citizens advisory committee state college, pennsylvania august 13, 2004
DESCRIPTION
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 - PowerPoint PPT PresentationTRANSCRIPT
Citizens Advisory Committee
State College, Pennsylvania
August 13, 2004
• 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
Susquehanna Sediments
Holtwood Dam
Conowingo Dam
Safe Harbor Dam
3,100,000 tons sediment
75,000 tons nitrogen
4,350 tons phosphorus
2,210,000 tons sediment (70%)
1,500 tons nitrogen (2%)
1,740 tons phosphorus (40%)
890,000 tons sediment
73,500 tons nitrogen
2,610 tons phosphorus
AVERAGE ANNUAL
INPUT TO RESERVOIR SYSTEM
AVERAGE ANNUAL
AMOUNT TRAPPED IN
RESERVOIR SYSTEM
AVERAGE ANNUAL
OUTPUT TO CHESAPEAKE BAY
70%
40%
2%
SEDIMENT
NITROGEN
PHOSPHORUS
Percentage trapped in reservoir system:
0 6 0 , 0 0 01 0 , 0 0 0 2 0 , 0 0 0 3 0 , 0 0 0 4 0 , 0 0 0 5 0 , 0 0 0
D I S T A N C E U P S T R E A M F R O M C O N O W I N G O D A M , I N F E E T
5 0
4 0 0
1 0 0
1 5 0
2 0 0
2 5 0
3 0 0
3 5 0
VE
RT
IC
AL
C
RO
SS
-S
EC
TI
ON
AL
A
RE
A,
I
N
SQ
UA
RE
F
EE
T
(´
1,
00
0)
E
A P P R O X I M A T E L E V E L O F
R E M A I N I N G S T O R A G E C A P A C I T Y
M A X I M U M S E D I M E N T - S T O R A G
C A P A C I T Y
1 9 2 8
1 9 5 9
1 9 9 0
1 9 9 3
1 9 9 6
SEDIMENT DEPOSITION
0
• Conventional estimate 17-20 years
• With assumptions: 20-30 years1. 10% decrease in transported load2. Statistically expected scour3. Trapping efficiency of 60%
Storage Capacity Status
• 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%)
1985 Sediment Loads
• Bay-wide: 4.15 m/tons
• Susquehanna: 0.96 m/tons
• James River: 0.94 m/tons
• Potomac: 1.49 m/tons
2010 Cap Load Allocations
• 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
Moving Forward
• 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
Lingering Issues
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 Years19919911
19919955
19919977
19919988
19919999
20020022
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 CONSUMPTI VE WATER USE I N THE SUSQUEHANNA RI VER BASI N
0
100
200
300
400
500
600
700
800
1970 1990 2020
YEAR
JUL
Y T
OT
AL
CO
NS
UM
PT
IVE
US
E (m
gd
)
STREAM FLOW AND CONSUMPTI VE USE
SUSQUEHANNA RI VER BASI N
0
5
10
15
20
25
30
JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
PE
RC
EN
T
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)
Additional Consumptive
Use up to 2020
Additional Consumptive
Use up to 1990
Consumptive Use up to 1970
Remaining Flow
(22%)
(56%)
(36%)
Moving Forward
• Warm Water IFIM
• Groundwater Management Plan
• PA Act 220 State Water Plan
• Water Budgeting
• Protected Area Designations