Situational Awareness (Wednesday, 2025-12-17)
According to information from the Middle Atlantic River Forecast Center (MARFC), there was no precipitation during the past 24 hours in the Potomac River watershed about Little Falls. MARFC ensemble forecasts indicate that the watershed will receive a cumulative average of approximately 1/2 inch of rain over the next 3 days.
Special Conditions
No river flow values are available for the USGS stream gage at Point of Rocks yesterday due to ice, and no flow values are available at that location today. Point of Rocks flows were estimated based on flows at the USGS’s gage at Shepherdstown, WV, (USGS Station No. 01618000) and a regression analysis of recent data.
Daily flows:
Little Falls gage flow 2025-12-16: 918 MGD (est., based on recently available real-time data) (1421 cfs)
Little Falls gage flow 2025-12-17: 937 MGD (est., based on recently available real-time data) (1450 cfs)
Note: Gage flow at Little Falls is measured after water supply withdrawals.
Point of Rocks flow 2025-12-16: 764 MGD (est. based on recently available flows at Shepherdstown) (1182 cfs)
Point of Rocks flow 2025-12-17: 867 MGD (est. based on recently available flows at Shepherdstown) (1341 cfs)
Yesterday's estimated daily flows:
Great Falls estimated flow 2025-12-16: 918 MGD (1421 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 (2025-12-16):
Fairfax Water Corbalis withdrawal - Potomac: 91 MGD
WSSC Water Potomac withdrawal: 147 MGD
Washington Aqueduct withdrawal - Great Falls: 125 MGD
Washington Aqueduct withdrawal - Little Falls: 0 MGD
Loudoun Water withdrawal: 12 MGD
Loudoun Water Broad Run discharge: 12 MGD
Total Potomac withdrawal: 375 MGD
Total net Potomac withdrawal: 363 MGD
Loudoun Water Potomac River (PR) flow values for drought operations protocol (based on yesterday's flows):
QPR: 1182 cfs (from estimated flow)
QPR, obs: 1182 cfs (from estimated flow)
QPR, WS: 0 cfs