWSC office, if
The file names of data retrieved from data        necessary. After the reviewer has thoroughly
loggers or DCPs or created electronically in      looked over the station, it is the
the field (SWAMI or CHIMP files) need to          responsibility of the hydrographer
be renamed as specified in FLWSC                  computing the station to address any
electronic file naming convention listed in       problems or comments from the reviewer.
Appendix 3b. The renamed file is copied           The station is then given back to the
into a directory where a local processing         reviewer for final acceptance. The
script picks up the file, puts it through         implementation of CRP has made the review
DECODES (same process as DEPS) and                process being done three to four times per
subsequently stores the data into the ADAPS       year in an attempt to finalize data within a
database. The data files are then temporarily     120-150 day period after its‘ occurrence.
archived. After the final reviews are done,       Records are now reviewed in shorter periods
the files are transferred to a permanent          than that of an entire year. The goal of the
archive.                                          Florida FLWSC offices is to have yearly
                                                  surface-water record computed and ready
                                                  for review by January 15, and to have the
                                                  record reviewed by March 1.

      After the records are completed, the      readings made by use of independent
Data Section, along with assistance of the      reference gages, comparison of inside and
Publications Unit and NWIS database             outside gages, examination of high-water
administrators, compiles the data, prepares     marks, comparisons of the redundant
the Annual Data Report, arranges for            recordings of peaks and troughs by use of
printing of the report, duplicates and          maximum and minimum indicators,
distributes CDs of the report, and makes the    examination of data obtained at crest-stage
report available on the Internet. The current   gages, and confirmation or updates of gage
Annual Data Report is available at the          datums by levels.
following web address:                                Accuracy of velocity data is ensured by
http://water.usgs.gov/pubs/wdr/#FL for          comparison of multi-bin data, scrutiny of
Water Years prior to 2005 and                   quality assurance parameters such as signal
http://wdr.water.usgs.gov/ for Water Years      strength, cell end, and temperature, and
after 2005.                                     specific structure information that gives
      Key elements for a SW/QA Plan             indication of the hydraulic conditions that
include ensuring the thoroughness,              might be expected at the site.
consistency, and accuracy of streamflow               Records computation includes
records. These records entail a variety of      examination of gage-height record, velocity
data, which include the gage-height record      record, and hydraulic structure parameters to
including instantaneous extremes, levels,       determine if the record accurately represents
ratings, datum and gage-height corrections,     the discharge or water level of the body of
shifts, hydrographs, station analyses,          water being monitored. Additionally, it
furnished records, and the daily values         includes identifying periods of time during
tables. The goals, procedures, and policies     which inaccuracies have occurred and
for each component differ.                      determining the cause for those inaccuracies.
                                                      When possible and appropriate,
Procedures for Working and Checking             inaccurate gage-height record is corrected.
Records                                         When corrections are not possible, the
                                                erroneous gage-height data are removed
     Procedures for ensuring the                from the set of data used for streamflow
thoroughness, consistency, and accuracy of      records computation. If backup gage-height
streamflow records are described in this        record is available, it should be copied to the
section of the SW/QA Plan. The goals,           primary data descriptor and noted on the
procedures, and policies presented in this      primary computation sheet and in the station
section are grouped in association with the     analysis. Whenever a correction is made,
separate components that are included in the    notes describing what the correction is based
records-computation process.                    on and how the correction was applied
                                                should be made on the primary computation
Discharge Surrogates                            sheet and in the station analysis. A unit-
                                                value plot of the gage-height record should
     The accuracy of surface-water              be made to check for periods of questionable
discharge records depends on the accuracy       record such as the float hanging or lagging
of discharge measurement, the accuracy of       intakes. The hydrographer working the
rating definition, and the completeness and     record is responsible for ensuring that the
accuracy of the gage-height record (OSW         final record contains all of the corrections
memo 93.07, app. 1j), the completeness and      needed, checkers and reviewers verify that
accuracy of velocity record, and the            the correct procedure was followed.
completeness and accuracy of hydraulic
structure data.                                 Levels
     Computation of streamflow records
includes ensuring the accuracy of gage-              Errors in gage-height data caused by
height record by comparisons of gage-height     vertical changes in the gage or gage-

supporting structure can be measured by                 For each gaging station, a copy of the
running levels. Gages can be reset or their       most recent digital rating table should be
readings can be adjusted by applying              located in the shelter, field, and office
corrections based on levels (Kennedy, 1983,       current folders. A graphical plot of the most
p. 6).                                            recent rating will be kept in the office rating
                                                  flat file (filing cabinet). An electronic copy
     Procedures for computing records for         and the graphical copy of an old rating will
each station include ensuring that the front      be kept in the station‘s archival directory
sheet has been completed for each set of          and old rating folder respectively. Generally,
levels, checking levels, ensuring that the        all high stage measurements that occur
level information was listed in the Historical    above bank full should be plotted and
Levels Summary, and ensuring that                 numbered on the graphical rating. All new
information was applied appropriately as          ratings must be approved by the senior
datum corrections. The individual                 hydrographer or the Data Chief before it is
computing the record is required to check         put into use. The hydrographer is
field notes for indications that the gages        responsible for entering the rating into the
were reset correctly by field personnel. In       computer and the checker verifies that the
the event that the gage was reset incorrectly,    rating was entered correctly. It is
the senior hydrographer is to be notified so      recommended that FLWSC hydrographers
that appropriate action can be taken. The         use the USGS provided software (GRSAT)
individual computing the records makes            for stage-discharge rating development and
appropriate adjustments to the gage-height        rating analysis.
record by applying datum corrections. All               Various FLWSC office procedures
changes or non-changes should be noted in         apply to ratings. Typically, the employee
the station analysis and on the primary           assigned to the station develops new ratings;
computation sheet.                                however, sometimes a reviewer or checker
                                                  develops the new rating. Personnel obtain
Rating                                            in-house reviews of ratings and shifts before
                                                  they are distributed outside the office. Final
      The development of the stage-discharge      ratings will be approved by the section chief
relation, also called the rating, is one of the   or senior technical person. Personnel
principal tasks in computing discharge            generally apply shifts to the rating when
record. The rating is usually the relation        measurements indicate a change in the rating
between gage height and discharge (simple         or previous shift of more than five percent.
rating, Figure 11). Ratings for some special      Shifts that extend over the entire range of
sites involve additional factors such as rate     the rating and/or persist for more than one
of change in stage or fall in slope reach         year, may reflect a fairly stable control
(complex ratings) (Kennedy, 1983, p. 14).         change and should be analyzed and drawn
The FLWSC offices employ four general             up as new ratings. Ratings should generally
types of relations in computing discharge         be extended no more than twice the
record. These ratings are stage-discharge         discharge of the highest direct measurement.
relation, stage-area and index-velocity to        Personnel should include all measurements
mean-velocity relations, and hydraulic            made to develop the new rating, along with
structure relation.                               the highest ten measurements made at the
      FLWSC personnel follow procedures           site. The old rating should be outlined
for the development, modification, and            lightly on the same sheet as the new rating.
application of ratings that are described in      Sheets showing the new and old rating
Kennedy (1984). Personnel also follow             should show the numbers of the ratings and
guidelines pertaining to rating and records       the dates they were first applied and ended,
computation that are presented in Kennedy         station name and number, measurement
(1983, p. 14) and in Rantz and others (1982,      numbers, the offset, and values for the x
Chap. 10-14 and p. 549).

Figure 12. Example of a stage-discharge rating curve.
                                                    the station records to ensure that all
and y axis (discharge and stage). The Data          measurements for the current year and all
Chief/Surface-Water Specialist or Senior            high-water measurements for the station are
Hydrographer provides the ultimate                  plotted on the current work plot of the
guidance to office personnel regarding              rating.
                                                          In general, changes in the stage-
Rating numbering                                    discharge relation that tend to be temporary
                                                    changes are addressed through the use of
     In general, index-velocity ratings are         variable-stage shifts. It is, however, left to
not revised unless, based on a number of            the discretion of the hydrographer working
discharge measurements, the rating has              the station records to determine if changes in
changed more than five percent. Ratings are         the relation are addressed with shifts, or if
stored with sequential identification               conditions warrant the introduction of a new
numbers and any modification to rating-             rating. In general, changes in the stage-
input points, including a change of scale           discharge relation that are deemed to be
offset, results in a new rating                     relatively stable and/or a well-defined trend
                                                    may warrant development of a new rating. It
     The goal of policies and procedures            is the responsibility of the hydrographer
pertaining to ratings is to promote efficiency      working the records to fully develop the new
and accuracy in the development and                 rating, enter all input values and offsets into
documentation of ratings. It is the                 the ADAPS computer program using
responsibility of the hydrographer working          standard USGS software, and plot the new
                                                    rating along with the measurement data. It is

the responsibility of the hydrographer                 A correction applied to the stage-
checking the station records to ensure that      discharge relation, or rating, to compensate
the rating-input points and offsets agree with   for variations in the rating is called a shift.
available measurement data. The checker          Shifts reflect the fact that stage-discharge
has the latitude to disagree with the scope      relations are not permanent, but vary from
and shape of the new rating and with the         time to time, either gradually or abruptly,
original decision of introducing a new           because of changes in the physical features
rating. The checker also can choose to           that form the control at the gaging station
develop a new rating for the station, if         (Rantz and others, 1982, p. 344). Shifts can
appropriate. It is the responsibility of the     be applied to vary in magnitude with time
checker, however, to discuss disagreements       and with stage (Kennedy, 1983, p. 35). The
with the original records worker. The two        use of the stage shift program, even for time
must come to a consensus on the appropriate      only shifts, is encouraged. All shifts should
rating to be used. If a consensus is not         be documented in the station analysis and
reached, it is their responsibility to present   entered into the measurement file. Care
the matter to a unit supervisor or the Data      should be taken to explain why a shift
Chief who will make a final determination.       occurred as well as how the shift was
                                                 applied. It is permissible to use average
                                                 shifts, even though they may be larger than
Datum corrections, gage-height corrections,      computed, provided they are within the
and shifts                                       limits of the measurement and represent an
                                                 average over a period of time.
      A correction applied to gage-height              In only limited cases are the index-
readings to compensate for the effect of         velocity ratings shifted. Velocity is shifted
settlement or uplift of the gage is usually      based on a series of discharge measurements
measured by levels and is called a "datum        and observed conditions at the site. Since
correction" (Kennedy, 1983, p. 9). Datum         ADAPS does not have the capability of
corrections are applied to gage-height record    automatically generating shifts for index-
in terms of magnitude (in feet) and in terms     velocity as it does for stage-discharge sites,
of when the datum change occurred. In the        these shifts must be well documented in the
absence of any evidence indicating exactly       station analysis, including procedures on
when the change occurred, the change is          how the shifts were obtained and how the
assumed to have occurred gradually from          shifts were implemented.
the time the previous levels were run, and             Datum corrections, gage-height
the correction is prorated with time (Rantz      corrections, and shifts are entered into
and others, 1982, p. 545). Datum                 ADAPS and are stored as finalized data
corrections are applied when the magnitude       upon completion of the end-of-year station
of the vertical change is greater than 0.015     record. The hydrographer processing the
ft.                                              station ensures that the gage-height and
      A correction applied to gage-height        discharge record are continuous over the
readings to compensate for differences           water year (computation period) boundary.
between the recording gage and the base          These applications are documented and
gage is called a "gage-height correction"        listed in the station analysis, and printouts
(Rantz and others, 1982, p. 563). These          are kept in the computation folder.
corrections are applied in the same manner
as datum corrections by use of the same
computer software. Gage-height corrections       Hydrographs
are applied so the recorded data are made to
agree with base-gage data. These corrections           A discharge hydrograph is a plot of
are applied when the difference between the      daily mean discharges versus time. The date
recording gage and the base gage is greater      is aligned with the horizontal axis and the
than 0.02 ft.

discharge is aligned with the logarithmic
vertical axis. In the process of computing
station records, this hydrograph is a useful
tool in identifying periods of erroneous
information, such as incorrect shifts or
datum corrections. Additionally,
hydrographs are helpful when estimating
discharges for periods of undefined stage-
discharge relation, such as during backwater
conditions, and in estimating discharges for
periods of missing record.

      Hydrographs are an important analysis
tool and should be used to check computed        Figure 13. Streamflow hydrographs of
record by comparison with nearby or similar      gaging stations in the upper Peace River
stations. A final hydrograph should be filed     basin.
in the water year folder. Information placed
on the hydrograph for each station includes           In general, the Data Chief and the Unit
the station name, station number, water year,    Supervisors provide instruction and
plot of daily mean discharge, and discharge      assistance in training FLWSC personnel on
measurements. Due to the changing                the goals and methods of hydrographic
conditions found at some FLWSC sites, an         comparison. Individuals with questions
individual plot of just one or two days of       about hydrographic comparison or questions
unit-value discharge and measurements are        about which specific sites are appropriate for
required to ensure the discharge                 comparison should address their questions to
measurements agree with the computed             their supervisor.
discharge. Comparing the hydrograph of one
gaging station to those of nearby gaging         Hydra
stations is an effective means to evaluate the
validity of shift, datum, or gage-height              Hydra is a powerful graphical editing
correction applications; to identify periods     tool available in ADAPS. It allows the
of faulty gage-height data; and to estimate      graphical estimation of unit and daily values
discharges for periods of missing record or      including adding or modifying unit values.
periods of no stage-discharge relation.          OSW memo 2003.02 discusses USGS policy
Hydrographic comparison, as described in         concerning hydra and its use as an
Rantz and others (1982, p. 575), is a            estimation tool. The FLWSC office policy
component of records computation for each        concerning the estimation of unit and daily
stage-discharge station processed by             values with Hydra is as follows:
FLWSC personnel.
                                                 1. Bad unit values (spikes, flat record) are
                                                    to be deleted;
                                                 2. Record that exhibits overall trend, but
                                                    unrealistic unit values can be
                                                    ―smoothed‖ out by graphical editing,
                                                 3. Estimated daily values calculated
                                                    outside of ADAPS can be put into
                                                    ADAPS by means of Hydra.

Station Analysis                                    Index velocity sites can also use
                                                    automated processing scripts external to
      A complete analysis of data collected,        ADAPS for more complicated ratings.
procedures used in processing the data, and         For hydraulic structures, a USGS
the logic upon which the computations were          approved program DAMFLO (Sanders,
based is documented for each year of record         2003) is used. This section explains
for each station to provide a basis for review      some of the forms and information
and to serve as a reference in case questions       necessary for discharge computation in
arise about the records at some future date         this program. A list of ADAPS data
(Rantz and others, 1982, p. 580). Station           descriptors used in discharge
Analyses are prepared and stored in the             computation is printed for reference.
FLWSC state-wide web based Site                  8. Discharge computations – A list of all
Information Management System (SIMS)                estimated and missing discharge daily
database. Topics discussed in detail in the         values is given along with explanations
station analysis include:                           as to why.
                                                 9. Remarks – Quality of record and any
1. Equipment – Type of equipment that is            other special circumstances surrounding
   currently at the site and brief history of       the record.
   what instrumentation was at the site in
   the past;                                           The preparation and writing of the
2. Datum corrections – Corrections applied       station analysis is the responsibility of the
   in ADAPS due to a change in station           hydrographer in charge of the station.
   measuring point or update of reference        During the year, this document should be
   mark;                                         updated any time computations are done.
3. Rating – This section talks about the         The hydrographer is to ensure that the
   discharge measurements made and how           computation process is comprehensive and
   they compared to the current rating in        complete. All aspects for the process are
   use at the site                               documented fully in the station analysis and
       a) Stage–discharge rating                 associated materials. The station is fully
       b) Stage–area rating                      reviewed during the end-of-year review
       c) Index-velocity rating                  process. It is the responsibility of the
       d) Hydraulic conditions rating            reviewer to ensure that all aspects of the
            (submerged orifice, free orifice,    records computation process for the station
            free weir, submerged weir,           were carried out correctly and completely
            pump ratings)                        and that all documentation is clear,
       e) Conversion of input rating;            complete, and accurate. If discrepancies are
4. Gage-height record – Explains any             found they are clearly noted on the review
   missing or erroneous record, lists data       form and given back to the hydrographer for
   corrections, lists any daily values that      further processing. It is then the
   are not available for publication;            hydrographer‘s responsibility to address any
5. Velocity record (if applicable) –             problems and return to the reviewer for final
   Explains any missing or erroneous             acceptance. If the hydrographer disagrees
   record, has table of history of               with the comments of the reviewer, they
   ADVM/transducer elevation, and                may bring their dispute to a supervisor who
   history of acoustic-beam range checks;        will look at the station and make a final
6. Gate record (if applicable) – Explains        decision. The review routing sheet describes
   any missing or erroneous record, lists        all the supporting documentation that is
   whether data was used from another            necessary for a complete end-of-year record
   agency or not;                                and publication. It is the responsibility of the
7. Determination of discharge – For stage-       site hydrographer and Unit Supervisors to
   discharge and index-velocity sites the        ensure all end-of-year documentation is
   standard ADAPS programs are used.             properly filed.

Furnished records                                primaries and daily-value table (which
                                                 includes those values stored in the daily-
      Surface-water data, collected under the    values electronic file) is done before the
supervision of other agencies, organizations,    station is ready for publication. This
or institutions, may also be received by         includes paying special attention to
FLWSC office personnel. Data for FLWSC           estimates that had to be hand entered into
stations that are used for publication in the    ADAPS. Any daily value that is considered
USGS Annual Data Report normally require         estimated must be flagged with an ―e‖ next
a minimum of two annual check                    to it. The person reviewing the station has
measurements and gage inspections. The           the responsibility of ensuring the
assurance program for the furnished data,        completeness and accuracy of the daily-
which includes mean daily discharge values       value table. After the station review is
and extreme stages and discharges, involves      complete, the daily values are set to
annual records reviews. These reviews            ―approved‖ so they are not accidentally
include checking the daily-values summary,       overwritten in the future. A printed copy of
list of discharge measurements, copies of the    the daily-value table is kept in the surface-
front sheets for the discharge measurements,     water files. An electronic copy is available
primary computation sheets showing gage-         in the ADAPS database for future retrieval
height and datum corrections and shifts, a       and analysis.
hydrograph and hydrographic comparison
with another station, rating tables and rating   Manuscript and Annual Data Report
curves, shift diagrams, and the station
analysis.                                             Information presented in the Annual
      In the case of errors in computation of    Data Report includes daily-discharge values
the furnished record, or of questions            during the year, extremes for the year and
regarding the standards under which the data     period-of-record, and various statistics.
were collected, the USGS will work with the      Additionally, manuscript station descriptions
furnishing agency to resolve these issues. If    are presented in the Annual Data Report.
an issue cannot be resolved, or the record is    Information contained in the manuscript
determined to be unreliable, the record          includes: physical descriptions of the gage
should be published as ―poor.‖ In extreme        and basin, history of the station and data,
cases, the record should not be published.       and statements of cooperation. In preparing
Documentation of the issues in these cases       the Annual Data Report for publication, the
should be made part of the station record        FLWSC offices follow the guidelines
and the USGS should work with the                presented in WRD Data Reports
furnishing agency to remedy the situation.       Preparation Guide (Charles E. Novak, 1985
Fortunately the FLWSC has a minimum              ed.) and supplemental guidelines provided
number of discharge stations from outside        by the publication webpage located at;
that are published in the annual data report.    http://water.usgs.gov/pubs/, specifically the
Several of these are located very near           Automated Data Report web page;
existing FLWSC stations and hydrographic         http://water.usgs.gov/usgs/adr/.
comparisons are the major tool utilized in
the checking and verification of these                 When record computations for the
records.                                         water year have been completed and the data
                                                 collected and analyzed by each of the
     Daily-values table                          FLWSC offices and have been determined
                                                 to be correct and finalized, the surface-water
     It is the responsibility of the             data for that water year are published, along
hydrographer to determine that the               with other data, in the Annual Data Report.
calculated discharge and stage for the station   The Annual Data Report is part of the series
accurately represent the actual conditions at    titled USGS Water-Data Reports.
the station. A comparison between the            Information presented in the Annual Data

Report includes daily discharge and stage       ensuring the quality of the information
values during the year, extremes for the year   contained in the Annual Data Report.
and period-of-record, and various statistics.
Additionally, manuscript station descriptions   Water Science Center office check-off list
are presented in the Annual Data Report.
Information contained in the manuscript               Each station will have a check-off sheet
includes physical descriptions of the gage      that is kept in the current folder. The sheet
and basin, history of the station and data,     will have at least all of the major headings
and statements of cooperation.                  previously discussed in this section. Space
                                                will be provided for the initials of the record
       Manuscripts for publication in the       worker and checker. Except for the approval
Annual Data Report are produced using           of ratings, stations will be completed before
word-processing software (Microsoft Word)       a checker initials any items on the check list.
available in the USGS computer system.
The table of daily values and streamflow        Review of records
statistics presented in the report are loaded
directly into the manuscript files from the           After completion of the water year, the
computer data files. Potential data-transfer    status of the progress on records
errors are minimized with the use of these      computation for each surface-water gaging
automated production tools. The Automated       station in each of the FLWSC Data Sections
Annual Report (AAR) Scripts for the Annual      is posted on the Data Section‘s webpage.
Data Report, UNIX-based scripts are used        The surface-water progress file is monitored
to automate the preparation of WRD's            and updated by personnel from each
Annual Data Report. The scripts retrieve        individual office‘s Data Section. FLWSC
data from ADAPS, QWDATA, and GWSI               has instituted the Records Management
and put them into annual report format as       System (RMS) as a tool in handling this
Microsoft Word files. Each information          task.
statement and data value presented on each            After streamflow records for each
page of the draft is checked and rechecked,     station have been computed, all FLWSC
followed by a detailed review of the entire     offices‘ gaging stations records are reviewed
report.                                         by experienced personnel from the Data
                                                Section or from the Hydrologic Studies
      To reduce the potential for systematic    Section. The goal of the review is to ensure
errors, a different person executes each step   that proper methods were applied
of the Annual Data Report checking and          throughout the process of obtaining the
reviewing process. A copy of the final          surface-water data and computing the
printed report is reviewed by the Data Chief    record. The findings of the review for each
and the supervisor of the Data Section‘s        gaging station are documented by use of a
Data Management and Publication unit. The       standardized review form based upon the
Data Chief and the Data Management and          type of discharge station. The review
Publication unit have the overall               documents along with additional typed
responsibility for presenting complete and      documents are available for review by the
accurate information in the station             Unit supervisors or the Data Chief. The
manuscripts and the Annual Data Report. It      review documentation is maintained in the
is the Data Chief and the unit supervisors in   station‘s yearly computations folder for
conjunction with the senior hydrographer,       future reference by the Data Chief.
however, who oversee all facets of the data
collection, data analysis, and report-               It is the responsibility of the unit
production process. Therefore, it is the Data   supervisors and the Data Chief to ensure that
Chief, the unit supervisors and the senior      any deficiencies identified in the review are
hydrographers who play the primary role in      corrected and that actions are taken to
                                                prevent the recurrence of those deficiencies.

It also is their responsibility to ensure that    maintained in the office station folder. A
positive aspects of the review are                brief station analysis is written each year
communicated to FLWSC personnel to                describing how the annual peak was
reinforce the continued use of correct            computed, identifying which rating was used
methods and procedures.                           and the type of flow condition, describing
                                                  how the dates of the peaks were determined,
Crest-Stage Indicator Gages                       and explaining any shift that may be applied.
                                                  Computing peak discharges and updating
     Records for crest-stage indicator gages      the manuscript for each CSI gage is the
(CSI) are computed with goals and                 responsibility of the hydrographer assigned
procedures very similar to those for other        to that station. Computations are checked by
gaging stations. The field notes are              a senior technical person by complete re-
examined for correctness and accuracy.            computation of the record and are reviewed
Peaks stages recorded by CSI gages are            by the Senior Hydrographer or Data Chief.
cross referenced with other available
information; the dates of the peaks are                 Responsibility for ensuring the correct
determined by analyzing available pre-            computation of annual peaks at crest-stage
cipitation data and peak data from recording      gages is held by the Data Chief. When
gages within the same basin or from nearby        incorrect actions or procedures are identified
basins.                                           during the review, the problems are
                                                  remedied by providing one-on-one training
      A discussion on the policies and            by the Senior Hydrographer or Data Chief.
procedures used for field aspects of              Responsibility for updating the peak flow
collecting data at CSI gages is included in       file promptly after peak data have been
this report in the section Collection of Stage    finalized is the responsibility of Data Chief.
and Streamflow Data. The discussion in this       A current listing of annual peaks is
section describes the analysis and office         maintained in the station folder for review
documentation of CSI data. This section           purposes (OSW memo 88.07, app. 1d).
does not pertain to data collected at CSI
gages installed solely for the purpose of         OFFICE SETTING
confirming peak stages at sites where
pressure-transducer gages are used.                     Maintaining surface-water data and
                                                  related information in a systematic and
     At sites where CSI gages are used to         organized manner increases the efficiency
compute peak discharges, an initial stage-        and effectiveness of data-analysis and data-
discharge relation, or rating, is developed for   dissemination efforts. Good organization of
the site by direct or indirect high-water         files reduces the occurrence of misplaced
measurements. The rating is verified or           information; misplaced data and field notes
adjusted on the basis of subsequent direct or     can lead to analyses based on inadequate
indirect high-water measurements.                 information, with a possible decrease in the
                                                  quality of analytical results.
     For each station, a list of all
measurements is maintained and each                    The following section of the SW/QA
measurement is assigned a chronological           Plan includes descriptions of how station
number. Ratings, both graphic and digital,        folders, reference maps, levels
are maintained and updated with the same          documentation, and other information
accuracy as a daily discharge station. For        related to surface-water data are organized
each station a list of peak gage heights is       and maintained. Additionally, this section
maintained and the gage heights are verified      provides an overview of how work activities
by checking against the field notes when the      are designed to be carried out within the
record is worked. Current station                 office setting.
descriptions and a summary of levels are

Work plan                                            set of 9-207 forms or Site Visit
                                                     discharge summary print out for each
      Each employee has a work plan which            water year for the period of record.
is reviewed and updated annually or more        3.   Station Analysis folder--The station
often if sudden changes in the work load             analysis folder contains a complete set
occur. The work plan outlines general areas          of station analysis that should describe
of work for which the employee is                    how each water year of record was
responsible. Specific work loads are                 worked. For stations with long periods
determined and field trips assigned by the           of record Compilation Report
Senior Hydrographer with general guidance            Summaries may need to be filed in this
by the Data Chief. The work plan outlines            folder to obtain a complete history.
tasks and the time frame for completion of      4.   Station Description folder--The station
the tasks, which allows the employee to be           description folder contains a complete
reviewed and rated based upon work                   set of superseded descriptions plus the
accomplished.                                        current station description.
                                                5.   Rating folder--The rating folder
File Folders for Surface-Water Stations              contains the original 9-207 forms and/or
                                                     tabular rating printout and the original
      This section of the SW/QA Plan                 graphical ratings of all superseded
describes the location and makeup of hard-           ratings.
copy files associated with surface-water        6.   Water Year folder--The water year
data. Information pertaining to electronic           folder contains:
files maintained in computer storage can be          a) primary computation printouts;
found in the Data-base Management section            b) monthly unit-value hydrographs;
of this report.                                      c) data-correction list;
                                                     d) shift analysis;
      For each gaging station, a separate set        e) applied shift list;
of file folders is maintained that include           f) end-of-year summary for both stage
folders for: 1) Current, 2) Measurement              and discharge;
(Site Visit discharge summary print out), 3)         g) working stage-discharge graphical
Station Analysis, 4) Station Description, 5)         rating;
Ratings, and 6) Water Year. The files may            h) V-diagrams used for shift
be arranged alphabetically or by                     computations;
downstream order number depending on the             i) ADAPS ratings;
office preference. Extraneous items are              j) daily-value table;
removed from the current folder each year            k) review routing sheet;
when the record is reviewed. Discontinued            l) 9-207 form or Site Visit measurement
stations are filed in a separate file and are        printout; and
generally combined into one folder. The set          m) any other supporting documentation
of current files for each station are grouped        used for discharge computation.
as follows:
                                                Field-Trip Folders
1. Current folder--The current folders
   contain a check off sheet for tracking             Typically, each field hydrographer in
   progress and ensuring that all steps are     the FLWSC offices has a set of field folders
   completed, a current digital rating,         for the stations for which they are
   station description, list of peaks, runoff   responsible. Each folder contains a list of
   computation sheet, level summary sheet       measurements, which gives the gage height,
   and any other information needed on a        discharge, and location where the
   continuing basis for working records.        measurement was made, a current station
2. Measurement folder--The                      description, and rating table. Additional
   measurement folder contains a complete       information, such as a copy of the level

summary, observers or land owners name,           management districts) and are available
address and phone number, and other               upon request.
information are also encouraged. Each
person is responsible for maintaining the         Station Descriptions
folder as long as the station is assigned to
them. Each group of stations for a                     The current station description, along
designated field trip should be kept in a field   with a copy of all superseded descriptions,
box, along with a current flood plan, and a       are kept in station description folder in the
detailed road map of the area.                    Data Section record file. In addition, a copy
                                                  of the current station description is kept in
     Some FLWSC offices, however, may             the current and field folders.
not maintain a set of field-trip folders due to
the changing nature of the field runs. All              Electronic station descriptions for every
maps, station information, and explanations       currently operating surface-water gaging
of the station are available in the station       station are kept at the Site Information
field description. This document serves as a      Management System (SIMS) website
substitute to field-trip folders.                 (http://simsmd.er.usgs.gov/field/sqlsims/Stati
                                                  onsRpt.asp). Discontinued sites that had an
Levels                                            electronic station description are kept in this
                                                  directory. Paper copies of the station
      Levels notes are filed in the level file    description are found in the surface-water
immediately after checking. A summary of          files, and at each individual station. Station
levels for each station is kept in the current    descriptions for discontinued sites are
station and field folders. All levels, current    located in the discontinued files. It is the
and back files, are kept in the same location     responsibility of the hydrographer to ensure
and are not removed from the office. All          that the electronic version is updated
levels should have a front cover sheet which      immediately after a change occurs (such as
summarizes the results of the levels and the      levels being run) and that this new version is
action taken. Electronic level summaries for      put in the gaging station shelter, during the
each station are maintained in the                next site visit. The surface-water files are
computerized database.                            updated, at a minimum, at the end of the
                                                  water year during the station review.
Benchmark Elevation
                                                  Discontinued Stations
      A search for benchmarks in a certain
area is accomplished by doing a search on               Station descriptions, station analyses,
the website                                       level summaries, ratings, correspondence,
http://data.labins.org/2003/index.cfm. This       and other long-term historical
is the LAnd Boundary INformation System           documentation associated with discontinued
(LABINS) which provides the State of              stations are maintained in specific, labeled
Florida benchmarks. Searches can be done          filing cabinets. Folders are grouped by
in a certain radius of a fixed point. Many        station, and the stations are arranged in
agencies are providing levels in NAVD 88          alphabetical order. If local filing space is not
even though the current datum used at most        available, water year folders are transferred
gages in the FLWSC offices is NGVD 29. A          to the Federal Record Center at this time.
program is available on the internet at
http://www.ngs.noaa.gov/cgi-                      1. Price AA and pygmy current meter
bin/VERTCON/vert_con.prl that will convert           discharge measurements are maintained
elevation between the two datum planes               in the historical discontinued
based on latitude and longitude. Benchmark           measurement files.
elevations are also available for a range of      2. ADCP discharge measurements are
state and local agencies (especially the water       maintained in files designated for ADCP

   measurements currently located in the          At this time there is an agreement between
   area of one of the ADCP measurement            the USGS and the Federal Records Centers
   team leaders.                                  (FRC) of the National Archives and Records
3. Original level notes for discontinued          Administration to hold original-data records
   stations are located in the level file         (memorandum from the Chief, Branch of
   drawer that contains all level notes           Operational Support, May 7, 1993).
   (ordered by station number) whether the              Surface-water information is sent to the
   station is current or discontinued.            FRC from each FLWSC office as needed,
4. For stations in which historical level         but generally about every 10 years. The Data
   notes could not be determined, they are        Chief is responsible for deciding what
   placed in the same 'level' file cabinet,       information is sent to the FRC, for ensuring
   but arranged in alphabetical order.            that the information is properly packed and
5. File folders containing primary                logged, and for ascertaining that the
   computations associated with the               information is received by the FRC. Records
   discontinued stations are archived.            of exactly what has been archived are
                                                  maintained in the office responsible for the
Map Files                                         records and are generally the responsibility
                                                  of the secretary of the office but can be
      The FLWSC Tallahassee office                assigned to other individuals. Personnel who
maintains the official USGS Drainage Area         have questions concerning archiving
Map file for the State. This file consists of a   procedures should address their questions to
state-wide set of 1:24,000 scale quadrangle       the Data Chief. Personnel who receive
maps on which the drainage areas for all          requests for information that require
gaging stations have been delineated and the      accessing archived records should obtain the
station number for the site identified. The       requested records from archives with
Surface-Water Specialist is responsible for       assistance from the person designated with
overseeing the maintenance of those files.        the retrieval responsibility. Project chiefs are
Copies of the 1:24,000 scale topographic          responsible for ensuring that appropriate
quadrangle maps, which cover most of the          project data are archived, with the Studies
FLWSC offices‘ study areas, are available         Chief ensuring that responsibility is carried
on site. These maps are used for determining      out.
and verifying township, section, and range
of surface-water and ground-water sites.          Communication of New Methods and
                                                  Current Procedures
                                                       In-house training sessions are to be
     All USGS personnel are directed to           held as needed to communicate any new
safeguard all original field records              methods or procedures relating to the
containing hydrologic, hydrogeologic, and         performance of data-collection activities.
geologic measurements and observations.           Formal training is provided to all personnel
Selected material not maintained in FLWSC         whenever the need arises.
offices are placed in archival storage.
Detailed information on what records have              The content of all policies issued
been removed to archival centers should be        through memorandums by Water Resources
retained in the office (WRD memo 77.83,           or OSW are communicated by the Data
app. 1r). The types of original data that         Chief to all personnel by means of written
should be archived include, but are not           communication through email or verbally as
limited to, recorder charts and tapes, original   necessary. For policy changes that have far-
data and edited data, observer‘s notes and        reaching consequences, policy change may
readings, station descriptions, analyses, and     be communicated to the entire group in a
other supporting information (WRD memo            data section meeting or through training.
92.59 (app. 1s) and Hubbard, 1992, p. 12).        Memorandums are not typically given to

each employee, but electronic copies of all      samplers are used in Florida for stations that
OSW memorandums are located at                   are monitored for daily sediment load.
http://water.usgs.gov/admin/memo/SW/auto.        Sediment sampling for bed load
html. For a list of memorandums by surface-      computations is rarely done in the FLWSC
water topic the web site is                      offices but is currently being done on the
http://water.usgs.gov/osw/pubs/oswtechmem        Kissimmee River for an ongoing project.
osum.html. Any questions on current or new
policy and procedure may be addressed to                Field methods for sediment sampling
unit supervisors or the Data Chief.              are documented in OSW memo 93.01.
                                                 Water samples obtained for the analysis of
COLLECTION OF SEDIMENT DATA                      sediment concentration and particle size are
                                                 not composite (OSW memo 93.01 and
     Surface-water activities in the FLWSC       Office of Water Quality (OWQ)
include the collection, analysis, and            memorandum 76.17. For samples that are
publication of sediment data. This data is not   split, the cone splitter is used (OWQ memo
typically collected for the purposes of          80.17.
calculation of bed load concentration, but             The individual in the FLWSC office
for purposes of suspended sediment               responsible for scheduling sediment-
concentration (SSC) determination and            collection activities at specific sites and
developing a relation between continuous         ensuring that personnel use correct
turbidity measurements and SSC. The              procedures to collect sediment data is the
sand/fine break is also analyzed for purposes    project chief in charge of that specific
of determining what portion of the               project. This individual establishes whether
suspended material is less than 0.62             or not correct procedures are being used by
millimeters. Reports about this use of           accompanying hydrographers who do the
sediment collection have been written by         sampling until satisfied that correct
Christiansen (2000), Runner (2002), and          procedures are being followed. The project
Christensen and others (2001). Although          chief may accompany the hydrographer if
acoustic backscatter as a surrogate for          they feel there are field deficiencies that
sediment concentration is not being used         need to be addressed. Answers to questions
currently, however reports by Patino (1996,      from FLWSC personnel concerning
2004) and Wall. Nystrom, and Litten, 2006        sediment-sampling techniques can be
discuss the possibility for use in FLWSC         provided by the FLWSC Water Quality
offices.                                         Specialist (although sediment sampling is
                                                 currently part of the OSW, the FLWSC
     A summary of memorandums issued             water-quality specialist should be current
since 1971 related to sediment and sediment      with policy and procedures regarding
transport is provided in OSW memo 92.08.         suspended sediment concentration sampling)
A summary of documentation that describes        or by project personnel directly involved in
instrumentation and field methods for            the work.
collecting sediment data is provided OSW
memo 93.01.                                      Field Notes

                                                       FLWSC office personnel are required
                                                 to fill out note sheets each time a site is
Sampling Procedures                              visited for the purpose of sediment sam-
                                                 pling. The employee completes the note
      FLWSC personnel collect suspended-         sheet in its entirety before leaving the site.
sediment data by using sampling methods          Original observations written on the note
that include both the equal-width-increment      sheets are not to be erased; data are
method (EWI) and the equal-discharge             corrected by crossing out the original
method (EDI). Automatic pumping-type             observations and writing the correct

information near the original value. The goal
of placing information on the field note          b
sheet is to describe the equipment and            .
methods used during the site visit as well as
to describe relevant conditions or changes
(OSW memo 91.15). For each site visit,
information included on the note sheet
includes, at minimum, fields indicated on
the sheet. The sheet is used for initial
readings, standard check readings, and any
calibrations that may need to be done. Upon
completion of each field trip, field notes are
given to the project chief with other            Figure 14. US DH-48 (a) and US D-74 (b)
inspection and calibration data. Field notes     sediment samplers.
are checked by the project chief every time
an inspection is done.                                 The measurement of turbidity is
                                                 accomplished by means of an optical
Equipment                                        backscatter turbidity probe/meter. The field
                                                 hydrographer is responsible for
     Care and maintenance of the sediment-       maintenance, verification of turbidity
data-collection equipment is the                 readings, and calibration if necessary of the
responsibility of the project chief. Parts       probe/meter during site visits. Minor repairs
replacement and repair of damaged                such as wiper replacement are to be done by
equipment is accomplished by the field           the field hydrographer. Major repairs such
hydrographer if they have the technical          as those caused by an electrical malfunction
knowledge to do so. It is the responsibility     are not to be performed and the equipment is
of the project chief to ensure that              to be returned to the manufacturer for repair
appropriate equipment is used at all             or replaced.
sampling sites. Sampling equipment is
selected based on the constituents that are      Sample Handling and Storage
being investigated, the type of analyses that
are to be performed, and site conditions,              The quality of sediment data provided
including velocity and maximum depth of          by a sediment laboratory is affected by the
water. The FLWSC offices follow                  quality of the samples received from the
equipment-design criteria and guidelines ref-    field (Knott and others, 1992, p. 2). FLWSC
erenced in OSW memo 93.01.                       personnel are required to prepare sample
                                                 labels, analysis instructions, and sample
                                                 documentation according to guidelines
 a                                               presented in Knott and others (1992).
                                                       Prior to when sample containers are
                                                 obtained for use on field trips, they are
                                                 weighed and labeled at the Kentucky
                                                 Sediment Laboratory and stored in the
                                                 warehouse water quality lab. During field
                                                 trips and prior to use, sample containers are
                                                 stored in the field vehicle tightly sealed and
                                                 secured in a crate or box. Once the
                                                 containers have been filled with sediment
                                                 samples, the samples are labeled and stored
                                                 for the remainder of the field trip tightly
                                                 sealed and secured in a crate or box. After

the field trip, samples are inspected to make    field personnel with information pertinent to
sure the labeling is correct and sent to the     sediment-sampling procedures for that
Kentucky Sediment Lab for analysis.              particular site. Station descriptions are
                                                 included in the field folder and are
High-flow Conditions                             maintained in the office files. Each
                                                 description includes specific information
     High-flow conditions at most streams,       explaining where the site samples are to be
unless the streams are subject to the effects    taken and what method is to be used.
of backwater, are associated with high-                Station descriptions are kept current,
energy conditions. The sediment load and         along with a copy in the gage shelter, by the
particle sizes associated with high flows are    hydrographer responsible for the station, and
significant factors in sediment studies          are reviewed by the project chief as
performed by the FLWSC personnel. To             necessary, but not less than once a year.
ensure that field personnel are aware of their   When a deficiency is identified during the
responsibilities in obtaining sediment           review of station descriptions, the deficiency
samples at appropriate sites during high-        is corrected by consultation between the
flow conditions, the project chief personally    project chief and hydrographer responsible
assigns a hydrographer to watch for high-        for the site. The project chief may choose to
flow conditions and be prepared to obtain        accompany the hydrographer on the
samples. The individual responsible for          sampling trip to ensure that appropriate
ensuring that sediment samples are obtained      protocols are followed.
during opportunities provided by high-flow
conditions is the project chief.                 PROCESSING AND ANALYSIS OF
                                                 SEDIMENT DATA
Cold-Weather Conditions
                                                       Sediment and associated streamflow
     Sediment-sampling activities by             data are compiled to produce suspended
FLWSC personnel rarely, if ever, would           sediment concentration records for specific
include obtaining samples during periods of      sites.
near- or sub-freezing temperatures.
Therefore, no guidelines are provided.           Sediment Station Analysis

Site Documentation                                     A sediment station analysis is written
                                                 for each sediment station operated by
     A station description is prepared for       FLWSC offices each water year. The
each new sediment-sampling site. At              sediment station analysis is a summary of
sampling sites where streamflow-gaging           the sediment activities at the station for a
activities occur, the description of sediment    given year. The analysis describes the
activities is included in the streamflow-        coverage of sampling, the types of samples
gaging-station description. Each station         and sampling, changes that might affect
description includes a list of elements, along   sediment transport or the record, and the
with an explanation of what items are            methods and reasoning used to compute the
included with each element (OSW memo             record. Information included in the sediment
91.15). At sites where sediment samples are      station analysis is presented in a thorough
collected, but other streamflow data are not,    manner, such that the checker and the
the sediment station descriptions are            reviewer can determine from the analysis the
structured similarly to those for streamflow-    adequacy of the activities in defining the
gaging stations, and contain similar             record and in accomplishing the objectives
informational items (Kennedy, 1983, p. 2).       defined for the station (OSW memo 91.15).
At sampling sites where gage shelters have
been installed, station descriptions are kept
in the shelter for the purpose of providing

Sediment Analysis Results                              Ultimately, it is the responsibility of
                                                 the FLWSC Associate Center Director for
      In the FLWSC offices, SSC has been         Data to ensure that surface-water-data files
analyzed primarily in conjunction with           are updated and that the data are correct.
specific projects that have investigated the     The Data Chiefs and Unit Supervisors,
relation between SSC and optic and/or            however, oversee all aspects of data entry
acoustic methods. Several investigative          and data management, except in situations
reports have been published by investigators     pertaining to water-quality files and specific
(Patino 1996, 2004, Wall, Nystrom, and           project files.
Litten, 2006). The project chief is
responsible for ensuring the quality of the           The hydrographer who collects the
data and its storage in NWIS.                    unit-value data is responsible for entering
                                                 the data into the NWIS database. Depending
Sediment Data Storage                            on the equipment that is used at each site,
                                                 generally the data are entered: automatically
      Paper files of SSC data associated with    by satellite telemetry, by downloading
specific projects are maintained by the          electronic data through a portable computer,
project chief including the paper files from     or manually. The task of entering the unit
the sediment laboratory. These data must be      values into the database can be delegated by
manually entered into NWIS using the             the Unit Supervisors and the Data Chiefs to
QWDATA system. A retrieval of these data         individuals other than those who collect the
should be compared to the data on the paper      original data. It is the responsibility of the
files to check for errors. If these do not       field hydrographer who computes the
correspond then updates need to be made to       records to ensure that the correct data are
NWIS to correct the inaccuracies. Quality        contained in the appropriate files for each
assurance is the responsibility of the project   gaging station and for ensuring that the
chief.                                           correct daily mean discharges and stage are
                                                 stored for each station.
                                                       During the end-of-year review, the
      The overall process of storing surface-    reviewer checks to see that the appropriate
water data collected by the FLWSC                data are contained in appropriate computer
personnel at continuous-record gaging            files for each station. The responsibilities of
stations includes entering the unit-value        maintaining the local computer programs
stage, velocity, and hydraulic structure data    and files and for updating the national data
into computer files, using ADAPS, the            base are assigned to a specific individual by
standard USGS database processor;                the Unit Supervisors and the Data Chiefs.
computing corresponding discharge and
stage values; computing daily mean                     The responsibility of updating the Peak
discharges and stage based on those unit         Flow File and ensuring that the data
values; and storing those daily means (when      contained in the Peak Flow File are correct
appropriate) in NWIS.                            is held by the Database Administrator. After
                                                 streamflow records for a water year have
      In addition, instantaneous peak            been computed and checked and the data
discharges and the associated peak gage          have been finalized, the Database
heights are determined for each gaging           Administrator ensures that the Peak Flow
station (that meets the OSW criteria for peak    File is updated to include the published peak
discharge sites) and stored in the Peak Flow     discharges and gage heights for each
File. Sediment data are stored in                applicable gaging station for the most recent
computerized water-quality files.                year. Following the computer-update
                                                 procedure, that individual ensures the
                                                 correctness of the data by comparing all

stored values for that updated year against
the published values. It is the responsibility          All interpretive writings in which the
of the Data Chiefs to ensure that the updates      USGS has a proprietary interest, including
to Peak Flow File are carried out correctly.       abstracts, letters to the editor, and all
It is the responsibility of the project chief to   writings that show the author's title and
ensure that all sediment data are stored           USGS affiliation must be approved by the
correctly in the water-quality data base.          Director before release for publication. The
                                                   objectives of the Director's review are to
PUBLICATION OF SURFACE-WATER                       final-check the technical quality of the
DATA                                               writing and to make certain that it meets
                                                   USGS publication standards and is
     The act of Congress (Organic Act) that        consistent with policies of the USGS and
created the U.S. Geological Survey in 1879         Department of the Interior. Director's
established the Survey's obligation to make        approval ensures that (1) each publication or
public the results of its investigations and       writing is impartial and objective, (2) has
research and to conduct, on a continuing,          conclusions that do not compromise the
systematic, and scientific basis, the              USGS's official position, (3) does not take
investigation of the geologic structure,           an unwarranted advocacy position, and (4)
mineral resources and products of the              does not criticize or compete with other
National domain (U.S. Geological Survey,           governmental agencies or the private sector
1986, p. 4). Fulfilling this obligation            (U.S Geological Survey, 1991, p. 10).
includes the publication of surface-water
data and the interpretive information derived           The Annual Data Report may be
from the analyses of surface-water data.           approved by the local Data Chief; however,
                                                   the hydrologic conditions section must be
Publication Policy                                 approved by the FLWSC Associate Center
                                                   Director for Data.
     The USGS has created specific policies
pertaining to publication of data and              Types of Publications
interpretation of those data. All FLWSC
personnel are required to abide by those                There are various types of book
policies. A brief summary of goals,                publications released by the USGS in which
procedures, and policies are presented in          surface-water data and data analyses are
U.S. Geological Survey (1986, p. 4-37).            presented. Publications of the formal series
     All information obtained through              include the Water-Supply Paper, the
investigations and observations by the staff       Professional Paper, the Bulletin, the
of the USGS or by its contractors must be          Circular, the Techniques of Water-
held confidential and not be disclosed to          Resources Investigations (currently
others until the information is made               Techniques and Methods), Special Reports,
available to all, impartially and                  and Selected Papers in the Hydrologic
simultaneously, through Director-approved          Sciences (U.S. Geological Survey, 1986, p.
formal publication or other means of public        42). Publications in the informal series
release, except to the extent that such release    include the Water-Resources Investigations
is mandated by law (U.S. Geological                Report (currently Scientific Investigations
Survey, 1986, p. 14). With the approval of         Report), the Open-File Report, and the
the Director, hydrologic measurements              Administrative Report (U.S. Geological Sur-
resulting from observations and laboratory         vey, 1986, p. 52). Included in the Open-File
analyses, after they have been reviewed for        Report series are data reports. Surface-water
accuracy by designated USGS personnel,             data collected by FLWSC personnel are
have been excluded from the requirements           published each year in a hydrologic data
to hold unpublished information confidential       report that belongs to the annual series titled
(U.S. Geological Survey, 1986, p. 15).             U.S. Geological Survey Water-Data

Reports. Factors considered by the office         with the draft report that is submitted for
when deciding which form of publication           approval. These same materials are grouped
should be used in presenting various types        as a report file and maintained for future
of information are presented in Green (1991,      reference. After the report is published, the
p. 14). Interpretive project data not             project chief or other office staff retains the
published in the annual data report may be        option to maintain these materials in the
published in a Data Series report format.         FLWSC office as an information resource. If
                                                  it is determined that the materials are no
                                                  longer needed on a current basis, the
Review Process                                    materials are archived.

      Procedures for publication and                    The ultimate responsibility for
requirements for manuscript review by the         presenting complete and accurate
USGS are summarized in U.S. Geological            information in the Annual Data Report
Survey (1991, beginning on page 36).              belongs to the Associate Center Director for
FLWSC personnel fulfill those requirements        Data. It is the Data Chief however, who
for review and approval of reports prior to       oversees all facets of the data-collection,
printing and distribution. All reports written    data-analysis, and report-production process
by USGS scientists in connection with their       for their respective office. Therefore, the
official duties must be approved by the           Data Chief plays the primary role in
originating Division and the Director. At         ensuring the quality of the Annual Data
least two technical reviews of each report        Report.
are required by the USGS (U.S. Geological
Survey, 1991, p. 36). Competent and                     In preparing the Annual Data Report
thorough editorial and technical review are       for publication, FLWSC personnel follow
the most certain ways to improve and assure       the guidelines presented in the report, WRD
the high quality of the final report (Moore       Data Reports Preparation Guide by Charles
and others, 1990, p. 24). Principles of           E. Novak, 1985 edition. The authority to
editorial review and responsibilities of          approve the Annual Data Report for
reviewers and authors are presented in            publication has been delegated by the
Moore and others (1990, p. 24-49). Open-          Florida Water Science Center Director to the
file reports are not required to receive          Associate Center Director for Data.
editorial review, but are reviewed for policy     Discussion of the steps taken to ensure the
and reproducibility (U.S. Geological Survey,      quality of the data that are included in the
1991, p. 36).                                     Annual Data Report are presented earlier in
      In addition to the standard checking        this report in the section, Procedures for
and reviewing of the data included in the         Working and Checking Records, under the
Annual Data Report the Data Chief and             heading Manuscript and Annual Report.
Senior Hydrographer are responsible for
reviewing the final manuscript copy of each             The supervisor of each office‘s Data
stations prior to submission in the SIMS          Management and Publication Unit and the
Records Publication site.                         Data Chief oversees the thorough review of
                                                  the final manuscript pages provided by each
      The FLWSC policy requires authors to        FLWSC office Data Section. A copy of the
provide written responses to all significant      report is prepared in Adobe Acrobat
comments and suggestions provided by              Portable Document Format (PDF). The PDF
colleague reviewers. The responses are            of the Annual Data Report is served from a
provided to the colleague reviewers prior to      persistent URL from http://water.usgs.gov in
the time that the draft report is submitted for   Reston Va. The information content must
approval by the Director for publication.         have Director‘s approval and the HTML
Review and response correspondence and            presentation requires approval of the
marked draft copies of each report are kept       Regional, or FLWSC Director.

                                                  communicating the need for improvements
      In addition, the Associate Center           to their supervisor. Supervisors are
Director for Data oversees the thorough           responsible for promoting safe practices in
review of the CD-ROM version and any              the work place and addressing safety issues
printed reports provided by the FLWSC.            expressed by those they supervise.
The basic data included on the CD-ROM
must match the content and style of the                An individual has been designated as
printed Annual Data Report. At least ten          Safety Officer by each FLWSC office. The
percent of the printed reports are selected       Safety Officer's duties include assisting the
from throughout those provided by the             Data Chief in making safety policies and
printer, and they are reviewed for print          procedures known to FLWSC personnel.
quality. If the printed reports are found to      The Safety Officer attends safety training
contain incorrect information or if the print     provided by the USGS to increase their
quality is found to be poor, the deficiencies     awareness of safety issues, requirements,
are corrected or reprints are made before any     and procedures. Personnel who have
copies are distributed. Printed copies are        questions or concerns pertaining to safety, or
distributed to meet local needs. The Data         who have suggestions for improving some
Chief is responsible for ensuring that            aspects of safety, direct those questions,
deficiencies are corrected.                       concerns, and suggestions to their supervisor
                                                  or FLWSC Safety Officer.
      Performing work activities in a manner
that ensures the safety of personnel and                 Ensuring that personnel obtain
others is of the highest priority for the USGS    knowledge of correct methods and
and FLWSC offices. Beyond the obvious             procedures is a vital aspect of ensuring the
negative impact unsafe conditions can have        quality of surface-water data and data
on personnel, such as accidents and personal      analysis. By providing appropriate training
injuries, they also can have a direct effect on   to personnel, the office increases the quality
the quality of surface-water data and data        of work and eliminates the source of many
analysis. For example, errors may be made         potential errors. Each office has a Training
when an individual‘s attention to detail is       Officer whose duties include ensuring that
compromised when dangerous conditions             all personnel are aware of the training
create distractions. So that personnel are        opportunities available to them. In addition,
aware of, and follow, established procedures      it is the responsibility of each Supervisor to
and policies that promote all aspects of          ensure that all new personnel complete the
safety, the FLWSC offices provide                 required training within the first three years
information and directives related to safety      of employment. The USGS provides a
to all personnel by individual and group in-      variety of training opportunities including:
house training, verbal and written                on the job, USGS sponsored, and other
communication between supervisors and             Agency training. In addition, many
staff, and public display of materials listing    publications such as the USGS Techniques
responsibilities and procedures. Specific         in Water Resource Investigations (TWRI)
policies and procedures related to safety can     and Techniques and Methods series are
be found posted on the office Safety Bulletin     available to each employee for reference.
Board and by request to the FLWSC Safety          Additional USGS training material is also
Officer. It is the responsibility of each         available on interactive CD-ROMs and the
employee to attend the required training          web
provided by the FLWSC and other approved          (http://training.usgs.gov/ntc/courses/cbt-
outside agencies, adhere to USGS and              cdrom/cbtindex.html).
FLWSC safety policies, and contribute to
the development of these policies by

SUMMARY                                           streams: U.S. Geological Survey Techniques
                                                  of Water-Resources Investigations, book 3,
     Information included in this Surface         chap. A6, 13 p.
Water Quality-Assurance Plan documents                  Dalrymple, Tate, and Benson, M.A.,
the policies and procedures of the Florida        1967, Measurement of peak discharge by the
Water Science Center offices that ensure          slope-area method: U.S. Geological Survey
high quality in the collection, processing,       Techniques of Water-Resources
storage, analysis, and publication of surface-    Investigations, book 3, chap. A2, 12 p.
water data. Specific types of surface-water             Davidian, Jacob, 1984, Computation of
data discussed in this report include stage,      water-surface profiles in open channels:
streamflow, sediment, and basin                   U.S. Geological Survey Techniques of
characteristics. The roles and responsibilities   Water-Resources Investigations, book 3,
of personnel for carrying out these policies      chap. A15, 48 p.
and procedures are presented, as are issues             Edwards, T.K., and Glysson, G.D.,
related to management of the computer data        1988, Gield methods for measurement of
base and issues related to employee safety        fluvial sediment: U.S. Geological Survey
and training.                                     Open-File Report 86-531, 118 p.
                                                        Fulford, J.M., 1998, User‘s Guide to
                                                  the U.S. Geological Survey Culvert Analysis
REFERENCES CITED                                  Program, Version 97-08: U.S. Geological
                                                  Survey Water-Resources Investigations
                                                  Report 98-4166, 70 p.
      Arcement, G.J., and Schneider, V.R.,
                                                        ____ 1994, User‘s guide to SAC, a
1989, Guide for selecting Manning's
                                                  computer program for computing discharge
roughness coefficients for natural channels
                                                  by the slope-area method: U.S. Geological
and flood plains: U.S. Geological Survey
                                                  Survey Open-File Report 94-360, 31 p.
Water-Supply Paper 2339, 38 p.
                                                        Green, J.H., 1991, WRD project and
      Barnes, H.B, 1967, Roughness
                                                  report management guide: U.S. Geological
characteristics of natural channels: U.S.
                                                  Survey Open-File Report 91-224, 152 p.
Geological Survey Water-Supply Paper
                                                        Hubbard, E.F., 1992, Policy
1849, 213 p.
                                                  recommendations for management and
      Benson, M.A., and Dalrymple, Tate,
                                                  retention of hydrologic data of the U.S.
1967, General field and office procedures
                                                  Geological Survey: U.S. Geological Survey
for indirect discharge measurements: U.S.
                                                  Open-File Report 92-56, 32 p.
Geological Survey Techniques of Water-
                                                        Hughes, W.F., and Brighton, J.A.,
Resources Investigations, book 3, chap. A1,
                                                  1991, Theory and problems of fluid
30 p.
                                                  dynamic: Schaurns Outline Series, McGraw-
      Bodhaine, G.L., 1982, Measurement of
                                                  Hill, 344p.
peak discharge at culverts by indirect
                                                        Kennedy, E.J., 1983, Computation of
methods: U.S. Geological Survey
                                                  continuous records of streamflow: U.S.
Techniques of Water-Resources
                                                  Geological Survey Techniques of Water-
Investigations, book 3, chap. A3, 60 p.
                                                  Resources Investigations, book 3, chap.
      Bos, M.G 1976, Discharge
                                                  A13, 53 p.
Measurement Structures, International
                                                        ____ 1984, Discharge ratings at gaging
Institute For Land Reclamation and
                                                  stations: U.S. Geological Survey Techniques
Improvement, The Netherlands, 464 p.
                                                  of Water-Resources Investigations, book 3,
      Buchanan, T.J., and Somers, W.P.,
                                                  chap. A10, 59 p.
1969, Discharge measurements at gaging
                                                        ____ 1990, Levels at streamflow
stations: U.S. Geological Survey Techniques
                                                  gaging stations: U.S. Geological Survey
of Water-Resources Investigations, book 3,
                                                  Techniques of Water-Resources Investi-
chap. A8, 65 p.
                                                  gations, book 3, chap. A19, 31 p.
      Carter, R.W., and Davidian, Jacob,
1968, General procedures for gaging

     Kilpatrick, F.A., and Schneider, V.R.,   velocity method in tidally affected areas:
1983, Use of flumes in measuring discharge:   U.S. Geological Survey Scientific
U.S. Geological Survey Techniques of          Investigations Report 2005-5004, 31 p.
Water-Resources Investigations, book 3,            Sanders, Curtis L., Jr., and Feaster,
chap. A14, 46 p.                              Toby D, 2003, Computation of Flow
     Matthai, H.F., 1967, Measurement of      Through Water-Control Structures Using
peak discharge at width contractions by       Program DAMFLO.2, U.S. Geological
indirect methods: U.S. Geological Survey      Survey Open-File Report 03-473.
Techniques of Water-Resources                      Sauer, V.B., and Meyer, R.W., 1992,
Investigations, book 3, chap. A4, 44 p.       Determination of errors in individual
     Morlock, S.E., Nguyen, H.T., Ross,       discharge measurements: U.S. Geological
J.H., 2002, Feasibility of acoustic Doppler   Survey Open-File Report 92-144, 21 p.
velocity meters for the production of              Schroder, L.J., and Shampine, W.J.,
discharge records from U.S. Geological        1992, Guidelines for preparing a quality
Survey streamflow-gaging stations: U.S.       assurance plan for the district offices of the
Geological Survey Water-Resources             U.S. Geological Survey: U.S. Geological
Investigations Report 01-4157, 56 p.          Survey Open-File Report 92-136, 14 p.
     Moore, J.E, Aronson, D.A., Green,             Shampine, W.J., Pope, L.M., and
J.H., Puente, Celso, 1990 Report planning,    Koterba, M.T., 1992, Integrating quality
preparation, and review guide: U.S.           assurance in project work plans of the U.S.
Geological Survey Open-File Report 89-        Geological Survey: U.S. Geological Survey
275, 81 p.                                    Open-File Report 92-162, 12 p.
     Mueller, D.S. and Wagner, C.R., 2009,         Shearman, J.O., 1990, User's manual
Measuring discharge with acoustic Doppler     for WSPRO-- A computer model for water
current profilers from a moving boat: U.S.    surface profile computations: U.S. Federal
Geological Survey Techniques and              Highway Administration Report, FHWA-IP-
Methods, book 3, chap. A22, 72 p.             89-027, 187 p.
     Nolan, M., Jacobson, N., Erickson, R.,        Smoot, G.F., and Novak, C.E., 1968,
Landon, S., 2003, Levels at Streamflow        Calibration and maintenance of vertical-axis
Gaging Stations—A CD ROM Based                type current meters: U.S. Geological Survey
Training Class: U.S. Geological Survey        Techniques of Water-Resources
Water-Resources Investigations Report 03-     Investigations, book 8, chap. B2, 15 p.
4002.                                              U.S. Geological Survey, 1986, Water
     Novak, C.E., 1985, WRD data reports      Resources Division publications guide;
preparation guide, Water-Resources            Volume I, Publications policy and text
Investigations, book 3, chap. C3, 66 p.       preparation, 2d ed., revised by D.W. Alt and
     Oberg, K.A., Morlock, S.E., and          K.T. Iseri: U.S. Geological Survey Open-
Caldwell, W.S., 2005, Quality-assurance       File Report 87-0205, 429 p.
plan for discharge measurements using              U.S. Geological Survey, 1991,
acoustic Doppler current profilers: U.S.      Suggestions to authors of the reports of the
Geological Survey Scientific Investigations   United States Geological Survey, 7th ed.,
Report 2005-5183, 42 p.                       revised and edited by W.R. Hansen: U.S.
     Patino, Eduardo, 1996, South Florida     Geological Survey special book publication,
Ecosystem Program; gaging flows in            289 p.
northeastern Florida Bay 130-96.                   Wall, G.R., Nystrom, E.A., and Litten,
     Rantz, S.E., and others, 1982,           Simon, 2006, Use of an ADCP to compute
Measurements and computation of               suspended sediment discharge in the tidal
streamflow, volumes 1 and 2: U.S.             Hudson River, New York: U.S. Geological
Geological Survey Water-Supply Paper          Survey Scientific Investigations Report
2175, 631 p.                                  2006-5055, 16 p.
     Ruhl, C.A. and Simpson, M.R., 2005,
Computation of discharge using the index-

Appendix 1a. OSW 83.07--Availability of hydraulics programs for Prime computers--
September 9, 1983

     Three hydraulic analysis programs               C374, E431, or J7540--and nnn should
maintained by the Surface Water Branch in      be replaced by the Amdahl remote terminal
the Watstore program library have been         number of the Prime site. This job sends
converted to run on the Prime computers of     punched-card images to the Prime RJE
the Water Resources Division's Distributed     facility at the specified site. The cards
Information System (DIS). In addition, a       alternatively could be sent by means of TSO
widely used but unofficial program for         or WYLBUR. Installation-specific
plotting open-channel cross sections for       procedures should be followed to receive the
step-backwater studies has been converted      card images and move them to an
and also extended to plot cross sections for   appropriate user directory. The card images
the slope-area and culvert-rating programs.    include the Fortran 77 source code, a test
The programs are identified as follows:        data set, and a set of Prime CPL commands
                                               that can be used to load and test the
        A526 SWCULRAT Stage-                   program. More detailed instructions are
discharge relations at culverts                contained in the first few card images of
        C374 SWSLOPE Slope-area                each deck. After the first few lines have
discharge determination                        been edited out, the remainder of the deck
        E431 SWBWFA             Step-          can be run as a single Prime CPL program
backwater and floodway analysis                that automatically will create all files,
        J754 SWPLOTXS Cross-                   compile the program, and run the test job.
section plots
              (in SWB. PROCLIB)                     We strongly urge that a separate User
                                               File Directory (UFD) be set up with the
     The converted programs use the same       name SWB to hold these programs and any
input formats, follow the same processing      other programs provided by the Surface
logic, and produce the same outputs as the     Water Branch. All users should have List-
versions in the Watstore library. Current      Use-Read access to this directory. By this
instructions for input data preparation        means, users will be able to prepare input
remain in effect. Data sets that have run on   data sets in their own directories and execute
the Amdahl should yield essentially            the programs by means of commands of the
identical results on the Prime.                following form:

     Until the DIS communications network            CPL SWB>xxx incards printout
becomes operational, copies of these           in which xxx is the program number, incards
programs may be obtained by running the        is the name of the user's input-card file, and
following job on the USGS Re-1 Amdahl          printout is the name of the user's file that is
computer:                                      to receive the printed output. (If the printout
                                               argument is omitted, the output will be
       //---- JOB ----                         spooled directly to the printer.) The
       /*JOBPARM C=800,L=5                     programs also can be run with the
       /*ROUTE PUNCH RMTnnn                    PHANTOM or JOB commands in the same
       //PROCLIB DD                            way.
       // EXEC                                      The following guidelines for use of
CARDPCH,UDS='SWB.xxx.TRANSFER/'                these programs should be observed until
    in which xxx should be replaced by the     further notice. The programs as distributed
appropriate program number--A526,              should compile, load, and execute without
                                               error. If any problems are encountered in

compiling, loading, or running these           updates or conversions to non-Prime
programs, please contact William Kirby,        computers.
Surface Water Branch, FTS 928-6804.                 The surface-water hydraulics specialists
(Questions about hydraulic methodology         and system administrators at all Prime DIS
and input data preparation should continue     installation are requested to make
to be directed to District and Regional        arrangements to retrieve, load, and test these
Surface Water Specialists). Please do not      programs in a UFD named SWB. Again,
attempt to debug, correct, or improve any of   please report any problems to William
these programs yourself--someone else may      Kirby, FTS 928-6804. Further information
already be working on the problem. Instead,    about any revisions of these programs and
contact the Surface Water Branch. Similarly,   release of new programs will be
please do not give machine-readable copies     disseminated as necessary.
(printouts are acceptable) to third parties,        Marshall E. Moss
including cooperators: contact Surface
Water Branch first for information on

Appendix 1b. OSW 85.17--Policy on Providing Low-Flow Information-- September 20, 1985

     Water Resources Division (WRD)             be made by one or more of the following
offices of the U.S. Geological Survey           methods and generally in the following
(USGS) receive many requests for low-flow       order of priority:
information at both gaged and ungaged sites.
Guidelines for determining low-flow                 1. From published reports describing
information are given in TWRI Book 4,           low-flow characteristics at specific sites.
Chapter B1, "Low-Flow Investigations," by
H. C. Riggs, and Surface Water Branch                 2. From actual low-flow data, either
(SWB) Technical Memorandum 79.06                continuous record or partial record.
(dated July 24, 1979). In the Southeastern      Techniques for frequency analysis and
Region the Southeastern Region Policy           correlation analysis as described in TWRI
Memorandum 74.18 contains additional            Book 4, Chapter B1, and SWB
guidelines. Other regions may have adopted      Memorandum 79.06 should be followed. If
similar guidelines. None of these               previously released information is updated
documents, however, address the approval        based on new data or new methodology, this
procedure for providing low-flow                fact should be made known to the user.
information. The only reference to approval
procedures is in the "WRD Publications               3. From published regional equations
Guide" (page 434) which states that data        which relate low-flow characteristics to
reports that contain low-flow statistical       basin, geologic, and climatic characteristics.
parameters that require assumptions about       Standard errors of estimate, if available,
type of frequency distribution, independence    should be given with estimates of this type.
of events, and adequacy of sample are
interpretive and must receive Director's             4. If a low-flow profile or seepage-run
approval. This memorandum is intended to        is available on a channel, estimates at
be a supplement to the "WRD Publications        intermediate main stream sites or of
Guide" to cover instances when a routine        tributary low flows may be made.
low-flow determination is needed at only
one or two sites.                                     5. If low-flow statistical data have
                                                been defined by measurements and records
     A low-flow workshop was held in the        in a region of similar hydrologic
Southeastern Region in Atlanta, February        characteristics and indicate little variability
26-27, 1985, and was attended by several        in unit low-flow characteristics in that
District personnel, the Southeastern Region     region, estimates may be made by
Surface Water Specialist, and two members       interpolation or by drainage-area ratio for
of the Office of Surface Water including the    other streams in that region that are known
Acting Chief of the Office of Surface Water.    to be unaffected by regulation, diversions, or
The approval policy for low-flow                return flow. An alternate procedure would
information and other low-flow guidelines       be to show the range in a low-flow
were discussed at length. Subsequently, the     characteristic in cubic feet per second per
approval policy was discussed in an Office      square mile for nearby sites and state that
of Surface Water meeting and reviewed by        the flow at the requested site may be within
the Surface Water Specialist in each Region.    this range.
As a result of those meetings and reviews,
the following guidelines were developed and          6. If many measurements in a similar
should be considered policy:                    hydrologic region during a 10-year or lesser
                                                drought show that practically all streams
      Methods--Estimates of low-flow            below a square miles drainage area (or other
statistical data for specific requests should   variable such as recession index) had no

flow, then an estimate of zero would be                New estimates made for one, or a few,
appropriate for an ungaged stream of less         individual sites may be provided to the
than a square miles drainage area.                requestor without Director's approval
                                                  provided they are fairly routine and are
     7. If none of the above is available for     made according to the above guidelines. If
making an estimate, do not make an                unusual conditions or anomalous estimates
estimate. Suggest that base-flow                  appear to exist, the Regional surface water
measurements could be made at the                 specialist should be consulted before
requested site to define low-flow                 releasing the data. The need for further
characteristics. Likewise, if an estimate is      review and approval will be decided at that
given that may be uncertain or have a high        time.
potential for significant error, then suggest
that more base-flow measurements be made.               For requests involving more than a few
                                                  sites or for regional studies and development
      Documentation--A systematic file of all     of low-flow equations and other estimating
low-flow statistical information released         techniques, Director's approval must be
should be maintained. The USGS                    obtained via the usual reports process. It is
downstream numbering system is preferred          recommended that available low-flow
for identification of sites; in some cases, the   information be organized, analyzed, and
site may fall between numbers and 9th and         published to expedite the estimating
10th digits will be needed. This file should      procedure and that the program to obtain
be checked before responding to any request       base-flow measurements and other
to avoid giving out two different estimates       information be accelerated to provide more
of low flow for a site.                           complete coverage. Regulated streams are a
                                                  special case that deserves much more
      Coordination--Before releasing low-         attention.
flow estimates and during the planning
stages of new interpretative reports, contacts    Verne R. Schneider
should be made with other Districts or            Acting Chief, Office of Surface Water
agencies that may have information at the
site, or for the area of interest.                    This memorandum is a supplement to
                                                  SWB Memorandum 79.06, the WRD
      Approval--Published low-flow                Publications Guide and TWRI Book 4,
statistical data and estimating techniques        Chapter B1.
have already received Director's approval
and obviously need no further approval for
dissemination to the public and cooperators.

Appendix 1c. OSW 87.05--Bridge Waterways Analysis: Research Report.-- March 6, 1987
by J. O. Shearman, W. H. Kirby, V. R. Schneider, and H. N. Flippo, Report No. FHWA/RD-
86/108, 112 p

      The purpose of this memorandum is to
distribute the subject report. The report             Some USGS offices are already using
describes the theory and methods used in a       WSPRO, especially those involved in
new Water-Surface PROfile computation            Federal Emergency Management Agency
model (WSPRO). The report also presents          projects. User's instructions for WSPRO are
the results of some limited model                currently in "draft" form and probably will
verification studies.                            be finalized in 6 to 8 months.

      WSPRO was developed as a                        Additional copies of the subject report
cooperative effort between the U.S.              (the supply is somewhat limited) and
Geological Survey (USGS) and the U.S.            additional information regarding use of the
Federal Highway Administration. Existing         model and user's instructions can be
step-backwater programs E431 and J635            obtained from the Office of Surface Water.
should be phased out in favor of WSPRO.          The primary contact for WSPRO
WSPRO provides improved computational            information is Jim Shearman. Jim can be
procedures for flow through bridges. It also     reached by telephone at FTS 959-5227 or
provides considerable flexibility for analysis   (703) 648-5227 or via E-mail at
of alternative designs. A "user-formatted"       JOSHEARMAN@RVARES.
concept for the vast majority of the input
data makes the model considerably easier to          Verne R. Schneider
use than existing programs.                          Chief, Office of Surface Water

Appendix 1d. OSW 88.07--Guidelines for the Operation of a Crest-Stage Program-- April
14, 1988

     Knowledge of the magnitude and                    2. Obtain direct or indirect
frequency of flooding is required for the         measurements every couple of years to
design of transportation facilities such as       verify the high-water range of the stage-
bridges and culverts, flood-control structures    discharge relation. Identify the priority of
such as reservoirs and levees, and for            making measurements at crest-stage stations
floodplain management and the                     in the District flood plan. Whenever
establishment of flood- insurance rates.          possible, measurements should be obtained
These flood-frequency analyses generally          for major flood events.
require only the instantaneous annual peak
discharge. Many years ago, the U.S.                    3. Maintain and utilize upstream and
Geological Survey (USGS) recognized the           down-stream gages if both upstream and
cost-effectiveness of using crest-stage gages     downstream water-surface elevations are
to collect instantaneous flood-peak data.         required to compute flow through the
These partial-record stations can be operated     culvert.
for a small portion of the cost of a
continuous-flow station. Even though these              At many culvert sites, the stage-
gages are relatively simple to install and        discharge relations were developed during
operate, the quality- assurance procedures        the days of the small-stream program. In
for computing annual peak discharges              many instances, these relations are being
should be comparable to those used at             used today without measurements or high-
continuous-flow stations. This                    water marks to verify the relation or flow
memorandum restates and clarifies                 condition. Not only is it important to verify
procedures for operating a crest-stage            stage-discharge relations by measurements,
program.                                          it also is important to obtain high-water
                                                  marks to verify the type of flow condition
      Existing crest-stage gages can be           and utilize elevations at upstream and
former flood-hydrograph sites operated as         downstream gages, if warranted.
part of the small-streams program,
discontinued continuous-flow gaging                    4. Plot the stage-discharge relation and
stations, or stations originally established as   all measurements above a certain stage and
crest-stage stations. In all cases, the primary   identify the types of discharge
problem is in establishing and maintaining a      measurements.
current stage-discharge relation. Suggestions
for developing a sound stage-discharge                 Documentation procedures
relation will be provided as well as
suggestions for improving documentation                1. Maintain a listing of direct and
procedures and analyzing the crest-stage          indirect measurements at each station, and
network.                                          clearly identify the type of measurement.

     Stage-discharge relations                          2. Number the stage-discharge
                                                  relations, identify the periods of
      1. Develop the stage-discharge relation     applicability, and document how each stage-
initially by making direct or indirect high-      discharge relation was developed.
water measurements, developing a
theoretical culvert rating, or using step-             3. Maintain current station
backwater techniques, depending on what is        descriptions, run levels at intervals identified
appropriate.                                      in the quality-assurance plan, and provide all
                                                  appropriate field offices copies of pertinent

information such as stage-discharge             and those continuous-flow stations used for
relations, station descriptions, level          regional information should be a part of
summaries, etc., so the station can be          every proposed regional flood study. Once
properly operated.                              the regional analysis is complete, an
                                                evaluation of the network requires minimal
     4. Write a brief station analysis          effort.
documenting how the annual peak discharge
was computed, identifying which stage-                2. Determine those existing crest-stage
discharge relation was used, the type of flow   stations that contribute most to reducing the
condition, noting whether measurements          prediction error of the regression equations.
were made on the peak, describing how the       Evaluate possible improvements in regional
dates of the peaks were determined, etc.        information by establishing new stations
                                                using the generalized least squares
      5. Update the Peak-Flow File promptly     regression procedure. Operate those stations
after the end of the water year and qualify     that maximize regional in-formation (i.e.,
all annual peaks appropriately. Maintain a      minimize prediction error) for a given
current listing of annual peaks and stages in   operating budget. Since most crest-stage
the station folder for review purposes.         stations are operated to define the flood
                                                hydrology of a region, the generalized least
    6. Maintain District quality-assurance      squares regression procedure provides a
procedures for reviewing the crest-stage        mechanism for determining the best
program, and document this review process.      locations for these stations. An example of
                                                using generalized least squares regression
     Regional/Network Analysis                  for network analysis in Kansas is given in
                                                Water-Supply Paper 2303.
      The recently developed generalized
least squares regression procedure provides          The successful operation of a crest-
a useful method for regionalizing               stage program requires a variety of skills
streamflow characteristics and for evaluating   including knowledge of hydraulics,
the stream-gaging network (see Office of        frequency analysis, and regionalization
Surface Water Technical Memorandum              techniques. Adequate training in all these
87.08 dated April 22, 1987). In particular,     areas should be obtained for those involved
this procedure is useful for evaluating the     in the operation of the crest-stage program.
crest-stage network and making
modifications in the network to maximize        Charles W. Boning
regional flood information. The following       Acting Chief, Office of Surface Water
comments on this procedure are pertinent.
                                                    This memo supersedes Surface Water
     1. Analyze the crest-stage network         Branch Technical Memorandum No. 74.17.
whenever a regional flood study is
completed, approximately every 5 to 10
years. An analysis of the crest-stage network

Appendix 1e. OSW 89.07--Policy to Ensure the Accurate Performance of Current Meters--
June 2, 1989

      The purpose of this memorandum is to       Carter, 1968). A timed spin test is unlikely
establish a policy that assigns responsibility   to reveal that a meter with bent cups will
for the care and maintenance of current          give inaccurate results. Perhaps the polymer
meters and to define the purpose and use of      rotor will eventually solve this problem,
the timed spin test. It is important that each   because they break instead of bending. For
hydrographer be aware of the requirements        a metal-cup rotor, however, a thorough
for testing and care of current meters and       visual inspection is necessary.
follows them closely. The accuracy of the
discharge measurements and the stage-                  It is the responsibility of the field
discharge rating depends on it.                  hydrographer to determine if the current-
                                                 meter rotor is moving freely and does not
      The current meters used by the U.S.        stop abruptly. A full spin test would
Geological Survey are usually supplied with      demonstrate this, but a much quicker
a standard rating. The use of standard           observation of the rotor as it comes to rest
ratings facilitates the field repair of meters   will do as well. The responsibility of the
and reduces the cost of the meter. The           field person does not end here, however. He
standard rating is made possible by              or she should monitor the meter for wear,
manufacturing the meter and each part of the     damage, and fouling. This monitoring
meter to a very tight specification to assure    process should be somewhat continuous in
that all parts are truly interchangeable. The    the field--before, during, and after
standard rating is developed by towing the       measurements. The procedures for
meter at a known constant speed in a tank of     protecting, cleaning, and lubricating the
still water (in the hydraulics laboratory at     meter as described in the applicable
the John C. Stennis Space Center). An            Techniques of Water-Resources
average rating is derived for a group of         Investigations and other manuals should be
meters which then becomes the standard           followed conscientiously (see Smoot and
rating. Since the meters used to develop the     Novak, 1968).
standard rating are new, the successful use
of the standard rating depends on                     These procedures will almost certainly
maintaining a current meter in "as-new"          guarantee the acceptable performance of a
condition.                                       meter. The full timed spin test should be an
                                                 office procedure between field trips, when
     The ultimate responsibility for the good    performance of a meter is suspect, and
condition and accuracy of a current meter        before and after repairs. It will not take the
rests with the hydrographer who uses it. His     place of continual care and inspection of the
or her conscientiousness and                     meter. Every field person eventually comes
professionalism are the only guarantees that     to know this truism, hence the rather poor
a meter is in proper operating condition         adherence to stated or implied policy that
when a discharge measurement is made. A          timed spin tests must precede and follow
timed spin test made a few minutes before a      each measurement.
measurement does not ensure that the meter
will not become damaged or fouled during               Timed spin tests are indicative of wear
the measurement.                                 or damage to the bearing surfaces. To record
                                                 spin tests, a current meter log will be kept on
     An important source of current-meter        file in the appropriate office as designated in
inaccuracy is bent cups (see Smoot and           the District quality-assurance plan. This log

will become part of the archived data of the
Water Resources Division. The format of           Ernest F. Hubbard Acting Chief,
the log is left to each District, but must        Office of Surface Water
include the name of the meter user, checker,
repairs, and the date and results of timed
tests. A suggested log format is attached,
which will fit on a discharge- measurement-
sized card. Logs will be inspected at the
periodic Office of Surface Water reviews of
District surface-water activities. Repairs
and other remarks also should be entered
along with the names of the persons making
the entry. In addition to spin tests between
field trips, after repairs, and when a meter is
suspect, the Office of Surface Water
recommends that periodic meter inspections
be made by the Data Chief, lead
hydrographer, or someone other than the

     The hydrographer should fill in the
blanks on the measurement front sheet to
indicate that he or she has inspected the
meter's condition as described above.
Notations such as "OK" or "free" are
acceptable. If the field person does make a
timed spin test, it should be noted on the
measurement note sheet.

      The following minimum acceptable
spin test time replaces previous guidance on
this subject:

   Pygmy Meters=0:45 seconds
AA Meters=2:00 minutes

     These are minimum spin times for field
use. Meters in good condition will perform
substantially better.


     Smoot, George F. and Carter, R. W.,
1968, Are individual current-meter ratings
necessary?: American Society of Civil
Engineers Journal, v. 94, no. HYZ
     Smoot, George F., and Novak, Charles
E., 1968, Calibration and maintenance of
vertical-axis type current meters: U.S.
Geological Survey Techniques Water-
Resources Investigations, book 8, chap. B2,
23 p.

Appendix 1f. OSW 89.08--Policy Statement on Stage Accuracy-- June 2, 1989

     The U.S. Geological Survey (USGS)           measurements at sites with unstable
collects water-level or stage data for many      channels or other problems and allows for
purposes. A common purpose is to obtain a        relaxing normal accuracy goals for these
flow characteristic that can be related          stations. Additionally, data needs such as
directly to discharge. Other uses are to         reconnaissance, special studies, and similar
determine stage in estuaries, lakes,             activities sometimes may be met with less
reservoirs, streams, and ground-water levels.    accurate stage observations. In these cases,
                                                 District management is responsible for
      This memorandum discusses policy as        determining acceptable accuracy
it relates to the measurement of stage for the   requirements.
purpose of determining stream discharge at
regular daily discharge gaging stations.               The intent of this memorandum is to
                                                 reaffirm the present stage accuracy goal of +
      The USGS has traditionally used a          or - 0.01 ft for daily discharge stations and
stage-accuracy goal of + or - 0.01 foot (ft).    also allow for cases where lower accuracy is
In recent years, many stage-sensing devices      appropriate. HIF's efforts to procure new
have been marketed which are incapable of        pressure-sensor systems for stage
meeting this accuracy objective. Extensive       measurement are a step towards achieving
testing and evaluation of a variety of sensor    this accuracy goal.
systems has been carried out at the USGS
Hydrologic Instrumentation Facility (HIF),            Data may be used for purposes not
and some pressure-based sensing systems          foreseen at the time of collection, and the
have been identified that offer acceptable       possibility of other uses should be
alternatives to mercury manometers and           considered before modifying the general
stilling wells.                                  accuracy criteria.

      Surface Water Branch Technical                  Ernest D. Cobb
Memorandum 85.08 acknowledges the                     Acting, Chief, Office of Surface Water
difficulty of obtaining high accuracy stage

Appendix 1g. OSW 92.09--Adjustment of Discharge Measurements Made at a Distance
from the Gaging Station during Periods of Changing Stage and Discharge--June 17, 1992

      Stage-discharge relations at streamflow     the inflow and outflow are the measured
gaging stations are defined by correlating        discharge and the discharge at the gage;
recorded gage heights (stages) with               which one is which depends on whether the
measured discharges. Practical                    measurement is made above or below the
considerations frequently require that the        gage. In either case, the equation can be
discharge be measured at some place other         solved for the flow at the gage as follows:
than the gage. When the flow is steady
(unchanging in time) and there are no lateral          Qg = Qm + WLdh/dt
or tributary inflows, the measurement may
be made at any convenient location, because            where Qg is the flow at the gage, Qm
the flow also is constant with respect to         the measured flow, dh/dt the average rate of
location along the stream course. When the        change of stage at the gage and
flow or stage is changing with time,              measurement sections during the
however, the flow also is varying from place      measurement, W the average channel top
to place along the stream. In this case, if the   width, and L the distance from the gage to
measurement cannot be made at the gage, an        the measurement section, measured positive
adjustment must be applied to make the            in the direction of flow. Both dh/dt and L
measured flow and the recorded gage height        have algebraic signs: dh/dt is negative if the
hydraulically comparable.                         stage is falling, positive if rising; L is
                                                  negative if the measurement is made
     Procedures for determining and               upstream from the gage, positive if
applying such adjustments are described in        downstream. This equation, computed with
Techniques of Water-Resources                     the rules for arithmetic with signed
Investigations (TWRI) Book 3, Chapter A8          quantities, is equivalent to the sign rules
(p.54-57), in Water Supply Paper (WSP)            given in the TWRI (p. 55-56) and in WSP
2175 (p.177-179), and in a former stream-         2175 (p.177) for the storage-change
gaging manual, WSP 888 (p.79). The                adjustment.
purpose of this memo is to explain the
hydraulic basis for these procedures, to               The storage-change adjustment is based
provide guidance for their practical              on the assumption that the storage change
application, and to correct an error in the       volume is adequately approximated by a
description of one of the procedures.             rectangular slab of length L, average width
                                                  W, and average height dh.
     The fundamental hydrologic principle
that governs this adjustment is the equation            Suitable average values of W and dh
of continuity or hydrologic storage equation      sometimes are not known with certainty. In
for a reach of stream channel between the         this case, alternative methods of adjustment
measurement section and the gage:                 may be sought.

     storage change = inflow - outflow.                 An alternative adjustment method is
                                                  based on the general observation that, in
      As explained in the TWRI and in WSP         upland (non-tidal) stream channels of
2175, the change of storage in this reach         generally uniform geometry and not
during a measurement can be computed              excessively affected by backwater or lateral
directly from knowledge of reach length,          or tributary inflows, streamflow peaks
top width, and stage changes at the               normally move downstream by pure
upstream and downstream ends of the reach.        translation, without appreciable change in
If there are no lateral or tributary inflows,     shape, over moderate distances. That is, the

discharge profile (plot of discharge versus            Although the quantity f' = dQ/dh is
distance along the channel) at a time t+dt        defined by usual gaging-station data, a
can be found by translating the profile at        suitable value for top width W, as previously
time t a distance L downstream, where L =         noted, is not always readily determinable.
cdt, and c is the speed of propagation            However, under channel-control conditions,
(celerity) of the flood wave. If the wave         Manning's or Chezy's formula can be used
celerity is known, a discharge measured at a      with a suitable cross-sectional shape to
particular time and location can be related to    approximate the stage-discharge rating
the discharge (and gage height) that              curve. The quantity (dQ/dh)/W can be
occurred at the gage at an earlier or later       evaluated for such a theoretical rating, and
time.                                             the wave speed c can be expressed as a
                                                  factor times the mean water velocity. As
     The speed of the flood wave, c, can be       shown in WSP 2175, p.415, the ratio of
determined by direct measurement of travel        wave speed to water speed ranges from
times, but this is not usually feasible unless    about 1.3 to 1.7 depending on the cross
discharge or stage hydrographs are available      section shape and choice of Manning or
at upstream and downstream sites. A               Chezy formula. The value of 1.3 seems to
theoretical estimate may be obtained by           be the most probable (WSP 2175, p. 415,
applying the continuity equation to a short       TWRI, p.57).
segment of the rising limb of the flood
wave. Because the segment is moving along               If the wave velocity c is known, a
with the wave, and the wave shape is not          discharge measurement made at a distance L
changing, the volume of water in the              downstream from the gage during a period
segment also is not changing. Thus, the           of changing stage can be adjusted as
continuity equation for the moving segment        follows. The segment of the flood wave that
is:                                               was measured at the measuring section at
     = (V + dV - c)(A + dA) - (V - c)(A)          time t passed by the gage at time t-dt, where
                                                  dt = L/c, and thus is hydraulically associated
     where c is the velocity of the wave (and     with the stage recorded at that time. It is
the moving segment), V and A are the water        immaterial whether the stage is rising or
velocity and area at the downstream face of       falling (i.e., whether the measurement is
the segment, and V+dV and A+dA are the            made on the rising or the falling limb of the
area and velocity at the upstream face. This      flood wave). A similar analysis applies to
equation can be solved for c:                     measurements made upstream from the
                                                  gage. All cases can be summarized by the
     c = dQ/dA = (dQ/dh)/W = f'/W                 formula:
                                                        Qm(t) = f( h(t - L/c) )
     where dQ = (V+dV)(A+dA) - VA, h =
gage height, and W = mean top width. The                in which Qm(t) is the discharge
quantity f' = dQ/dh is the slope, in cubic feet   measured at the measurement section at time
per second per foot of stage rise, of the         t, h(t-L/c) is the recorded gage height at time
stage-discharge rating curve drawn on             t-L/c, c is the wave speed, L is the distance
arithmetic (rectangular) plotting paper. This     from the gage to the measurement section,
derivation of the wave speed can be found in      measured positive in the direction of flow,
many standard open-channel hydraulics             and f is the stage-discharge relation, which
texts under the heading of monoclinal or          expresses the discharge at the gage at any
uniformly progressive wave. The result is         time as a function of the corresponding stage
often called Seddon's (Trans. ASCE, 1900)         h.
principle. It also can be derived by similar
analysis of the receding limb of the                   The above equation implies that Qm(t),
hydrograph.                                       the discharge measured at time t, is to be
                                                  plotted on the stage-discharge rating curve

in association with h(t-L/c), the stage           the stage-discharge relation, which plots as a
observed at time t-L/c. Under conditions of       straight line between 8 and 10 ft on
changing stage, the stage plotted on the          rectangular coordinates, is 8500 cfs/ft. The
rating is computed as a discharge-weighted        adjustment by the storage-change method is
average of stages observed at selected times      as follows:
ti' during the course of the measurement.
For measurements made at a distance from               Qg = Qm + WLdh/dt
the gage, the weighted stage can be
computed as a discharge-weighted average               = 43,610 + (340)(-3.3x5280)(-
of the time-adjusted recorded stages, h(ti'-      (1+.3)/2)/(1x60x60)
L/c). Alternatively, a weighted gage height            = 43,610 + 1070 = 44,680 cfs (GH
hw can be computed in the usual way               = 8.76 ft)
without any time adjustment, such that hw =
weighted average of the h(ti'); the time of            For adjustment by the travel-time
occurrence, t", of hw then can be looked up       method, two estimates of the flood wave
in the stage record, adjusted by L/c, and         speed are available: c = 1.3V = 1.3x8.8 =
used to read off the time-adjusted weighted       11.4 ft/s = 7.8 mph, and c = f'/W = 8500/340
gage height from the stage record as h(t"-        = 25.0 ft/s = 17.0 mph. The corresponding
L/c). This computation can be summarized          calculated gage-height adjustments are:
by the formula:
                                                       ha = hw - h'L/c = (8.76) - (-0.3)(-
     ha(t) = h(t" - L/c) = hw - (L/c)h'           3.3)/(7.8) = 8.76 - 0.13 = 8.63 ft

     in which ha(t) is the time-adjusted gage          ha = hw - h'L/c = (8.76) - (-0.3)(-
height associated with the measured               3.3)/(17.0) = 8.76 - 0.06 = 8.70 ft
discharge Qm(t), hw is the weighted mean
gage height computed without time                      For wave speed c = 1.3V (travel time
adjustment, h' = dh/dt is the average time-       25 min), the discharge-weighted mean of
rate of change of stage between times t" and      time-adjusted recorded stages is 8.67 ft; the
t"-L/c, and L and c are as defined                recorded gage height 25 min after the time
previously.                                       of occurrence of the unadjusted weighted
                                                  gage height was 8.68 ft. For wave speed c =
     The travel-time and storage-change           f'/W (travel time 12 min), the corresponding
adjustments are alternative methods for           gage heights were 8.72 and 8.70 ft. These
accounting for the single fact that the flow at   values differ from the above ha-values
the measurement site is not the same as the       because the rate of change of stage was not
flow passing the gage at the time of              perfectly uniform. The adjusted gage
measurement. A measurement may be                 heights are plotted against the measured
adjusted by one method or the other, but not      discharge (Qm = 43,610 cfs) on the rating
both. The two methods can be illustrated and      curve. The results may be compared with
compared by an example. A measurement             the rating curve as follows:
was made on a falling stage at a site 3.3
miles upstream from the gage. During the               Method              GH (ft) Q (cfs)
approximately 2-hour measurement period,                 Qr (cfs)          dQ/Qr (pct)
the stage dropped at a rate of 1.0 ft/hr at the
measurement site and at 0.3 ft/hr at the gage.          Storage            8.76     44,680
The measured discharge was 43,610 cfs, the                42,540           5.0
weighted-mean gage height (without travel-              Travel (1.3V)      8.63     43,610
time adjustment) was 8.76 ft, and the mean                41,440           5.2
velocity (Q/A) was 8.8 ft/s. The average top            Travel (f'/W)      8.70     43,610
width of the channel, scaled at 10 points on              42,030           3.8
a topographic map, was 340 ft. The slope of

      Travel (wtd 25)     8.67    43,610           arithmetic with signed quantities yield the
        41,780            4.4                      proper signs for the adjustments.
      Travel (t"+25)      8.68    43,610
        41,860            4.2                           The discussion of the travel-time
      Travel (wtd 12)     8.72    43,610           adjustment in the TWRI and WSP 888
        42,200            3.3                      includes a verbal rule for determining the
      Travel (t"+12)      8.70    43,610           algebraic sign of the correction to times
        42,030            3.8                      observed at the stage recorder. This rule,
                                                   which includes consideration of whether the
     These results illustrate that the travel-     stage is rising or falling, is incorrect. (The
time and storage-change adjustments give           rule would have given the correct sign for
generally comparable results. For a perfect        adjustment to gage height, but does not give
translatory wave in a uniform channel the          the correct sign for time.)
travel-time adjustment (with c = f'/W) and
the storage-change adjustment yield the                 To prevent any future confusion or
same difference between the plotted                error, the rule for application of the travel
measurement and the rating curve. The              time adjustment should be corrected on page
results also illustrate, however, that the         57 of the TWRI to read as follows:
travel-time adjustment is sensitive to
judgments and assumptions that may be hard              In applying the time adjustment, the
to verify and subject to dispute. The              time of travel is subtracted from the
difference in rate of change of stage at the       observed time at the measurement section if
gage and measurement sections in this case         the measurement is made below the gage
introduces additional uncertainty. The             and is added if the measurement is made
storage-change adjustment, on the other            above the gage. The resulting adjusted time
hand, involves only straightforward                is used to look up the corresponding gage
calculations on measurable data. Therefore,        height in the gage-height record. (Corrected
as stated in the TWRI, p.57, the storage-          per OSW Technical Memorandum 92.09,
change method generally is preferred; WSP          June 17, 1992.)
2175 does not even mention the travel-time
adjustment for discharge measurements.                  A similar correction should be made to
                                                   the corresponding statement on page 79 of
      The formulas given in this memo for          any copies of WSP 888 that may still be in
adjustment of measured discharge, time, and        use. In addition, necessary steps should be
stage are computed using the normal rules of       taken to ensure that all personnel who make,
algebraic signs, where L is a signed               use, or review discharge measurements are
quantity, positive if the measurement is           familiar with the principles and
made downstream from the gage, negative if         computations summarized in this memo.
upstream. The computation of corrected
times does not depend on whether the stage              Charles W. Boning
is rising or falling. The computation of                Chief, Office of Surface Water
corrected gage height, ha(t), involves in
addition the signed quantity h', which is
negative if the stage is falling and positive if
the stage is rising. The standard rules of

Appendix 1h. OSW 92.10--Guidelines for Identifying and Evaluating Peak Discharge
Errors-- July 2, 1992

      Recent examinations of U.S.                       1. Transfer data from the WATSTORE
Geological Survey (USGS) files, especially         peak-flow file to a local relational data base.
peak-flow files, by District personnel have        Use of a relational data base will simplify
identified significant errors. Some of these       the retrieval and display of the data. All data
errors have resulted from entering incorrect       elements in the peak-flow file should be
station numbers, entering information under        transferred, including county and
the wrong station number, failing to correct       hydrologic-unit codes, latitude, longitude,
for digital recorder errors, and data entry        dates, discharges, gage heights, historical
(keypunch) errors. In addition, questions          information, and qualification codes, for
have been raised about the accuracy of peak-       both annual and secondary peaks above the
flow determinations in steep streams with          threshold.
highly movable beds. There is concern that
some peaks that have been computed as                   2. Retain a copy of all data as retrieved
water flows were actually debris flows.            from WATSTORE for future use in quality
Also, questions are being asked about the          assurance of the review and updating
accuracy of assigned roughness values in           processes (step 13).
channels with coarse bed material. Some
investigators suggest that actual Mannings              3. Proofread the data against the
"n" values are higher than those typically         published record. This step is important
assigned to such channels. This                    because there is concern that an unknown
memorandum has been assembled to call              fraction of the data has been corrupted by
attention to the importance of our peak-flow       clerical errors such as entering data under
data base and to describe procedures to            the wrong station number. Most of this work
ensure the integrity of that data base.            can be done by clerical staff, concurrently
                                                   with technical review of the data by the
      The USGS databases are used for a            hydrologic staff. The clerical work can be
wide variety of purposes and by many               eased by using the data base to print out old
public and private entities. It is critical that   data by station number and date for
data we provide to the nation be as accurate       comparison with the mid-60's flood
as current technology allows. It is                compilations (USGS Water-Supply Papers
imperative that keypunch or other forms of         1671-1689) and to print out the newer data
mechanically based errors be identified in an      by year and station for comparison with the
expeditious manner and correct values              annual data reports. Check all data elements,
entered into the data base. It is also             including station numbers, dates, gage
important that peak-discharge events that          heights, and qualification codes. Keep
may actually have been debris flows be             permanent copies of the data listing showing
critically examined.                               a check mark for each item checked?

      The burden of maintaining the accuracy            4. If any discrepancies are found, keep
of our data files lies with the Districts. The     a permanent record of the correction and the
California District has been involved in           basis for the correction. Prepare necessary
searching for anomalies in their peak-flow         input and images for updating the
files and correcting erroneous values. We          WATSTORE peak-flow file, but do not
encourage all Districts to review and revise,      change either the local data base or the
if necessary, their data bases using similar       WATSTORE file until the review is
procedures. The following suggested                complete.
procedures are based, in large part, on the
California District's experience.

      5. Concurrently, with the clerical               8. Determine if the site is susceptible
review, conduct a technical review of the         to debris flows and, therefore, if the peak
data with emphasis on identifying and             could have been caused by a debris flow
critically examining apparent outliers. Use       rather than by a clear-water flood. Review
data-base graphical facilities to plot            photographs taken during indirect discharge
discharge versus drainage area by State,          measurements for evidence of debris flows.
county, or hydrologic unit code. Draw
smooth envelope curves that enclose about              9. Determine if the site is susceptible
95 percent of the data, and identify apparent     to scour and fill. Review photographs taken
outliers (low as well as high).                   during indirect discharge measurements for
                                                  evidence of channel scour.
     6. Where appropriate, compare
recorded peaks with values computed by the             10. Review the location and drainage
Rational Formula or by appropriate regional       area for the site in question. This has been
flood-frequency equations, or with data from      found to be especially important for sites
the daily-values and measurement files.           smaller than 5 square miles and for sites at
Identify apparent outliers.                       which drainage areas were determined on
                                                  15-minute maps. This has required some
      7. When apparent outliers are found,        field verification.
remember that just because a peak is
anomalous does not mean that it is incorrect;           11. Review historic-peak (and "highest-
this is just a screening criterion. When an       since") information. Review the definition
apparent outlier is found:                        of items "historic" and "systematic" on
                                                  pages C-44 and 45 of the WATSTORE
      a. Compare the peak with the published      manual, vol. 4, Ch. I, and ensure that the
values and with original data; look for           historic-peak qualification code (see pages
transposed numbers and values repeated            A-18 and A-19 of WATSTORE manual,
from previous years, and ensure that the          vol. 4, Ch. I) is used properly. Determine the
station ID is correct.                            specific technical basis and exact source of
                                                  all historical information and make a
      b. Determine the basis of the peak.         permanent record of it; if the specific basis
      (1) If it was an estimate, check that it    and exact source cannot be determined,
was coded as such.                                acknowledge that fact in the record and
      (2) If it was an indirect measurement,      provide whatever information is available. If
review the measurement; give special              any specific information is available for a
scrutiny to measurements rated poor or            historic peak (e.g., gage height or "highest
based on one or two cross sections.               since" year), ensure that it is stored in the
      (3) If the peak was from a rating           peak-flow file, with a historic-peak
extension, look for other evidence to verify      qualification code, even if the discharge
the extension and the peak.                       cannot be determined. Ensure that values
      (4) Use data-base graphical facilities to   subject to high uncertainty (greater than 25
plot discharge against gage height to check       percent) are coded as estimates. Discharges
for datum changes and possible                    subject to very high uncertainty (greater than
misapplication of shifts.                         50 percent) either should not be stored in the
      (5) Make a permanent record of the          file or should be stored as lower-limit
review, including the conclusion reached,         estimates with a "greater-than" qualification
the basis for the conclusion, and any             code; both of these cases are treated the
necessary corrections or revisions.               same by the J407 flood-frequency program.
      (6) Prepare any necessary input cards
for updating the WATSTORE peak-flow                    12. If any revisions are necessary,
file, but do not change either the local data     make a permanent record of the revision and
base or the WATSTORE file.                        the basis for it. Prepare input cards for

updating the WATSTORE peak-flow file.            was obtained. Our understanding of some
After all reviews have been completed and        processes has, however, advanced since the
all corrections and revisions have been          time of the collected information. The
determined, run a job to update the              reviewer should be careful to make technical
WATSTORE data base. Do not update the            revisions only where there are technical
local data base as the data as originally        reasons to do so. Revisions, especially those
retrieved will serve as documentation for        based on roughness characteristics, should
revisions to WATSTORE.                           not be based simply on "second guessing"
                                                 by different personnel.
     13. Retrieve the data from the
(updated) WATSTORE peak-flow file and                  Anomalous indirect measurements or
compare it with the data previously retrieved    anomalous peaks derived from ratings based
(Step 2). The PRIMOS CMPF command, or            on indirect measurements should be
the UNIX DIF command, can be used to             critically examined by hydrologists with
print only the differences between the old       debris flow knowledge and with knowledge
and new data sets; review the differences to     of movable bed dynamics. It is not possible
ensure that all updates were made correctly      to provide specific guidelines and criteria on
and that no inadvertent changes were made.       which to base judgments as to the character
Keep a permanent record of this review for       of any specific flow or conclusions that any
quality assurance.                               indirect measurement is erroneous because
                                                 of improperly assigned "n" values. Some
     14. Keep a permanent machine-               general guidelines regarding recommended
readable copy of the updated WATSTORE            indirect measurement technique include
peak-flow data. This file can be used as the     obtaining a minimum of three cross sections,
basis for future comparisons with the            limiting conveyance ratios to between 0.7
WATSTORE peak-flow file, for quality             and 1.4, avoiding sections that result in flow
assurance of the annual peak-flow records-       moving in and out of critical flow, and other
production process.                              general criteria as given in "Measurement of
                                                 Peak Discharge by the Slope-Area Method,"
      The procedures noted above are aimed       Techniques of Water-Resources
at examining extreme high (and low) peaks.       Investigations Book 3, Chapter A2,
These procedures should not be taken to          (Dalrymple and Benson, 1968) and in the
imply that other values, such as those within    "Users Manual for WSPRO - A Computer
the envelope curves of plots of discharge        Model for Water Surface Profile
versus drainage area (step 5), are error free.   Computations," Report No. FHWA-IP-89-
Such errors could be found using procedures      027, 187p (Shearman, 1989).
outlined above, but it becomes more
difficult to decide which peaks to choose for          Violation of any one of the guidelines
such an analysis.                                and criteria given in the references
                                                 mentioned above does not necessarily
     As noted, simple and obvious errors         invalidate any indirect measurement. The
should be corrected without delay. Such          decision to accept or reject a measurement
problems require little hydrologic judgment      requires the hydrologic judgment of
to ascertain that corrections are needed.        qualified persons in each District.
However, anomalies that result from              Measurements that are questionable and
possible mischaracterization of debris flows     difficult to assess should be reviewed by
as water flows, or from possible errors in       specialists outside the District, such as the
assigned roughness values require careful        Regional Surface-Water Specialists or others
scrutiny and sound judgment before data          known to be authorities in surface-water
values are revised. Experts usually carefully    hydraulics or debris flows.
reviewed high discharges and most indirect
measurements at the time the information

     It is recognized that a thorough review     USGS and to our cooperators. Such a
of the entire flood-peak data file requires      review might be included in plans for
substantial investments of time, money, and      statewide or regional flood-frequency
efforts of clerical, computer, and hydrologic    studies; reviews for subsequent studies
personnel. However, the flood data that we       would be much simplified by preservation of
collect and disseminate serves important         machine-readable files of the updated data
national safety-related purposes. There are      base, as suggested in step 14. It would be
growing national concerns for safety and for     desirable to have the review completed
quality-assurance of basic data and scientific   before the transfer of the peak-flow file from
analyses of safety-related issues. The effort    WATSTORE to NWIS-II.
of reviewing our flood data base and making
necessary corrections and revisions,                  Charles W. Boning
therefore, will be well worthwhile to the             Chief, Office of Surface Water

Appendix 1i. OSW 92.11--Flow Process Recognition for Floods in Mountain Streams-- July
21, 1992

      Whenever floods are investigated,          associated with water floods and debris
especially in small, mountainous basins, one     flows. Attachment 1 is entitled, "Rheologic,
of the most important tasks is to properly       Geomorphic, and Sedimentologic
identify the flow process that occurred in the   Differentiation of Water Floods,
basin. This responsibility may be                Hyperconcentrated Flows, and Debris
overlooked despite the fact that debris flows    Flows," by Costa (1988).
can occur in steep terrain throughout the
country. Incorrect identification and                 Attachment 2 is an informal summary
documentation of flow events can result in       on "Describing and Naming Detrital
questionable discharge estimates.                Sediments," which was prepared by Tom
Historically, some debris flows in mountain      Pierson in Vancouver, Washington, to guide
drainage basins have been analyzed as water      field work in basins of known debris-flow
floods (Costa and Jarrett, 1981). As noted in    activity. The debris-flow process can be
Office of Surface Water Technical                viewed on a videotape (Open-file Report 84-
Memorandum 92.10, recent review of the           606, "Debris-flow Dynamics" by J. E. Costa
peak-flow data base in California has            and G. P. Williams (1984), 22.5 minutes)
emphasized concerns that some peaks              available for loan from any Regional
computed as water floods were actually           Surface-Water Specialist, the National
debris flows. Misrepresentation of such peak     Training Center videotape library, or the
flows could have profound impacts on             Office of Surface Water.
flood-frequency estimates. The purpose of
this memorandum is to bring the importance             In reading the attached papers, you will
of flow-process identification to the            notice that the term hyperconcentrated flow
attention of Division personnel and to           is assigned to flows that are intermediate
provide guidance on how to properly              between clear-water floods and debris flows.
identify flow processes.                         It is generally thought that traditional
                                                 hydraulic computational methods can be
     When debris flows occur, water is           applied to hyperconcentrated flows.
mixed with sufficient volumes of sediment
to cause water and sediment to no longer              Following is a synopsis of the two
behave as two separate phases; they move as      attachments. A glossary of terms is printed
a single, almost plastic-like body. Peak         at the end of this memorandum to assist
discharge determinations based on                readers who are unfamiliar with terminology
traditional indirect measurement methods         used in these descriptions.
will be flawed when debris flows occur. Not
only will a significant amount of the cross-          Deposits usually associated with water
sectional area below high-water marks            flooding:
represent sediment rather than water, but the
hydraulic properties of a plastic-like water-          Deposits typically are stratified. Beds
sediment mixture (a non-Newtonian fluid)         are likely to show horizontal stratification,
differ significantly from those of water (a      cross-bedding, and/or imbrication.
Newtonian fluid), on which traditional
hydraulic theory is based.                             Individual beds within deposits usually
                                                 are thin: a few mm (a mm equals about .003
     The shear strength of debris-flow           ft) to several tens of cm thick (1 cm equals
material results in diagnostic sedimentology     about .03 ft).
and landforms. Two papers are attached that
summarize sedimentology and landforms

    Deposits are very loose and friable.               Vegetation in the channel can sustain
There are often voids between clasts in           great damage. Damage to vegetation may be
gravel deposits (an open-work structure).         minimal at the edges of the flow (see figure
                                                  5 in Attachment 2).
     Sizes of individual sediment grains are
generally characterized by a log-normal                Because the water-sediment mixture
frequency distribution. Particles can be of a     has some strength, sediment tends to be
wide range of sizes. Clasts are usually           "pushed" to the outside of meander bends
rounded (see fig. 2 in Attachment 2).             where it may be deposited. This is the
Sediment can be moderately to poorly              opposite of water floods where sediment
sorted, particularly for flash floods (see fig.   tends to be deposited on the inside of
4 in Attachment 2).                               meander bends.

     Sediment usually is deposited as bars,            All personnel responsible for
fans, or sheets.                                  investigating floods in mountainous basins
     Sediment tends to be deposited on the        need to be aware of the importance of
inside of meander bends.                          correctly identifying flow processes and
     Channels have large width-to-depth           should have or be given adequate training
ratios.                                           and experience in flow-process
     Deposits usually associated with debris      identification using geomorphic and
flows:                                            sedimentological evidence. Training classes
                                                  that discuss indirect-discharge methods
     Deposits usually are massive and             sponsored by the National Training Center
unstratified. Weak imbrication is sometimes       and Regional Offices now include
present. Inverse grading often is found near      instruction on ways to correctly identify
the base of deposit (see fig. 5 in Attachment     flow processes. Personnel are encouraged to
1 and figures 1 and 3 in Attachment 2).           take advantage of this training. The Office
                                                  of Surface Water and the Regional Surface
    Beds are typically thick; 0.3 to 1 or 2       Water Specialists are available to answer
meters (1 m equals 3.28 ft).                      questions about processes associated with
                                                  any flood event.
      Deposits often consist of muddy, sandy
gravel or muddy, gravelly sand. Some mud-             Glossary of terms used in this memo:
-silt or clay--is nearly always present. Grains       (Except where noted, definitions are
are typically angular but can include some        from "Glossary of Geology" by Bates and
rounded clasts picked up from the channel         Jackson (1987).
                                                        Alluvial fans--low, outspread, relatively
      Deposits typically are compact and          flat to gently sloping mass of loose rock
difficult to dig out. There are seldom voids      material, shaped like an open fan or a
between gravel clasts in the deposits.            segment of a cone, deposited by a stream at
                                                  the place where it issues from a narrow
     Sediment usually is deposited as             mountain valley.
marginal levees or fronts (snouts) of very
coarse material. The snout is usually steep            Bar (streams)--ridge like accumulation
and lobate in form and contains a large           of sand, gravel, or other alluvial material
concentration of boulders (see figure 5-E in      formed in the channel, along the banks, or at
Attachment 2).                                    the mouth, of a stream where a decrease in
                                                  velocity induces deposition.
    Channels tend to be semicircular or
even "U"-shaped.

    Bed--informal term for strata that are           Stratified--formed, arranged, or laid
incompletely known (after Bates and               down in layers or strata.
Jackson, 1980)
                                                       Sheet (deposits)--deposit that is
      Clast--individual constituent, grain, or    generally stratiform, more or less horizontal,
fragment of a sediment or rock, produced by       and areally extensive relative to its thickness
the mechanical weathering (disintegration)
of a larger rock mass.                                 References:

     Debris flow--flows in which solid                 Bates R.L. and Jackson, J.A., 1980,
particles and water move together as a single     Glossary of Geology, Second Edition:
viscoplastic body (after Johnson, 1970).          American Geological Institute, Alexandria,
                                                  Virginia,749 p.
     Detrital sediment--sediment formed by             Bates R.L. and Jackson, J.A., 1987,
the accumulation of detritus, especially that     Glossary of Geology, Third Edition:
derived from pre-existing rocks and               American Geological Institute, Alexandria,
transported to the place of deposition.           Virginia,788 p.
                                                       Beverage, J.P. and Culbertson, J.K.,
     Friable--said of a rock or mineral that      1964, Hyperconcentrations of suspended
crumbles naturally or is easily broken,           sediment: Journal of Hydraulics Division,
pulverized, or reduced to powder, such as a       American Society of Civil Engineers, v.
soft or poorly cemented sandstone.                90(HY6), p. 117-128.
                                                       Costa, J.E., 1988, Rheologic,
    Hyperconcentrated flows--flows with           Geomorphic, and Sedimentologic
concentrations greater than 40 percent by         Differentiation of Water Flood,
weight (20 percent by volume)(after               Hyperconcentrated Flows, and Debris
Beverage and Culbertson, 1964).                   Flows, in Flood Geomorphology edited by
                                                  V.R. Baker, R.C. Kochel and P.C. Patton:
     Imbrication--sedimentary fabric              John Wiley and Sons, Inc., New York,
characterized by disk-shaped or elongated         p. 113-122.
clasts dipping in a preferred direction at an          Costa, J.E. and Jarrett, R.D., 1981,
angle to the bedding.                             Debris flows in small mountain stream
                                                  channels of Colorado and their hydrologic
     Inverse grading (reverse grading)--type      implications: Bulletin of the Association of
of bedding that displays an increase in grain     Engineering Geology, v. 18, p. 309-322.
size with distance up from the base.                   Costa, J.E. and Williams, G.P., 1984,
                                                  Open-File Report 84-606, Debris-flow
    Lobate--having or consisting of a long        Dynamics, 22.5-minute videotape.
tongue-like projection.                                Johnson, A.M., 1970, Physical
                                                  Processes in Geology: Freeman and
     Newtonian fluid--substance in which          Cooper, San Francisco.
the rate of shear strain is proportional to the
shear stress.                                          Charles W. Boning
                                                       Chief, Office of Surface Water
     Rheology--the study of the deformation
and flow of matter.

Appendix 1j. OSW 93.07--Policy Statement on Stage Accuracy-- December 4, 1992

      The purpose of this memorandum is to       accurate stage data or to define an accurate
generalize and clarify USGS policy on            stage-discharge relation, stage data should
accuracy goals for collection of surface-        be collected with the greatest accuracy
water stage (water-level) or gage height         feasible, using instruments and methods
data. For a number of years, USGS practice       appropriate for the field conditions.
in stage data collection has been guided by
statements in USGS Water-Supply Paper                 The accuracy of surface water
(WSP) 2175, page 63, and USGS                    discharge records depends on the accuracy
Techniques of Water-Resources                    of discharge measurement, the accuracy of
Investigations, Book 3, Chapter A-7, (TWRI       rating definition, and the completeness and
3A7), page 24, that an accuracy of 0.01 foot     accuracy of the gage-height record.
usually is needed for stage records used in      Accuracies of discharge records for
computation of discharge. These statements       individual days commonly are about 5 to 10
are expressed as an accuracy goal and policy     percent. Individual discharge measurements
for stage data collection in OSW TM 89.08.       seldom are better than 2 percent. Stage
In all cases, the accuracy has been expressed    discharge relations commonly have slopes
as an absolute magnitude of 0.01 ft,             of about 3 on logarithmic plots in which
independent of the stage being measured.         discharge is plotted as a function of effective
Widespread use of stage sensors other than       stage (gage height minus offset, where offset
floats in stilling wells and increased concern   commonly is approximately equal to gage
for assurance of record quality have led to a    height of zero flow). This implies that a 1
need for reassessment, explanation, and          percent error in the effective stage input to
generalization of this policy.                   the rating would translate into a 3 percent
                                                 error in the computed discharge.
      Although stage data are collected for
various purposes, the predominant use is for          The total uncertainty in discharge
computation of discharge from a stage-           computed from a stage discharge relation is
discharge relation. Because the uses to          the square root of the sum of squares of this
which stage data may be put cannot be            error and other unavoidable errors and
predicted, it is OSW policy that surface         approximations in the flow measurement
water stage records at stream sites be           and rating development procedures.
collected using instruments and procedures       Examination of the equation x = \r(z2 + 7y2)
that provide sufficient accuracy to support      shows that improvement in the stage-
computation of discharge from a stage-           accuracy component (z) much beyond the
discharge relation, unless higher accuracy is    combined accuracy of the other error
required. A specific numerical accuracy          sources (y) will have rapidly diminishing
criterion is given in a following paragraph.     effect on the improvement of the overall
At non-stream (reservoir, lake, and estuary)     accuracy (x). Thus, although 0.01 ft stage
sites, the same numerical accuracy goal is to    accuracy may be needed at low stages and
be used unless higher accuracy is required.      discharges, that degree of accuracy is not
Higher accuracy may be required for              essential for accurate determination of
computation of storage changes in reservoirs     discharge at high stages.
or for computation of discharge using slope
ratings or unsteady-flow models; in such              An acceptable balance between stage-
cases, the instruments and procedures            measurement accuracy and other
needed to achieve the required accuracy          components of discharge-record accuracy
should be used. When field conditions such       can be achieved by using instruments
as high velocities, wave action, or channel      capable of sensing and recording stage with
instability make it impossible to collect        an accuracy of either 0.01 ft or 0.2 percent

of the effective stage being measured,              accuracy and field performance of any
whichever is less restrictive. For example,         instruments under consideration.
the required accuracy would be 0.06 ft at 30
ft effective stage, 0.02 ft at 10 ft, and 0.01 ft        Accurate stage measurement requires
at all effective stages less than 5 ft. In this     not only accurate instrumentation but also
context, effective stage is the height of the       proper installation to ensure that the stage of
water surface above the orifice or other            the water body is accurately transmitted to
point of exposure of the sensor to the water        the sensor. In addition, continual monitoring
body; the instrument should be installed in         of the performance of all system
the field with the orifice only slightly below      components is necessary to ensure that
the zero-flow stage.                                accuracy does not deteriorate with time. The
                                                    standard methods for stage measurement
     When evaluating instrument accuracy            described in WSP 2175 and TWRI 3A7
specifications, it should be noted that many        were developed for this purpose; these
instruments are rated in terms of full-scale        methods include frequent reading of
percentage accuracy. An instrument with             independent reference gages, comparison of
50-ft range and 0.2-percent full-scale              inside and outside gages, observation of
accuracy has an absolute error tolerance of         high water marks, redundant recording of
0.10 ft, applicable throughout the range of         peaks and troughs by use of max/min
stage, and thus would not have sufficient           indicators, use of crest stage gages, and
accuracy at low stages.                             regular maintenance of gage datums by
                                                    levels. These checks should be augmented
      Realistic evaluation of instrument            as appropriate for unusual field conditions
accuracy requires a combination of                  and instrument types not discussed in the
specialized laboratory testing and field trials     standard references. Hydrographers should
under controlled conditions. The laboratory         notice and keep records of instrument
tests evaluate instrument accuracy by               performance, including comparisons of
comparisons with known measurement                  recorded stages with reference gage
standards over a range of specified stages,         readings, and any corrections applied.
temperatures, and other conditions; the field       These records should be considered in
tests evaluate the instrument's ability to          evaluations of instrument suitability, in
operate reliably and maintain its accuracy          maintenance of District quality assurance
with time under a range of field operating          plans, and in planning of future operations.
conditions. One of the major functions of the
USGS Hydrologic Instrumentation Facility                 Charles W. Boning,
(HIF) is the performance of laboratory and               Chief Office of Surface Water
field evaluations, which are carried out
through the Test and Evaluation Section.                 This memorandum supersedes Office
Results of laboratory and field tests of            of Surface Water Technical Memorandum
pressure sensor systems for stage                   No. 89.08.
measurement regularly are distributed to
WRD offices in the HIF newsletter (WRD
Instrument News) and in the
INSTRUMENTS continuum on the
QVARSA node of the USGS DIstributed
Information System (DIS). When selecting
stage-measurement instrumentation,
Districts should refer to the HIF newsletter
and the INSTRUMENTS continuum, and
should consult with the HIF and other
appropriate sources for information on

Appendix 1k. OSW 93.12--Techniques of Water-Resources Investigations (TWRI) Book 3,
Chapter A19--Clarification of Leveling Procedure-- February 4, 1993

      The purpose of this memorandum is to              The instructions in the TWRI
clarify procedures concerning the                  acknowledge, however, that side shots are
establishment of turning points as discussed       acceptable, if the side shot is taken twice,
in TWRI Book 3, Chapter A19, "Levels at            and from different HI's.
Streamgaging Stations."
                                                        The policy of WRD is that level
     Instructions in the TWRI state on page        procedure shall be considered acceptable, if
16, "Run the level circuit or series of circuits   a complete circuit is run such that at least
from the reference mark that appears most          one turning point is taken, and all marks are
stable, turning on the other marks until the       shot twice and from different HI's. The two
farthest one is reached. Then, continue each       shots on each mark could be either two
circuit back to its starting point, turning on     foresights from different HI's or a foresight
the same marks in reverse order." These            followed by a backsight. The circuit should
statements, and the examples in the manual,        be closed by a final shot on the base
imply a requirement that the instrument be         Reference mark to allow determination of
reset after each foresight, and a backsight        error of closure.
taken to establish a new height of instrument
(HI).                                                   Charles W. Boning,
                                                        Chief Office of Surface Water

Appendix 1l. OSW 2002.02--Policy and Technical Guidance on Discharge Measurements
using Acoustic Doppler Current Profilers-- December 7, 2001

     The purpose of this memo is to provide    streamflow measurements from moving
policy and technical guidance for the          vessels.
measurement of discharge using acoustic
Doppler current profilers (ADCP's). The             Field Measurements
term ADCP is used here to describe acoustic
Doppler profiler instruments used for               The following policies for
making velocity-profile and discharge          measurements of streamflow using ADCP‘s
measurements from moving platforms and         are provided:
does not refer to any specific brand or
model. This memo supersedes Office of               1. After the ADCP is mounted and
Surface Water (OSW) Technical                  deployed on the boat and prior to each
Memorandum 96.02, Interim Policy and           measurement, the depth of the ADCP in the
Technical Guidance on Broadband Acoustic       water should be measured and recorded. The
Doppler Current Profilers.                     depth of the ADCP is the vertical distance
                                               from the water surface to the center of the
     Policy and technical guidance             transducer faces. When measuring the
described in this memo is based on             ADCP depth, make sure that the roll and the
knowledge and experience with ADCP‘s           pitch of the boat are similar to roll and pitch
obtained by the USGS during the past 8         during the discharge measurement. A bias in
years, OSW training materials, and the         the ADCP depth measurement can result in
report Quality Assurance Plan for Discharge    a significant bias in the resulting measured
Measurements Using Broadband Acoustic          discharges.
Doppler Current Profilers (Lipscomb, 1995).
Although this report still is mostly                 2. A minimum of four (4) transects
applicable, it currently is in revision.       (two in each direction) will be made under
Policies and guidance discussed in this        steady-flow conditions. The measured
memo supersedes information found in           discharge will be the average of the
Lipscomb (1995). The policies described in     discharges from the 4 transects. If the
this memo have been reviewed by the OSW        discharge for any of the 4 transects differs
Hydroacoustics Work Group (OSW                 more than 5 percent from the measured
Memorandum).                                   discharge, a minimum of 4 additional
                                               transects will be obtained and the average of
     ADCP performance and operational          all 8 transects will be the measured
characteristics are changing frequently as     discharge. Whenever possible, reciprocal
hardware and software continue to improve.     transects should be made to reduce potential
Frequent revisions of software, firmware,      directional biases.
and documentation revisions are expected in
the foreseeable future. Thus, policy and             3. It may be necessary to use individual
technical guidance will be subject to change   transects as discrete measurements of
and revision, and some information may be      discharge under rapidly varying flow
specific to a particular system, version, or   conditions. The rationale for using
manufacturer.                                  individual transects as measurements should
                                               be documented and permanently stored with
    Policies                                   the discharge measurement or applicable
                                               station analyses or files. However, whenever
     The following policies apply to use of    possible, pairs of reciprocal transects should
the ADCP‘s for making velocity-profile and     be made to reduce directional biases.

      4. It is important to select appropriate   and then proceed with your discharge
sites for streamflow measurements. The           measurement (using bottom tracking as the
guidelines provided in Water Supply Paper        velocity reference). Although this
2175 (Rantz and others, 1982) still are          measurement will be biased low – at least it
applicable and should not be ignored when        will provide some indication of the true
using an ADCP. Many ADCP measurement             discharge and is better than not having a
problems can be solved by moving to a            measurement. The DGPS must be capable of
better measurement section.                      sub-meter accuracy. When using a DGPS, it
                                                 is necessary to properly calibrate the internal
     5. A moving bed test must be recorded       compass of the ADCP, and to measure or
prior to making any measurements. At least       obtain an accurate estimate of the local
one section of the river should be identified    magnetic variation. For more information on
where the potential for bed movement is          compass calibrations and use of DPGS,
greatest. Although the location of maximum       users are directed to the OSW ADCP Web
potential bed movement cannot easily be          pages, manufacturer help files, and are
predicted a priori, it often occurs in the       encouraged to attend the Advanced ADCP
region of maximum water velocity.                Applications training class
However, at times, bed movement is               (http://hydroacoustics.usgs.gov/training/).
observed in the low-water flood plain area.
When in doubt, make moving-bed tests at 3-            Average boat speed for each transect
5 sections across the river.                     should be less than or equal to the average
                                                 water speed. Where safe and practicable, a
      The vessel used to make the moving         non-ferrous tag line can be used to allow
bed test should be held in a stationary          more control over boat speed when making
position for about 10 minutes, provided that     low-velocity measurements. Under certain
this can be done safely. While in this           conditions it may not be possible to keep the
stationary position, ADCP data should be         boat speed less than the water speed. As a
recorded and examined for any apparent           result, additional transects should be made
upstream movement of the boat relative to        or the estimate of measurement quality
the channel bottom. If apparent upstream         downgraded. When using DGPS it is very
boat movement is measured, then the water        important to keep the boat speed as low as
velocity measured by the ADCP will be less       practical because errors in compass
than the true water velocity and the             calibrations are additive and will increase
discharge measured by the ADCP will be           with boat speed.
less than the true discharge.
                                                      Edge distances for estimation of edge
      For sites where a moving bed condition     discharge must be measured using an
is observed, a differentially corrected global   electronic-distance measuring device, a
positioning system (DGPS) supporting             tagline, or some other accurate measuring
NMEA-0183 output (Trimble Navigation             device. OSW ADCP Web pages contain
Limited, 1999, Appendix D) should be used        information on various devices for
instead of bottom-tracking to compute            measuring edge distances
vessel velocity when this condition is           (http://hydroacoustics.usgs.gov/distance.htm
present. The presence of a moving bed            l).
condition likely will be flow-dependent.              ADCP‘s may not accurately measure
This information should be included in the       depths in streams with high sediment
station description for the streamgaging         concentrations and/or high bedload
station in question. If you discover a moving    transport. In these instances it may be
bed condition at your site and do not have a     necessary to use a vertical depth sounder.
DGPS with you, it is suggested that you          The sediment concentration or bedload
make multiple moving bed tests at different      transport rate at which it becomes necessary
locations in the measurement cross section       to use a depth sounder is not presently

known. As we learn more about his issue,
further guidance will be provided. If you
have a ―moving bed condition‖ at your
measurement site we recommend that you
make several trial measurements using a
vertical depth sounder to determine if the
ADCP depths are representative under a
variety of flow conditions. It may be
possible for USGS offices to temporarily
borrow an echo sounder by contacting Kevin
Oberg (kaoberg@usgs.gov).


     Personnel collecting and reviewing
ADCP data for discharge measurements
must have completed the USGS training
class, Measurement of Streamflow using
ADCP‘s. For more advanced applications
and measurement situations, including the
use of DGPS; users are strongly encouraged
to complete the USGS training class,
Advanced ADCP Applications. Information
regarding USGS ADCP training classes may
be found at:


     Users are responsible to keep current
with policies, and recommended procedures
and practices. Attendance of a recent ADCP
training classes or the USGS Hydroacoustics
Workshop, subscription to the acoustics
mailing list, and review of the OSW ADCP
Web pages are all valid ways of keeping

Measurement Documentation and
Processing                                          For additional information regarding
                                               these policies and guidance, please contact
     Measurements made with the ADCP           Kevin Oberg by phone (217-344-0037 ext
should be documented using the acoustic        3004) or by email (kaoberg@usgs.gov)
profiler discharge measurement note sheet
(Attachment A--                                    References
tml). When processing ADCP                          Trimble Navigation Limited, 1999,
measurements, measurement data should be       AgGPS 124/132 Operation Manual: Trimble
carefully reviewed. Listed below are the       Navigation Limited, Sunnyvale, CA, USA,
most common problems found when                170 p.
reviewing ADCP data.                                Lipscomb, S.W., 1995, Quality
                                               assurance plan for discharge measurements
    No moving bed test                         using Broadband acoustic Doppler current
    ADCP depth incorrectly set                 profilers: U.S. Geological Survey Open File
    Boat speed too fast                        Report 95-701, 12 p.
    Incorrect extrapolation method                  Rantz, S.E., and others, 1982,
    Edge distances not measured                Measurement and computation of
    Poor field notes                           streamflow, Volume 1, Measurement of
    Incorrect blanking distance                discharge: U.S. Geological Survey Water-
    Incorrect number of depth cells            Supply Paper 2175, 631 p.
    Poor data-archival procedures
    Use of ferrous metal mounts                    J. Michael Norris
                                                   Acting Chief, Office of Surface Water
     The Hydroacoustics Work Group
currently is developing tutorials on finding   SUPERCEDES OSW Technical
and correcting some of these problems.         Memorandum No. 96.02
When they become available on the OSW
ADCP Support World Wide Web pages
(http://hydroacoustics.usgs.gov/), an
announcement will be made to the acoustics
mailing list (acoustics@simon.er.usgs.gov).

Appendix 1m. OSW 2002.03--Release of WinRiver Software (version 10.03) for Computing
Streamflow from Acoustic Profiler Data--December 7, 2001

     The purpose of this memorandum is to      personnel who own and use ADCP‘s
announce the availability of WinRiver 10.03    manufactured by RDI at
for collecting and processing data collected   http://hydroacoustics.usgs.gov/downloads/se
with RD Instruments (RDI) acoustic             tupex.exe.
profilers (Broadband, Rio Grande,
Workhorse, and others). The WinRiver                 The following sections contain
software was developed by RDI, in              information about two major enhancements
cooperation with the USGS, as a part of a      in WinRiver 10.03, the addition of a
Cooperative Research and Development           configuration wizard for configuring the
Agreement (CRADA). The use of WinRiver         ADCP and the addition of data-screening
software by USGS offices was announced in      tools. In the following sections, italicized
Office of Surface Water Technical              text refers to menu options or buttons in the
Memorandum No. 2000.03.                        WinRiver software.

     The WinRiver software continues to be          Configuration Wizard
updated and improved. Various new features
are included in this release of WinRiver and        The configuration wizard is a tool that
many known problems have been fixed.           can be used to set up an ADCP for data
Lists of new features, changes to existing     collection. The goal of the configuration
features, and bugs fixed are provided in       wizard is to guide the user through the
Attachment A. At least one known bug           ADCP setup process and reduce the need to
remains in WinRiver 10.03. Attachment B        remember all direct commands. The OSW
documents this bug, as well as two other       hopes that the addition of this feature will
bugs that appear to have been fixed. All       minimize some of the common mistakes that
USGS users who collect streamflow data         occur when setting up ADCP‘s for discharge
must upgrade to WinRiver 10.03. The latest     measurements.
version of the software is available to USGS

    The configuration wizard is invoked in Acquire mode by selecting Configuration Wizard
under the Settings menu or by pressing Shift-F6. An example of the configuration n wizard is
shown below.

      When the Run Wizard button is                       Pressing OK will apply the wizard-
pressed, the wizard verifies that the required      generated settings to the currently loaded
fields have been entered by the user and uses       configuration file. The user then can select
these values to generate a configuration file       Save or Save As from the File menu to save
for the measurement. The appropriate direct         the configuration file. After the
commands are specified, based on rules              configuration wizard window is closed, the
supplied by the USGS to RD Instruments,             configuration file settings created by the
including depth cell size, number of depth          wizard can be viewed in the Configuration
cells, ambiguity velocity, and water mode.          Settings window. The direct commands
The wizard also scales the chart properties         generated by the configuration wizard are
accordingly based upon the entered values.          listed under the Commands tab of the
Although the software has been tested and           Configuration Settings window in the
we are reasonably confident that the                second column labeled Wizard Commands.
configuration wizard will work well, users          Wizard Commands can override Fixed
always should check to make sure that the           Commands and User Commands can
direct commands are appropriate. In                 override Wizard Commands.
particular, users should pay attention to the
Configuration Wizard Warnings generated                 Data Screening Tools
after running the wizard.
                                                         The capability of WinRiver 10.03 to
      After running the configuration wizard,       screen data in software provides a better
pressing Save As will save the configuration        approach to processing data that should
file as a WinRiver configuration file.              result in more accurate measurement of

discharge. Previously all screening was done        for removing data containing obvious
in the firmware of the ADCP. The new                ambiguity errors or data with high error
data-screening switches and threshold               velocities because of nonhomogeneous flow.
variables are found in the Configuration            By appropriately setting the error and
Settings window, under the Processing tab.          vertical velocity thresholds, WinRiver 10.03
                                                    will mark these data as invalid and compute
      The first set of screening tools is for the   discharge in these areas from neighboring
acceptance or rejection of 3-beam solutions.        valid data. By default, the thresholds are set
In the past, users determined whether to            very high, which for practical purposes turns
allow 3-beam solutions using the EX                 off the screening. Reasonable values for the
command. This determination was an                  error velocity thresholds are a function of
irreversible decision that applied to both          the standard deviation of the velocity
water-track and bottom track data that had to       measurement in a single bin, which is
be made before data collection. With this           dependent on the frequency of the ADCP,
new screening tool all raw data can be              the bin size, and the ambiguity velocity
collected by setting the EX command                 setting for mode 1 data. The objective of
(EX10111) to accept 3-beam solutions                screening is to reject only the obviously bad
(which is now the default in WinRiver) and          data and because the errors are normally
then accepting or rejecting 3-beam solutions        distributed, a threshold of 3 to 4 times the
in WinRiver after the user reviews the data.        standard deviation of the velocity
Three-beam solutions often indicate that a          measurement is reasonable (see table 1).
fish or other object has interfered with one
beam, which can cause the sound reflected
by that object to contaminate the
neighboring beams. Thus, simply throwing
out the bad beam and accepting a 3-beam
solution can cause errors in the measured
velocity. In most situations, 3-beam
solutions should be rejected and the default
setting for water-track is to reject 3-beam
solutions. The cause of 3-beam solutions in
bottom-track data is different and it
generally is acceptable to use 3-beam
solutions for bottom tracking, and the
default setting is to accept 3-beam solutions
for bottom tracking.

      The next set of screening tools allows
the rejection of data in individual bins based
on the error velocity and (or) vertical
velocity in that bin. Ambiguity errors and
areas of highly non-homogeneous flow
cause high values in the error and vertical
velocity magnitudes. Contour plots of the
error or vertical velocity with the
appropriate color scale can be used to
identify data that obviously are different
from the surrounding data. Likewise, time-
series plots of the boat speed or water speed,
and the stick ship-track plot, can show
unreasonable spikes. Prior to the release of
this version, no mechanism was available

     Table 1. Reasonable error velocity thresholds.

     [WM refers to the WM command used to set the water mode in RDI profilers. WS refers to
     the WS command used to set the depth cell size in RDI profilers.]
             ADCP                           Depth            Standar Error Velocity
         Frequency           Water     Cell Size (m) d Deviation1 Threshold
         (kHz)          Mode [WM] [WS]                 (ft/sec)        (ft/sec)
                             1              1.00             0.59            1.8
             300             5              0.20             0.03            0.1
                             8              0.20             0.86            2.5
                             1              0.50             0.59            1.8
             600             5              0.10             0.03            0.1
                             8              0.10             0.86            2.5
                             1              0.25             0.59            1.8
             1200            5              0.10             0.02            0.1
                             8              0.10             0.81            2.5
     1 The standard deviation for mode 1 measurements shown in this table are computed
     assuming a mode 1 ambiguity velocity (WV) of 170 centimeters per second.

     Setting the threshold for the vertical           we gain experience. Additional information
velocity is not as straightforward as the error       regarding the use of thresholds will be made
velocity threshold. The vertical velocity             available through the OSW ADCP Web
threshold only should be used if the user has         pages (http://hydroacoustics.usgs.gov/).
a reasonable knowledge of the vertical
velocities in the measurement section and                 J. Michael Norris
(or) observes patterns or banding in the                  Acting Chief, Office of Surface Water
vertical velocity contour plot. The vertical
velocity threshold then can be set based on               Attachments (2)
the user‘s judgment to remove obviously
erroneous data.                                           SUPERCEDES OSW TECHNICAL
                                                          MEMORANDUM NO. 2000.03
      The last screening tool allows users to             Distribution Code: A, B, FO, PO
apply a fish-detection algorithm in the
WinRiver software. When using WinRiver,               Attachment A – Changes to WinRiver since
by default, a firmware fish detection                 release of version 10.01
algorithm is implemented by sending the
direct command, WA50. However, in the                 Features Added
WinRiver software users now can select
different values for intensity amplitude for          1. Implemented Configuration Wizard.
detecting and removing data that potentially          2. Added near-zone correction for
are contaminated by echoes from fish. This            backscatter.
feature has the advantage of collecting all           3. Added features to go to a specific
the raw data and screening the data in post-          ensemble number (Ctrl-Home).
processing rather than having the instrument          4. In User Options, a field on the Acquire
reject the data based on the configuration            Mode tab was added to enter Terminal
setting.                                              Program path (like BBTalk, DumbTerm, or
     Because screening data by use of these           5. Added menu item to execute a Terminal
thresholds is a new feature, we expect that           Program from within Acquire Mode.
guidance regarding their use will change as

6. Added F12 key shortcut to toggle display      1. Changed behavior for the subsection. If
of Discharge History Tabular view.               the file is positioned at the end of the
7. Added F9 key shortcut to toggle display       subsection and a new selection for ―All
of Ensemble Header Tabular view.                 Ensembles‖ is made, the file will be reset to
8. Added F11 key shortcut to toggle display      the beginning and played to the end.
of Composite Tabular and Discharge Detail        2. Changed order of the way units were
Tabular views.                                   displayed. First selection is ―English‖ units.
9. On the Discharge History Tabular              3. Changed temperature display on the
window all transects greater than 5% from        Standard Tabular view from °C to °F, if
the average (based on Total Discharge) now       English units are selected.
have a red font color.                           4. Expert parameters in User Options are
10. Added 3-beam solutions screening.            reset to defaults on exiting the program.
11. Added error velocity screening.              Before, they were saved to registry.
12. Added vertical velocity screening.           5. Changed the order of fixed commands to
13. Added capability to screen out data          be alphabetical.
contaminated by fish within with the             6. Changed default for cross-sectional area
acoustic beams.                                  computation to ―Parallel to Average
14. Added ―Q/Area‖ to Discharge History          Course‖.
Tabular view.                                    7. Changed description on Discharge Detail
15. Added ―Go To Ensemble‖ feature.              Tabular view from ―Flow Speed‖ to
16. Added F8 key shortcut to toggle              ―Q/Area‖.
left/right bank.                                 8. Changed ―Shore Pings‖ to ―Shore
17. Added F2 key shortcut to set the Mean        Ensembles‖.
Flow Dir. as Projected Angle.                    9. Changed default of EX10101 to EX10111
18. Added accelerator character keys in          to allow software screening of 3-beam
configuration window to allow easier             solutions
navigation without a pointing device.            10. Changed behavior of Recent File Lists –
19. Subsectioning values are now saved to        in Playback mode, only rawdata files are
the configuration file so that when a file is    shown, in Acquire mode, only configuration
loaded it automatically is subsectioned, if it   files.
previously had been subsectioned.                11. Changed default maximum number of
20. Show on status bar that data are             bins from 128 to 255.
averaged (right low corner).                     12. Removed Resets page in Acquire mode.
21. Process control bar changes color when       13. Changed default value of shore
a transect has been subsectioned.                ensembles to 10 (from 1).
22. Generate a warning if ws*wn<measured
depth.                                           Bugs Fixed
23. Ship track plot is no longer frozen while
not recording.                                   1. Fixed the problem with ASCII out
24. The user now can set a starting file         repeating velocity values for invalid data.
number for raw data files.                       2. Fixed problem with Win2K
25. CL0 now is added automatically to            communications.
fixed commands when "===" is selected for        3. Fixed the problem with calculating
break.                                           backscatter for up-looking data.
26. Added Reset button to reset                  4. Fixed problem with bin mapping (bin
configuration parameters back to *w.000          mapping also was implemented on the ship
parameters.                                      data, which were bin mapped by the
27. Added checking COM1-COM256                   instrument‘s software).
instead of COM1-COM9.                            5. Changed Depth Sounder scale factor
                                                 range (Configuration Settings, DS/GPS tab)
Changes made to existing features                from 0 – 2 to 0.5 – 1.5. Allowing 0 as a

valid entry had caused problems in               20. Fixed problem with resetting values in
WinRiver.                                        the configuration settings dialog window. If
6. Fixed problem with displaying of the          you right clicked and set a new value in a
discharge column on Velocity Tabular view.       variable, then right clicked to set a new
The data were not averaged if averaging was      value in another window, the first variable
selected.                                        reverted to its original value.
7. Fixed the display of ―DS Depth‖ on            21. Fixed problem when switching between
Navigation and Composite Tabular views.          Playback and Acquire configuration
8. Fixed the implementation of GPS Time          information was not saved automatically.
Delay.                                           22. Fixed zoom feature, which would reset
9. Fixed the problem where the last bin was      after each new ensemble.
calculated if the ―Cut off bins above side-      23. Fixed the behavior of Configuration
lobe‖ was selected and there were bad bins       Settings property pages during Acquire (it
near the side-lobe.                              use to gray out during Acquire).
10. Fixed display of fixed commands
loaded from w.000 file.                          Attachment B – Known/Possible Bugs with
11. Fixed saving of fixed commands to            WinRiver Version 10.03
w.000 file (line feeds were missing).
12. Fixed magnetic variation correction for      1. Some users have reported that WinRiver
earth data.                                      will sporadically enter into an infinite loop.
13. Fixed the problem with marking below         We believe that this bug has been fixed.
bottom for up-looking data.                      However, if anyone does experience this
14. Fixed problem with calculating average       problem, please contact Kevin Oberg
water speed for up-looking data.                 (kaoberg@usgs.gov) or Dave Mueller
15. Fixed some displays for up-looking data.     (dmueller@usgs.gov) to report the problem.
16. Fixed the problem with Boat Speed            The bug does not affect the computations
Time series view. When bottom reference          and only is an occasional problem.
was set to ―none‖, the Boat Speed Time           2. Some users have reported problems with
series plot did not display the boat speed. If   printing color plots from WinRiver. The
the user sets the bottom reference to ―none‖     resulting plots were printed in gray scale
– WinRiver will display boat velocity data       even on color printers. For the present, the
based on bottom track, providing it is           software has been set to default to a color
available.                                       plot (as opposed to a grayscale plot). This
17. Fixed a problem with ASCII-out. If the       change seems to have fixed the problem for
bottom reference is set to ―none‖ some           color printers at present. Again, if you
parameters where still 0 (distance traveled,     observe more problems, please contact
distance made good, etc.).                       Kevin Oberg or Dave Mueller. In general,
18. Fixed ASCII out option.        When a        we suggest that users copy the plots of
user chooses to display velocity As              interest into a word-processing package,
Received From ADCP, the velocity now             such as Microsoft Word, and print the plots
written to the ASCII-Out file is the velocity    from that package. This procedure usually
data as collected by the ADCP. For               eliminates any problems in printing, and it
example, if a user collects data in beam         allows the user to adjust the size of the plots,
coordinates, the Ascii-Out file created now      etc.
will contain the radial velocities for each      3. The correction of the bug identified in
beam.                                            Attachment A, Bugs Fixed, number 9 could
19. Fixed problem in plots; changing             result in some minor changes in discharge
sections would not change tick marks             when transects are played back in version
properly.                                        10.03.

Appendix 1n. OSW 2003.04--Release of WinRiver Software version 10.05 for Computing
Streamflow from Acoustic Profiler Data—May 19, 2003
                                                    streamflow data using RDI ADCP‘s
The purpose of this memorandum is to                should upgrade to WinRiver 10.05.
announce the availability of WinRiver 10.05         The software is available to USGS
for collecting and processing data collected        personnel who own and use
with RD Instruments (RDI) acoustic                  ADCP‘s manufactured by RDI at
profilers (Broadband, Rio Grande,                   http://hydroacoustics.usgs.gov/softw
Workhorse, and others). The WinRiver                are/.
software was developed by RDI, in             2.    OSW strongly recommends that
cooperation with the USGS, as a part of a           users begin to use the file-locking
Cooperative Research and Development                feature immediately. Proper use of
Agreement (CRADA). The use of WinRiver              this feature will help insure that (a)
software by USGS offices was announced in           inadvertent changes are not made to
Office of Surface Water Technical                   the data after the streamflow record
Memorandums No. 2000.03 and 2002.03.                is finalized and (b) ADCP data files
                                                    are not archived with possible
RDI released version 10.04 of WinRiver to           inadvertent changes.
the public in late January 2003. However,     3.    Use of the new Discharge
while this release memo was in review, two          Measurement Wizard (DMW) is
some minor infrequently occurring bugs              mandatory starting immediately for
were identified. Therefore, a new version of        discharge measurements made in the
WinRiver, version 10.05, is now being               basic streamflow data collection
released.                                           program. Use of the wizard will
                                                    help standardize measurement
RDI has continued to update and improve             summaries and make reviewing
the WinRiver software. Various new                  measurements easier. The ultimate
features are included in WinRiver 10.05 and         goal is to import the measurement
known problems have been fixed since the            summary information into NWIS.
release of WinRiver                           4.    OSW strongly recommends that
10.03. Attachment A contains detailed               users always make use of the
        information about major                     Configuration Wizard (CW) rather
        enhancements in WinRiver                    than existing configuration files.
        10.05, including                            The Configuration Wizard was
         implementation of configuration file       described in Office of Surface
         locking,                                   Water Policy Memo 2002.03. Each
                                                    time a site is visited, the wizard
         addition of a discharge measurement
                                                    should be used in order to insure
         summary wizard,
                                                    that current site conditions are
         updates to the configuration wizard        reflected in the measurement
         for configuring RDI ADCP‘s, and            configuration. If any user
         addition of new velocity profile           commands are used to override
         extrapolation techniques.                  direct commands created by the
                                                    configuration wizard, users must
The following policies and guidance are             document the reason for their use in
offered regarding the use of WinRiver               the measurement notes.
10.05 with RDI ADCP‘s. (A more detailed       5.    With the implementation of new
explanation of items 2 – 5 are presented in         extrapolation techniques, OSW does
attachment A.)                                      not believe that there is any instance
                                                    where a user should set the bottom
1.       All USGS users who collect                 extrapolation method to Constant.

                                                    Attachment A (See attached file:
Lists of new features, changes to existing          sw2003_04AttachmentA.pdf)
features, and bugs fixed are provided in            Attachment B (See attached file:
Attachment B. For further information on            sw2003_04AttachmentB.pdf)
use of the WinRiver, please refer to the Help
menu and to the software release notes and          Distribution:    Data Chiefs Surface-Water
documentation. If you have any questions or                          Specialists     Office of
comments about the policies and guidance in                          Surface Water HAWG Cc:
this memo, please contact Kevin Oberg                                A, B, District Chiefs
(kaoberg@usgs.gov) or the OSW
Hydroacoustics Work Group
(hawg@simon.er.usgs.gov).                           In the following sections, italicized
                                                    text refers to menu options or
                                                    buttons in the WinRiver software.

                                                    Configuration File Locking

                                                    Configuration files for each transect can
                                                /   now be ―Locked‖ and ―UnLocked‘ in
                                                s   Playback mode by selecting Lock/Unlock
                                                i   Configuration File under the File menu,
                                                g   clicking the lock/unlock quick button on the
                                                e menu bar          , or by pressing Ctrl-L. If a
                                                d configuration file is locked, any changes
                                                / made to the configuration file while in
                                                  playback mode will not be saved unless the
                                                  file first is unlocked. This action prevents
                                                S accidental saving of changes made to
                                                t configuration files while ―experimenting‖
                                                e with different settings or while reviewing
                                                p discharge measurements. Locking also is
                                                h important because the new Discharge
                                                e Measurement Wizard (DMW) processes
                                                n transects in the background. Locking the file
                                                  ensures the configuration file is set up the
                                                F way you intended for each transect when
                                                . processed by the DMW. If a file is not
                                                  locked when processed by the DMW a ―U‖
                                                B is placed to the right of the corresponding
                                                l transect on the printout. Configuration files
                                                a should be locked for each transect after all
                                                n settings have been confirmed and prior to
                                                  running the DMW. A locked file signifies to
                                                a checkers and reviewers that the
                                                r configuration settings for these transects
                                                d have been verified as correct for processing.

                                                    Discharge Measurement Wizard

The DMW is a tool that allows the user to       File menu or by pressing Control-Q.
summarize the transects that constitute a       Afterwards, a dialog box similar to that
single discharge measurement. The DMW           shown in figure 1 will be displayed. The
lets you enter station information (station     dialog box shown in figure 1 already
number, station name, gage height, and          contains user input. The user only needs to
other information about the measurement)        complete the entries in the dialog box. The
and creates a summary of the                    diagnostic test, moving bed test, and comp
measurement that can be printed and/or          ass calibration test files can be selected
saved to a file.                                using the button to the right of the respective
The DMW can be run in Playback mode by
selecting Q Measurements Wizard from the

                    Figure 1.--Discharge Measurement Wizard dialog box
When data entry on this form is complete,       the DMW dialog box (fig. 1). An example
the user can select the rawdata files that      of file selection is shown in figure 2. All
comprise the measurement by clicking the        files to be used for the measurement must be
Select/Process Files button at the bottom of    selected at the same time. Multiple files

may be selected by holding down the Ctrl        key while clicking on the desired files.

        Figure 2.--File selection dialog box for the Discharge Measurement Wizard
Once the files are selected and processed,      measurement data files. The DMW printout
the DMW processes the files in the              can be trimmed and folded to standard
background. The results then can be             measurement note size (5x8 inches).
displayed on the screen and, subsequently,
printed by clicking the Print button from       The DMW summary includes user-entered
DMW dialog box. Finally, the results of the     data (shaded areas in figure 3) and values
DMW can be saved by clicking the Save As        computed from the selected transects. An
button. It is recommended that the DMW          example output from the DMW is shown
file be saved and archived with the other       in figure 3.

Figure 3.--Example output from Discharge Measurement Wizard

Configuration Wizard                             quality and with many fewer mistakes. The
                                                 CW is invoked in Acquire mode by
The configuration wizard (CW) is the tool        selecting Configuration Wizard under the
that should be used to set up an ADCP for        Settings menu or by pressing Shift-F6.
data collection. Since this feature became       OSW recommends that the CW be used
available in version 10.03, the number of        every time a site is visited, so that the user
user errors in configuring an ADCP has           can enter information that reflects the
been greatly reduced. Data collected when        current site conditions. An example of the
the CW has been used tends to be better          configuration wizard is shown below.

                                                mode is set to Auto, and the CW always
 Figure 4.--Configuration Wizard Dialog         selects bottom mode 5 by default. OSW
                   Box                          suggests that the Hydroacoustics Work
When the Run Wizard button is clicked, the      Group (HAWG) (hawg@simon.er.usgs.gov)
wizard verifies that the required fields have   be contacted for guidance prior to use of
been entered by the user and uses these         these modes. It also is important to
values to generate a configuration file for     remember that these modes are not available
the measurement. The appropriate direct         on every ADCP.
commands are specified, based on rules
supplied by the USGS to RD Instruments,
including depth cell size, number of depth
cells, ambiguity velocity, and water mode.
Any questionable configuration settings are
displayed in the Configuration Wizard
Warnings window. The CW also scales the
chart properties accordingly based upon the
entered values.

Support for new water and bottom modes
has been added to the CW. OSW currently
does not have guidance on the use of water
modes 11 and 12, or bottom mode 7;
therefore care should be exercised prior to
using these water modes. Water modes 11
and 12 never are chosen when the water

Velocity Profile Extrapolation                    estimated by linearly interpolating between
Techniques                                        the first depth cell with valid data
                                                  immediately above and the first depth cell
     As a result of suggestions by the            with valid data immediately below the depth
USGS, RDI has implemented two new                 cell with missing data. In this case, the
extrapolation methods in WinRiver 10.05           measured discharge (the discharge for that
based on algorithms the USGS proposed.            part of the water column directly measured
                                                  using the ADCP and NOT including the top,
3-point Slope Method                              bottom, left and right discharge estimates)
                                                  reported by WinRiver will be different from
      The 3-point slope method uses the           that reported if either the Constant or power
velocity cross-product for the top 3 bins to      curve methods are used.
estimate a slope. This slope then is applied
from the first depth cell below the water              Although the WinRiver software and
surface having valid velocity data to the         the two methods described above have been
surface. If there are less than 6 depth cells     tested thoroughly prior to the release of
with valid data in the profile, a constant        10.05, the methods are new and OSW
value or zero slope is assumed. It is             suggests that users exercise caution when
believed that this method may prove useful        applying them. Please contact either Kevin
in situations where the ADCP measurements         Oberg (kaoberg@usgs.gov) or David
indicate that there is bidirectional flow or      Mueller (dmueller@usgs.gov) if you have
wind induced shear. However, this method          questions about the application of the
should be used with caution, especially in        software and/or methods. Users never
situations where the slope of the velocity        should choose the Constant extrapolation
cross-product is large in the top 3 depth         method for the bottom.
                                                      Attachment B – Changes to
No-Slip Method                                    WinRiver since release of version 10.03
                                                  and Known Problems with version 10.05
       The No-Slip method is used for
extrapolation near the bed. A power curve         Features Added
is fit to the velocity cross-product data for     1. Added the Discharge Measurement
depth cells having valid data in the lower        Wizard
20% of the water column and assuming the          2. Add configuration file locking.
power curve is zero at the bed. In the            3. Added 3-point slope and no-slip
absence of valid velocity data in depth cells     extrapolation methods
located in the lower 20% of the water             4. Add new plot windows
column, the velocity cross-product for the        Combo Shiptrack Plot. Plots both
last valid depth cell is used and the power       bottom track and GGA reference (DGPS)
curve is assume d to be zero at the bed.          shiptrack on one plot when available.
When electing to use the no-slip method, the      Total Discharge Time Series Plot. Plots the
user is specifying that a power curve does        total discharge of each transect in the
not accurately represent the entire profile.      discharge tabular history and time.
                                                  5. ASCII out Batch Processing
      Normally, the power curve method is         Multiple files can be selected for ASCII out
used to estimate discharges for depth cells       batch processing at one time. After selecting
that (a) have invalid velocity data and (b) are   various files, the program loads, processes,
NOT located such that they are either the         and outputs ASCII data to files (with
first (near surface) or last (near bed) depth     automatically generated names *t.000). Any
cell in the profile. However, if the No-Slip      existing file with the default ASCII name
method is selected, discharges for depth          will be overwritten automatically without
cells with invalid or missing data are            any warning. Clicking the Cancel button on

the message box that appears while              valid bin, n = the number of valid bins, N =
processing can stop the conversion.             the number of ensembles, and Dt = total
6. Default direct commands now include          time of all bins (both valid and invalid) in
&E000000011                                     the average.
7. GPS update rate added to the GPS             4. Stick Ship track Stick Magnitude now is
Tabular View.                                   scaled to the chart properties maximum
8. In Acquire mode configuration comments       velocity magnitude.
are open now for edit until recording has       5. Changed BX to be twice the old length in
been turned off.                                the configuration wizard, to correct
9. Default user options setting has been        inconsistency with the way the firmware
changed to NOT start pinging immediately        handles BX and &R.
upon entering acquire mode.                     6. Changed the way ensembles are flushed
10. Added menu item to execute an external      to the hard drive. File buffers are flushed
program for running a self-test, and for        every ensemble instead of every 20
executing an external program for               ensembles.
calibrating and reading a pressure sensor.
11. Minor serial communications changes.        Bugs Fixed
Ensemble size limited to 10 kilobytes
12. A Date/Time stamp corresponding to the      1. Fixed the problem with PC clock time in
time when a transect was started now can be     navigation file in the $RDENS line
added automatically to the file name prefix.    2. Fixed problem with number of pings per
This option is enabled with a checkbox in       ensemble in averaged data (ASCII-out).
the configuration settings under the            The number would stay constant during
recording tab.                                  averaging.
13. Added capability to edit comment lines      3. Changed software break from "===" to
during data collection. If this option is       "======". Users had problems in stopping
checked each transect will have a unique        pinging when using modems.
filename prefix. This is not recommended        4. Fixed problem with computer not
for discharge measurements                      responding at the end of long transects.
14. Added depth screening option. Filters       5. Fixed auto-detect function that still was
out a beam depth if the depth is greater than   sending a hardware break even when a soft
1.75X any other beam. This option is            break was selected.
disabled by default and should only be          6. Fixed bug in ASCII Out when "as
enabled to remove obvious depth errors.         Received from ADCP" was selected.
                                                7. Increased DBT section size by 10 bytes.
Changes made to existing features               In the previous versions, 38 bytes were
                                                reserved and a customer had an echo
1. Added functionality to the Configuration     sounder that sent a longer string.
Wizard.                                         8. Fixed problem with incorrect scaling of
2. Modified Subsection behavior. When a         VTG velocity.
user changes the subsectioning if the current   9. Fixed auto-detect function. The program
ensemble is equal to the last ensemble and      would crash on some machines.
the new last ensemble is greater than the       10. Fixed the problem with opening ports >
current ensemble, WinRiver assumes that         COM9.
they want to playback the file to the end       11. Fixed a typo on Expert Menu.
(new last ensemble).                            12. Fixed a bug that happened when a user
3. Discharge profile now plots the bottom       opened a discharge measurement wizard file
and top fit used for both the top and bottom    that had GPS as the reference. The values
extrapolation methods. The measured             displayed in the DMW summary were
discharge displayed on this plot is computed    incorrect.
as Q        q / dt n Dt N where q = the         13. Changed the method for detecting
discharge of a valid bin, dt = time of the      available COM ports. Some COM ports

were not always correctly detected by            load a different configuration file?‖ If the
WinRiver.                                        user selects ―No‖, the program can crash if a
14. Fixed a problem in properly handling the     configuration file has never been loaded in
decoding of GPS data when no data were           Acquire mode.
available in the GGA string (ie., no satellite
fix was available).                                   This problem can be avoided by first
                                                 running WinRiver in Acquire mode, either
Known Problems                                   by double-clicking the corresponding
                                                 desktop icon or by going to the start menu
1. After installing WinRiver 10.05, it is        and selecting "Programs—RD
possible for the program to crash when           Instruments—WinRiver (Acquire)" menu.
switching from Playback Mode to Acquire          After that, the user should load an existing
Mode (Ctrl-M). A description of the              configuration file or create a new one. After
problem follows. When switching from             doing so, and exiting WinRiver, this
Playback Mode to Acquire Mode, the user is       problem should not occur again.
prompted as follows: ―Would you like to

Appendix 1o. OSW 2004.04--Policy on the use of the FlowTracker for discharge measurements.--June
2, 2004

     The purpose of this memorandum is to      (http://hydroacoustics.usgs.gov/reports/SEM
provide information and guidance regarding     paper.pdf).
the use of SonTek/YSI’s FlowTracker for
making wading discharge measurements.                In November 2002, 31 FlowTrackers
More than 100 FlowTrackers have been           were tested in a tow-tank at the USGS
purchased for use by the U.S. Geological       Hydraulics Laboratory at Stennis Space
Survey (USGS) as of October 2003.              Center, Mississippi to ascertain the
Although the Office of Surface Water           performance of a large batch of instruments.
(OSW) continues to conduct laboratory tests    FlowTrackers were tested at eight tow-cart
of these instruments, we can state that the    speeds, ranging from 0.10 to 2.99 feet per
FlowTracker performs well in many stream       second (ft/s). Unfortunately, data analysis
environments. Guidance on the general use      indicated various problems related to the test
of FlowTrackers is important, especially for   procedures. These problems included
their use in low-backscatter environments      acoustic interference caused by operating
and with boundaries, such as rocks, logs, or   instruments simultaneously, residual
large stream bedforms.                         currents in the tow-tank, and possible test-
                                               equipment-induced noise. Testing
    Background                                 hydroacoustic instruments in a tow-tank is a
                                               difficult process and the USGS and other
     The Water Resources Discipline            organizations still are experimenting on how
(WRD) Instrumentation Committee (ICOM)         to properly conduct these tests. A revised
funded a project in the Indiana District,      tow-tank test plan
beginning in October 2000, to guide the        (http://hydroacoustics.usgs.gov/downloads/fl
adaptation of hydroacoustic current meters     owtracker.field.test.pdf) was drafted based
for discharge measurements in shallow,         on the November 2002 test experience. In
wadeable streams. SonTek/YSI designed          March 2003, new tests were conducted in
the FlowTracker to be used for making          the tow-tank based on the revised test plan.
discharge measurements in wadeable             Additional tests of the FlowTracker also
streams using a standard USGS wading rod.      were conducted in a jet tank at the
During the last 4 years, OSW worked with       Hydraulics Laboratory. Data from both these
SonTek/YSI to provide guidance on              tests currently are being analyzed.
standard USGS discharge-measurement
methods and algorithms. WRD and                     Acoustic Doppler Velocimeters (ADV),
SonTek/YSI personnel also conducted a          of which the FlowTracker is a special
number of field and laboratory tests of the    adaptation, have been tested and shown to
FlowTracker.                                   be an accurate instrument. ADV‘s
                                               commonly are used in laboratory and field
    Tow-tank tests of the FlowTracker          investigations in hydraulics. A list of
                                               selected papers published in peer-reviewed
     In April 2002, two FlowTrackers were      journals that relate to testing and evaluation
tested in a tow-tank at the USGS Hydraulics    of ADV‘s is provided in the ―Selected
Laboratory at Stennis Space Center,            References to ADV Evaluations‖ section at
Mississippi. FlowTrackers were tested at       the back of this memorandum. The results
various tow-cart speeds in order to            of these and other papers provide confidence
determine their accuracy. These                in the underlying technology that is used in
FlowTrackers met Price AA and the              the FlowTracker for making velocity
manufacturer‘s specified accuracy limits for   measurements.
most tow-tank runs

     FlowTracker results in low backscatter           In July 2003, SonTek/YSI made
environments                                    hardware upgrade available for
                                                FlowTrackers that involves a new high-
      Field tests at 29 sites in 2001 and 5     sensitivity receiver component. The
sites in 2002-03 have shown that the            manufacturer states that this upgrade can
discharge-measurement algorithms used by        improve the SNR by 5 to 10 dB, which may
the FlowTracker are correct. For the 2002-      dramatically improve the capability to work
03 field tests, FlowTracker discharge           in low backscatter environments. OSW has
measurements were within 5 percent of           not yet tested FlowTrackers equipped with
discharges measured with Price AA or            this upgrade, but has plans for testing in the
pygmy meters, with mean velocities ranging      next 6-12 months. The hardware upgrade is
from 0.48 to 1.9 feet per second (ft/s), mean   available from SonTek/YSI and is standard
depths ranging from 0.7 to 2.1 ft, and          in all FlowTrackers shipped since July 15,
measured discharges ranging from 12 to 120      2003.
cubic feet per second (ft3/s). Whereas
FlowTracker measurements compared                   FlowTracker results in streams with
favorably with mechanical current meter         potential boundary effects
measurements, all measurements were made
in streams with few boundary effects, and in          Recently reviewed FlowTracker
streams that carried enough suspended           discharge measurements indicate numerous
backscatter material to produce adequate        boundary effect problems. A boundary
FlowTracker signal-to-noise ratios (SNR).       effect occurs when the sampling volume for
Data from FlowTracker measurements made         the FlowTracker includes some solid,
in the last 6-9 months have indicated           stationary boundary such as a cobble or
potential data-quality problems in streams      boulder in the stream. These problems
with low suspended backscattering material.     generally are more common in streams with
                                                rough beds and at shallow depths. The
     SonTek/YSI indicates that the SNR          volume of water used by the FlowTracker to
should be greater than 10 decibels (dB) for     make velocity measurements (called the
optimal data quality (SonTek FlowTracker        sample volume) is approximately 0.25 cubic
Operation Manual, Section 1.4.1), but           centimeters in size and is located 10
FlowTrackers may collect reliable data          centimeters (about 4 inches) away from the
when the SNR is lower. Field and laboratory     center transmitting transducer on the
data analyses have indicated that velocity      FlowTracker (figure 1). If the FlowTracker
data are unreliable when the SNR is below 4     sample volume includes or is near a solid
dB.                                             boundary, the velocity data will be corrupted
                                                and biased low. The low bias is caused by
     In June 2003, SonTek/YSI released          the FlowTracker measuring a zero velocity
firmware version 2.4. It is recommended         from the solid, stationary boundary for at
that all FlowTrackers be upgraded to            least some part of the sample volume.
firmware version 2.4 by contacting
SonTek/YSI. This firmware version                   Guidelines for use of FlowTrackers in
includes changes that may increase data         making discharge measurements
quality in some low backscatter
environments. Information on obtaining the           FlowTracker users should take the
firmware upgrade can be obtained from           following actions when making discharge
http://www.sontek.com/e/0307a/ftupgrade.ht      measurements:
ml or by contacting SonTek/YSI by email at
support@sontek.com or by phone at (858)              1. Under appropriate conditions and use
546-8327.                                       as described below, the FlowTracker can be
                                                used in place of the mechanical Pygmy and
                                                Price AA meters for wading discharge

measurements. The same procedures and             readings that are less than 4 dB. The
policies for use of the mechanical meters         FlowTracker will display a warning at the
apply to the use of the FlowTracker; these        end of a velocity measurement if the SNR
include:                                          for any beam is less than 4 dB. If the SNR is
                                                  below 4 dB, try moving to a different
     • Measurement site selection -- the          measurement section where backscatter may
measurement section should be within a            be higher. If a section with an acceptable
straight reach, where streamlines are             SNR cannot be located, the FlowTracker
parallel. The streambed should be relatively      should not be used to make a discharge
uniform and free of numerous boulders,            measurement.
debris, and heavy aquatic growth. The flow
should be relatively uniform and free of                4. Avoid measurement sections with
eddies, slack water, and excessive                abrupt changes in bed topography. These
turbulence.                                       changes can result because of such things as
                                                  large rocks or cobbles in the measuring
     • Velocity sample time – under normal        section. Abrupt changes in bed topography
measurement conditions, each point velocity       may cause boundary effects leading to
measurement should be sampled for a               inaccurate velocity measurements. During
minimum of 40 seconds. Under extreme              the measurement, velocities should be
flow conditions, such as rapidly changing         monitored for unrealistically low velocities,
stage, a shorter sample time may be used to       and also for unusually large SNR values (a
lessen the time needed to complete the            solid boundary should cause an increase in
discharge measurement.                            the SNR). Be aware of the location of the
                                                  FlowTracker sample volume when
     • Location of velocity observations in       measuring. The sample volume typically is
each vertical – at depths below 1.5 feet, the     10 centimeters (about 4 inches) from the
0.6-depth method should be used; at depths        center transmitting transducer (figure 1).
between 1.5 and 2.5 feet when a non-              Avoid placing the sample volume within 2
logarithmic velocity distribution may be          inches from any solid boundary. Although
present and the 0.8 depth sample location         this recommended placement does not mean
would be more than 2 inches from any              that the FlowTracker cannot be used closer
boundary, the two-point method should be          to boundaries, nevertheless, extra care
used; and at depths greater than 2.5 feet, the    should be taken in those situations.
two-point method should be used. If a non-
logarithmic velocity profile is discovered             5. Pay close attention to the flow angle
when using the two-point method, the three-       reported by the FlowTracker. The wading
point method should be used.                      rod (with FlowTracker attached) always
                                                  should be held perpendicular to the tagline,
     2. Prior to each field trip, or about once   so that the pulse generated by the transmitter
per week, perform a FlowTracker                   (see figure 1) is parallel to the tagline.
ADVCheck (FlowTracker Operation                   Ideally, the tagline should be set up in the
Manual Section 6.5.4). The ADVCheck               cross section to be measured such that flow
should be logged to a file and archived. The      is perpendicular to the tagline.
name of the ADV check file should be
written on the measurement note sheet.                 Flow angle, as calculated by the
Perform FlowTracker field diagnostic              FlowTracker, is defined as the direction of
procedures (FlowTracker Operation Manual          flow relative to the x-direction of flow, so
Section 3.3.2) prior to starting every            that

     3. Monitor the FlowTracker SNR
readings during the measurement for SNR                where, Vy is the velocity in the y-
                                                  direction (parallel to the tagline) and Vx is

the velocity in the x-direction (perpendicular        • .DIS file average subsection velocities
to the tagline) used to calculate discharge.     or SNR readings appear to be inconsistent
                                                 across the measurement section or
      The flow angle calculated by the           unrealistic for site conditions;
FlowTracker can result from two sources:
(1) the flow is not perpendicular to the             • SNR readings are observed to fall
tagline, and (2) the flow is perpendicular to    below 4 dB any time during a discharge
the tagline but the wading rod is not being      measurement;
held correctly relative to the tagline, as
described above. Regarding (1), some small           • The .DIS file shows unrealistic
angles and variation in the flow angle at a      subsection velocity spikes;
site is not unusual. However, if large
fluctuations of flow angles are reported,            • The .DIS file shows subsection
measurements should be made at another           boundary variable values of 3 (poor);
section with more uniform flow. Regarding
(2), holding the FlowTracker such that it is           • The mean standard error of velocity
skewed at any angle relative to the tagline      for the measurement shown in a DIS file
will result in a measurement of velocity that    exceeds 5 percent of the mean velocity for
is biased low. Small angles do not result in     the measurement; or,
significant biases, but because of these
biases, users should be careful to minimize           • There is any reason to suspect data-
this error. If the FlowTracker is held such      quality problems (such as the presence of
that it is skewed at an angle of                 irregular bedforms or other solid boundaries
approximately 8 degrees from the tagline,        that could interfere with the sample
the measured velocity may be in error by as      volume).
much as 1% (assuming that flow is
perpendicular to the tagline).                         The FlowTracker software contains a
                                                 velocity spike filter (number of spikes
     Large variations in flow angles may be      filtered is displayed in the .DIS file);
indicative of poor or inconsistent alignment     however, the spike filter may not remove all
of the wading rod or poor site selection for     bad or questionable velocity data from the
the measurement.                                 subsection average. Furthermore, boundary
                                                 variables of 1 (best) or 2 (good) do not
      6. Each FlowTracker measurement is         necessarily mean that boundaries did not
stored in a binary file (.WAD extension) that    cause velocity biases in the measurement
a user can download to the computer and,         data. Users should refer to the FlowTracker
using FlowTracker software, extract four         Operation Manual Section 1.4 and become
files containing the measurement data.           familiar with the detailed descriptions of
These files include a summary of the             SNR‘s, standard error of velocity, boundary
measurement (.DIS) with average subsection       variables, and velocity spike filtering.
velocities and SNR readings, and a ―raw‖
data file (.DAT) that lists 1-second                  OSW is making available a program
velocities and SNR readings. The effect of       called DatView, written by Mike Rehmel of
unrealistic velocities may not be apparent in    the Indiana District, to facilitate the rapid
the average subsection velocities in the .DIS    review of FlowTracker data contained in the
file. Thus, users should review the 1-second     .DAT file. At present, this program is
velocity and SNR data in the .DAT file if        considered Beta software – but appears to be
any of the following results are observed:       stable. The program allows users to load
                                                 FlowTracker .DAT files and examine plots
     • Average subsection SNR readings in        of measurement velocities and SNRs. An
the .DIS files are less than 10;                 example of a plot generated using DatView
                                                 for a measurement with low SNRs and

associated velocity spikes is attached (figure   (http://hydroacoustics.usgs.gov/), and
2). DatView can be obtained at                   through the Acoustics mailing list.
http://hydroacoustics.usgs.gov/download/Da            Questions concerning the information
tView.exe.                                       presented in this memorandum should be
                                                 directed to Kevin Oberg
     Low SNR readings and velocity spikes        (kaoberg@usgs.gov, 217-344-0037 ext.
can degrade the FlowTracker measurement          3004) or Mike Rehmel
quality. For this reason, users should           (msrehmel@usgs.gov, 317-290-3333 ext.
consider downgrading the quality of              158). Specific questions concerning the
measurements made in low-backscatter             DatView program should be directed to
environments.                                    Mike Rehmel.

     Summary                                         Stephen F. Blanchard
                                                     Chief, Office of Surface Water
     Test data collected to date indicate that
FlowTrackers are accurate instruments for            Selected References to ADV
making wading discharge measurements in          Evaluations
many stream environments. If a
FlowTracker is used outside of its designed           Kraus, N. C., Lohrmann A., and
operating environment, data can be               Cabrera R., 1994, New acoustic meter for
compromised resulting in inaccurate              measuring 3D laboratory flows: Journal of
measurements. Until OSW completes field          Hydraulic Engineering, v. 120, p. 406-412.
and laboratory testing, users of                      Snyder, W.H., and Castro, I. P., 1999.
FlowTrackers should make comparison              Acoustic Doppler Velocimeter Evaluation in
measurements with Price AA current meters        Stratified Towing Tank: Journal of
in various stream environments per OSW           Hydraulic Engineering, v. 125, no. 6, p. 595-
memorandum regarding Acoustic Doppler            603.
Velocimeter, dated October 4, 2001. A test            Song, T., and Graf, W. H., 1996.
plan for FlowTracker comparison                  Velocity and turbulence distribution in
measurements can be obtained at                  unsteady open-channel flows: Journal of
http://hydroacoustics.usgs.gov/downloads/F       Hydraulic Engineering, v. 122, no. 3, p. 141-
lowTracker.field.test.pdf.                       154.
                                                      Voulgaris, G., and Trowbridge, J. H.,
     OSW requests that any FlowTracker           1998, Evaluation of the Acoustic Doppler
users share results of their experiences and     Velocimeter (ADV) for Turbulence
other information regarding FlowTracker          Measurements: Journal of Atmospheric and
use. Please send information to Mike             Oceanic Technology, v. 15, no. 1, p. 272-
Rehmel, Indiana District,                        289.
(msrehmel@usgs.gov), 317-290-3333 ext.
158 or to the USGS Hydroacoustics Work
Group (hawg@simon.er.usgs.gov). OSW is
interested in receiving information regarding
measurement comparisons, problems
identified with the instrument or software,
possible hardware or software
enhancements, and other important issues to
users. Field and laboratory tests of these
instruments are continuing and test results
will be communicated in future
memorandums, by the OSW Hydroacoustics
Web pages

(a) Ideal FlowTracker measurement                       (b) FlowTracker measurement
conditions                                        illustrating conditions with potential for
                                                  interference from a solid boundary

Figure 1.--Schematic showing FlowTracker (a) sampling volume and (b) proximity to a fixed boundary in
the stream

Figure 2.--Example Plot of FlowTracker .DAT File Using DatView

Appendix 1p. OSW 96.05-- Policy Concerning Accuracy of Stage Data.—February 5, 1996

      The purpose of this memorandum is to reaffirm and clarify the U.S. Geological Survey (USGS) policy
on accuracy goals for collection of surface-water stage data, which was previously stated in Office of
Surface Water (OSW) Technical Memorandum No. 93.07. In summary, the previous memorandum states
that stage data are to be collected with sufficient accuracy to support computation of discharge from a stage-
discharge relation and that procedures and equipment used are to be capable of sensing and recording stage
with an uncertainly of no more than 0.01 ft or 0.20 percent of indicated reading, whichever is larger.

      This accuracy goal addresses the intended uses of the stage data collected by the USGS and applies to
the final result of the stage-data collection process. The goal expresses the combined accuracy of the total
assemblage of instruments, equipment, and procedures to be used in any USGS stage-data collection system.
The goal is not intended as a specification for accuracy of any single component of the measurement system
and is not intended as a specification for procurement of any particular kind of instrumentation or

     The accuracy statement refers to the complete stage-measuring system, which includes all the
instrumentation and equipment used at a site to measure stage and record its value. In addition to the stage-
sensing component, a number of other components of instrumentation and equipment are needed for this
purpose. These components include:

   o The means by which the river stage is brought into communication with the stage-sensing
component, such as a stilling well or bubbler system

     o The means by which the response of the sensing component is converted into a form suitable for
recording, such as

conversion of mechanical movement or electrical signal

    o The means by which the data are recorded and uploaded, such as paper chart, punched tape, or data

    o The means by which the recorded and uploaded values are verified and calibrated against direct field
observations of river stages, such as by comparison with wire-weight, electric-tape, or staff-gage readings

     All of these components contribute incremental errors to the overall error or uncertainty in stage data.

      In designing the installation of instrumentation and equipment for stage-data collection and recording at
any particular site, the accuracy characteristics of all components of the system must be considered in
combination. That is, the accuracy specified for any component of the system should be considered in
relation to the interconnections among the system components, the accuracies of the other components, and
the overall accuracy goal. The accuracy requirement for any single component generally will be more
stringent than the requirement for the system as a whole.

     For procurement of non-submersible pressure sensors for use in surface-water stage measurement, the
Office of Surface Water and the Hydrologic Instrumentation Facility jointly considered the errors inherent in
the various components of gas-purge systems and agreed on the accuracy that would be required for the
pressure-sensor component to enable the total stage-measurement system to meet the overall accuracy goal.
In addition to pressure-sensor calibration errors, the errors considered include (but are not limited to) errors
in reading reference gages and in setting pressure sensors in the field, movement of reference gages and gas-

purge system orifices, obstruction of the orifice by sediment or debris, and exposure of the orifice to
dynamic (velocity-head) pressure effects. Qualitative assessment of error magnitudes and of achievable
accuracies of the various system components led to an agreement between the Office of Surface Water and
the Hydrologic Instrumentation Facility to adopt the larger of 0.01 ft or 0.10 percent of reading as the
accuracy standard for the procurement of non-submersible pressure-sensor instruments.

Thomas Yorke
Chief, Office of Surface Water

Appendix 1q. OSW 90.10-- Frequency of Levels at Streamflow Gaging Stations.—February 28, 1990

      The present recommendation for the               The OSW recommends that levels at
frequency of levels at streamflow gaging          regular gaging stations be run at least every
stations is that they be run at least every 3     5 years if stability is shown to exist. It is
years (Kennedy, 1988, p. 20). There are           also recommended that levels at crest-stage
many stations that are located in stable areas    gages be run at least every 3 years.
for which levels could be run less                Additional levels may be needed if a major
frequently. This memorandum discusses             flood, or other event, occurs that could
guidelines for when less frequent levels may      disturb some part of the gaging station.
be run.
                                                        As a matter of practice, it is also
      The guidelines for levels frequency         recommended that when levels are run, the
given by Kennedy (1988, p. 20) are to be          station description be reviewed and updated.
followed unless it can be shown that the          This is not meant to preclude updates of the
station is stable. Stability involves the well    station description at other times as needed.
and shelter, staff gages, wire-weight gages,
reference points, and reference marks. If any
of these items is unstable, then Kennedy's             If a variance in frequency from that
recommendations are to be followed.               proposed by Kennedy (1988) is needed, a
                                                  plan for frequency of levels is to be prepared
     If after at least 5 sets of levels over a    by the District and kept in the District files.
period of at least 10 years, the gaging station   The District policy for frequency of levels
is shown to be stable, a lesser frequency of      should be made a part of the District's
levels may be adopted. Level summary              quality-assurance plan.
sheets should be prepared for all gages to
provide for easy determination of gage                 REFERENCE
stability. A recommended summary sheet
format is shown in                                     Kennedy, Edward J., 1988, Levels at
                                                  streamflow gaging stations: U.S. Geological
      Figure 18 of the report by Kennedy          Survey open-file report 88-710, 42 p.
(1988) and a form for this purpose that can
be copied for District use is located on the      Charles W. Boning,
last page of Kennedy's report.                    Chief Office of Surface Water

Appendix 1r. WRD 77.83--Retention of Original Water Records--March 30. 1977

Appendix 1s. WRD 92.59--Policy for Management and Retention of Hydrologic Data of the U.S.
Geological Survey
                                             and preservation of data. OFR 92-56 was
     The purpose of this memorandum is to    widely circulated in WRD for comment
announce the adoption of the                 prior to publication. Following the
recommendations contained in Open-File       committee's response to the comments, the
Report (OFR) 92-56 "Policy
Recommendations for Management and                SPG recommended that the report be
Retention of Hydrologic Data of the U.S.     published as an OFR.
Geological Survey" as Water Resources
Division (WRD) policy. A copy of this             OFR 92-56 is not a manual; it deals
report is attached.                          with policy matters. Provisions for
                                             implementing some of the policies will be
     The report is organized into five       built into NWIS-II. Instructions for
sections with one section for each of the    implementation will either be contained
following issues:                            within the documentation for NWIS-II, be
                                             issued by the Assistant Chief Hydrologist
1. What are original data?                   for Program Coordination and Technical
2. What data should be placed in archives?   Support (ACH/PC&TS) for aspects of data
3. What data should be maintained on line in archiving, or be received from other sources.
the National Water Information System II
(NWIS-II)?                                   New Provisions
4. What data, besides that collected by
WRD, should be stored in NWIS-II?                 The recommendations of the
5. Who should have access to the data stored committee, now WRD policy, generally
in NWIS-II?                                  follow existing WRD policy or custom.
                                             There are, however, some areas where
     The recommendations in each section     significant new policies are established.
now describe WRD policy on the issue.        They are:

Background                                     Issue 1. What are original data?
                                               * The term "original data" is given a broader
      The Strategic Planning Group (SPG)       definition (than that usually accepted in the
composed of WRD senior managers                past) to include data received from
engaged in planning and directing the design   laboratories and outside sources.
and development of NWIS-II, established        * Guidance is provided as to what
the Committee on Hydrologic Data Policy.       constitutes original data for legal purposes.
Members of the committee were chosen to
represent a wide range of career experience     Issue 2. What data should be placed in
and technical expertise within WRD. The        archives?
SPG charged the committee to consider the      * An updated list of the kinds of data that
five issues above, which are critical to the   should be placed in archives is included in
planning and design of NWIS-II.                the report.
                                               * The responsibility for coordinating the
      As well as being important to NWIS-II,   archiving of data is assigned to the
the first two issues are fundamental to the    ACH/PC&TS.
management and retention of hydrologic
data in WRD. The resulting                         Issue 3. What data should be
recommendations result from questions that     maintained on line in NWIS-II?
are frequently posed by those in the field     * Tables give a schedule of when data
charged with the collection, management,       should move in NWIS-II from areas of high

accessibility (on line) to areas of less        Disposition of hydrologic data is described
accessibility (eventually off line)             in the document "Water Resources
* Data, once approved and moved from
working files, will be archived in NWIS-II           Division Mission-Specific Records
and receive the protection necessary for that   Disposition Schedule, October 1990." The
status.                                         policies established by this memorandum
* Once NWIS-II is functional, paper copies      are intended to be consistent with this
will no longer have to be made for archiving    schedule.
hydrologic data that are in electronic form.
                                                Superseded Documents WRD Memorandum
      Issue 4. What data, besides that          No. 77.83 is superseded.
collected by WRD, should be stored in
NWIS-II?                                        The provisions in WRD Memorandum No.
* The policy that all WRD data will be          87.85 will be superseded when NWIS-II is
stored in NWIS is expanded to include data      operational.
from outside sources that are used in support
of WRD published conclusions and are not        WRD Memorandum No. 86.28 is
archived or published elsewhere.                superseded.
* Placing the results of hydrologic model
simulations into NWIS-II is restricted to       Office of Surface Water Technical
those models that are approved specifically     Memorandum No. 78.05 is superseded but
for this purpose by the discipline offices of   will be updated to conform with OFR 92-56.
PC&TS. (The only model known to
presently have this status is BRANCH.)          Philip Cohen
                                                Chief Hydrologist
     Issue 5. Who should have access to the
data stored in NWIS-II?
* District offices are allowed to give access
to the local approved data base to
cooperators and others at their discretion.
Access to unapproved data should be
granted only to cooperators through a
Memorandum of Agreement that spells out
terms and conditions of access. Access by
others or to national retrievals, however,
should be arranged through the facilities of
the National Water Data Exchange.


     OFR 92-56 was prepared with
consideration of the provisions of OFR 91-
525 "System Requirements Specification for
the NWIS-II." The policies established by
this memorandum are intended to be
completely compatible with the provisions
of OFR 91-525.

     The Survey Manual and the Handbook
for Managing USGS Records (432-1-H)
prescribe how records shall be managed.

Appendix 1t. WRD 95.19--Policy for Making Provisional Water-Resource Data Available on the
Internet--March 10, 1995

     This memorandum establishes policy to       the Interior seal may also be displayed. If
prevent, insofar as possible, the misuse by      the data are provisional, the disclaimer
unwary users of the data made available on       "provisional data, subject to revision" or
the Internet--for example, the placing of        similar wording must also be prominently
greater-than-warranted confidence in the         displayed.
accuracy of provisional data--and to ensure
the data are identified as having been                It is required that provisional data be
provided by the U.S. Geological Survey.          accompanied by the following full
      Several districts, other Water Resources
Division units, and at least one cooperating     WARNING--PROVISIONAL DATA,
agency have been making streamflow data--        SUBJECT TO REVISION
stage or discharge--available on the Internet.
In some cases these data have been limited             Some data collected in the last 18
to final published data; in other cases          months--including stream discharge, water
provisional data are made available,             levels, and data from water-quality
including data received directly by              monitors--are preliminary and have not
telemetry. In the near future, water-quality     received final approval. Data relayed by
and ground-water data will also be               satellite or other telemetry have received
disseminated via the Internet.                   little or no review. Inaccuracies in the data
                                                 may be present because of instrument
     The practice of making our data             malfunctions or physical changes at the
available on the Internet is encouraged. We      measurement site. Subsequent review may
need, however, to exercise caution by            result in significant revisions to the data.
making clear to the user the potential errors
in provisional data. The following are new            Quality-control data are included, when
division policies regarding such release.        available, to aid data users in estimating bias
                                                 and precision of the environmental data.
      The only water-quality data that should    However, the quality-control data are also
be released as provisional are data from         provisional and may be revised. (Use this
water-quality monitors. All data from            paragraph when appropriate for water-
analytical laboratories are to be thoroughly     quality data.)
reviewed by the project chief and/or District
Water-Quality Specialist prior to release to          Information concerning the accuracy
the public. If quality-control data are          and appropriate uses of these data or
associated with environmental samples, they      concerning other hydrologic data may be
must be included with the environmental          obtained from (title or name of data chief or
data.                                            responsible person) of the U.S. Geological
                                                 Survey at (address), telephone (area code
     All tables, screens, and graphs must        and number), or Internet address
show prominently the name of the bureau          (userid@wrdmail.er.usgs.gov).
"U.S. Geological Survey." It is not
sufficient that the Survey seal contains the          The disclaimer should be linked by
bureau name, because Internet users with         hypertext, having the wording
text-only browsers will not be able to see the   "IMPORTANT WARNING!‖ from a screen
seal on the screen. The U.S. Department of       preceding viewing or retrieving the data. A

template, containing the basic disclaimer
and space for special provisions, may be
obtained at:

     Organizational units or individuals
making data available on the Internet are
responsible for the timely update of
provisional data, leading to more accurate
provisional data or to final approved data.
The disclaimer does not alleviate this basic

     The Water Resources Division strongly
supports the dissemination of data through
the Internet. Taking measures as described
above will allow us to do so responsibly.

Robert M. Hirsch
Chief Hydrologist

Appendix 1u. WRD 97.17--Disseminating Real-time Streamflow Data through the World Wide Web--
April 11, 1997

     WRD Memorandum No. 95.19                     existing configuration management files will
established policy for making provisional         not be over written by the install program
water-resources data available on the             and changes to old configuration files are
Internet and the World Wide Web (WWW).            not required to use rt_www.
Following this policy, many districts have
begun to serve real-time streamflow data on            The new rt_www system has features
the WWW. As a result, public interest in and      for displaying real-time streamflow data
use of our data have increased and many           within the context of historical data. This
long-time cooperators have begun to use our       includes the capability of displaying
data in new and innovative ways.                  floodstage or other stage or discharge
                                                  thresholds on data graphs. The median flow
     In an effort to facilitate standardization   for each day of the year can also be
of data display formats and to provide a          displayed. Districts should include these or
common software base from which future            other reference values in district
software expansions can be developed, the         implementations of rt_www or other real-
Office of Surface Water and the Office of         time data systems.
Water Information have worked with the
Montana District to develop improved real-        Quality assurance of real-time data
time data software for the WWW. The
purpose of this memorandum is to announce               While posting real-time data
the release of a new version of this software,    complicates the data quality-assurance and
rt_www rev 1.0, and to establish guidance         review process, the U.S. Geological Survey
for use of the software and for quality           remains committed to quality assurance of
assurance of real-time streamflow data.           all of its data products including real-time
                                                  streamflow data. Districts must ensure that
Software for real-time data                       real-time data are subjected to a frequent
                                                  and ongoing process of screening and
     The rt_www software replaces all             review. On normal workdays, screening
versions of the rts_www software previously       should consist, at a minimum, of a daily
released by the Montana District. Old             review of hydrographs of telemetered unit
versions of the program will no longer be         value data for the current work day and for
supported.                                        some appropriate preceding period (7 days,
                                                  for example). Obvious erroneous data, such
      The rt_www is written in the Python         as that caused by stuck instruments or
programming language and uses G2 Rev3             dropped or added digits should be corrected
and ghostscript 3.53 from DIS Applications        or deleted from the ADAPS database so that
Software Release 9 to produce graphs of           they are no longer presented to the public
stage and discharge. Instructions for             through the WWW. The new rt_www
retrieving and installing the rt_www rev 1.0      program indicates missing data of 4 or more
software can be obtained via the WWW at           hours as a break in the hydrograph.
the following URL:
http://montana.usgs.gov/rt_www_info                    There are a number of screening
                                                  devices built into the NWIS-I software.
     The rt_www system is configured and          These include extreme high/low value
maintained by a user interface program that       screens for faulty data such as dropped or
is supplied with the distribution. However,       added digits; high/low screens for

environmental thresholds, such as unusual        ancillary data (high- and low-flow frequency
high or low flows or stages; and rate of         discharges, etc.); building templates to help
change thresholds and missing data screens       districts develop and implement image maps
and flags. These thresholds, screens, and        for depicting current streamflow conditions
flags help detect outliers and missed or         in a State or region; and adding support for
omitted data and should be employed              additional streamflow or metrological
extensively in the quality-assurance of real-    parameters.
time streamflow data.
                                                      Districts are undoubtedly aware of
     The rt_www program provides for             other needs. Headquarters cannot fund
varying levels of access to station data based   development of software to meet every
on the host Internet address. Sites for which    contingency, but in addressing their own
the data may be questionable or that require     needs, districts will be developing code that
extensive experience for proper                  can be used by other districts faced with
interpretation can be "turned off" or the        similar problems. Districts are encouraged to
display can be restricted to viewing by          continue to develop, use, and explore ways
specific agencies.                               of disseminating our data through
                                                 appropriate WWW outlets. When possible,
Enhancements                                     expansion of the rt_www software should be
                                                 considered as the preferred means of adding
      The rt_www was developed in order to       new real-time data functionalities.
provide a robust and efficient way for                To facilitate discussions about rt_www
districts to serve current conditions data to    and other real-time data needs or ideas,
the general public through the WWW.              WRD personnel are encouraged to post
Enhancements to the program are being            questions, suggestions, and comments on the
considered to address additional needs.          usgs.rtdata netnews group.
Priorities include automating the data
quality-assurance process; extending the         Thomas H. Yorke
hydrograph and tabular displays to include       Chief, Office of Surface Water
provisional data collected prior to the 7 days
now shown on hydrographs; adding

Appendix 1v. WRD 99.34--Quality Assurance Measures for Serving Real-time Water Data on the
World Wide Web--February 28, 2000

          This memorandum establishes a policy         from being served in the first place. This
    for the implementation of quality-assurance        memorandum describes some of the tools that
    measures for real-time water data being served     are currently available for this automatic
    on the World Wide Web (WWW). It builds             checking. These tools can be very effective if
    on the information provided in Water               used correctly and even better tools are being
    Resources Division (WRD) Memorandum No.            developed to enhance this process. However,
    95.19 and No. 97.17. Memorandum 95.19              even the best automatic process will not
    established a policy that the nature of            eliminate all of the spurious data. Thus, we
    provisional data available on the WWW              need to supplement the automatic processes
    would be clearly identified and Memorandum         with frequent visual inspection of hydrographs
    97.17 provided guidance for use of the             followed-up with rapid deletion of the bad
    rt_www software for serving real-time              data.
    streamflow data.
                                                            Frequent inspection should be taken to
         Including the WWW in our real-time data       mean at least once per work day although
    delivery system has significantly increased the    many of our offices already have procedures
    visibility of these data. Although WRD has         for checking even on weekends and holidays.
    been providing real-time streamflow data to        However, at times when users most rely on
    selected cooperators for over 25 years, our        our data (floods and droughts) even more
    feedback shows that the public is now using        frequent checking may be appropriate. It is far
    our data in ways we never anticipated.             better for us to indicate that the data are
    Unfortunately, our ability to quality assures      missing, and that we are aware of the problem
    these data has not kept pace with our ability to   and will work to resolve it, than it is to
    provide it. Erroneous and spurious data (such      continue to serve the bad data.
    as spikes due to transmission errors) that
    appear on our web pages are problematic for             The NWISWeb software, once
    two reasons. First, these data can lead users to   implemented, will be used to serve our historic
    make bad decisions involving lives or              and real-time surface water, ground water and
    property. The second is that bad data, even if     water quality data on the WWW. Information
    not used for a decision, undermine the             on NWISWeb development, requirements
    credibility of the vast majority of good data      documents, and quality-assurance measures
    we are serving. When the bad data persists on      associated with the current release of
    our web pages for several days, it suggests a      NWISWeb software will always be available
    lack of attention to quality assurance.            from:
    Although provisional data statements clearly
    warn users about potential errors, it must be           The QA measures detailed below apply to
    our goal to avoid serving data that we know to     the surface water WWW data currently being
    be seriously in error.                             served using the rt_www software. The
                                                       NWIS Web software will continue to use these
          Ensuring that the data provided to the       measures.
    public are the best we can offer will require a
    concerted effort to review data before and              The rt_www rev 2.0 software will
    after it is available on the web and make          automatically mask from web display any
    appropriate corrections to the displayed data.     unit-value data that is flagged by ADAPS as
    Our approach to ensuring the quality of our        exceeding the thresholds for Very-high-value,
    real-time data must be made up of two parts.       Very-low-value, Very-rapid-increase, and
    First, we need to use the software tools           Very-rapid-decrease. When any data for a day
    available to automatically prevent bad data        is masked in this way, a small black triangle

will appear at the top axis of the graph            appropriate. For a streamgaging station, this
indicating the condition.                           might be 0.01 feet higher than the bottom of
                                                    the instrument shelf.
      Also included in rt_www 2.0 is a web-
based "quick-view" utility which provides data           The Very-low-value should be set to
reviewers an easy way to sequentially view          eliminate values that are less than the lowest
stage (and optionally discharge) graphs for         possible value; therefore, a value that is 0.10
monitoring data quality. This utility is            units lower than the lowest possible value that
especially useful for reviewing graphs from         can be measured by the sensing and recording
the field using a cellular-capable modem.           equipment at the site would be appropriate.
When viewed on the district LAN, graphs can         For a streamgaging station, this might be 0.10
be sequentially drawn to the screen once every      feet below the point-of-zero flow of a stable
3 seconds allowing all real-time stations to be     control.
reviewed as often as necessary. The visual
review of the real-time data using the quick-             The VERY RAPID INCREASE and
view utility is useful for catching subtle errors   VERY RAPID DECREASE threshold can be
that may pass through the threshold filters.        used by the rt_www software to provide an
                                                    alert about a possible erroneous jump between
Minimum Quality Assurance Procedures                successive unit values. Currently, because
                                                    there is no standard method to determine valid
      Memorandum 97.17 established policy           rapid increases and decreases these thresholds
for the daily review of data and for making         are not required, although a knowledgeable
corrections when necessary. The ―quick-view‖        streamgager can determine these values for
utility can be used to conduct a review of the      each site by examining the historical unit-
data once a day under normal conditions.            values record and then calculating values for
During flood or drought, keep in mind that          both of these thresholds.
there is higher visibility of data and errors are
potentially compounded, therefore, it is                 The requirement to review data served on
important that data being served be checked         the WWW at least once a business day under
and corrected, as necessary, more frequently.       normal conditions and the establishment of
A completely spurious data spike during a           Very-high-value and Very-low-value
flood should not be displayed on the WWW            thresholds in ADAPS is policy of WRD. Other
for more than 24 hours. During more normal          guidelines for quality assuring real-time data
conditions, such a spike should not be              were distributed with OSW Technical
displayed for more than a few hours into the        Memorandum No. 99.07 as part of the
next work day.                                      addendum to Open-File Report 94.382,

     At a minimum, the ADAPS Very-high-                  "A Workbook for Preparing Surface
value and Very-low-value must be set for            Water Quality-Assurance Plans for Districts of
every station with data displayed on the            the U.S. Geological Survey, Water Resources
WWW in real time. The values for each of the        Division."
threshold filters must be defined by                     Using the two-part approach: automatic
individuals that are knowledgeable about the        screening to prevent bad data from appearing,
hydrologic and historical flow characteristics      coupled with visual screening and editing at
of each site.                                       least once per work day, we can significantly
                                                    lower the amount of erroneous data we serve.
      The Very-high-value should be set to          This will be of benefit to the public we serve
eliminate values that are greater than the          and maintain the high level of credibility that
highest possible value; therefore, a value that     USGS streamflow data rightfully enjoy.
is 0.10 units higher than the highest possible
value that can be measured by the sensing and       Robert M. Hirsch
recording equipment at the site would be            Chief Hydrologist

Appendix-1w OSW 2006.01--Collection, Quality Assurance, and Presentation of Precipitation
Data--December 28, 2005

SUBJECT: Collection, Quality Assurance, and Presentation of Precipitation Data

Executive Summary

        This memorandum provides policy and guidance in collecting, processing, presenting, and
archiving precipitation data and is to be implemented in the 2006 water year. Significant policy
requirements described in the memorandum are summarized below:

1. ―Permanent‖ daily and unit value precipitation data subject to archival and future retrieval,
provided to cooperators, or displayed on the Internet must be quality assured and published in the
Water Science Center‘s (WSC) annual data report. Requirements for such stations include calibration
of precipitation gages and archival of station descriptions, annual station analyses, calibration forms,
and original field inspection notes.
2. ―Temporary‖ data not intended for archival/publication may be displayed on the Internet for 31
days when accompanied by a standard qualifier. Though temporary data will remain in the National
Water Information System (NWIS) database, it should not be in a DD marked ―Primary‖ and should
never be adjusted or flagged as approved.
3. Every WSC that publishes precipitation data must have a pertinent section in their Surface Water
Quality Assurance Plan that details procedures to be used to collect, process, review, and archive the
4. Station description documents must be developed and kept current for all sites (temporary or
permanent data).
5. A separate station analysis (apart from streamflow) must be written each year for stations providing
permanent data.
6. The recording interval for precipitation gages providing permanent data will be 15 minutes or less.
7. Minimal procedures for routine field inspections are provided for permanent data stations.
8. Calibration procedures for new and existing stations are provided. Adjustments at sites collecting
permanent data should be made if tipping bucket gages are not within 5 percent of actual volume or if
weighing bucket gages are not within 0.1 inch of actual volume.
9. Data corrections are discouraged in most cases.
10. Estimation of precipitation records where permanent data are missing for long periods of time
(multiple events over a period of more than three days) is not recommended. If circumstances dictate,
estimates may be made using approved techniques. When the total volume over a few days is known,
the daily distribution should be estimated using nearby gages and the results published as estimated
11. No formal quality ratings will be assigned to published data based on calibration tests, site
conditions, or the amount of estimated/missing record. Records associated with field calibration
results having errors in excess of 10 percent (tipping bucket gages) or 0.1 inch (weighing bucket
gages) should not be published.
12. Similar to streamflow policy, spurious precipitation data spikes during a major storm should not
be displayed on the Internet and less obvious errors (detected by comparison with nearby gages)
should be revised within a few weeks. ADAPS screening thresholds should be applied to all data
presented on the Internet via NWISWeb. A standard disclaimer should accompany all real-time
precipitation data. These minimal QA/QC requirements apply to both permanent and temporary data
displayed over the Internet.


     The purpose of this memorandum is to provide policy and guidance in collecting, processing,
presenting, and archiving precipitation data within the Water Resources Discipline. This policy

applies to precipitation data (1) displayed on the World Wide Web (Internet) or (2) published in
USGS reports (data or interpretive), provided to cooperators, or archived in the NWIS database. This
policy is to be implemented in the 2006 water year.

      Precipitation data have been collected by the USGS since the early 1900‘s. Collection of
precipitation data is a logical and cost-efficient extension of the USGS streamflow data collection
infrastructure. Routine publication and public display of precipitation data on the Internet has evolved
to be commonplace within the USGS. Our precipitation data applications range from simple gaging
station add-ons used only to direct internal operations during flood events (minimal accuracy
requirements) to critical components of cooperative real-time flood warning networks. Though
precipitation data prior to about 1990 were archived in office files or our database and is available
upon demand, unit and daily value precipitation amounts were not published in our annual data
reports. While precipitation monitoring has proliferated over the last few decades, a lack of
guidelines has made it necessary for Water Science Centers (WSCs) to develop their own policies,
many of which are not consistent with other WSCs or even within their own State over time. In order
for precipitation records to be consistent across time and space, the Office of Surface Water (OSW)
has formulated a policy that sets the minimum standards outlined below.

      For the purposes of this memorandum, the term ―permanent data‖ refers to all unit and daily
value precipitation data that is quality assured and thus intended for public display, distribution,
publication, and archival in the NWIS database. ―Temporary data‖ (precipitation data that is only
minimally quality assured, such as data used solely to facilitate decision support activities during
flood operations) should not be modified, published, distributed to cooperators, or made available for
retrieval by the public following the 31-day display period.

      The purpose of a precipitation station should be to obtain a representative time series of
precipitation values for a particular location. Unlike streamgaging, the principles of fluid mechanics
do not apply. Thus, precipitation gages only a short distance apart may not give identical readings.
For this reason, small errors are tolerable but all data (even temporarily-displayed data) should still be
meaningful. Every WSC that publishes precipitation data must have a pertinent section of their
Surface Water Quality Assurance Plan (QA) that details procedures to be used to collect, process,
review, and archive the data. QA plan criteria can be more, but not less, stringent than those outlined
in this memorandum.

     This memorandum does not apply to data collected to National Weather Service (NWS)
standards, which vary according to type of special purpose network. If cooperator requirements
dictate monitoring precipitation to NWS standards, WSCs should refer to NWS directives instead of
this memorandum. The NWS directives are available at the URLs below:

     http://www.nws.noaa.gov/directives (directives)
     http://www.weather.gov/om/coop/Publications/coophandbook2.pdf (cooperative
     program guidelines)

     This Memorandum does not apply to data collected for the National Atmospheric Deposition
Program (NADP). Data collected for this program should follow NADP protocols for site selection
and installation at URL:

     and for station operation at URL:

     This memorandum does not cover other meteorological parameters (air temperature, solar
radiation, etc.) or snow depth/snowpack measurement.
     Specific topics covered in this memo include:

     1. Precipitation data collection
        a. Siting (gage location and stability)
        b. Station descriptions, naming, and numbering conventions
        c. Standardization of recording interval
        d. QA/QC procedures for routine visits
        e. QA/QC procedures for calibration visits

     2. Precipitation data processing
        a. Data corrections
        b. Estimation of missing record
        c. Use of cumulative versus incremental data as the measured input parameter
        d. Station analyses

     3. Precipitation data presentation
        a. Annual data reports (EXPLANATION OF RECORDS section, statistics [daily, monthly,
        and annual])
        b. Qualification of records
        c. Internet display and ADAPS storage

     4. Precipitation data archival (supportive field notes, calibration forms, station analyses)


      Siting of precipitation gages
      The exposure of a precipitation gage is very important for obtaining accurate measurements. As a
general rule, the windier the gage location, the greater the precipitation error will be. Gages should
not be located close to trees and buildings, which may obstruct wind-driven precipitation or alter the
amount of precipitation collected due to erratic turbulence. To avoid other problems related to
excessive wind, it is recommended that gages not be located in wide-open spaces or on elevated sites,
such as the tops of buildings. The best site for a gage is one that is protected in all directions, such as
in an opening in a grove of trees. Ideally, the distance between the protection and the gage should be
twice the height of the protection above the collector but not less than the height of the protection (top
of building or canopy should leave an open cone of between 25 and 45 degrees above the collector).
Gages should be installed as close to the ground as possible without being subject to splash and on a
sturdy structure that does not shake in the wind causing unintentional bucket-tips or fluctuations in
weight. Rarely will an ideal site be available and judgment must be exercised in choosing between
sites, each of which may have shortcomings.

      In the absence of any other wind protection, wind shields may be used to minimize the loss of
precipitation. This loss is much greater during snowfall than rainfall, so shields are seldom installed at
stations unless at least 20 percent of the annual precipitation falls in the form of snow. In areas that
are expected to have significant snow accumulations, gages should be mounted on towers at a height
considerably above the maximum level to which snow accumulates.

     Good exposures are not always permanent and site conditions should be evaluated at each
routine site visit. Over time, alterations by humans or vegetative growth may make the exposure
unsatisfactory, necessitating clearing of trees/brush or relocation to a better site. Under no
circumstances should data be published or displayed on the Internet (includes temporary data sites) if
gage readings are severely compromised by known conditions that could bias the data, such as
roadway splash or drip from vegetation or overhead utility lines.

     There are many types of instruments used by the USGS to collect precipitation data; a brief
description of the principal types and limitations is provided in Appendix 1 of this memorandum.
There are compelling site conditions and financial constraints which do not allow a single type of
instrument to be recommended for all installations. In general, a tipping bucket type of installation
(with a heater in climates where needed) would be the best choice for accuracy. However, if the AC
power needed for the heater is not available, a weighing bucket (spring, strain, or wire strain type)
may be the only economically feasible option. Although tipping bucket gages have been known to
under-register during periods of intense precipitation, such as thunderstorms, there are inexpensive
self-calibrating tipping bucket models with a post-processor that purportedly reduces or eliminates the
error for rainfall intensities between 0 and 25 inches per hour by adjusting the number of tips
according to intensity.

     In addition to intensity, another common problem with tipping bucket or well/float rain gages is
clogging from bird waste or other small debris. To address both problems, one might consider
siphoning rainfall sensors, which have orifice sizes of about one inch instead of the more typical
quarter-inch orifice. The unit has a larger-diameter funnel drain that does not clog easily and a siphon
to control the flow so that the tipping mechanism will not under-register during intense storms, though
there may be a short lag in response time.

     The weighing rain gage has the advantage that all forms of precipitation are weighed and
recorded as soon as they fall into the gage (snow and ice do not collect in the un-heated funnel
undetected, as is the case with tipping bucket mechanisms or collection well float systems). However,
the weighing gage requires more frequent maintenance than the tipping bucket gage, and older spring
types are sensitive to strong winds, which can rock the gage, causing spurious readings.

     Collector well/float system rain gages with siphons are discouraged because they can affect
holding well volumes and may, themselves, become plugged or partially plugged, prolonging the
siphon-draining period and thus increasing the likelihood that some rainfall may be missed.

      Station descriptions, naming, and numbering conventions
      Station descriptions containing details on location, deployment dates and methods, instrument
type, model number, and calibration method and frequency must be developed and kept current for
stations providing any type of data (temporary or permanent). Descriptions should be a living
document containing a chronological history of the types of instrumentation that have been operated
and any siting issues that affect(ed) the record. Be sure to note whether the data being collected is
permanent or temporary and, if mixed, provide a listing of the time periods associated with each.

     Some WSCs have assigned separate 15-digit station numbers and names to all precipitation sites
in their database. Others simply have rain gages organized as a different parameter collected under
the same station number and name as the streamgage it is co-located with. The more typical situation
for WSCs is to have some combination of both of these systems, since at least some precipitation
gages are not associated with or even near a streamgage. Logically, precipitation should not be tied to
downstream station numbers, and the likely structure of our database in the future will be geared
towards assigning separate station names and numbers to gages that monitor different parts of the
hydrologic cycle, regardless of location. Although the current mix of station name and numbering
schemes is acceptable for existing networks, future precipitation gage installations (after October 1,
2005) should be set up in the NWIS database with separate names and 15-digit station numbers. A
separate electronic/paper filing system for precipitation gages (containing station descriptions,
analyses, and archived records) should be set up for new stations as well. An example station
description is provided as Appendix 2.

     Standardization of recording interval
     The recording interval for precipitation gages intended to produce permanent data must be 15
minutes or less, starting at the top of every hour. If the instrumentation being used is an event
recorder, zero precipitation can be assumed between events (interim unit values do not need to be

filled in with zero values). The recording interval at gages where the data will only be temporarily
displayed can be established according to cooperating partner or science center objectives.
      QA/QC procedures for routine visits
      Temporary data -- Though the expectations for temporary data are much-reduced, no data should
be displayed if collected by equipment that has been neglected or is in a state of disrepair. As such,
many of the following procedures should be adhered to even though formal inspection records are not

     Permanent data -- Routine maintenance visits to permanent data sites should be made
approximately 6-8 times each year, similar to streamflow station measurements. A separate form
(example inspection form is shown in Appendix 3) should be filled out during each site visit and filed
with the analysis made at the end of each water year. Routine field inspections should document the
following procedures:

Float system gages:
     Visual check for 45-degree clearance above collector.
     Note collector, funnel, and screen conditions.
     Clean or repair collector, funnel and screen, if necessary, and note.
     Inspect the tube connecting the storage well to the collector for leaks or blockages. Check the
         storage well for leaks and debris that may have fallen in.
     Record water levels in the storage well and drain storage well every visit to ensure that a
         maximum amount of cumulative precipitation can be recorded. Close the drain valve.
     Add antifreeze during winter months as needed.
     Fill out inspection sheet.

Weighing bucket gages (spring type):
    Visual check for 45-degree clearance above collector.
    Record bucket level.
    Note collector, funnel, and screen conditions.
    Clean or repair collector, funnel and screen, if necessary, and note.
    Empty and clean bucket as necessary and replace.
    Remove or replace evaporation shield at beginning and end of winter period, respectively.
    Check gage for proper movement throughout range of motion.
    Check dashpot oil level; refill if more than 0.25 inches from top.
    Clean inside of gage as necessary.
    Check to make sure gage is level in both directions. Level as needed.
    Add about 0.2 inches of oil Isopar or mineral oil (and antifreeze during winter visits) and record
        bucket level upon departure.
    Fill out inspection sheet.

Tipping bucket gages:
    1. Visual check for 45-degree clearance above collector.
    2. Note cup, screen, and funnel condition (clean or dirty).
    3. Clean cups, screen, and funnel, if necessary, and note.
    4. Re-level the instrument if necessary (collector must be vertical).
    5. Lubricate the pivot hinge with a plastic-safe lubricant or silicone oil (as recommended by the
    6. Make sure the small drain holes at the bottom of the gage are not plugged with dirt or other
        material (drill them larger if problem becomes chronic). Record water levels in accumulation
        can and empty it.
    7. During warm weather site visits, the collector funnel and tipping buckets should be waxed
        (liquid car wax). This will reduce corrosion and decrease the number of water droplets that
        might cling to the side/bottom of the collector.
    8. Perform a manual test tip procedure to check the integrity and operation of the

         gage sensor and wiring as follows:
         The gage cover is removed. The bucket mechanism is gently tipped ten times at a rate of
         about one tip every three seconds being careful not to allow a bounce that could create a
         double reading of the switch. This is repeated two additional times with a time period of
         about fifteen second between each set of tips. The number of tips from the data logger or
         field computer is recorded. If the number of recorded tips is not equal to 30, troubleshoot the
         system and rerun the test. If the gage fails a second time it must be replaced. Replace the
         cover being careful not to cause a tip. Delete test tips from the data logger while at the site.
      9. Turn on heater during winter months.
     10. Fill out inspection sheet

      QA/QC procedures for calibration visits
      Calibration of precipitation gages must be performed either in the field or office prior to
extended field operation. Thereafter, calibration tests must be made at least annually for all types of
gages (even those meant to collect only temporarily-displayed data) Calibrations are also required
when an ongoing pattern of unfavorable comparisons with nearby gages is discerned, or when
physical damage to the instrument or its components is noted that would make testing prudent.
Remedial actions at sites that collect permanent data should be taken when calibration test errors
exceed 5 percent (tipping bucket gage) or 0.1 inch (weighing bucket gage). Adjustments at temporary
data sites are indicated when calibration tests exceed 10 percent (tipping bucket gage) or 0.2 inch
(weighing bucket gage). Each calibration should be documented on a separate form to be placed with
the end-of-year station analysis (permanent data station) or station description (temporary data
station) and archived. An example calibration form for a tipping bucket rain gage is provided as
Appendix 4.

Calibrating float system gages

     The inside diameter of float system storage wells (such as 3-inch galvanized pipes) may vary
slightly by manufacturer. Therefore each gage needs to be calibrated before the gage is put to use.
The general procedure for checking the accuracy of a float system is simply to pour a known volume
of water into the collection well and compare the reading against the expected value. For example,
                                                            2            3

the area for a standard 8-inch collector tube is 324.335 cm . If 2500 cm (or milliliters) of water is
                                                                                         3                  2
poured into the collector funnel, the change in reading should be 3.03 inches (2500 cm / (324.335 cm
x 2.54 cm/in) = 3.03 in.). If the above test was made and resulted in a reading of 2.85 in., the
correction factor for all data collected at this site would be 3.03/2.85 = 1.06. This should be checked
at least annually to ascertain float problems; generally the correction factor is constant, a function of
varying manufacturer specifications related to volume, and is unaffected by intensity. For less
sensitive, large-diameter storage wells, the diameter should be measured in two or three different
locations to get an average diameter. The rise in the water level of the larger storage well should be
equal to the number of inches put in the smaller 8-inch collector times the ratio of the area of the
small collector to the area of the larger diameter holding well.

Calibrating weighing bucket gages

     Spring type: Check calibration (with the bucket out) for the full range of the bucket. Using a set
of precipitation calibration weights purchased from the manufacturer, record all of the values as you
add one at a time to the gage (each weight represents 1 inch of precipitation) at 1-inch increments
from 0.0 to 20.0 inches. Adjust the spring tension if the reading is off by more than 0.1 inch (0.2 inch
at temporary data sites), being careful to adjust for trends as well. For example, if at a lower value,
such as 3.0, the gage registers 2.9 and at a greater value, such as 18.0, the gage registers 18.1 you may
want to make some adjustments to account for this trend even though neither error is greater than 0.1

   Strain and vibrating wire-strain types: See instruction manual and follow suggested
manufacturer procedure for calibration.

     Calibrating tipping bucket gages

     The accuracy of the tipping bucket precipitation gages should be determined using constant head
bottles fitted with nozzles representing a variety of rainfall intensities. Kits with several nozzle sizes
may be purchased from several companies, including NovaLynx Corporation and Qualimetrics.
Every precipitation gage should be calibrated using the nozzle that simulates a precipitation intensity
of 2 inches/hour according to the manual instructions before it is installed in the field (even new gages
may be out of calibration despite manufacturers specifications). If desired, additional calibration tests
can be made with nozzles having different diameters and therefore different simulated precipitation
intensities. The larger the nozzle used, the higher the represented rainfall intensity, and the wider the
expected variability in the number of tips recorded.

     Using the NovaLynx kit as an example, several plastic orifices are provided, each with a
different orifice diameter and length (the length is used only to assist in visually identifying orifice

     Orifice Diameter             Nozzle Length       Simulated Precipitation Rate
      (inches)                      (inches)                          (inches/hr)
     1/32‖ (smallest)                 3/16‖                                 2
     1/16‖                            5/16‖                                 6
     3/32‖                            3/8‖                                  12
     1/8‖ (largest)                   5/8‖                                  26

     To calibrate a tipping bucket precipitation gage, the calibration bottle is filled with a known
volume of water which corresponds to a certain number of inches of precipitation, or number of
bucket tips, (table below is for an 8-inch diameter precipitation gage). Assuming no water is spilled,
the size of the orifice does not influence the number of bucket tips; it only affects the calibration time.

     mL of Water           inches of precipitation # of bucket tips allowable         # of tips
     450                          0.55                     55                         52-58
     501 (bottle line)            0.608                    60.8                       58-64
     750                          0.91                     91                         86-96
     947 (full-bottle line)       1.15                     115                        109-121

     The permissible error range in the number of tips in subsequent calibration tests for that gage
must be no more than 5 percent (10 percent for temporary data sites). If the computed correction
factor is between 0.95 and 1.05 (0.90 and 1.10 for temporary data sites), no recalibration is needed
and no corrections should be considered.

     Field calibration procedure (for an 8-inch collector):
     1. Note current precipitation readout.
     2. The proper amount of water (501 mL, for example) should be measured in the office using a
         graduated cylinder and carried to the field in bottles (any marking on the calibration bottle
         should be used as a rough check only). Carefully transfer the water into the calibration bottle.
     3. Screw 1/32‖ (2 inches/hour) orifice on bottom of base plate, hand tight.
     4. Screw base plate onto calibration bottle (base plate inverted), hand tight.
     5. Plug orifice with finger and turn calibrator over (to prevent water from splashing out) and
         place in the bucket.
     6. Allow the water to drain out completely.
     7. Make sure all water has dripped out of the bottle and base plate into the
         funnel/bucket when removed.

     8. Note the resulting precipitation reading.
     9. If 0.58 to 0.64 inches (58 to 64 tips) of precipitation was recorded during the test, no
         adjustment is necessary and you may skip to step 11. The test should yield
         60.8 tips (although you can‘t read fractions of a tip).
     10. If the test results are outside of the allowable range on the first calibration, re-level the
         instrument and make appropriate adjustments to correct the instrument error (see the
         equipment manual for adjustment techniques). Repeat steps 1-9 after adjustment. If the test
         results of the second calibration are still outside the allowable range, replace the instrument
         with a spare unit and diagnose the problem back in the office.
     11. Check one more time to be sure instrument is level.          Then reset the DCP or other
         datalogger back to the reading observed before the calibration test (or remove test
         precipitation data from ADAPS upon return to the office).

A sample template for permanently documenting tipping bucket calibration tests is provided as
Appendix 4 of this memorandum.


      Data corrections
      There are few instances when there will be sufficient data to support how and when data
corrections should be applied. Therefore, in most cases, corrections should not be applied to a
precipitation record even when calibrations indicate the record may be in error by more than 5
percent. Under no circumstances should data corrections be made to temporary data site records. If
the tipping bucket gage has a cumulative precipitation collector, that information should be used to
ascertain storm totals for short periods of missing record or to check for gross errors from instrument
malfunctions; this should be checked even if the record appears to be complete.

     Corrections are made to unit values. In the current version of ADAPS (4.5), small corrections
may round off to zero correction by default (for example, a 9 percent correction to 0.05 inches would
result in a 2-decimal place number that rounds back to the uncorrected value of 0.05 inches). Thus,
daily values should be checked and edited as necessary to ensure proper adjustment. Edited values
should be marked appropriately in the published record.

     Estimation of missing or erroneous record
     Two types of ―missing‖ record at permanent data sites are addressed here: (1) long periods with
multiple events wherein no data have been transmitted or recorded, and (2) short periods of up to 3
days in which the total volume is known but the timing is uncertain due to missed transmissions,
plugged funnels, or snow/ice effects. This section does not apply to sites at which temporary data is
being collected.

     As a general rule, missing precipitation record in the first case should not be estimated. The
period should be deleted and the record classified as missing. If however, cooperator or project needs
dictate, daily precipitation may be estimated but supporting documentation must be archived and an
appropriate/approved technique must be described somewhere in the station analysis and report. An
acceptable method is the reciprocal-distance-squared equation used by the National Weather Service.
This has been verified on both theoretical and empirical bases (U.S. Department of Commerce, 1972,
p. 3-11). Other methods for interpolating missing daily values of point precipitation data may be used
if approved by your Regional Surface Water Specialist. Additionally, the policies outlined in OSW
Technical Memorandum 2005.07 providing guidance for the use of Program HYDRA to estimate or
modify edited unit values from ADAPS are also applicable to precipitation data.

      In the second case, publication of a known total for a short time period is considered to be
measured (not a computed estimate). The volume is accurately measured and only the time
distribution must be estimated. Non-heated tipping bucket records must be carefully analyzed for

      snow/ice effects. Event totals manually inserted on the last day of an event in order to make our
      database and annual data report totals match are discouraged. Daily distributions should be estimated
      using nearby unaffected gages, marking each daily value with an ―e‖ remark code in order to maintain
      the correct monthly value. As before, in some cases (such as when snowfall exceeds the depth of the
      collector), a WSC may elect to simply delete those days and that period of record would be
      considered as missing.

           Cumulative versus incremental data as the measured input parameter
           A cumulative (running total) is preferred as the form for input data (though all computed unit
      values are incremental). The use of incremental values for input data is discouraged because of
      problems associated with lost data when transmitting them. Each WSC must decide which form is
      most appropriate for the location and type of equipment being used.

            The resolution of some data loggers decreases when the cumulative precipitation reaches a
      particular value. Thus it is important to reset the cumulative precipitation value at each inspection or,
      at least, long before that value could occur. Resetting the gage on the first inspection of each year
      would facilitate the comparison of running annual totals with nearby sites.

           Station analyses
           A separate station analyses (apart from streamflow) must be written each year for permanent
              data sites and archived similarly to discharge records. A sample station analysis is provided
              as Appendix 5 and should minimally include:
           Station -- Provide station number, name, and location information.
           Gage -- Describe the current sensor, recorder, DCP, and shelter, including the height of the
              collector above the ground. Describe any changes to the site instrumentation made during the
           Precipitation record -- Describe any problems noted in periodic inspections. Note periods of
              missing or doubtful record and reasons.
           Computations and calibrations -- Provide the results of any calibrations
              performed, corrections made, and how they were applied.
           Remarks -- Describe any analyses or comparisons with nearby stations.
           Extremes (optional) -- For complete records, give the maximum daily precipitation total for the
              current year (and period of record) and associated date(s). Maximum intensity data also may
              be included.
           Recommendations (optional) – Note any impending work or site conditions that will potentially
              affect operation of the gage in the near future.
           Names of persons computing, checking, and reviewing the data and dates of analysis.


     Annual data reports
     Data collected by the USGS and used in interpretive investigations, distributed formally to cooperators, or
stored in the NWIS database must be quality assured and published in the WSC‘s annual data report. Where
daily data are missing and not estimated, no monthly sum for that month will be presented and no annual
amount will be given. Monthly and annual sums can only be provided when the record is complete or when
missing daily values have been estimated or are known from accumulation totals.

     Publication of intensity-duration-frequency statistics from unit value computations spanning more than one
calendar day is meaningful and encouraged if the WSC has access to tested utility programs capable of such
analyses. Publication of daily value extremes from ADAPS for the current year and for the period of record is
discouraged. Such statistics have dubious value because they are arbitrarily constrained to reflect calendar day
information instead of ―true‖ 24-hour maximums.

      Some WSCs currently publish precipitation records alongside of streamflow records with the same 8- or
10-digit station number with NWIS site type flags indicating both climatological and streamflow data as
present. Those WSCs also may have precipitation gages that are operated independently of any streamflow
station. In the latter instance, precipitation gages (1) have no river name associated with them, (2) are assigned
separate 15-digit station numbers, and (3) are published in a separate section of the annual data report. Many
WSCs have re-organized their databases and data reports, assigning separate 15-digit station numbers to all of
their precipitation sites, which are published in a different part of the data book regardless of whether they are
operated in conjunction with a streamgage or not. As with station names and numbers (see Station descriptions,
naming, and numbering conventions section of this memorandum), the current mix of publication schemes is

     Precipitation records for stations installed after October 1, 2005 are to be identified and published
separately from any streamflow station they may be co-located with. Be sure, however, to cross-reference any
information collected at the same site by providing (in the REMARKS paragraph) the station number, name,
and parameter published elsewhere in the annual data report.

   A sample template of recommended wording for the Introduction of the annual data report and a sample
manuscript are provided as Appendix 6.

     Qualification of records
     Site conditions, especially those which deviate from the criteria in the section on siting precipitation gages
above, should be carefully described in the GAGE section of the station manuscript to assist the end-user in
assessing the accuracy of the data. No quality ratings will be assigned based on the calibration test results, site
conditions, or amount of estimated/missing record because any such rating would be subjective. The ―e‖ flag,
used to denote data that were either missing or of poor accuracy, will sufficiently alert the user to the fact that
such data are of lesser quality than other daily values. If a uniform method is not used for all stations and cited
in the DATA PRESENTATION section of the introduction, a statement should be made in the REMARKS
paragraph of each station manuscript describing/citing the estimation method used for that individual station.

     Records associated with calibration tests for tipping bucket gages having greater than 10 percent error
should not be published. Weighing bucket gage records with calibration errors in excess of 0.1 inch should also
not be published.

     Internet display and storage in ADAPS
     Permanent data – WRD Policy Memorandum 99.34 already requires all offices to review streamflow data
served on the Internet at least once each business day under normal conditions and to establish ―very-high-
value‖ and ―very-low-value‖ stage thresholds in ADAPS (see below). Similarly, a completely spurious
precipitation data spike during a major storm/flood should not be displayed on the Internet for more than 24
hours. During more normal conditions, such a spike should not be displayed for more than a few hours into the
next work day. Less obvious errors that can only be ascertained via careful comparison with nearby
precipitation gages should be deleted or revised within 2 or 3 weeks.

ADAPS screening thresholds should be applied to all data presented on the Internet as follows:
   If input is incremental precipitation:

    1. Set the very high threshold to above the highest value possible in the recording interval (for
        example: 3 inches in 15 minutes).
    2. Set the very low value to -0.01 (negative values are not possible with incremental input and          will
always result in transmission/DECODES issues).
    3. Do not use the very rapid increase and very rapid decrease thresholds.

     If input is cumulative precipitation:

     1. Set the very high and very low thresholds to beyond the range of the counter. For example, for        a 0-
20 inch weighing-bucket set the very high threshold to 21 inches and the very low            threshold to -0.5 (as
readings slightly beyond the normal range are possible). For a tipping- bucket counter that can record up to
         99.99 inches, set the very high threshold to 100 and set the very low threshold to -0.01.
     2. Set the very rapid increase and very rapid decrease thresholds to the maximum possible rate           in
inches per minute. For example, a very rapid increase setting of 0.2 would equal 3 inches            of
precipitation in a 15-minute period.

     Temporary data – Precipitation data not intended for archival or publication may be temporarily displayed
on the Internet for up to 31 days primarily for operational needs and uses. ADAPS screening thresholds should
be applied as described immediately above. To limit the display time for temporary data to 31 days, such sites
are to be set up to display unit values only. The display must be accompanied by the standard qualifier shown
below. The absence of routine inspections throughout the year precludes reliable interpretation/adjustment of
the data at a later date. Temporary data (1) must NOT be stored in a DD marked ―Primary‖, and (2) must never
be flagged as ―Approved‖ (it can be protected from subsequent editing by flagging it ―In Review‖). It is further
recommended that the DD description field contain the phrase ―Temporary Data‖ to ensure that the temporary
status is made clear in perpetuity.

     A standard qualifier-disclaimer statement must accompany the NWISWeb real-time display of temporary
data as follows:

         The X-hour precipitation data for this station are temporary and will only be displayed             for
31 days. Time series of X-hour or cumulative daily values will NOT be available for         retrieval following
the 31-day display period. Although the instrumentation is calibrated at least once/year, the temporary
classification means that documented routine inspections and     other quality assurance measures are not
performed that would make the data acceptable for       archival, retrieval, or future use in general scientific or
interpretive studies.

     The standard qualifier-disclaimer above must be added to each individual temporary precipitation station
real-time data page. The disclaimer text should be inserted following any cooperator acknowlegements at the
top of the real-time station page. Instructions on how to insert the standard disclaimer are available from the
NWISWeb Manual – Frequently Asked Questions web pages at URL:


The following standard disclaimer in HTML format can be cut-and-pasted directly into your site-text file as per
the instructions in the NWISWeb FAQ:
     <table border="1" cellpadding="5" width="576">
  <td><b>The X-hour precipitation data for this station are
  temporary</b> and will only be displayed for 31 days. Time
  series of X-hour or cumulative daily values will NOT be
  available for retrieval following the 31-day display
  period. Although the instrumentation is calibrated at least
  once/year, the temporary classification means that documented
  routine inspections and other quality assurance measures are
  not performed that would make the data acceptable for
  archival, retrieval, or future use in general scientific or
  interpretive studies.
     </tr> </table>

    Other guidelines for quality assuring real-time data were distributed with OSW Technical Memorandum
No. 99.07 as part of the addendum to Open-File Report 94.382, "A Workbook for Preparing Surface Water
Quality-Assurance Plans for Districts of the U.S. Geological Survey, Water Resources Division."

     Archival of supportive materials

     Station descriptions, annual station analyses, calibration forms, and original field inspection notes must be
archived as part of the permanent record.

     U.S. Department of Commerce, National Oceanic and Atmospheric Administration, 1972, Technical
memorandum NWS HYDRO-14: National Weather Service river forecast system                 forecast procedures,
Washington, D.C., 251 p.
     Arvin, Donald V., 1995, A workbook for preparing surface water quality-assurance plans for
        districts of the U.S. Geological Survey: U.S. Geological Survey Open-file Report 94-382, 40     p.
     Water Resources Division Policy Memorandum 99.34 – Quality assurance measures for serving          real-
time water data on the World Wide Web.
     Office of Surface Water Technical Memorandum 99.07 – Addendum to Open-File Report "A
        Workbook for Preparing Surface Water Quality-Assurance Plans for Districts of the U.S. Geological
Survey, Water Resources Division."
     Office of Surface Water Technical Memorandum 2005.07 – Use of the program HYDRA to estimate or
modify edited unit values from ADAPS.

     Stephen F. Blanchard
     Chief, Office of Surface Water
     WRD Distribution: All Water Employees

Appendix 1 - Types of Precipitation Monitoring Instruments Typically Used Within the U.S. Geological

     1. Weighing bucket collectors (spring type, strain type, or vibrating wire strain type) -- measure
precipitation by recording the weight of accumulated precipitation in a container. The storage container for this
type of gage is topped off with an oil to minimize evaporative losses and is also charged with a mixture of
propylene glycol and ethanol during the winter months to ensure proper registration of snow. The drawback
with older ―bucket-on-a-spring‖ models is that precipitation may only be reported to the nearest 0.1 inch. Also,
because positive increments are counted as precipitation, oscillations from wind, diurnal thermal expansion, etc.
often result in record that requires extensive manual editing. The newer strain or vibrating wire strain models
are designed to provide accuracy to 0.01 inch and can compensate for errors caused by evaporation or wind-
induced gage movement. Strain-type gages have an elastic sensor whose electrical resistance is a function of
applied strain. As pressure from the weight of accumulated precipitation increases, a pressure sensor measures
the deflection of a membrane by monitoring the change in resistance of an attached strain gage, converting
force into an electrical signal. In vibrating wire strain gages, a bucket is suspended by three vibrating wire
sensors that continuously weigh the collection bucket. The vibrating wire, when excited with 12V DC, outputs
a frequency relative to the weight of the water in the collection bucket. The frequency measured for each
sensor is averaged each hour and the hourly frequency maximum and minimum is calculated for each of the
three sensors and reported independently along with the precipitation calculated for each 15-minute period.

       2. Tipping bucket collector -- measures precipitation through the use of two equal-sized chambers
which alternately fill and drain. As each chamber fills, it tips, simultaneously draining it, bringing up the
second bucket under the collector funnel and recording a known amount of precipitation, usually 0.01 inch.
The precipitation total for each day is computed by summing the number of tips during the day. During winter
months a heating device may be used to melt incoming snow or ice. Data from tipping bucket instruments are
reported to the nearest 0.01 inch. Some models may only be accurate for intensities at or below the calibration
rate – more intense storm amounts may be biased low. There are inexpensive self-calibrating tipping bucket
models with a post-processor that purportedly reduces or eliminates the error for rainfall intensities between 0
and 25 inches per hour by adjusting the number of tips according to intensity.

Some tipping-bucket collectors have only one bucket. The accuracy of those instruments has not been broadly
established and their use is not recommended in a field setting.

     3. Collector well/ float systems -- There are several types of float systems. In one type, a standard 8-inch
diameter funnel diverts precipitation to a 3-inch diameter collector pipe. A float connected to a recorder pulley
of specific diameter is used to convert the stage in the well to accumulated precipitation, measured to the
nearest 0.01 inch. Such sites are usually drained each visit and are limited to about 10 inches of precipitation
between inspections. Antifreeze may be added to prevent freezing. A second type of float gage is similar to the
one just described except that the ratio of collector-to-well diameters is much smaller, making it able to
function in areas of high annual precipitation amounts but with much less sensitivity. Such data are only
reported to the nearest 0.1 in.

     4. Non-recording collectors – cumulative volume systems are normally used to verify tipping bucket type
gages following intense storms or to provide monthly and annual totals. No guidance is provided for this type
of instrumentation.

Appendix 2 Example Precipitation Station Description

                                              Prepared by: J.M. Smith (Oct. 16, 2000)
                                        Revised by: W. J. Jones (Oct. 22, 2003)

                               PRECIPITATION STATION DESCRIPTION

373823103465601 Upper Storm Canyon Precipitation Station near Downpour, CO

LOCATION.--Lat 37° 38' 23", long 103° 46' 56" (NAD 1983), in SW 1/4, NW 1/4, sec. 3, T. 28S., R.
57W, Las Animas County (Sheep Canyon 1:24000 quadrangle), Hydrologic Unit 11020010, on Pinon
Canyon Maneuver Site, approximately 80 feet north of Military Supply Road 1A, 1.2 miles above
Stage Canyon, 6.7 miles west of Rourke Road 1, 12.9 miles east of Downpour, and 27 miles south of
La Junta.


                        PRECIPITATION GAGE
Leg mi.     Total mi.     Directions
  0.0         0.0         Turn east through main gate at Pinon Canyon Maneuver Site (PCMS), mile
                          marker 24.0 on State Highway Route 350. ENTRY PERMISSION
                          REQUIRED. Preferably call PCMS Security at 984-611-2806 or check in
                          at PCMS headquarters. Continue straight on gravel road MSR 1.
  0.45        0.45         Turnoff to Cantonment precipitation gage. Stay straight.
   0.4        0.85         Junction with MSR 2, which exits right. Stay straight, continuing east.
   2.8        3.65         Cross Big Arroyo.
   5.1        8.75         Road curves north.
  0.45         9.2         Intersection with MSR 3 and Pipeline Road. Bear left on Pipeline Road
                           and drive northwest.
  2.05        11.25        Road makes series of sharp turns.
  1.15        12.4         Cross branch of Lockwood Arroyo, continue straight.
   2.6        15.0         Turnoff to Lockwood Arroyo precipitation gage, stay straight.
   1.0        16.0         Cross gas pipeline.
   0.7        16.7         Low-water crossing.
   3.2        19.9         ―T‖ in road, bear left and drive northeast.
   1.1        21.0         Cross Red Rock Arroyo. Continue straight.
   1.1        22.1         Intersection with MSR 1A, turn left and drive north on MSR 1A.
   3.0        25.1         Low-water crossing (Stage Canyon Arroyo). Stay straight.
  0.25        25.35        Turnoff to Stage Canyon precipitation gage. Stay straight.
  2.25        27.6         Cross Storm Canyon Arroyo. Stay straight.
   1.5        29.1         Park here. Site is 80 feet north of road.

GAGE.--A 12-inch High Sierra 2400-10 tipping-bucket precipitation gage is located 100 feet north of a USGS
ground-water well shelter (see sta. no. 373822103465601). The top of the collection funnel is 6 feet above the
ground surface and is not equipped with a wind shield. Rainfall is recorded at a resolution of 0.01-inch. The

data from both the ground water well and precipitation gage are transmitted every hour via Handar high data
rate DCP transmitter. The station is solar-powered. Elevation of station is 4,860 feet above sea level, from
topographic map.

HISTORY.--Temporary data collected from March 1980 through June 1983. Permanent data collected from
July 1983 to current year. July 1983 to September 1998, published as Bent Canyon Precipitation Gage above
Stage Canyon near Delhi. Prior to 1992, the precipitation equipment type was a weighing bucket collector with
a precision of 0.1 inch. The site was operated during the 1983-92 water years as part of a hydrologic study of
the Pinon Canyon Maneuver Site, data published in various Open-File Reports. The site is operated year round.

COOPERATION.--The site is operated by the U.S. Geological Survey in cooperation with the U.S. Army
Pinon Canyon Maneuver Site to provide data for the Land Condition Trend Analysis (LCTA) program, long-
term climatic data, precipitation data for storm-runoff modeling, and to allow management of operations
during training rotations.


           373823103465601 Upper Storm Canyon Precipitation Station near Downpour, CO

                                    Policy Exemptions at this Site
Ice measurements.
PFD usage.
Confined space.

                          Recommended Protective Clothing and Equipment
Survival gear for winter months.
Adequate food rations.
Adequate drinking water.
Cell phone and 2-way radio for communication with military personnel.

  JOB/Job Steps                 Potential Hazards                   Recommended Safe Job Practices

   LIGHTNING          Danger from lightning strikes.              Avoid site during electrical storms.

     ACCESS           Accessibility problems during military      Contact Pinon Canyon Maneuver Site
                      training operations. Site is remote         range control during military
                      despite being adjacent to military supply   operations. Carry adequate survival
                      road (especially during winter storms).     gear (primarily during winter, adequate
                                                                  food and water. There is cell phone
                                                                  coverage at the site. A 2way radio is
                                                                  necessary for communication with
                                                                  military personnel. Although close to
                                                                  gravel road, during wet conditions the
                                                                  site will be marginally accessible with
                                                                  a 4-WD vehicle.

Prepared by: W.J. Jones (10-23-00)
Revised by: J.M. Smith (10-22-03)
Reviewed and approved by supervisor: R.D. White (11-07-03)

Appendix 3 - Example routine field inspection form


     Station Number _________________________________________ Insp. No. _______

     Station Name ____________________________________________________________

     Date ___________________, ______ Party __________________________________

     Timing error: __________ F S Logger time: __________ Watch time:_________

     Timing reset? Y / N Record Removed? Y / N Log File: ____________

     Weather: Clear Partly cloudy Light   Medium Heavy Snow Rain

     Wind: Calm Light Breezy      Very gusty other: _______________________
     Wind Direction: ________________ Temperature _____ F

     Precipitation reading: Arrival _________ inches         Departure ________inches
     Check for 45 obstruction-free cone above collector: ________________________

     Funnel/screen condition: Plugged Plugged/draining Clear Frozen Other:__________

     Instrument condition: Out-of-level Level Cups clean/dirty Other: ______________

     Pivot hinge lubricated (tipping bucker)?                  Yes    No    N/A
     Antifreeze and/or mineral oil added as necessary?         Yes    No    N/A
     Dashpot oil level checked?                                Yes    No    N/A
     Collector well drained?                                   Yes    No    N/A
     Alter shields intact?                                     Yes    No    N/A
     Heater turned on?                                         Yes    No    N/A
     Calibration made (on separate form)?                      Yes    No


                                                         Manual tip test

No. of manual tips   No. of tips                                Comments
                                        Initial test

                               Additional test (if necessary)

Appendix 4 - Example calibration test form

 Tipping Bucket Precipitation Gage Volumetric Test Calibration Form

Station No.: ________________________
Station Name: ______________________________________________________
Manufacturer: ________________________
Model No.: ________________________
Serial No.: ________________________
Party: ________________________
Calibration date: ________________________
Calibration time: ________________________

                                                  Desired Acceptable Recorded         Correction
Test Nozzle Volume Start End Elapsed                                          Percent
                                                   no. of  range of   no. of          factor
no. size    (ml)   time time time                                             error
                                                    tips     tips      tips           needed

Was gage level on arrival? Yes____ No _____ On departure? Yes____ No _____
Was funnel free of obstructions on arrival? Yes____ No____ On departure? Yes____ No _____
DCP set back to initial value of _____ at _____.
Remarks (include any adjustments made to the instrument, if any):

Appendix 5 - Example Station Analysis

                          2004 PRECIPITATION STATION ANALYSIS

373823103465601 Upper Storm Canyon Precipitation Station near Downpour, CO

LOCATION. — Lat 37° 38' 23", long 103° 46' 56" (NAD 1983), in SW 1/4, NW 1/4, sec. 3, T.
 28S., R. 57W, Las Animas County (Sheep Canyon 1:24000 quadrangle), Hydrologic Unit
 11020010, on Pinon Canyon Maneuver Site, approximately 80 feet north of Military Supply
 Road 1A, 1.2 miles above Stage Canyon, 6.7 miles west of Rourke Road 1, 12.9 miles east of
 Downpour, and 27 miles south of La Junta.

GAGE. — A 12-inch High Sierra 2400-10 tipping-bucket precipitation gage is located 100 feet
 north of a USGS ground-water well shelter (see sta. no. 373822103465601). The top of the
 collection funnel is 6 feet above the ground surface and is not equipped with a wind shield.
 Rainfall is recorded at a resolution of 0.01-inch. The data from both the ground water well and
 precipitation gage are transmitted every hour via Handar high data rate DCP transmitter. The
 station is solar-powered. Elevation of station is 4,860 feet above sea level, from topographic map.

PRECIPITATION RECORD. — A small tree 30 feet north of the gage was removed on April 5
 to prevent interference (though it is not believed to have had any effect). The gage had apparently

  been hit by a vehicle and was found leaning badly on July 8 . Calibration tests were made before
  and after the gage was re-leveled. Those tests showed that recorded precipitation since the

  previous visit (May 15 ) may be in error by 9 percent, though the exact date is uncertain. Data for
  that period (May 15-July 8) should be considered less accurate than other periods but still useable.

  The instrument was within calibration standards upon departure on July 8 .

COMPUTATIONS AND CALIBRATIONS. — Calibrations were made on two occasions during

  the year – once on February 10 during a routine annual calibration and twice after the gage was

  found damaged on July 8 as shown in the table below. No corrections were made to the data and
  the record for the year was complete except for the period October 1-5 before the gage was
  installed. Record for that period was not considered missing (zero precipitation was inserted for
  those 5 days) since 3 NWS observation stations within 20 miles all reported no precipitation on
  those days (Sample City, Rivertown, and La Junta).

                     Desired Acceptable Recorded
         flow Volume                             Percent
Date                  no. of  range of   no. of          Remarks
          rate  (ml)                              error
                       tips     tips      tips
Feb.       2    501    60.8    58-64       62      +2    Routine
 10                                                      annual
July       2    501    60.8    58-64       66      +9    Found gage
 8                                                       badly out of
July       2    501    60.8    58-64       63      +4    Calibration
 8                                                       after re-
                                                         leveling gage.

REMARKS. — Record good except for period May 15-July 8 [gage was damaged sometime during
 this period]. The records for that period were not estimated (revised) but are considered less
 accurate than the record for other periods. No other stations within 5 miles for comparison, but
 non-thunderstorm readings compare well with the NWS observation station 10 miles away in
 Sample City.

RECOMMENDATIONS. — Two or three protective posts should be cemented around the gage to
 prevent damage from traffic to/from a nearby storage yard.

                                         Computed by: A.B. Black 1-1-05 Checked by:
                                         C.D. White 1-5-05 Reviewed by: E.F. Gray 1-

Appendix 6 - Example text for annual data report


Data Collection and Computation
    Precipitation data generally are collected using weighing bucket gages, collector well/float
systems, or tipping-bucket precipitation gages coupled with electronic data loggers that record
precipitation amounts every 5 to 15 minutes.

    A weighing bucket collector measures precipitation by recording the weight of accumulated
precipitation in a container. The precipitation total for each day is simply the difference in recorded
values between the beginning and ending daily values. This type of collector is topped off with an oil
to minimize summertime evaporative losses and, during the winter months, is charged with a mixture
of propylene glycol and ethanol to ensure proper registration of snow. Precipitation data from
weighing bucket gages are reported to the nearest **X.XX inch depending on type of instrumentation
used by the WSC**.

    Collector well/float gages are usually one of two types. In one type, a standard 8-inch diameter
funnel diverts precipitation to a 3-inch diameter collector pipe. A float connected to a recorder pulley
of specific diameter is used to convert the stage in the well to accumulated precipitation, measured to
the nearest 0.01 inch. Such sites are usually drained each visit and are limited to 10 or 15 inches of
precipitation. Antifreeze may be added to prevent freezing. A second type of float gage is similar to
the one just described except that the ratio of collector to well diameters is much smaller, making it
able to function in areas of high annual precipitation amounts but with much less sensitivity. Such
data are only reported to the nearest 0.1 in.

    Tipping bucket type instruments measure precipitation through the use of two equal-sized
chambers, which alternately fill and drain. As each chamber fills, it tips, simultaneously draining it,
bringing up the second bucket under the collector funnel and recording a known amount of
precipitation, usually 0.01 inch. The precipitation total for each day is computed by summing the
number of tips during the day. During winter months a heating device may be used to melt incoming
snow or ice. Data from tipping bucket instruments are reported to the nearest 0.01-inch. Most
tipping-buckets are calibrated to a two inches per hour rainfall intensity and data may be biased low
when storm amounts exceed this rate. Certain models, however, have a post-processing module that
adjusts values to eliminate under-registration.

    Twenty-four hour precipitation totals (in inches) are tabulated and presented from data having a
recording interval of 15 minutes or less. A 24-hour period extends from 00:00:01 of the current day
through [including] the 00:00:00 hour reading for the next day (to include rainfall from the next-to-
last recording interval observation through midnight. The total precipitation for each complete month
is shown on a line below the daily-sum table. Missing daily or monthly values are indicated by the
symbol ―---―in the table. Daily values for periods of missing record were estimated by **cite uniform
methodology used within Water Science Center OR state that method used at each site will be
documented in the REMARKS section of the manuscript**. The collection, computation, and
publication of precipitation data do not necessarily conform to standards used by the National
Weather Service. Records published in this report are for general scientific use. Original purposes
for collecting this data include, for example, (1) interpretive studies such as watershed modeling and
estimation of aquifer recharge, (2) flood warning networks in metropolitan basins subject to flash-
flooding, or (3) flood forecasting or daily operational decisions by other Federal agencies.

    Several factors can affect the precipitation recorded at a site, including the elevation of the
collector above the land surface, the presence of vegetation, buildings or other barriers near the
collector, or wind around the collector. Snowfall-affected data can result during cold weather
when snow fills the precipitation-gage funnel and then melts as temperatures rise. Snowfall-
affected data are subject to time distribution errors and total volume errors when snowfall depths
exceed the collector funnel height.

Data Presentation
     Precipitation records collected at surface-water gaging stations may be identified with the same
station number and name as the stream-gaging station. Where a surface-water daily-record station is
not available, the precipitation record is published with its own name and latitude-longitude
identification number.

    Information pertinent to the history of a precipitation station is provided in descriptive
headings preceding the tabular data. These descriptive headings give details regarding location,
period of record, and general remarks.

    The following information is provided with each precipitation station. Comments that follow
clarify information presented under the various headings of the station description. LOCATION.--See
  RECORDS section of this report (same comments apply). PERIOD OF
RECORD.--See Data presentation in the EXPLANATION OF STAGE-AND
WATERDISCHARGE RECORDS section of this report (same comments
apply). REVISED RECORDS.--See Data presentation in the EXPLANATION
(same comments apply).

GAGE.--This paragraph provides information on the current and historic types of instrumentation
 used at the station, including the height above land surface and elevation above National Geodetic
 Vertical Datum of 1929 (NGVD of 1929); it is reported with a precision dependent on the method
 of determination.

REMARKS.--Remarks provide added information
 pertinent to the collection, analysis, computation, or
 accuracy of records. EXTREMES FOR PERIOD OF
 RECORD (optional).-- Maximum daily precipitation
 value for period of record. EXTREMES FOR
 CURRENT YEAR (optional).-- Maximum daily
 precipitation value for current year.

Example manuscript for body of annual data report
(Example for a combination streamflow and precipitation monitoring site with a common
name and station number)

                          SAMPLE RIVER BASIN 2003 Water Year

LOCATION.—Lat 32°38'56", long 81°50'27" referenced to North American Datum (NAD) of
1983, Screven-Jenkins County line, Hydrologic Unit 03060202, on downstream side of Downpour
Road bridge, 2.1 miles west of Big City, ND.

DRAINAGE AREA.—240 square miles.

COOPERATION.—USGS National Streamflow Information Program (NSIP).


September 26, 2002 to current year. GAGE.—Satellite telemetry with a water-stage recorder. Datum
of gage is 134 feet above

National Geodetic Vertical Datum (NGVD) of 1929 (from topographic map).
REMARKS.—Records fair.

EXTREMES FOR CURRENT YEAR.—Maximum gage-height recorded, 13.92 feet,
March 23; minimum height recorded, 2.74 feet, October 8, 10, and 11.

                      PRECIPITATION RECORDS
PERIOD OF RECORD.—September 26, 2002 to current year.

GAGE.—Unshielded, standard 8-in. diameter, tipping-bucket precipitation gage, mounted on top of
gage house with the top of the collector 8 ft above the ground.

REMARKS.—No record January 2-10, 2003. Records for July 15-August 30 may be less accurate
than other periods (gage damaged but operational and within ten percent of calibration limits).

Appendix-1x OSW 2010.02 -- Flow Meter Quality-Assurance Check - SonTek/YSI FlowTracker
Acoustic Doppler Velocimeter-- December 30, 2009

SUBJECT: Flow Meter Quality-Assurance Check - SonTek/YSI FlowTracker Acoustic Doppler

The purpose of this memorandum is to establish policy regarding routine quality-assurance (QA)
checks on SonTek/YSI FlowTracker acoustic Doppler velocimeters (ADVs) used for making velocity
and discharge measurements in the U.S. Geological Survey (USGS). This memorandum states the
policy and provides a description of how the QA program will work.
Although this memorandum is specific to the FlowTracker, it is the intent of the USGS Office of
Surface Water (OSW) and the Hydrologic Instrumentation Facility (HIF) to expand this program to
include other velocity meters as they become available and more widely used throughout the Water
Resources Discipline (WRD). Separate guidance will be issued to cover other meters as they are
added to the program; the purpose and structure of the overall program will remain the same
regardless of the velocity meter type or manufacturer.

FlowTracker Quality Assurance Program Policy
Beginning in fiscal year 2010, the OSW is implementing a QA program for checking the calibration
and documenting the performance of all FlowTrackers used in the USGS. Every FlowTracker used
for making velocity and discharge measurements in the USGS will be required to be checked by the
Hydrologic Instrumentation Facility’s Hydraulic Laboratory (HIF-HL) at least once every three years.
As a part of this program, every FlowTracker used in the USGS is required to be registered and
tracked in a database maintained by the HIF. USGS Water Science Centers (WSC) will be notified
when a FlowTracker is due for a QA check based on the information in the database. FlowTrackers
selected for QA checks will be sent to the HIF-HL. The HIF-HL will check the meter’s ability to 1)
measure 2 velocities, 18.0 cm/s (0.59 ft/s) and 33.5 cm/s (1.1 ft/s), within the manufacturer’s
tolerances for accuracy and precision; 2) measure the temperature within ± 2 degrees Celsius of a
National Institute of Standards and Technology (NIST) traceable reference thermometer; and 3) pass
peak signal position and signal-to-noise difference (beam check) tests. FlowTrackers passing the QA
check will be shipped back to the WSC. Meters failing the QA check will, at the WSC’s option, be
sent directly to the manufacturer for repairs and rechecked by HIF-HL, or removed from service. The
repair costs will be the responsibility of the WSC.
Existing registered meters may continue in use until they are scheduled for a QA check sometime
during the first 3 years. In addition to QA checks on existing FlowTrackers, all new FlowTrackers
purchased directly from SonTek/YSI and/or meters sent to the HIF or to SonTek/YSI for repair, must
be QA checked in the HIF-HL before being placed into service for the first time or back in service.
Meters purchased through the HIF will be QA checked as part of the HIF’s standard QA/QC process.

How the QA Program Will Work
Registration of FlowTrackers - FlowTrackers in use by the USGS must be registered in a central
database developed and maintained by the HIF. Data entry into the FlowTracker database will be
made using a web-based user interface. The URL for the registration interface is
http://1stop.usgs.gov/flowtracker/. After the user logs into the interface using their Lotus User ID, the
following information needs to be entered to register each meter:
1. meter serial number;
2. probe type (2D or 3D);
3. probe cable length (2 meter, 3 meter, or 5 meter);
4. primary contact name and email address
5. secondary contact name and email address;
6. office location (the WSC is automatically included in the database based on the user ID of the
person entering the meter information); and
7. the date of purchase.

The OSW is requesting that all FlowTrackers be registered by February 5, 2010. The completion of
registration by this date will allow the QA checking to start during the second quarter of FY 2010.
The HIF obtained a list from SonTek/YSI of all the FlowTrackers sold to the USGS, including the
serial number and the date purchased; this information has already been entered into the HIF
registration system database and is accessible through a pull-down menu. Those WSCs that 1) have
purchased FlowTrackers from the HIF after August 15, 2009, 2) have purchased FlowTrackers with
ARRA funding, or 3) rent FlowTrackers from the HIF, need only update items 4 through 6 in the
above list (items 1, 2, 3, and 7 remain as is). These meters have already been entered into the database
and only require editing.
Notification that QA check is due and scheduling - The HIF will send an email to the primary and
secondary contacts listed in the FlowTracker database and the Data Chief of the WSC, requesting that
the office contact the HIF-HL to schedule the QA check of their meter. The QA checks will be spread
out over the entire fiscal year to distribute the workload at the HIF-HL. Emails will be sent out at the
beginning of each quarter so the WSCs can schedule the shipping of their meters around their
scheduled field work. The number of meters scheduled for QA checks from any one office in any one
year will not exceed 1/3 + 1 of the meters registered at the WSC office. Following the QA check and
any associated updates to firmware and hardware, the meter will be returned to its owner. If requested
by the WSC, a replacement meter can be loaned to the WSC office at no cost. If meters are scheduled
1 to 2 weeks ahead of time with the HIF-HL, it is anticipated that turnaround time will be less than 5
working days.
QA check at HIF-HL - When a meter arrives at the HIF-HL it will be inspected for physical damage.
A beam check will then be conducted and recorded to verify the meter is working correctly. The
meter will then be towed at 2 speeds in the HIF-HL small acoustic towing tank. The towing speeds
are 18 cm/s (0.59 ft/s), the speed used by SonTek/YSI to generate the beam transformation matrix,
and 33.5 cm/s (1.1 ft/s). The 18 cm/s speed is used to verify that the transformation matrix is still
valid at the speed at which it was generated, and the second speed is used to verify that the
transformation matrix is valid at a speed other that the one used to generate it. The HIF-HL will also
measure the temperature within ± 2 degrees Celsius of a NIST traceable reference thermometer. If the
existing transformation matrix is found to be invalid, the meter will be recalibrated using the
SonTek/YSI routines and a new matrix loaded into the unit. (Copies of the old and new matrices will
be kept on file.) The report describing a summary of the meter’s performance during the QA check
will be emailed to the contacts in the database and the WSC Data Chief. An electronic copy of the
QA report, as well as the meter’s QA check data files, will be accessible from the database once the
meter has been checked.
If electronic or physical problems are found with the meter, the WSC office will be contacted and
given the option to remove the meter from service or have the HIF send the meter to the manufacturer
for repair at the expense of the WSC. Repaired meters will have the QA checks repeated by the HIF-
HL before return to the WSC.
WSC Costs
The cost to the WSCs for the QA check of their FlowTrackers will be the cost of shipping the meters
to the HIF-HL using a trackable method and any repair costs that may be required. The cost of the
FlowTracker QA check and return shipping will be covered by the OSW.
It is possible that a WSC may want to have a FlowTracker QA checked outside of the normal 3-year
cycle outlined in this memorandum. This may be necessary as a result of the meter being physically
harmed in some way or because the routine field QA checks show a problem. If a WSC wishes to
have a FlowTracker QA checked or recalibrated, they can contact the HIF and schedule the meter for
the QA check. The cost for QA checking or recalibration of a meter is currently $200.00 per meter
(subject to change).
Additional Information
If you have any questions regarding the FlowTracker database, you can contact Karen Ray at
ktray@usgs.gov (228-688-1528). If you have any questions regarding the FlowTracker QA program
or meter calibrations/performance checking, please contact Kirk Thibodeaux at kgthibod@usgs.gov

1 Any use of trade, product, or firm names in this document is for descriptive purposes only and does
not imply endorsement by the U.S. Government.

Appendix – 1 y OSW 2005.08 -- Policy and Guidance for Archiving Electronic Discharge
Measurement Data

SUBJECT: Policy and Guidance for Archiving Electronic Discharge Measurement Data

The purpose of the memorandum is to provide policy and guidance for archiving discharge
measurement data collected with acoustic Doppler current profilers (ADCPs), acoustic Doppler
velocimeters (ADVs), and with other types of electronic discharge measurement equipment. As
electronic methods for collecting discharge measurement data are increasing, it is important that
procedures be established for archiving these data.
U.S. Geological Survey (USGS) policy states that all original field notes, measurements, and
observations shall be archived indefinitely (Hubbard, 1992). This is necessary because the original
data may be needed for legal requirements, support for future research, or support of published data
and reports. Although all electronic data should be stored in the USGS National Water Information
System (NWIS), no capability for storing electronic discharge measurements in NWIS exists at
present (2005).
Any electronic files created while making a discharge measurement, with any type of equipment,
must be permanently archived, along with any paper field notes. These files include but are not
limited to raw data, configuration information, moving-bed tests, instrument checks, calibration
information, and discharge measurement notes. Procedures outlined in this memorandum are based
on the assumption that every USGS Water Science Center (WSC) already has existing systems and
procedures for performing routine backups for electronic information stored on WSC servers.
Every WSC must establish a documented system for collecting and storing electronic discharge
measurement data. The procedures must include a consistent naming-convention for data files and
directories. The following guidelines should be used to develop archival procedures for both field and
office computers. These procedures must be documented in the WSCs Surface Water Quality-
Assurance Plan.

Care must be taken to ensure that irreplaceable data files collected in the field are permanently
archived on a WSC server. Steps should be taken to prevent loss of data because of accidental
deletion, computer damage or failure, or files simply being lost or forgotten about because of poor file
Field notes should document the names of all electronic files generated for a measurement. It is
recommended that all files for each measurement be stored in one directory or folder on the field
computer. It is up to each individual to organize and safeguard measurement data until it is
permanently stored on WSC servers.
A temporary backup of all files collected as part of a discharge measurement must be made in the
field on some kind of removable non-volatile data storage medium (CD-ROM, a USB flash drive, a
PCMCIA flash card, etc.) and kept separately from the computer. A field backup is recommended
after every discharge measurement. However, at a minimum, all data files collected during a day of
field work must be temporarily backed up on some kind of removable non-volatile data storage
medium at the end of each day during a field trip or permanently stored on a server as outlined in the
Guidelines for Archiving Office Data section that follows.

Each WSC collecting electronic discharge measurement data must have a written policy on
permanent file archiving procedures. This policy should detail file and directory naming conventions,

server directory structure, how soon data must be placed on the server after it is collected, and how,
when, and where server data will be archived on stable archival media. This policy should be
included in the WSC’s Surface Water Quality-Assurance Plan.
Paper measurement notes associated with an electronic discharge measurement should be filed and
archived with other paper discharge measurement notes in accordance with current USGS and WSC
policies and procedures.
Each discharge measurement with multiple electronic data files should have its own directory, which
contains all of the files collected or created as part of the measurement. The naming convention for
the directories in the archival directory structure must include some combination of measurement
dates, water years, and/or instrument types. Below are two examples of directory structures that meet
these requirements. These examples are illustrated using three discharge measurements for USGS
streamgaging station 03378500 and measurements made with a Price AA current meter and
AquaCalc; an ADCP, and a Flowtracker.

Office Archival Directory Structure Example 1
The office archival directory structure example below uses dates and instrument types shown in table
1. In this example, the directory name includes the measurement number assigned to the
measurement, the date of the measurement, and the instrument used.
Table 1.—Information for archiving discharge measurement data for example 1.
[Relative path name for this example is: /data/WY2003/03378500/measurements/]
Meas.No.     Date        Instrument          Directory name           Discharge measurement file(s)
  542      11/17/2002                    542.20021117.aquacalc     1 AquaCalc measurement file: 542.txt
  543      12/31/2002      ADCP            543.20021231.adcp        All files for 1 ADCP measurement
                                                                        All files for 1 Flow-tracker
  544      01/21/2003    Flowtracker    544.20030121.flowtracker

Office Archival Directory Structure Example 2
The office archival directory structure for example 2 is a simplified version of example 1. In this
example, measurement dates and instrument types are not used in the directory names. Furthermore,
since only 1 file is created for the AquaCalc measurement (number 542), no directory was created for
that measurement.

Table 2.—Information for archiving discharge measurement data for example 2.
[Relative path name for this example is: /data/03378500/measurements/]
Meas.No.      Date          Instrument       Directory name         Discharge measurement file(s)
   542     11/17/2002   Price AA/AquaCalc          --           1 AquaCalc measurement file: 542.txt
   543     12/31/2002         ADCP                543             All files for 1 ADCP measurement
   544     01/21/2003      Flowtracker            544          All files for 1 Flow-tracker measurement

It is recommended that data be transferred to the permanent storage directories on the WSC server
within 2 work days of returning to the office. The WSC must provide a method to efficiently transfer
data from the field computers used to collect electronic discharge measurement data to WSC servers
for archiving the data. Direct connection of the laptops to the local area network is recommended.
Provisions should be made to allow for processing of archived data with the software version that was
used for data collection. Versions of the software used for processing measurements should be
available within the same archival data structure used for storing the data. For example, if data were
collected with XYZ software version 9.13, a copy of XYZ version 9.13 should also be archived.
Because it cannot be ensured that the software will run on computer operating systems some years
into the future, it is also essential that electronic discharge measurement summaries be saved in the
ASCII format and printed out and archived with paper measurement notes.
All electronic discharge measurement data stored on WSC servers should be archived according to
the standard WSC back-up procedures on stable archival media but should, at a minimum, be done
annually. The directory structure of the data shall be preserved on the archival media. A minimum of
two copies should be made and stored in different locations, with at least one located outside of the
office. Examples of good archival media are CD-R, DVD-R and DVD+R. Re-writeable media such
as CD-RW, DVD-RW and DVD+RW are not recommended. Archival media should be stored
according to manufacturers’ recommendations.
After the office archival directory structure has been established using the above guidelines, all
electronic files created while making a discharge measurement must be stored using this directory
structure. WSC’s are also encouraged, but not required; to store electronic discharge measurement
files collected prior the issuance of this memo in this same office archival directory.
If you have any questions or comments about the policies and guidance in this memo, please contact
Kevin Oberg (kaoberg@usgs.gov) or the OSW Hydroacoustics Work Group
References cited
Hubbard, E.F., 1992, Policy recommendations for management and retention of hydrologic data of
the U.S. Geological Survey: U.S. Geological Survey Open-File Report 92-56, 32 p.

Appendix 1z – OSW 2007.01 – SonTek/YSI FlowTracker firmware version 3.10 and software
version 2.11 upgrades and additional policy on the use of FlowTrackers for discharge

        The purpose of this memorandum is to (1) announce the availability and
recommended use of new SonTek/YSI FlowTracker firmware and software and (2) clarify
existing policy on the use of FlowTrackers for making wading discharge measurements
described in Office of Surface Water (OSW) Technical Memorandum No. 2004.04.
New software and firmware released by SonTek/YSI offer improved quality-control methods
for FlowTracker discharge measurements. FlowTracker software version 2.11 is backward
compatible with all FlowTracker firmware versions. The new FlowTracker firmware version
3.10 is compatible with most FlowTrackers. However, some early versions of the
FlowTracker with serial numbers below P135 have a hardware limitation that is incompatible
with the new firmware version 3.10 unless the FlowTracker hardware is upgraded. Contact
SonTek/YSI for information on the process and cost for upgrading the FlowTrackers with
incompatible hardware. The software and firmware upgrades are free for compatible
FlowTrackers. The new firmware and software updates are available on the SonTek/YSI web
pages (http://www.sontek.com/product/fw/ftfw.htm).
Evaluations comparing previous FlowTracker firmware and software with test versions of the
new firmware and software indicate that the new firmware and software use the same
algorithms to measure velocity and calculate discharge. Differences found when comparing
the new FlowTracker software with previously released versions are the result of a change in
the number of decimal places used during the calculations. Results of these comparisons are
shown in Attachment A.
All USGS users who collect streamflow data with the SonTek/YSI FlowTracker should
upgrade to the FlowTracker software version 2.11 as soon as possible. All USGS users who
collect streamflow data with a SonTek/YSI FlowTracker capable of utilizing the new
firmware should upgrade to firmware version 3.10 as soon as possible. FlowTrackers that are
not compatible with the firmware version 3.10 should obtain the hardware upgrade so that
firmware version 3.10 can be installed to take advantage of the new firmware features.
In the following sections, enhancements to the FlowTracker firmware and software are
described and existing policies regarding beam checks and velocity measurement methods
for the FlowTracker are clarified.
New Firmware version 3.10 and Software Version 2.11
FlowTracker firmware version 3.10 contains many new features designed to improve
discharge-measurement quality and make the FlowTracker easier to use. A number of
quality-control tests have been added that verify system operation and warn the user of
possible measurement problems. These built-in tests should be very helpful in making
FlowTracker users aware of possible problems, allowing users to take any necessary
corrective action while making a discharge measurement.
The firmware contains some new features not routinely used by the USGS such as: (a) the
Mean Section and Japanese discharge calculation methods; (b) Kreps velocity measurement
method; and (c) translation to four additional languages. These features (a-c) have not been
verified during USGS testing. The core velocity-measurement routines and mid-section
discharge-calculation algorithms used by the USGS have been verified and have not changed
from previous versions of the firmware. The mid-section discharge equation should continue
to be used for all FlowTracker discharge measurements. OSW-recommended settings for the
new FlowTracker firmware are provided in table 1. Quality-control thresholds are checked
with each velocity measurement and when the “End Section” key is pressed. Measurement
locations containing suspect data may be deleted and velocity measurements redone while in
the process of making a discharge measurement in the field.
The new FlowTracker software and firmware can report two different types of discharge
uncertainty values. One is based on an International Organization for Standardization (ISO)
method for calculating uncertainty and the other is based on a USGS developed method (the
Interpolated Variance Estimator or IVE) that uses statistical comparisons of neighboring
verticals. Both values can be a useful indicator of relative measurement quality. The OSW,
however, still is evaluating if either method represents the desired quantitative value of
measurement uncertainty. Hydrographers are encouraged to consider these estimates when
developing ratings and shifts.
Table 1. Recommended FlowTracker Settings. (Values that are underlined and in bold
differ from the default settings.)
Parameter                    Recommended Value
Language                     English
Units                        English
Average Time                 40 seconds
SNR Threshold                10 dB
Standard Error of Velocity
                             0.033 ft
Spike Threshold              10%
Max Angle                    20º
Discharge Equation           Midsection
Repeat Depth                 No
Repeat Velocity              No
Maximum Section Discharge    10%
Maximum Depth Change         50%
Maximum Location Change      100%
Reference                    Rated
                             2-6-8=Y, Ice=Y, Kreps=N, 5 point=N,
Methods Displayed
                             Multi point = N
Uncertainty                  Stats
The spike filtering algorithm in the new firmware removes outliers in the 1-second velocity
data more effectively than previous firmware. The new filtering algorithm may result in a
greater number of spikes being identified and filtered out of the mean velocities. This is the
only known change to the velocity sampling scheme from the previous firmware.
The FlowTracker software version 2.11 contains a new discharge measurement summary
report that will display and print a summary of a FlowTracker discharge measurement. The
summary report includes cross-section plots of velocity, depth, and percent discharge per
section. Attachment B contains a sample discharge measurement summary report.
FlowTracker firmware version 3.10 contains the ability to perform and store an automated
field BeamCheck with each measurement, labeled “QC Test.” It is recommended that this
automated QC Test be completed as part of each discharge measurement. However, this test
does not replace the office BeamCheck (called ADVCheck in previous software versions)
performed with the FlowTracker software on a PC. The office BeamCheck should be
performed, recorded, and archived prior to each week of use. During BeamChecks the signal
amplitude for each beam should plot on top of each other and peak at the sample volume
location. See attachment C for more detailed guidance on performing a BeamCheck.
Velocity Sampling Methods
The six-tenths-depth (0.6) method should be used in depths 1.5 ft or less. For depths greater
than 1.5 ft, the two-point (0.2/0.8) method should be used. If the velocity measurement at the
0.8 depth could be corrupted by the sample volume being located on or near a boundary,
then, in this case a six-tenths method should be used. If a non-standard velocity profile is
found while making a two-point velocity measurement (for example, the 0.8 depth velocity is
greater than the 0.2 depth velocity or the 0.8 depth velocity is less than half the 0.2 depth
velocity), a three-point method (0.2 depth, 0.6 depth, and 0.8 depth) should be used. Users
should not switch to a Price AA meter in streams with depths between 1.5 and 2.5 ft to avoid
using the two-point velocity method. The existence of very low velocities at the 0.8 depth
velocity measurement is not a valid reason to use the six-tenths depth method. As long as the
FlowTracker can measure the water velocity accurately at the 0.8 depth, the two-point
method should be used in depths greater than 1.5 ft.
The ability to use the two-point method for collecting water velocities in depths between 1.5
and 2.5 ft is an advantage of the FlowTracker over Price AA meters. The two-point method
gives more consistent and accurate results than the six-tenths-depth method. Previously, the
stated policy on when to switch from six-tenths-depth (0.6) method to a two-point (0.2/0.8)
method was not as rigid because of concerns that the user would not recognize boundary
issues during the measurement. The new quality control checks in the FlowTracker firmware
version 3.1 should alert users of boundary issues during the discharge measurement, allowing
them to modify the sample location to correct the problem.
If you have any questions or comments about the policies and guidance in this memorandum,
please contact Mike Rehmel (msrehmel@usgs.gov) or the OSW Hydroacoustics Work
Stephen F. Blanchard (signed)
Chief, Office of Surface Water
Attachment A - Software and Firmware Data Comparisons
To compare the FlowTracker software versions 1.30 and 2.11, 40 previously made discharge
measurements were processed using each version of software. The total discharges from the
40 pairs of processed discharge measurements were compared with software versions 1.30
and 2.11 (figure A-1). The new software provided accurate calculations comparable to the
previous version. The largest difference in total discharge was 0.01 percent. The differences
result from a change in the number of decimal places used during the calculations.

Figure A-1. Comparison of 40 discharge measurements computed, using version 1.30 and
2.11 FlowTracker Software.
To compare the FlowTracker firmware versions, two FlowTracker discharge measurements
were made at the same site, using the same tagline stationing. The measurements were made
at existing USGS streamgaging stations under near-steady flow conditions. The FlowTracker
discharge measurements were made in accordance with all USGS methods, procedures, and
policies regarding conventional discharge measurements. There was typically more than 30
minutes between the collection of the two velocity samples at a location. While effort was
made to use the same sample locations with each firmware, small differences in sample
volume placement are likely. From these discharge measurements, one-hundred-fifty 40-
second velocity samples where compared (figure A-2). The mean difference between the 40-
second sample data collected with firmware version 2.4 and the test versions of firmware
3.10 was +1.1 percent with a median difference of +0.6 percent. The small positive
differences may be a result of fewer boundary issues in the data collected with new firmware
versions that contain the additional quality indicators. However, temporal and sample volume
placement differences, along with the natural stream pulsations, likely account for most of
the variation found.

Figure A-2. Comparison of one-hundred-fifty 40-second velocity samples collected with
FlowTracker firmware 2.4 and 3.1 (test versions).

Attachment B – New FlowTracker Software Version 2.11 Output
The following files should be exported (figure B-1) and archived with the original binary
data file (.WAD) in accordance to OSW Policy Memorandum 2005.08 “Policy and Guidance
for Archiving Electronic Discharge Measurement Data”:

       ASCII Discharge file (.DIS)
       ASCII Control file (.CTL)
       ASCII Summary file (.SUM)
       ASCII Data file (.DAT)

At a minimum, a printout of either the discharge-summary portion (figure B-2) of the new
Discharge Summary Report or the ASCII Discharge file (.DIS) must be attached to each
discharge-measurement note sheet. A printout of the entire Discharge Summary Report
(figures B-2, B-3, B-4, B-5) may be attached, depending on office policy. A Water Science
Center should have a written policy for consistency of discharge-measurement notes within
each office.

Attachment C – Correct BeamCheck Procedures
BeamCheck is a diagnostic program for the FlowTraker that displays and records the return
signal strength versus the range for each receiver on the probe. A BeamCheck should be
performed in the office prior to each week of use. The FlowTrackers built-in automated QC
field test does not replace the requirement to perform the office BeamCheck.
All users should read section 6.5 of the FlowTracker Technical Manual. The manual provides
detailed instructions on how to use the BeamCheck software and interpret the results.
Items of importance when performing a BeamCheck:

       Keep the FlowTracker at least 2 inches from the bottom of the bucket and the transmitting transducer
       about 8 to 12 inches from the far wall of the bucket (figure C-1).
       Start pinging and allow the FlowTracker to collect a few pings prior to enabling recording. If the
       FlowTracker is placed correctly in the bucket, the plot should look similar to figure C-2. If the plot
       looks very noisy (i.e., figure C-3), change the placement of the probe to ensure the sample volume is
       not too close to a boundary.
       Record at least 20 pings with the probe properly located in the bucket.
       BeamCheck should be archived in accordance with the electronic archival policies stated in accordance
       to OSW Policy Memorandum 2005.08 ―Policy and Guidance for Archiving Electronic Discharge
       Measurement Data.‖

Figure C-1. Picture showing correct placement of FlowTracker probe in bucket of
water to perform a BeamCheck. Note that the probe is located 2 inches from the
bottom of the bucket.

Appendix 2a      Index velocity station installation form.

ADVM Installation and Set up
Station Number:

Station Name:

Date Installed:                                     By:
System serial number:            HIF number:                             USGS W-
System Model:                          System Frequency:                 Firmware:
Cable Length:                   meters

Initial Beam Check performed: Yes No          Filename:
Boundary reflection identified at:                   feet meters
Independent water temperature:                       ADVM water temperature:

ADVM mounted on:           Left bank   Right bank       Other:

Mid-transducer face depth

Gage Height:              - depth to transducers = GH of transducers:                ft m
Elevation of ADVM above bottom:                  feet  meters

Note: White Molex connector (jumper) connected for RS-232 communications and
unplugged for SDI-12 communications.

ADVM Configuration

Out Format                             Recorder ON        SDI12 Address:
AI               seconds               SI          seconds

Cell Begin (CB)                        Cell End (CE)

Blanking Distance (BD)                 Cell Size (CS)                    Ncells

Salinity (SAL)                                PowerPing          ON      OFF

Internal Clock
Date:                                  Time set @
Compass heading:                       Pitch:                    Roll:
Deployment Name:

Site diagram on back.

Appendix 2b   Index velocity station field form.

Appendix 3a. Florida WSC electronic file archive directory structure.

Appendix 3b. Florida Water Science Center electronic file naming conventions.
Under the Current WY Directory (see Appendix 3a)

         o     Log files downloaded from DCP and datalogger equipment
                     If the original file from the DCP must be converted to something else before
                        loading into decodes, BOTH files must be archived
                     Filenames must begin in the format ‘EDL_station number_YYYYmmdd’
                                 Use the date the file was downloaded from the DCP in the filename
           o Electronic files generated from programs such as SWAMI and CHIMP
                     The default naming convention from these programs is OK
           o Scanned copies of paper inspections
                     Filenames must begin in the format ‘INSP_station number_YYYYmmdd’
           o Electronic files generated from programs such as “Levels”
                     The default naming convention from these programs is OK
           o Scanned copies of paper level notes
                     Filenames must begin in the format ‘LEVEL_station number_YYYYmmdd’
           o For each measurement, there must be a sub-folder that contains all of the relevant
               files and information for that measurement
                     The name of the sub-folder must be the measurement number
                     Measurement files within the sub-folder should begin with
                        ‘station number_YYYYmmdd’ wherever possible (depending on software)
                     Be sure to include any QA data associated with the measurement
           o Index-velocity and Stage-Area rating files in excel (or similar) and measurement
               summaries should be stored here
           o Stage-Q ratings from GRSAT could also be saved here
           o Filenames must include the station number, rating number, and water year
       Station Analysis
           o Station Analyses in word processor documents or saved to an electronic file from
                     Filenames must include the station number and water year
       Station Description
           o Station Descriptions in word processor documents or saved to an electronic file from
                     Filenames must include the station number and water year

         o Files generated from the SWReview script
        o Electronic files related to velocity meters that are used at Index-velocity gages
               Includes beamchecks, data files, configuration files, etc.
               Filenames must either:
                            Begin with the station number and date of download, or
                            Create a subfolder named with the date of the inspection that
                            includes all of the velocity related files for that inspection
     Water Quality
        o Spreadsheet used to determine corrections and/or data quality ratings
               Filename must include the station number and relevant WY
        o Electronic ASR forms or other files related to QW sampling

Station Information

     DCP Programs

         o   Copies of DCP/EDL configurations

                    Filenames should uniquely identify their corresponding station and include
                     the date they were created or downloaded from the DCP

                              If the DCP software allows it, filenames must begin in the format
                              ‗Station number_YYYYmmdd‘ (02305000_20091201)

                              If the DCP software limits the filename to 8 characters, use the first 4
                              characters to uniquely identify the station name and the last 4
                              characters should be MMYY

                                  o   For example, a DCP program for station ―Muddy Creek near
                                      Acme, FL‖ that was downloaded on March 1, 2010 could be
                                      named ―mudc0310‖

     Levels Summary

         o   An electronic version or a scanned copy of the level summary for the station

                    Filenames must begin in the format ‗LEVEL_SUMMARY_station number‘


         o   Any photos, sketches, etc. relating to the station

         o   Filenames should describe the subject (control, gagehouse, etc.) and include the date


  o    This area is meant to provide permanent, stable pathnames to be used when linking
       items to SIMS

  o    For example, if a picture of the control is taken with every measurement, that picture
       can be linked to the SIMS station analysis

              A stable link can be established in SIMS -

              All photos should be stored in the ―Pictures‖ folder, but the most recent
               picture would be copied to the SIMS folder and renamed simply

              Whenever you want a new picture in SIMS, you‘d simply paste the new
               picture into the SIMS directory and rename it

  o    Some examples of pictures you might want linked to SIMS include:

              Low-water control, High-water control, gage, upstream, downstream,
               measurement location, staff, PZF, Levels sketch, crest-stage gage, etc.


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