Daily Potomac flow and demand update (Friday, 2025-11-07)

Submitted by admin1 on Fri, 11/07/2025 - 13:10

Situational Awareness (Friday, 2025-11-07):
No precipitation fell in the basin yesterday. The Middle Atlantic River Forecast Center predicts about 0.01 to 0.5 inches of rain over the next three days. 

Special Conditions:
None

Daily flows:
Little Falls gage flow 2025-11-06: 1467 MGD (2270 cfs)
Little Falls gage flow 2025-11-07: 1280 MGD (est., based on recently available real-time data) (1980 cfs)
Note: Gage flow at Little Falls is measured after water supply withdrawals.
Point of Rocks flow 2025-11-06: 1377 MGD (2130 cfs)
Point of Rocks flow 2025-11-07: 1441 MGD (est., based on recently available real-time data) (2230 cfs)

Yesterday's estimated daily flows:
Great Falls estimated flow 2025-11-06: 1524 MGD (2358 cfs)
Note: Estimated flow below Great Falls intake is flow at Little Falls plus Little Falls water supply withdrawal.

Yesterday's Washington metropolitan area Potomac River withdrawals and discharges (2025-11-06):
Fairfax Water Corbalis withdrawal - Potomac: 89 MGD
WSSC Water Potomac withdrawal: 126 MGD
Washington Aqueduct withdrawal - Great Falls: 75 MGD
Washington Aqueduct withdrawal - Little Falls: 57 MGD
Loudoun Water withdrawal: 11 MGD
Loudoun Water Broad Run discharge: 8 MGD
Total Potomac withdrawal: 358 MGD
Total net Potomac withdrawal: 350 MGD

Loudoun Water Potomac River (PR) flow values for drought operations protocol (based on yesterday's flows):
QPR: 2130 cfs
QPR, obs: 2130 cfs
QPR, WS: 0 cfs

Note to Loudoun Water: See NWS ensemble flow forecasts (HEFS, GEFS, NAEFS) for Point of Rocks flow for the next 7 days – https://www.weather.gov/erh/mmefs_marfc?id=PORM2&model=NAEFS. See US Army Corps of Engineers Potomac River Basin page for observed releases from Savage and Jennings Randolph reservoirs - https://water.usace.army.mil/office/nab/; See US Army Corps of Engineers North Branch Potomac River and Savage River page for scheduled releases - https://water.usace.army.mil/office/nab/releases/north-branch.

Note: Potomac River flow at Point of Rocks has dropped below the low-flow threshold of 2,000 cfs. When this occurs, per the Water Supply Coordination Agreement of 1982, CO-OP begins daily monitoring and reporting of Potomac flows and withdrawals on behalf of the CO-OP suppliers, Fairfax Water, Washington Aqueduct, and WSSC Water. Suppliers can review data at CO-OP's Data Portal at www.icprbcoop.org. Reports formatted in approved templates should be submitted by email to coop@icprb.org by 8:00 am for automated processing. Published monitoring reports are at http://icprbcoop.org/products/monitoring-reports.

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AM Report
Daily Monitoring