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Susquehanna River Basin Commission - Chesapeake Bay Program.ppt

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Susquehanna River Basin Commission - Chesapeake Bay Program.ppt Powered By Docstoc
					Citizens Advisory Committee
State College, Pennsylvania
      August 13, 2004
         Susquehanna Sediments

•   Historic highs: 9 million tons per year
•   Current transported load: 3.1 m/tons
•   Lower Susq dams: 50-70% trapping efficiency
•   Net delivered load to Bay: .9 to 1.1 m/tons
•   Net delivered load 1985: 1.178 m/tons
•   Net delivered load 2002: 1.060 m/tons
     3,100,000 tons sediment
                                                   AVERAGE ANNUAL
          75,000 tons nitrogen
                                        INPUT TO RESERVOIR SYSTEM
      4,350 tons phosphorus


                                                          Percentage trapped in reservoir system:




                                 Safe Harbor Dam                             SEDIMENT
                                                                    70%




                                     Holtwood Dam                            2%



          AVERAGE ANNUAL
                                                                                        NITROGEN
        AMOUNT TRAPPED IN
         RESERVOIR SYSTEM

2,210,000 tons sediment (70%)
                                                       Conowingo Dam
      1,500 tons nitrogen (2%)
 1,740 tons phosphorus (40%)
                                                                                           40%      PHOSPHORUS




                                                    890,000 tons sediment
         AVERAGE ANNUAL                               73,500 tons nitrogen
 OUTPUT TO CHESAPEAKE BAY                          2,610 tons phosphorus
                                                            0

VERTICAL CROSS-SECTIONAL AREA, IN SQUARE FEET (´ 1,000)
                                                           50


                                                          100


                                                          150


                                                          200
                                                                                                 1928
                                                          250                                    1959
                                                                                                 1990
                                                                                                 1993
                                                          300                                    1996
                                                                                                 APPROXIMATE LEVEL OF
                                                                                                   MAXIMUM SEDIMENT-STORAGE
                                                          350                                      CAPACITY
                                                                                                 REMAINING STORAGE CAPACITY
                                                                                                 SEDIMENT DEPOSITION
                                                          400
                                                                0   10,000    20,000    30,000      40,000     50,000    60,000
                                                                     DISTANCE UPSTREAM FROM CONOWINGO DAM, IN FEET
       Storage Capacity Status

• Conventional estimate 17-20 years

• With assumptions: 20-30 years
          1. 10% decrease in transported load
          2. Statistically expected scour
          3. Trapping efficiency of 60%
         1985 Sediment Loads

• Bay-wide:    5.8 m/tons

• Susquehanna: 1.2 m/tons (20%)

• James River: 1.3 m/tons (22%)

• Potomac:     2.0 m/tons (35%)
      2010 Cap Load Allocations

• Bay-wide:    4.15 m/tons

• Susquehanna: 0.96 m/tons

• James River: 0.94 m/tons

• Potomac:     1.49 m/tons
             Moving Forward

• C2K: “By 2003, work with the SRBC and others
  to adopt and begin implementing strategies that
  prevent the loss of the sediment retention
  capabilities of the lower Susquehanna River
  dams.”

• Pennsylvania tributary strategy: 1.1 m/tons with
  full implementation
              Lingering Issues

• Reservoir feasibility study

• What about the wild cards?
    - scour
    - episodic nature of precip
    - flow and bank loss
    - system storage and the great purge

• Stay the course, but manage expectations
             The
Water Quantity-C2K Connection:

 The Implications of Flow for
Water Quality and Vital Habitat
  Protection and Restoration
Basin Overview
• 27,510 square mile
  watershed.
• 32,000+ miles of streams.
• Normal Flow of
  Susquehanna River is 18
  million gallons per minute
  at Havre de Grace, MD.
• Susquehanna River is
  largest tributary to
  Chesapeake Bay.

• Population of 4.2 million
   Project Review Regulations

• Consumptive Water Use > 20,000 gpd

• Surface-Water Withdrawals > 100,000 gpd

• Ground-Water Withdrawals > 100,000 gpd
 Surface-Water Withdrawals
• Regulatory threshold; 100,000 gpd

• Protection of instream/downstream uses

• Conservation releases

• Passby flow requirements

• Cold water fisheries – IFIM analysis

• Warm water fisheries – 20 % ADF
             Groundwater
       in the Susquehanna Basin
• Nearly 69 billion gallons.
• Most of the potable water is within 300 ft of
  ground surface.
• Groundwater supplies stream flow, upwards
  of 90% of base flow during extended
  droughts.
• Withdrawing groundwater results in about a
  1-to-1 reduction in flow downstream.
Drought Years
  1991

  1995

  1997

  1998

  1999

  2002
            Groundwater
      in the Susquehanna Basin
• Over 50% of the basin’s population uses
  groundwater for water supply

• To date, SRBC has approved the
  withdrawal of more than 232 million gpd of
  groundwater.
       Groundwater Use in the
    Susquehanna Basin (1995 data)

•   Water Supply   195 mgd = 50%
•   Mining          90 “ = 23%
•   Industrial      48 “ = 12%
•   Agriculture     42 “ = 11%
•   Other           16 “ = 4%
•   Total          391 mgd
  Ground-Water Withdrawals
• Regulatory threshold; 100,000 gpd

• Avoid impacts to resource and other users

• Pump test guidance

• Ground-water availability analysis

• 48-hour constant-rate pump test
     Consumptive Water Use

• Regulatory threshold; 20,000 gpd

• Water used and not returned to the basin

• Out-of-basin diversions

• Compensation requirements
    Compensation Options For
     Consumptive Water Use
• Discontinuance

• Releases from storage

• Payment into the Water Management Fund

• 30,000 acre/ft of pooled water storage
                                         PEAK CONSUMPTIVE WATER USE IN THE SUSQUEHANNA RIVER BASIN


                                   800
JULY TOTAL CONSUMPTIVE USE (mgd)




                                   700

                                   600

                                   500

                                   400

                                   300

                                   200

                                   100

                                     0
                                                 1970                  1990                 2020
                                                                      YEAR
                             STREAM FLOW AND CONSUMPTIVE USE
                                  SUSQUEHANNA RIVER BASIN



          30

          25

          20
PERCENT




          15

          10

           5

           0
               JAN   FEB   MAR   APR    MAY   JUN    JUL   AUG    SEP   OCT   NOV   DEC

                       MO. CONSUMPTIVE USE AS % OF YEARLY TOTAL

                       MIN. MEAN MO. DISCHARGE AS % OF YEARLY TOTAL
 Past, Present and Projected Consumptive Use as a
Percentage of Susquehanna River Historic Low Flow
                    (1250 mgd)

        Remaining
          Flow




                                         Additional
                                        Consumptive
  Consumptive                           Use up to 2020
  Use up to 1970                             (56%)
     (22%)
                        Additional
                       Consumptive
                       Use up to 1990
                            (36%)
         Moving Forward
• Warm Water IFIM

• Groundwater Management Plan

• PA Act 220 State Water Plan

• Water Budgeting

• Protected Area Designations

				
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