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									                DRAFT-2
         Preliminary Assessment
     of the Safe Yields & Operations
            of New York City’s
     Major Water Supply Reservoirs
          with NJDEP Findings
                DRAFT-2
                       Prepared by
                Division of Water Supply
  New Jersey Department of Environmental Protection
Prepared April 13, 2007; Last Revised December 13, 2007
                                                          1
                        OBJECTIVES
The objective of New Jersey is to establish the need for:
   Reassessment of NYC reservoirs affecting the Delaware Basin
   Interstate equity assurance
   Conjunctive use of Hudson & Delaware reservoirs
   Optimization of all reservoir operating programs
 Needs:
     An objective reassessment of NYC’s Delaware Reservoirs,
      including alternative operations changes to improve drought
      management, increase minimum Montague flows and reduce
      flood probability.
     An objective assessment of the conjunctive use of NYC’s
      Delaware & Hudson Systems to optimize water resource
      management of both systems.
     Consideration of effect of partial to full restoration of NJ’s
      D&R Canal diversion, permanently.
                                                                       2
                   BASIS FOR REASSESSMENT
 The 1983 “Good Faith Agreement” (Sect. 8) calls for periodic
  review and recommends such modifications as may be
  required to respond to changing conditions.
    NYC’s use conditions have changed substantially and a
     thorough reassessment of NYC’s yields is warranted.
 Significant improvements may be possible due to
  fundamental changes in NYC’s operating conditions.
  Alternate operations need to be assessed to improve public
  safety and enhance multiple uses, including:
    Water supply, drought management, flood mitigation,
     Montague flows, fisheries.
 The 1983 “Good Faith” assumption of equity between the
  Montague flow reduction, NYC’s diversion curtailments and
  NJ’s D&R Canal curtailments were done without a
  fundamental understanding between the affects of curtailing
  diversions from storage, which can improve safe yield, and
  curtailing diversions from run-of-river sources, which
  provides no such improvement.
                                                               3
                            BACKGROUND
 In 1954, a Supreme Court Decree established operating criteria
  for NYC’s Delaware Basin Reservoirs between NYC, NJ, NY,
  PA and DE, that is, the Parties to the Decree.
• In 1954, NYC’s combined systems’ safe yield was estimated at
  1,665 mgd.
 A minimum flow of 1,750 cfs was set at the Montague Station on
  the Delaware River, to be maintained by NYC.
 The Safe Yield of NYC’s Delaware Reservoirs was estimated at
  800 mgd (with Montague minimum flow maintained at 1,750
  cfs) for the original Design Drought of 1929-32.
 1954 operating criteria included the Excess Release Quantity
  (ERQ):
       • ERQ = NYC’s highest year’s combined total Hudson &
         Delaware Systems’ consumption (i.e., use), plus an additional
         7.25 bg to account for the following year’s possible growth,
         subtracted from the total combined systems’ safe yield, and the
         remaining quantity, if any, multiplied by 83 %. The ERQ is to
         be reserved for the lower basin states’ use the following year.
                                                                      4
                    BACKGROUND (cont’d)
 Essentially, the Supreme Court Decree reservoir operating
  criteria was rendered obsolete by a more severe drought, the
  Drought of the 60’s. The Good Faith Agreement operating
  plan was adopted in 1983 to address this more severe
  drought. (Docket D-77-20-CP, Revised (REV 1). The Good
  Faith operating plan entailed:
    Reducing the minimum Montague flow target from 1,750
     cfs to 1,100 cfs (37% reduction) in drought emergency.
    Reducing NYC diversions from 800 mgd to 520 mgd
     (35% reduction) during drought emergency.
    Reducing D&R Canal diversion from 100 mgd to 65 mgd
     (35 %), during drought emergency.
    Introduction of a “Vernier Scale” schedule of releases to
     increase minimum Montague flows if salinity threatened
     the Delaware Estuary public water supply intakes.
                                                             5
              BACKGROUND (cont’d)
 In 1983, apparently Montague low flow targets and
  NYC & NJ D&R Canal diversion curtailments were
  set without a thorough assessment of the resulting
  safe yields or equity of impact comparing the:
   Montague flow cutbacks
   The Delaware & Hudson system safe yield equity
   The Delaware Reservoirs safe yield, alone.
   The D&R Canal curtailment
 Neither the Army Corp’s Daily Flow Model (DMF),
  nor the current OASIS Model derived from the
  DFM, have been used to assess the safe yields of the
  Delaware Reservoirs.
                                                     6
         NJDEP Preliminary Assessment
 The NJDEP performed a preliminary review &
  assessment of safe yields and operations:
   The safe yields of the Delaware Reservoirs,
    (Neversink, Pepacton & Cannonsville) were
    generated by post-processing the results of the DRBC
    OASIS Model.
     The technique for post processing the OASIS
       Model is explained in the Technical Slides portion
       of this slide set.
   The safe yields of the Hudson System Reservoirs
    were based on several historic 60’s Drought
    Assessment Reports.
   A partial summary of the reference Reports used by
    the NJDEP to assess both the Delaware and Hudson
    Systems’ safe yields and operations follows:

                                                        7
               The NJDEP reviewed 10 independent Reference Reports:
•   REPORT 1: NY State Department of Health
    ”Comprehensive Public Water Supply Study for the City of New York and County of Westchester”,
    1967; Sponsored by the New York State Department of Health; performed by Metcalf & Eddy, Hazen &
    Sawyer, and Malcolm Pirney, Engineers.
•   REPORT 2: United States Geological Survey (USGS)
    ”Probability Analysis of Allowable Yield of New York City Reservoirs in the Delaware River Basin”,
    1968, by the USGS; sponsored by the DRBC.
•   REPORT 3: US Army Corps of Engineer (USACE)
    “Hydraulic Analysis of the New York City Water Supply System”, 1974, by Quirk, Lawler & Matusky,
    Engineers for Northeastern United States Water Supply Study, sponsored by US Army Corps of
    Engineers.
•   REPORT 4: Task Group Report, DRBC Docket No. D-77-20
    “Appraisal of Upper Basin Reservoir Systems, Drought Emergency Criteria and Conservation
    Measures”; March, 1979.
•   REPORT 5: Department of Atmospheric Science, NY State University at Albany
    ” The 1980-81 Drought in Southeastern New York”, July, 1985
•   REPORT 6: Department of Physics and Atmospheric Science, Drexel University, Phila, PA.
    ” The 1980-81 Drought in Eastern Pennsylvania”, 1983
•   REPORT 7: City of New York
    “Mayor’s Intergovernmental Task Force on New York City Water Supply Needs, 1992”
•   REPORT 8: USGS, Lloyd T. Brooks, 2005
    “Flood of September 18-19, 2004 in the Upper Delaware River Basin, New York”
•   REPORT 9: USGS, Thomas P. Suro and Gary D. Firda
    “Flood of April 2–3, 2005, Neversink River Basin, New York”
•   REPORT 10: Hazen and Sawyer for NYSDEC
    “Delaware-Lower Hudson Region Water Resources Management Study ”, Sept, 1989                    8
                                                                                                         4
  REPORT 1: NY State Department of Health, 1967
• The Report 1 study assessed the reduced, post drought
  of the 60’s, safe yield of all the NYC reservoirs as of
  1967. The Report 1 study assessed the City’s safe yields
  under conditions that:
   – Minimum Montague flow was maintained at 1,750 cfs at
     all times
   – NYC diversion was on a continuous daily basis
   – 67 BG of Reserve Capacity, i.e., 25 % of the capacity of
     the Hudson Basin Systems’ Rondout, Ashokan and
     Croton Reservoirs is not used in the Safe Yield
   – Zero Reserve Capacity is held in the Delaware reservoirs
     (Pepacton, Neversink & Cannonsville)
                                                                9
From Report 1: NY State Dept of Health Report, 1967
 Safe Yields of Delaware & Hudson Reservoirs after 60’s Drought




                                                                  10
   From Report 1: NY State Dept of Health Report, 1967
 Storage used for Safe Yields of Delaware & Hudson Reservoirs after 60’s Drought
  Basin     Reservoir Full Capacity (BG) % Reserved Cap. Used in Safe Yield (BG)
Delaware Pepacton                      140                0                        140
          Cannonsville                  97                0                         97
          Neversink                     34                0                         34
Hudson Rondout                          50               25                         38
          Croton                        94               25                         71
          Ashokan                      123               25                         92
          Scholharie                    17                0                         17
              Total Cap                555                                         488
            DIFF (BG)=                                                              67
Note: The FFMP applies a model that incorporates a temporary designation of 35
mgd for fishery use, taken from NYC’s 800 mgd diversion. This modeling
technique is meant to simulate constructing13 bg of theoretical storage. This is
also equivalent to reducing NYC’s reserve storage in the Hudson System from 25
% to 20 %; i.e., from 67 bg to 54 bg.; or it is approximately the difference between
480 mgd & 510 mgd in safe yield estimates between Report 1 and 2.
                                                                                  11
    Findings from REPORT 1: NYS Dept of Health (Cont’d):
• Alternative actions identified by NY State in Report 1 to
  increase NYC’s Safe Yield to offset 60’s Drought, included:
   • Conservation (Long term strategy, not implemented until
     1990’s)
   • Flood skimming Susquehanna River to augment Cannonsville
     Res
   • Several new reservoirs and/or reservoir modifications including
     addition of about 13 bg additional storage to Cannonsville.
• Recommended as most expedient interim solution?
   • Having lower Delaware Basin states agree to Montague
     flow reductions.
   • This resulted in:
      • Increasing NYC’s Delaware Reservoirs, alone, safe yield from 510
        mgd to about 630 mgd. (See Technical Slides for NJDEP analysis)
      • Montague flow reduced up to 37% during Drought Emergency
      • NYC Delaware Reservoir diversions reduced up to 35%
      • NJ D&R Canal diversion reduced by up to 35%
                                                                     12
     REPORT 2: USGS Safe Yield Analysis, 1967
• Report 2, sponsored by the DRBC, provides a range
  of safe yields of Delaware Reservoirs, relative to a
  range of Montague flows to be maintained
  continuously. (see next graph)
   – New York City’s Safe Yield is estimated at 482
     mgd while maintaining a minimum flow of 1,750
     cfs at Montague at all times.
• In USGS Study, all rates of diversion, whether 800
  mgd or less, and all corresponding Montague
  minimum flow maintenance targets are continuous.

                                                    13
                                                             Report 2: USGS Safe Yield Analysis (cont’d)
                                                                Fom USGS Study: Diversion Rate (mgd) vs Montague Flow Rate (cfs)
                                           1,000
                                                                    20-Year Drought               1929-32 Drought                                                            10-Year Drought
                                                                                                                                                                             20-Year Drought
                                            900                                                                                    10-Year Drought                           50-Year Drought
NYC Delaware Reservoirs Safe Yield (mgd)




                                                                                                                                                                             100-Year Drought
                                            800                                                                                                                              200-Year Drought
                                                                                                                                                                             500-Year Drought
                                                                                                                                                                             1929-32 Drought
                                            700
                                                                                                                                                                             1961-67 Drought
                                                                                                                                                            50-Year Drought
                                                          855 mgd for 1929-31
                                            600          Drought with Montague
                                                              at 1,750 cfs                                                                           100-Year Drought

                                                                                                                                                   200-Year Drought
                                            500                                     1961-67 Drought
                                                                                                                                             500-Year Drought

                                                          482 mgd for 1961-67
                                            400          Drought with Montague
                                                              at 1,750 cfs
                                                                                                                                              1,750 cfs
                                            300
                                                   800

                                                          900

                                                                 1,000

                                                                         1,100

                                                                                 1,200

                                                                                         1,300

                                                                                                 1,400

                                                                                                           1,500

                                                                                                                   1,600

                                                                                                                           1,700

                                                                                                                                   1,800

                                                                                                                                           1,900

                                                                                                                                                    2,000

                                                                                                                                                             2,100

                                                                                                                                                                     2,200

                                                                                                                                                                              2,300

                                                                                                                                                                                      2,400

                                                                                                                                                                                              2,500

                                                                                                                                                                                                      2,600
                                                                                                         Montague Flow target (cfs)
                                                                                                                                                                                                      14
              Comparison of Reports 1 & 2 Findings:
 The 60’s Drought reduced the safe yield of NYC’s Delaware
  Reservoirs to between 510 mgd, (Report 1) & 480 mgd (Report 2)
  when Montague minimum flow is maintained at 1,750 cfs (not
  reduced during drought events). Report 1 appears more accurate,
  with the participation of several prominent engineering firms.
 NYC’s peak month to average annual use ratio until the mid 1990s
  was nearly 1 to 1. Peak month and average annual demand were
  nearly the same and per capita use was approximately 200 gpcd.
 In 1983, both Montague flows and NYC diversions were varied
  according to drought rule curves established in the “Good Faith
  Agreement”. Thereafter, the actual safe yield can only be
  determined by a time-step model for various drought events. This
  has apparently never been done by the DRBC or any of the Lower
  Basin States.
   – NOTE: NYCDEP has operations models which may provide a means to
     explore conjunction operating alternatives if integrated with the DRBC
     OASIS Model, to improve the combined total Delaware & Hudson System
     uses under various optimization plans. The NJDEP recommends that
     NYCDEP provide such models for use by all the Parties to the Decree and to
     the DRBC prior to any future negotiations of the Good Faith Agreement. 15
        Comparison of Reports 1 & 2 Findings (cont’d):

 The 1,290 mgd safe yield NYC utilizes in the FFMP IERQ
  calculation is 40 mgd less than the safe yield NY State calculated in
  1967, (1,330 mgd) with Montague maintained at a minimum of
  1,750 cfs. It is 5 mgd greater than the entire D&R Canal
  curtailment, 35 mgd, set in 1983.
 The 1,290 mgd safe yield NYC utilizes in the FFMP ERQ
  calculation is about 150 mgd less than the resultant REV 1
  Delaware Reservoirs’ safe yield of 630 mgd, with NYC’s diversion
  assumed at 800 mgd whenever possible, which is no longer how
  NYC operates by design. NYC’s current operating plan increases
  its equivalent service population to over 11 million people.
 NYC’s practical operating peak month limit from the Delaware
  Reservoirs is greater than 800 mgd, closer to 900 mgd. If the
  appropriate seasonal demand pattern were applied this peak
  month demand could be met, and with appropriate rule curves,
  drought period curtailments might be set at far less than 35 %.
 The 25 % storage reserved in the Hudson System, including         16
  Rondout, and 9 mgd of unaccounted-for safe yield in Kensico
  Findings from REPORT 3: USACE Safe Yield Analysis, 1974
 USACE analyzed aqueduct capacities, operational options,
          physical limits & alternative tunnels.
   – USACE considers 510 mgd as correct safe yield for Delaware
     Reservoirs w/Montague maintained at 1,750 cfs at all times as
     determined in Report 1).
• USACE used same safe yields for Hudson System as
  found in NYS Dept. of Health Report, Report 1.
• USACE suggests 25 % reserve capacity appears too
  conservative & NYC safe yield could be increased simply
  by reducing the reserve capacity.
• Report 3 describes two hydro-electric turbines (NYC
  owned):
   – Pepacton Tunnel Turbine (22 MWs at 457 mgd) and;
   – Neversink Tunnel Turbine (31 MWs at 360 mgd +-)
      • Note: Brookfield Power owns a 7.5 MW West Delaware
        Hydro plant built on the West Delaware Tunnel, which
        operates only when diversions are less than 300 mgd.

                                                                     17
          Findings from REPORT 3: (USACE, cont’d)
• NYC owned combined output = 53 MWs, (for
  comparison, Lake Wallenpaupak, PPL, produces about
  45 MWs)
• Combined diversion rate of approximately 800 mgd
  maximizes electric generation from Pepacton &
  Neversink.
   – NJDEP analysis of NYC’s diversion records indicate
     NYC maximizes diversions from Neversink & Pepacton
     in summer for most economical power production and
     maximizes releases from Cannonsville for Montague
     flow maintenance whenever possible, but also routinely
     uses Cannonsville, as needed, during drought periods.
   – NJDEP analysis of NYC operating records also indicate
     water quality of Cannonsville Reservoir is only a
     marginal problem, routinely offset by blending with
     Neversink and Pepacton Reservoirs as well as
     conjunctive use of Hudson System water.

                                                              18
    Findings from REPORT 4: DRBC Task Group, 1979

•   Minimum flow recommended at Montague, 1,525
    cfs, at all times.
•   NYC’s diversion reduced as low as 430 mgd in
    drought.
•   Conjunctive use of the Hudson & Delaware System
    was to be evaluated by Task Group, however, there is
    no evidence in the Task Group Report that this was
    done.
•   Like the Good Faith operating plan, the Task Group
    recommendations were based on NYC drafting 800
    mgd until onset of drought, when severe cutbacks of
    both Montague & NYC’s diversions are needed to
    offset previous over-drafting.
•   Appropriate at the time, before NYC’s current,
    normalized, use pattern, there was a genuine need 19
    for NYC to meet a peak month to average ratio of 1.
           Findings from REPORT 5 & 6: Departments of Atmospheric
           Sciences, NY, State U. at Albany, 1985 & Drexel U, PA 1983
•       The drought of 1980-81was a “storage drought”, a
        drought principally caused, not by a severe precipitation
        deficit, but by NYC’s inability to restrain usage during a
        heat wave; that is, leakage and loss and lack of
        conservation programs added to the demand surge.
    –      Therefore, the Good Faith Agreement’s drought rule curves
           & curtailment schedule appear to be principally derived
           from the emergency actions taken in response to the
           “Storage Drought” of 1980-81 as described in the Delaware
           River Master Reports from 1980 & 1981.
    –      NYC’s continuous drafting at a peak demand of 800 mgd is
           now a permanent characteristic of the operating plan but is
           no longer appropriate under NYC’s current
           physical/operating constraints and system demand
           characteristics.
                                                                        20
  From REPORT 5: Department of Atmospheric Science, NY, 1985
   New York City 1980-81 Percent of Total Storage (Delaware + Hudson)
           Compared to 13-year Average (between 1968-80)




 Taken from Report 5,
“The 1980-81 Drought in Southeastern New York”

 ---     13 year Average of Percent of
       Delaware + Hudson System Storage
 ------ Actual Percentage of Delaware +
      Hudson System Storage



                                                                        21
     REPORT 7: Mayor’s Intergovernmental Task Force on New York
                    City Water Supply Needs, 1992; &
    Report 10: Delaware-Lower Hudson Region Water Resources
                          Management Study
•    In Reports 7 & 10, Hazen & Sawyer recommends
     normalizing NYC’s use pattern by implementing typical
     conservation practices, such as universal metering, leakage
     & loss reduction and conserving plumbing, to normalize
     NYC’s use pattern.
•    NYC’s conservation program is nearing completion &
     enables NYC to serve over 11 million people with a demand
     of 1,470 mgd.
    – The combined total minimum safe yield due to the 1983
         Good Faith Agreement is 1,440 mgd. With about 10 %
         reserve capacity in the Hudson System, the combined
         total would be about 1,470 mgd, the demand goal in the
         Reports & & 10. This suggests NYC already designs its
         operations around its true safe yield and this should be
         reflected in a new Delaware Basin Operating Rule Curve.

                                                                   22
            Findings from REPORTS 7 & 10 (cont’d)
•   By normalizing its per capita use, NYC can now
    rely on the Good Faith Agreement operating plan
    & the proposed FFMP to provide NYC the ability
    to serve over 11 million people, even without using
    any of its 25 % reserve storage in the Hudson
    System.
•   NYC’s original peak demand and yield needs have
    been nearly fully protected via the Montague flow
    reductions insofar as NYC can meet peak demands
    from the Delaware Reservoirs of well over 800
    mgd, often at peak months of over 900 mgd.
    –   See the following chart, taken from Report 7, on
        normalizing NYC’s water usage and expanding
        NYC’s service population to over 11 million people
        per Hazen & Sawyer, Consulting Engineers to NYC:

                                                         23
REPORT 7: Mayor’s Intergovernmental Task Force on New York City Water Supply Needs, 1992
          New York City Projected Safe Yield Ranges with Conservation Affects




                                                                                           24
  The Delaware Reservoirs’ Demand & Physical Limits
…….Safe Yield is not only a function of net
 reservoir inflow but also of:
• Physical conveyance limits
    – On a monthly average basis, Delaware Reservoirs’ water can not be
      diverted at rates significantly greater than the physical limits of the
      Delaware Aqueduct
• Seasonal demand patterns
    – On a monthly average basis, Delaware Reservoirs’ water cannot be
      diverted at rates significantly greater than the actual need.
• The current OASIS model runs assume a NYC demand of 800 mgd at
  all times, which does not reflect the NYC’s actual operations, nor is it
  an appropriate application of current or future design criteria.
    – Demand curves that reflect average and peak seasonal variation, and the
      physical limits and demand constraints of NYC’s system, should be used in
      the OASIS Model
    – Various improvements to Montague flow, fisheries, D&R Canal
      restoration, lower basin storage and Estuary salinity should be
      investigated relative to actual demand pattern. See following graph

                                                                                25
                                                 1,000
                                                                        Trial NYC Seasonal Diversion Patterns for Continuous Average Rates
                                                             Applying normalized seasonal demand                                                  Peak Month Average, as
                                                  900
                                                             rates, like those shown, and & Drought                                               Limited by Demand &
NYC Total Delaware Reservoirs' Diversion (MGD)



                                                             Diversion Rule Curves may provide NYC                                                Physical Conveyance
                                                  800        adequate safe yield to serve over 11                                                 Properties, about 840 to
                                                                                                                                                  900 mgd
                                                             million people & may allow for increased
                                                             Montague flow and reduced drought
                                                  700        events.

                                                  600


                                                  500
                                                                                                          Continuous Average, as Limited by
                                                                                                          Demand & Physical Conveyance
                                                  400                                                     Properties, about 600 mgd
                                                             Off-Peak Minimums Averages, as Limited
                                                             by Demand & Physical Conveyance
                                                  300        Properties, between 410 and 540 mgd


                                                  200                 From Actual use Records: Jan-Dec 2001
                                                                      Seasonal Varying Curve: Continuous Avg (mgd)= 657 Max Month Diversion (mgd) = 851
                                                                      Seasonal Varying Curve: Continuous Avg (mgd)= 600 Max Month Diversion (mgd) = 840
                                                  100                 Seasonal Varying Curve: Continuous Avg (mgd)= 624 Max Month Diversion (mgd) = 899
                                                                      Seasonal Varying Curve: Continuous Avg (mgd)= 586 Max Month Diversion (mgd) = 878
                                                                      No Use Variation: Continuous Average (mgd)= 600
                                                    0
                                                         J        F        M       A        M         J         J        A         S          O         N        D
                                                                                                                                                                             26
   The Delaware & Hudson System Reservoirs should be
Equitably Optimized by Appropriate Conjunctive Operations
• The safe yield of the Hudson System reservoirs can
  be estimated, conservatively, under various
  percentages of reserve storage.
• The critical duration for the Hudson Valley area
  reservoirs can be estimated by extrapolating from
  precipitation records of the Hudson Valley.
• The time between the onset of the steady decline
  from the yearly average precipitation of about 42
  inches until the onset of a steady rise in
  precipitation is used in a weighted average for the
  likely critical duration.
• The following graph demonstrates the method:
                                                       27
100
                                                       Estimated Critical Duration from
                                                   12-Month Average Running Precipitation
                                                Hudson Valley & Northeastern NYS & NJ Regions
                                                                (LOG SCALE)
inches




                  NYState-Hudson Valley precipitation begins decline when
                  running 12-month average is less than 42 inches on 7/15/61.
                  End Decline 7/31/65.
                  Estimated Critical Duration=1,478 Days
                                                                                      12-Mo Running Avg NYState-Hudson Valley Precip

 10
         Jan-60




                              Jan-61




                                                  Jan-62




                                                                    Jan-63




                                                                                      Jan-64




                                                                                                        Jan-65




                                                                                                                          Jan-66




                                                                                                                                            Jan-67




                                                                                                                                                               Jan-68
                     Jul-60




                                       Jul-61




                                                           Jul-62




                                                                             Jul-63




                                                                                               Jul-64




                                                                                                                 Jul-65




                                                                                                                                   Jul-66




                                                                                                                                                     Jul-67
                                                                                                                                                              28
              1000
                                              Peak Safe Yields, Hudson Reservoirs Only
                                          at Varius % Reserve Capacity (Minimum Estimates)

                   950
                                   W/20% Reserve in Safe Yield                    EST. CRITICAL DURATION =
                                   Hudson System                                  1,478 DAYS MAXIMUM PEAK
SAfe Yield (mgd)




                                   W/15% Rreserve in Safe Yield                   SAFE YIELD, w/NO RESERVE
                   900             Hudson System                                  STORAGE LIMITS=855 MGD
                                   W/10% Reserve in Safe Yield
                                   Hudson System
                                                                        PEAK SAFE YIELD =837 MGD (10%)
                   850             W/ 0 % Reserve Safe Yield
                                   Hudson System                        PEAK SAFE YIELD =828 MGD (15%)

                                   W/ 25 % Reserve Safe Yield           PEAK SAFE YIELD =820 MGD (20%)
                                   Hudson System                        PEAK SAFE YIELD =810 MGD (25%)
                   800
                         0   100    200   300   400   500   600   700    800   900 1,000 1,100 1,200 1,300 1,400 1,500 1,600
                                                             Critical Duration (days)
                                                                                                                      29
                   1000
                                     Estimated Combined Hudson System Safe Yield;
                   900                       Increase per % Reserve Storage
                   800


                   700          With 10% Reserve Storage, Hudson System Total
                                Safe Yield is about 840 mgd. If the Safe Yield of the
                   600
                                Delaware Reservoirs (630 mgd) is added, total Safe
Safe Yield (MGD)




                   500          Yield is 1,470 mgd. (1,480 mgd with Kensico safe
                   400
                                yield). If a varible demand pattern were modeled, safe
                                yield may increase further. A safe yield of only 1,280
                   300
                                mgd enables NYC to meet a peak month demand of
                   200          1,665 mgd at its normalized demand Peak Mo to
                                Annual Average use ratio of 1.3 to 1.
                   100

                                                           Reserve Storage (%)
                     0
                          0%            5%               10%               15%         20%            25%
                           Catskill per % Reserve Stor                  Croton per % Reserve Stor
                           Rondout per % Reserve Stor                   Hudson Systm per % Reserve Stor
                                                                                                     30
          Findings Relative to REPORTS 8 & 9:
    USGS Reports on Flood of Sept, 2004 and April 3, 2005
•     By inspection of the flow record, the consequence of NYC’s
      normalized seasonal demand pattern appears to be an increased
      probability of spilling reservoirs, which decreases the frequency of
      storage voids that provided flood mitigation in the past.
•     Using the USGS method to estimate the attenuating affects of the
      Cannonsville Reservoir presupposes…..
    –     peak inflow, from gages upstream of the reservoirs, weighted and
          summed, reasonably represents the peak inflow to the reservoir.
         • This method over-estimates the peak inflow. The peak inflows
             to the reservoirs are not cumulative nor directly proportional
             to drainage area since they are dependent on time of
             concentration and watershed characteristics, not simple area
             ratios. {Average Daily Flows, ADFs, are more appropriately
             & typically extrapolated by area ratios.}
•    Since the USGS method for estimating peak inflows tends to over-
     estimate the inflow, by comparison, the USGS method makes full
     reservoirs appear to provide greater attenuation than they
     actually do.

                                                                        31
West Branch Delaware River at Walton, Stilesville & Hale Eddy




                                                            32
                       Findings Relative to USGS REPORTS 8 & 9: (Floods of Sept, 2004 & 2005)
                  45,000
                                      Cannonsville Reservoir Estimated Peak Inflow vs.
                  40,000             Peak Outflows at Stilesville, West Br. Delaware River
                                                             (NOT A HYDROGRAPH)          From 2001 onward flood
                  35,000                                                                 probability and intensity appears
                                        Stilesville Peak= Peak Outflow                   to increase, possibly due to
                  30,000                Cannonsville USGS Estimated Peak Inflow          increased probability & affect of
Peak Flow (CFS)




                                        Peak Inflow NJDEP Extrapolation                  splling reservoirs
                  25,000


                  20,000


                  15,000


                  10,000


                   5,000
                              Pre-Cannonsville       Post-Cannonsville
                      0
Year                   J-52   J-56     J-60   J-64   J-68   J-72    J-76   J-80   J-84   J-88     J-92    J-96     J-00      J-04
            Pre-reservoir peak inflows were extrapolated using USGS methods & compared to gaged peaks at
            Stilesville, just downstream of the reservoir, which should be nearly identical; they were not. Therefore,
            USGS estimated peak inflows, post reservoir, are likely over-estimated. By comparison , then, post-
            reservoir Stilesville peak flows make Cannonsville Reservoir appear to provide more peak flow
            attenuation than it may. The NJDEP method related Walton & Stilesville peaks. NJDEP extrapolations
            of peak inflow, (triangles) using the more conservative method show lower peak inflows and therefore,
            by comparison , less attenuation. This is preliminary and needs to be examined in a reassessment.

                                                                                                                                    33
East Branch Delaware River between Margaretville & Fishs Eddy




                               Pepacton Reservoir




                                                           34
      Findings Relative to USGS REPORTS 8 & 9: (Floods of Sept, 2004 & 2005)
70,000
                 Pepacton Reservoir Estimated Peak Inflow vs Peak Outflows at
60,000                       Downsville, East Br. Delaware River
                                                (NOT A HYDROGRAPH)

50,000                                      Downsville Peak = Peak Outflow
                                            USGS Method Estimated Peak Inflow
                                            NJDEP Estimated Peak Inflow
40,000
                                     Post-Pepacton
30,000

20,000

10,000
cfs




                   Pre-Pepacton
      0
          J-38    J-43   J-48     J-53   J-58   J-63   J-68   J-73   J-78   J-83   J-88   J-93   J-98   J-03
 Pre-reservoir peak inflows were extrapolated using the USGS method & compared to actual gaged
 peaks at Downsville, which should be nearly identical; they were not. Therefore, USGS estimated peak
 inflows, post reservoir, are likely over-estimated also. By comparison , then, post-reservoir Downsville
 peak flows make Cannonsville Reservoir appear to provide more peak flow attenuation than it may. The
 NJDEP method related Margaretville & Downsville peaks. NJDEP extrapolations of peak inflow,
 (triangles) using the more conservative method show lower peak inflows and therefore, by comparison,
 less attenuation. This is preliminary and needs to be examined in a future reassessment.

                                                                                                               35
Neversink River between Claryville and Neversink




  Neversink Reservoir


                         Pepacton Reservoir




                                                   36
                     Findings Relative to USGS REPORTS 8 & 9: (Floods of Sept, 2004 & 2005)
          40,000
                                          Neversink Reservoir Estimated Peak Inflow vs.
          35,000                         Peak Outflows at Neversink Gage, Neversink River
          30,000                                                Neversink at Neversink=Peak Outflow
                                                                NJDEP Method
                                                                USGS Method
Peak Flow (cfs)




          25,000

          20,000
                                                       Post-Neversink
          15,000

          10,000

                  5,000

                      0
                                 Pre-Neversink
                          J-41    J-45   J-49   J-53     J-57     J-61   J-65   J-69   J-73   J-77   J-81   J-85   J-89   J-93   J-97   J-01   J-05
                  Pre-reservoir peak inflows were extrapolated using USGS methods & compared to gaged peaks at
                  Neversink, just downstream of the reservoir, which should be nearly identical; they were not. Therefore,
                  USGS estimated peak inflows, post reservoir, are likely over-estimated. By comparison then, post-reservoir
                  Neversink peak flows make Neversink Reservoir appear to provide more peak flow attenuation than it may.
                  The NJDEP method related Claryville & Neversink peaks. NJDEP extrapolations of peak inflow, (triangles)
                  using the more conservative method show lower peak inflows and therefore, by comparison , less
                  attenuation. This is preliminary and needs to be examined in a reassessment.

                                                                                                                                                 37
       Findings from USGS REPORTS 8 & 9 (cont’d)
   Hydrographs comparing the extrapolated Average Daily Flow
    (ADF) into the reservoirs ADF outflow, indicates a pattern of
    use for the Delaware Reservoirs that shows:
•   Cannonsville outflows trend closer to inflows; that is,
    Cannonsville is releasing a greater % of inflow than Pepacton
    & Neversink. Since Pepacton and Neversink are used
    preferentially for water supply and power generation, releases
    from Cannonsville are primarily for maintaining Montague
    flows as often as possible.
•   When Montague flows are self-maintaining, all the Delaware
    Reservoirs trend toward full or spilling, which may contribute
    to flood probability, especially in off-peak demand seasons, i.e.,
    fall, winter and spring.
•   Outflow from Pepacton & Neversink indicate more inflow is
    held for preferential use for public water supply.
•   ADF outflow is trending closer to inflow in recent years, most
    probably due to the unintended consequences of NYC’s
    normalized demand pattern.
                                                                    38
                                                   Findings from USGS REPORTS 8 & 9 (cont’d)
  100000

                                                             Cannonsville ADF Inflow vs Outflow

           10000
Average Daily Flow (cfs)




                     1000




                           100



                                                                                                               D-77-120-CP goes into effect 1977:
                                                                                                      Lowest outflows increase for fisheries maintenance by
                           10                                                                                        about 30 mgd on avg.

                                                                                                    Cannonsville Extrapolated ADF Inflow
                                               Pre-Reservoir           Post-Reservoir               Stilesville Gage=Cannonsville ADF Outflow
                            1
                                 Jul-52


                                          Jul-56


                                                    Jul-60


                                                              Jul-64


                                                                         Jul-68


                                                                                  Jul-72


                                                                                           Jul-76


                                                                                                     Jul-80


                                                                                                              Jul-84


                                                                                                                       Jul-88


                                                                                                                                Jul-92


                                                                                                                                         Jul-96


                                                                                                                                                  Jul-00


                                                                                                                                                              Jul-04
Date

                                                                                                                                                               39
                                   Findings from USGS REPORTS 8 & 9 (cont’d)
      100,000
                                            Pepacton ADF Inflow vs Outflow

                10,000
Average Daily Flow (cfs)




                           1,000




                            100


                                                                                D-77-120-CP goes into effect 1977:
                                                                        Lowest outflows increase for fisheries maintenance,
                             10                                                       about 35 mgd, on avg.

                                                                      Pepacton Extrapolated ADF Inflow
                                   Pre-Reservoir   Post-Reservoir     Pepacton Gaged ADF Outflow

                              1
                                   Oct-34
                                   Oct-36
                                   Oct-38
                                   Oct-40
                                   Oct-42
                                   Oct-44
                                   Oct-46
                                   Oct-48
                                   Oct-50
                                   Oct-52
                                   Oct-54
                                   Oct-56
                                   Oct-58
                                   Oct-60
                                   Oct-62
                                   Oct-64
                                   Oct-66
                                   Oct-68
                                   Oct-70
                                   Oct-72
                                   Oct-74
                                   Oct-76
                                   Oct-78
                                   Oct-80
                                   Oct-82
                                   Oct-84
                                   Oct-86
                                   Oct-88
                                   Oct-90
                                   Oct-92
                                   Oct-94
                                   Oct-96
                                   Oct-98
                                   Oct-00
                                   Oct-02
                                   Oct-04
                                   Oct-06
                                                               Date
                                                                                                                     40
                                    Findings from USGS REPORTS 8 & 9 (cont’d)
        10000
                                                     Neversink ADF Inflow vs Outflow



                   1000
Average Daily Flow (cfs)




                           100




                            10



                                                                            D-77-120-CP goes into effect 1977:
                                                                           Lowest outflows increase for fisheries
                             1
                                                                            maintenance, about 20 mgd on avg.

                                                                          Neversink ADF Inflow Extrapolated
                                                                          Neversink ADF Outflow (gaged)
                                 Pre-Reservoir   Post-Reservoir
                             0
Date
                                 Oct-41
                                 Oct-43
                                 Oct-45
                                 Oct-47
                                 Oct-49
                                 Oct-51
                                 Oct-53
                                 Oct-55
                                 Oct-57
                                 Oct-59
                                 Oct-61
                                 Oct-63
                                 Oct-65
                                 Oct-67
                                 Oct-69
                                 Oct-71
                                 Oct-73
                                 Oct-75
                                 Oct-77
                                 Oct-79
                                 Oct-81
                                 Oct-83
                                 Oct-85
                                 Oct-87
                                 Oct-89
                                 Oct-91
                                 Oct-93
                                 Oct-95
                                 Oct-97
                                 Oct-99
                                 Oct-01
                                 Oct-03
                                 Oct-05
                                                                                                                    41
         Findings from USGS REPORTS 8 & 9 (cont’d)
•       Attenuation of Average Daily Flow (ADF) during
        flood storms is often not significant. That is, the ADF
        outflow is often the same as ADF inflow.
    –     In the 2005 flood, Neversink ADF peak outflow was
          greater than the ADF peak inflow
•       Compared to the many years when NYC’s use was
        closer to a continuous 800 mgd due to uncontrolled
        use and leakage & loss, the reservoirs had a higher
        probability of being drawn down, thereby providing
        a degree of unplanned flood control.
•       The following hydrographs demonstrate the
        maximum peak events, usually lasting from a few to
        several hours, and the ADF impacts from the floods
        of 2004, 2005 and 2006 for Cannonsville, Pepacton &
        Neversink Reservoirs:
                                                              42
      25,000

                            Sept 18th, 2004 Flood:
                                                                                 22,600 cfs
                        Cannonsville Inflow vs Outflow
      20,000
                       Average Daily Flow (ADF) & Peak
                                                                                 19,278 cfs
                        Cannonsville Extrapolated ADF Inflow CFS
                        Stilesville Gage=Cannonsville ADF Outflow
                        USGS Estimated Peak Inflow
      15,000            NJDEP Extrapolated Peak Inflow
                        Stilesville Peak =Cannonsville Peak Outflow
                  Cannonsville provided significant attenuation of
                  the ADF in the 2004 Flood. Peak outflow was
      10,000      reduced but not by as much in comparison to the                             10,200 cfs
                  over-estimated inflow, 22,600 cfs, generated in
Q (cfs)




                  the USGS method. The effectiveness of flood
                  attenuation from a spilling reservoir is dependent
                  on time of concentration, geometry and storm
          5,000   development and one storm is not a good
                  indicator of future performance.



             0
Date
           13-Sep-04    14-Sep-04    15-Sep-04    16-Sep-04    17-Sep-04   18-Sep-04    19-Sep-04    20-Sep-04
                                                                                                           43
     40,000
                                  Sept 18th, 2004 Flood:                                    37,500 cfs
     35,000                    Pepacton Inflow vs Outflow.
                             Average Daily Flow (ADF) & Peak
     30,000
                             Pepacton Extrapolated ADF Inflow
     25,000                  Pepacton Gaged ADF Outflow                                     24,315 cfs
                             USGS Estimated Peak Inflow
     20,000                  Pepacton Extrapolated Peak Inflow                              20,200 cfs
                             Gaged Downsville Peak=Pepacton Peak Outflow
     15,000         Pepacton was spilling prior to this 2004 storm and provided
                    modest attenuation of the ADF. Peak outflow was reduced,
     10,000         but not nearly as much in comparison to the over-estimated
                    inflow, 37,500 cfs, projected by the USGS method. Future
Q (cfs)




                    storms may have unpredictable results.
          5,000


             0
Date         12-Sep-04    13-Sep-04   14-Sep-04   15-Sep-04   16-Sep-04   17-Sep-04   18-Sep-04     19-Sep-04
                                                                                                         44
             10,000
                                  Neversink Reservoir:                              9,677 cfs

              9,000             Flood of Sept 18th, 2004;
                                 ADF Inflow vs Outflow
              8,000             & Peak Inflow Estimates                             7,900 cfs

              7,000          Neversink ADF Inflow Extrapolated
                             Neversink ADF Outflow (gaged)
              6,000
                             Neversink Reservoir Extrapolated Peak Inflow (USGS)
                             Neversink Reservoir Extrapolated Peak Inflow (NJDEP)
Flow (cfs)




                             Neversink R at Neversink=Peak Outflow
              5,000
                        Use records indicate that while NYC diverted
                        significant water from Neversink Reservoir
              4,000                                                                 4,020 cfs
                        prior to the 2004 Flood, Pepacton and
                        Cannonsville were not used at all, though
              3,000     spilling. NJDEP estimates there was about 3
                        to 5% void space in the Neversink and that
              2,000     even this small amount may have
                        contributed to significant reduction of the
                        ADF.
              1,000


Date              0
                13-Sep-04   14-Sep-04   15-Sep-04   16-Sep-04   17-Sep-04   18-Sep-04     19-Sep-04   20-Sep-04
                                                                                                          45
     30,000
                     April 3rd, 2005 Flood: Cannonsville Inflow vs Outflow
                               Average Daily Flow (ADF) & Peak
     25,000               Cannonsville Extrapolated ADF Inflow CFS                 25,442 cfs
                          Stilesville Gage=Cannonsville ADF Outflow
                          USGS Estimated Peak Inflow                               22,131 cfs
                          NJDEP Extrapolated Peak Inflow
     20,000               Stilesville Peak =Cannonsville Peak Outflow

                  In the 2005 Flood, Cannonsville was spilling but
                  again attenuated the ADF as during the 2004 flood.
     15,000       Whether the amount of ADF reduction is a significant             14,800 cfs
                  benefit remains to be assessed. Significantly ADF
Q (cfs)




                  attenuation relative to various voids also remains for
                  future assessment.
     10,000




          5,000




Date         0
           28-Mar-05 29-Mar-05 30-Mar-05 31-Mar-05 1-Apr-05        2-Apr-05   3-Apr-05   4-Apr-05   5-Apr-05
                                                                                                       46
          40,000
                                    April 3rd, 2005 Flood:
          35,000                 Pepacton Inflow vs Outflow
                                                                             33,629 cfs
                               Average Daily Flow (ADF)& Peak
          30,000
                          Pepacton Extrapolated ADF Inflow
                          Pepacton Gaged ADF Outflow
          25,000
                          USGS Estimated Peak Inflow
                                                                             22,866 cfs
                          Pepacton Extrapolated Peak Inflow
          20,000          Gaged Downsville Peak=Pepacton Peak Outflow        19,400 cfs
                         Pepacton during 2005 Flood provided
          15,000         minor attenuation of ADF. USGS method
                         overestimates peak inflow and, by
          10,000         comparison, makes attenuation appear
                         greater than it actually is.
Q (cfs)




           5,000


               0
Date
             30-Mar-05         31-Mar-05      1-Apr-05       2-Apr-05   3-Apr-05          4-Apr-05
                                                                                             47
       25,000
                                     Neversink Reservoir:           23,100 cfs

                      Flood of April 3rd, 2005; ADF Inflow vs Outflow &
                                    Peak Inflow Estimates
       20,000

                            Neversink ADF Inflow Extrapolated
                            Neversink ADF Outflow (gaged)                                17,391 cfs
                            Neversink Reservoir Extrapolated Peak Inflow (USGS)
       15,000               Neversink Reservoir Extrapolated Peak Inflow (NJDEP)
                            Neversink R at Neversink=Peak Outflow
 Flow (cfs)




                        The Neversink reservoir was spilling prior to the 2005 Flood. The USGS          12,300 cfs
                        extrapolated a peak inflow of 23,100 cfs by drainage area ratios from a
       10,000           peak inflow of 16,600 cfs. The NJDEP extrapolation of peak inflow is
                        17,391 cfs.
                        The ADF is not attenuated. However, all conclusions are subject to
                        some uncertanty since the flows must be extrapolated when no direct
                        monitoring is available.
              5,000




 Date             0
                28-Mar-05     29-Mar-05    30-Mar-05   31-Mar-05     1-Apr-05      2-Apr-05       3-Apr-05      4-Apr-05

The peak ADF out of the reservoir is greater than the peak ADF into the reservoir.
This is possible when the energy of the incoming flood wave causes a prolonged
surge in the reservoir’s spilling. In other words, the spilling reservoir alters the
mass volume distribution of the incoming ADF, magnifies the ADF peak, and
makes flooding worse than flooding would be without the reservoir.
                                                                                                                     48
          45,000

                        June 28th, 2006 Flood:
          40,000                                                                           40,621 cfs
                    Cannonsville Inflow vs Outflow
                   Average Daily Flow (ADF) & Peak
          35,000
                                                                                           34,249 cfs
                                                                                           33,100 cfs
                           Cannonsville Extrapolated ADF Inflow CFS
          30,000           CFS (from Hale Eddy)
                           USGS Estimated Peak Inflow
          25,000           NJDEP Extrapolated Peak Inflow
                           Stilesville Peak =Cannonsville Peak Outflow
          20,000
                     Peak flow attenuation is significantly less
                     than extrapolated compared to USGS
          15,000
                     method. The ADF is not significantly
                     attenuated.
          10,000
Q (cfs)




           5,000


Date           0
             22-Jun-06   23-Jun-06   24-Jun-06   25-Jun-06   26-Jun-06   27-Jun-06   28-Jun-06   29-Jun-06   30-Jun-06
                                                                                                                49
    35,000
                                June 28th, 2006 Flood:
    30,000                   Pepacton Inflow vs Outflow                                     30,364 cgs

                           Average Daily Flow (ADF) & Peak
    25,000
                            Pepacton Extrapolated ADF Inflow
                            Pepacton Gaged ADF Outflow                                      21,370 cfs
    20,000                                                                                  20,000 cfs
                            USGS Estimated Peak Inflow
                            Pepacton Extrapolated Peak Inflow
    15,000                  Gaged Downsville Peak=Pepacton Peak Outflow
                       Peak flow attenuation is significantly less than
    10,000             extrapolated compared to USGS method. The
                       ADF is not significantly attenuated .

         5,000
Q(cfs)




             0
Date
           22-Jun-06    23-Jun-06   24-Jun-06   25-Jun-06   26-Jun-06     27-Jun-06   28-Jun-06   29-Jun-06
                                                                                                     50
  20,000

                         Neversink Reservoir: Flood of June 28th, 2006;
                         ADF Inflow vs Outflow & Peak Inflow Estimates
                            Neversink Reservoir Extrapolated Peak Inflow (USGS)                 15,989 cfs
  15,000                    Neversink ADF Outflow (gaged)
                            Neversink Reservoir Extrapolated Peak Inflow (USGS)
                            Neversink Reservoir Extrapolated Peak Inflow (NJDEP)
                            Neversink R at Neversink=Peak Outflow                               12,108 cfs


  10,000                 The USGS method yields a peak inflow of 15,989
                         cfs. The NJDEP extrapolation yields a peak inflow
Flow (cfs)




                         of 12,108 cfs. The ADF appears to be not                               7,840 cfs
                         significantly reduced.


      5,000




Date 0
             22-Jun-06     23-Jun-06    24-Jun-06    25-Jun-06    26-Jun-06   27-Jun-06   28-Jun-06     29-Jun-06
                                                                                                             51
       Summary: New Jersey DEP Findings (cont’d)
1. Curtailing diversions and Montague releases from the
   Delaware Reservoirs conserves NYC’s storage, extends
   NYC’s yield, & increases its ability to export water.
   NYC’s ultimate demand can be met by continued
   normalization of its use with or without reserving 25 %
   storage in its Hudson reservoirs. There is no reserve
   storage in the Delaware Reservoirs
2. New Jersey’s D & R Canal is a “run of river” system with
   no on-stream storage (i.e. diversion cutbacks translate
   directly to safe yield reductions)
  A.   Raritan System storage must be used to offset the D&R Canal
       diversion reduction in droughts.
  B.   For all practical purposes, the lowest curtailment of the D&R
       Canal diversion, 65 mgd, is the peak yield for allocation and safe
       yield design.
  C.   The safe yield of the Canal has been 65 mgd for the past 25 years

                                                                        52
             Summary: New Jersey DEP Findings (cont’d)
3.       NYC, due to Montague flow reductions and its normalized demand,
         can now serve over 11 million people, 2 million more than its current
         demand, to design year 2035.
4.       Restoring 20 mgd of the D&R Canal diversion has no significant
         affect on NYC’s safe yield or lower basin storage recreational use. It
         is 10 mgd less than the difference between the 480 mgd NYC claims
         as its safe yield & the 510 mgd safe yield assessment NY State did in
         1967. It is 20 mgd less than the difference of 1,290 mgd and the 1,330
         mgd total yield estimated in NY State’s Report 1.
5.       The draft USACE 3-D model needs to be applied to assessing varying
         Montague flows to better understand and gauge the impact on
         salinity.
6.       According to the OASIS* model runs, the operating modifications for
         increased fishery releases alone have a greater impact to lower basin
         storage than partial restoration of the D&R Canal alone.
     *      OASIS Model runs assess the impacts of various release alternatives,
            but OASIS is not being run with NYC’s actual operating and
            demand pattern. OASIS applies an obsolete rule curve and therefore,
            produces unrealistically high numbers of drought days and gives no
            indication of the excess water that may be available.

                                                                              53
         Summary: New Jersey DEP Findings (cont’d)
7.   The physical constraint on NYC’s Delaware Aqueduct
     conveying combined Delaware & Rondout storage) is
     about 890 mgd, monthly. Further, an operational
     constraint is the peak month to average annual use ratio
     of 1.3. Therefore, the maximum continuous safe yield
     under NYC’s current demand pattern is approximately:
       890 mgd / 1.3 (Peak Mo. to Annual Avg) = 685 mgd.
8.   Since the physical/operational constraints of NYC’s
     system result in a safe yield of 685 mgd via it’s Delaware
     Aqueduct, and since Rondout Reservoir alone has a safe
     yield of at least 100 mgd, (w/25 5 reserve capacity) the
     Delaware Reservoirs need only maintain 595 mgd on a
     continuous average basis.
9.   NYC cutting back to 765 mgd is still approximately 170
     mgd greater than its demand pattern and physical
     constraints show can be used or is needed on a continuous
     average basis.
                                                             54
               Summary: New Jersey DEP Findings (cont’d)
10. At 630 mgd, under Rev 1, the safe yield of the Delaware Reservoirs
    alone exceeds the current physical-operational constraints of NYC’s
    system and results in frequently spilling reservoirs during the off-
    peak or “recharge” seasons, and increases spillage probability.
11. The current total combined safe yield of 1,290 mgd (used in the
    current FFMP) is 40 mgd less than NYC’s (Report 1) estimate of
    its safe yield, 1,330 mgd, with Montague maintained at 1,750 cfs at
    all times. The FFMP IERQ should use, at a minimum1,330 mgd as
    the safe yield, not 1,290 mgd when Montague is maintained at 1,750
    mgd & 1,440 mgd after a drought year
12. The safe yield of Kensico is 9 mgd; the safe yield of the Hudson
    System, without 25 % reserve capacity is a minimum of about 850
    mgd; the safe yield of the Delaware Reservoirs with Montague flow
    reductions under REV 1 fishery release improvements, is about 630
    mgd. The total combined NYC safe yield is about 1,490 mgd. Using
    the maximum month total demand of 1,665 mgd, the reduction of
    safe yield is about 10 %. Using 25 % reserve capacity in the Hudson
    System, NYC’s total safe yield is about 1,450 mgd. Utilizing the
    Decree safe yield of 1,665 mgd, the reduction is about 13 %. Either
    calculation shows far less an impacts to water supply safe yield than
    35 % .

                                                                      55
    Summary: New Jersey DEP Findings (cont’d)
13. The FFMP is predicated on 13 bg of additional storage.
    Such a storage project is expected to require an EIS,
    including an assessment of need and alternatives. A
    reassessment is expected to demonstrate additional storage
    is unneeded when alternative operations & true yields are
    examined.
14. The 1983 operating plan appears to have been derived
    from the emergency actions taken during the drought of
    1981, which occurred during the Good Faith negotiations.
    The responses to that particular drought appear to have
    served as a template for the 1983 REV 1 Operating.
    However, the 1980-81 drought was a storage drought due
    more to the uncontrolled use spurred by a heat wave
    rather than a precipitation deficit. It is no longer an
    appropriate drought scenario under today’s use and
    conservation programs.


                                                            56
                   Summary: New Jersey DEP Findings
15. Although there’ve been assessments of the effects of global
      warming (see The Metropolitan East Coast Regional
      Assessment: http://ccsr.columbia.edu/cig/mec/index.html ), on flood,
      drought, sea level & water supply, there has never been an
      assessment of the potential increase in flood probability due to
      the normalization of NYC’s demand.
    •     While Reports 7 & 10 to NYC include estimates of increased
          yield & service population relative to conservation, no Report
          considers the potential for increased spill and flood
          probability due to the operating changes.
    •     Data shows it is far more likely that recent floods (as well as
          droughts) have been made more probable and more severe by
          NYC’s demand change and the obsolete rule curves, not by
          new or extreme weather patterns. Even if flood improvement
          operations could not be applied, early warning flood
          procedures might have been beneficial or more effective.
16. The rule curves no longer correlate to NYC’s normalized use
      patterns. Storage records show that upper basin drought
      conditions occur even during average rainfall years due to the
      current obsolete operating plan.
          (see following storage hydrographs)
                                                                             57
Graphs comparing various storage levels prior to normalizing NYC demand. NYC’s
operations cause average precipitation years to be equivalent to drought years. (inches
rainfall from Oct to Sep, Hudson Valley) This puts Delaware Basin in unnecessary droughts.




    1991 =Average Precip Year (43.1 in)            1993= Average Precip Year (40.9 in)




  1995 Below Average Precip Year (31.3 in)            1997= Average Year (42.8 in)

                                                                                         58
    Affect of Rule Curves in Recent Drought Years under
                 NYC’s Normalized Use Pattern
   The winter and early spring droughts that have
    occurred recently are only an expression of an obsolete
    rule curve predicated on an 800 mgd demand, even in
    winter.
   The NYC “curtailment” to 520 mgd is still more than
    100 mgd greater than NYC’s current off-season
    demand, by NYC’s current design. Such a “curtailment”
    although not actually below NYC’s off-season needs,
    still results in Montague flows that could be severely
    reduced and inequitably affect the 3 lower basin states.
   And, NYC cannot use 800 mgd year round for future
    growth; as explained previously, NYC’s ability to serve
    future growth is dependent upon reducing, or
    NORMALIZING, off season demand.
   The Rule curves & resultant storage are inconsistent
    with existing NYC demand characteristics.

                                                          59
                                                 The NYC winter droughts of
                                               1998-99 & 2001-02 caused NYC
                                                  “curtailment” to 520 mgd,
                                                 which is still about 100 mgd
                                                  greater than NYC’s winter
                                                demand. Such a “curtailment”
                                                 reduces Montague flow too
                                                  severely and the rule curve
                                               sends the Delaware Basin into a
        1999 = Average Precip Year (43.3 in)   Drought Emergency that might
                                                     be avoidable via an
                                                   appropriate, alternative,
                                                        operating plan.




2001=Below Average Precip Year (31.3 in)       2002= Below Average Precip Year (35.6 in)


                                                                                   60
                      Recommendations:
1.    Cooperatively modify operations of the Delaware
      Reservoirs with consideration of conjunctive use
      effects of the Hudson Basin System to support
      fisheries, reduce lower basin droughts and mitigate
      upper basin flood probability.
     • Coordinate drought conditions, precipitation, snow
         pack, between two basins for predictive
         improvements.
     • Preserve as much of NYC’s peak and average yield
         as practically warranted relative to design
         population, but try to improve flood mitigation,
         drought protection & fisheries in the Delaware
         Basin without substantial impacts to the Hudson
         Basin.
     • NYCDEP should provide any operations or safe
         yield models for use by all the Parties to the Decree
         and to the DRBC prior to any future negotiations of
         the Good Faith Agreement.
                                                                 61
                    Recommendations:
2. Construct a new operating plan that considers;
  •   Removing the “water year” that promotes the over-
      draft/under-draft” approach
  •   Raising NYC’s peak month diversion rate but also applies
      the appropriate average, peak and off-peak demand rates
  •   Recalibrating the Drought Rule Curves to apply
      appropriate percents of flow & diversion reduction more
      akin to typical conservation actions, between 5% and 15%
      of the actual ultimate demand curve.
  •   Conducting trial model runs to:
      •   Restore full Montague flow
      •   Apply one lesser Montague flow to serve all drought
          conditions.
      •   Raise minimum & lower maximum Montague flows
  •   Assess the accuracy of salinity affects to better relate the
      response, if any, between short term and long term
      Montague flows to Estuary salinity.
  •   Restoration of the full D&R Canal diversion

                                                                     62
                   Recommendations (Cont’d):
3.   Increase minimum conservation releases in the event of a
     tailwater only drought condition.
4.   Maintain the existing rule curves as a back up, (the same or
     similar), based on a condition of NYC’s need to divert up to
     800 mgd, continuously, in the event of a Hudson System shut
     down or partial failure. (Various scenarios of severity would
     need to be assessed)
5.   Conduct an appropriate flood probability analysis relative to
     NYC’s actual demand curve and compared to alternate rule
     curves. The alternatives should include earlier sustained
     withdrawal and greater releases to Montague to reduce off-
     season spillage and improve the potential for void space and
     flood mitigation. Alternate operations and proper flood
     routing methods should be coordinated with the Flood task
     Force efforts.
6.   Considering the elimination of the ERQ to create a better
     operating plan for conjunctive use should be considered.


                                                                 63
        END,
GENERAL PRESENTATION

     Technical
     Reference
       Slides
      Follow


                       64
                               NJDEP Method for Estimating
                         NYC’s Delaware System Safe Yield (cont’d)
    Safe Yield is not ONLY a Function of inflow deficits, it is also a
    Function of the:
•   Efficiency of the system.
     • Large leakage & loss has same effect as Reducing reservoir inflow
     • Conservation has the same effect as Increasing reservoir inflow
•   Demand Pattern can have effect of Increasing storage in reservoir.
     • Peak to average use rates greater than 1 to 1 save off-season storage.
•   Safety Factors used.
     • Only 75% of the available storage is used for Hudson System safe yield.
     • ZERO % is reserved for calculating the Delaware Reservoirs safe yield.
•   Operating Plan Criteria, such as the conjunctive use of all storage reservoirs
     • Delaware Basin waters are used substantially to fill Rondout Reservoir, (50
        bg), West Branch Reservoir, (10 bg), and Kensico Reservoir, (30 bg
        connected to both the Catskill and Delaware Aqueducts) and add to the
        safe yield. All are gravity fed.
          • It is likely that the Delaware Reservoirs are preferentially used to recharge
            Kensico Reservoir (30 bg), almost as large as the Neversink (34 bg). Use of
            Delaware Basin waters to recharge Kensico effectively extends the Delaware
            Reservoirs’ storage capacity. That NYC’s new claim that Kensico Reservoir
            must be kept nearly full should be substantiated. Even so, it would not
            necessarily substantially lessen the effectiveness of the 34 bg of storage in
            the estimated 9 mgd safe yield; it may be only a timing of transfer issue.
                                                                                        65
                   NJDEP Method for Estimating
             NYC’s Delaware System Safe Yield (cont’d)
• To estimate the Safe Yield of the Delaware System under the
  1983 REV 1 operating plan, the OASIS Model was used as
  follows:
   – The DRBC provided OASIS runs covering both the 30’s & 60’s
      droughts. Model runs provide the combined storage volume of
      the NYC Delaware Reservoirs during drought periods.
   – From the Storage Curve, the Critical Duration of the drought
      can be found, as well as any excess storage remaining.
        • The Delaware Reservoirs’ Critical Duration for the 30’s
          Drought starts June 13, 1929; the minimum storage of 24.3
          bg is reached on Feb 18, 1931. That is 614 days.
        • The Delaware Reservoirs’ Critical Duration for the 60’s
          Drought starts June 30, 1961; the minimum storage of 18.3
          bg is reached on Sept 16, 1965. That is 1,538 days.
• The following two graphs show storage volumes with NYC
  operating at 800 mgd, when able, & display the Critical
  Durations for the 30’s and 60’s Droughts, respectively.

                                                                  66
                              300                                                                                                     4

                                               Storage During 1954 Design Drought, 1929-31
                              250




                                                                                                                                          Drought Index Numbers (0, 1, 2 & 3)
                                                                                                                                      3
Combined Total Storage (BG)




                              200                   Critical Duration


                              150                                                                                                     2


                              100
                                                                                                                                      1
                               50                                                                               Minimum
                                                                                                                Remaining
                                                                                                                 Storage
                                0                                                                                                     0
                              13-Jun-29                             13-Jun-30                             13-Jun-31
                                    Drought of 1930's Drought Index Numbers
                                    Total Days of Critical Duration= 613 Days
                                    Remaining Minimum Storage During Drought of 30s = 27.8 BG
                                    Date of End of Critical Duration February 18, 1931
                                    (SumDivert + RemainStor + PPL Stor)/(Crit Duration) = (457+27.8+4.1)BG*1000/(614 Days)= 798 MGD
                                    NYC Delaware Reservoirs Combined Storage (BG)
                                                                                                                                      67
                              300                                                                                             4
                                             Storage During Drought of Record; 1961-66

                              250




                                                                                                                                   Drought Index Numbers (0, 1, 2 & 3)
                                                     Critical Duration
Combined Total Storage (BG)




                                                                                                                              3

                              200



                              150                                                                                             2



                              100

                                                                                                                              1

                               50

                                                 Minimum Remaining Storage
                                0                                                                                             0
                              30-Jun-61   30-Jun-62         30-Jun-63           30-Jun-64       30-Jun-65         30-Jun-66
                                           Drought Index Numbers Drought of 1960's
                                           Total Days of Critical Duration 1,538 Days
                                           Remaining Minimum Storage During Drought of 60s = 18.3 BG
                                           Date of End of Critical Duration September 16, 1965
                                           Safe Yield= (SumDivert+Remaining Storage)/(Critical Duration) = 629 MGD
                                           NYC Delaware Reservoirs Combined Storage (BG)
                                                                                                                              68
          NJDEP Method for Estimating
     NYC’s Delaware System Safe Yield (cont’d)
• After finding the Critical Duration, the OASIS
  Drought Index Numbers were used to generate the
  Mass Demand Curve, a summation of the daily
  allowable diversions relative to the current Drought
  Operating Curves.
   – The Mass Demand Curve was compiled starting
     June 30, 1961 and the total diversion at the end of
     the Critical Duration, on September 11th, 1965, was
     943 bg with 17.1 bg remaining in storage.
• The 17.1bg extra storage was added to the total 943 bg
  diverted and divided by the number of days, 1,533, to
  obtain the Drought of the 60’s Safe Yield of 626 mgd
  (about 630 mgd w/PPL added) for the 3 Delaware
  Reservoirs, alone.
                                                       69
               NJDEP Method for Estimating
          NYC’s Delaware System Safe Yield (cont’d)
• A sinusoidal use curve that corresponds to NYC’s maximum
  demands and system characteristics was generated & used to
  construct a Mass Demand Curve for the Drought of the 60’s, a
  period that covers the entire Critical Duration of 1533 days. The
  Peak month to yearly average ratio used was 1.3, which projects
  NYC diverting up to 1.3 x 630 mgd during peak seasons, i.e., up
  to 820 mgd during the peak demand periods, July & August.
• A typical ratio of off-peak withdrawals to the yearly average is
  0.66; this equates to an allowable diversion of 0.66 x 630 = 422
  mgd, close to current off-season usage. This ratio was used for the
  minimum winter months off-season Mass Demand Curve.
• The following graph illustrates the NJDEP method for the 60’s
  Drought. (The reconstructed Mass Demand Curve, dashed line,
  shows the sinusoidal effect of the summation of peak and off-peak
  demands.)


                                                                  70
                              1,800                                                                                                 4
                                                OASIS Mass Diversion Curve for NYC; Drought of Record; 1961-66
                              1,600     Red Curve simulates New York City's Normalized use.
                                        NYC's Normalized Use enables Peak Month diversion of
                                        well over 800 mgd through a repeat of 60's Drought,




                                                                                                                                         Drought Index Numbers (0, 1, 2 & 3)
                              1,400     although its Continuous Average Safe Yield is about 630                                     3
                                        mgd under the 1983 Good Faith Operating Plan (REV 1)
Combined Total Storage (BG)




                              1,200     with the addition of about 4.1 BG due to the PPL Plan.
                                        This simulation includes no Hudson Basin Storage nor
                                        Delware Basin waters storage in Rondout, Kensico and
                              1,000     West Branch Reservoirs, nor any of NYC's 25 % reserve
                                        capacity from its Hudson System.                                                            2
                               800


                               600

                                                                                                                                    1
                               400


                               200                                      Critical Duration

                                  0                                                                                                 0
                                30-Jun-61           30-Jun-62            30-Jun-63            30-Jun-64   30-Jun-65     30-Jun-66
                                               Drought Index Numbers Drought of 1960's
                                               PEAK 30-DAY AVERAGE USE (Adjusted Safe Yield)= 835 mgd
                                               MIN 30-DAY AVERAGE USE (Adjusted Safe Yield)= 478 mgd
                                               OASIS Mass Curve of NYC Diversions Starting from June 30, 1961
                                               NYC Mass Diversion Using Total Adjusted Safe Yield Continuous Average = 629 MGD
                                               1930s Drought NYC Mass Diversion Using Continuous Diversion Diversion of 800 MGD
                                                                                                                                    71
             NJDEP Method for Estimating
        NYC’s Delaware System Safe Yield (cont’d)
• To verify the accuracy of the method for finding NYC’s
  Delaware Reservoirs’ Safe Yield relative to the 60’s
  drought, the same method was applied to find the Safe
  Yield of the 30’s Drought.
• Without Rondout Reservoir, the Safe Yield was 791 mgd,
  without PPL & 798 mgd with PPL. This is very close to
  the original 800 mgd estimate, considering additional
  fishery releases of the OASIA Model offset the USGS 1867
  estimate of the 1930’s Drought safe yield of about 850
  mgd.
• The following graphs illustrate the NJDEP method for
  deriving the safe yield from the OASIS Model:

                                                             72
                              700                                                                                 4
                                           OASIS Mass Diversion Curve for NYC; Drought of Record; 1929-31
                                    Black Curve simulates New York City's diversion
                              600   under OASIS Model Drought Rule Curves as per
                                    the 1983 Good Faith Agreement (REV 1) Operating     Sum of Diversion on




                                                                                                                       Drought Index Numbers (0, 1, 2 & 3)
                                    Plan. NYC's allowable diversion of 800 mgd,         Feb 18, 1931=457 BG
                                                                                                                  3
                              500   whenever possible, is shown through the 30s
Combined Total Storage (BG)




                                    Drought with the addition of about 4.1 BG due to
                                    the PPL Plan. This simulation includes no Hudson
                              400   Basin Storage nor Delware Basin waters storage in
                                    Rondout, Kensico and West Branch Reservoirs,
                                    nor any of NYC's 25 % reserve capacity from its                               2
                                    Hudson System.
                              300


                              200
                                                                                                                  1
                                                                 Critical Duration
                              100


                                0                                                                                 0
                              13-Jun-29                            13-Jun-30                       13-Jun-31
                                              Drought of 1930's Drought Index Numbers
                                              Date of End of Critical Duration February 18, 1931
                                              Total Days of Critical Duration= 613 Days
                                              Remaining Minimum Storage During Drought of 30s = 27.8 BG           73
                                              Safe Yield= (SumDivert + RemainStor + PPL Stor)/(Crit Duration) =

								
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