Situational Awareness (Tuesday, 2025-12-09)
Dry conditions persist. According to information from the Middle Atlantic River Forecast Center, the southern portion of the Potomac watershed received a small amount of precipitation during the past 24 hours, ranging from 0.01 to 0.1 inches. A small amount of precipitation is expected in the northern portion of the watershed over the next 3 days.
Special Conditions
The US Geological Survey conducted a site visit at the Potomac River at Point of Rocks gage on December 5. Based on their measurement of discharge (ie river flow) on that day, they have revised the site’s stage-discharge formula. Recent past estimates of river flow have therefore been revised downward somewhat.
Daily flows:
Little Falls gage flow 2025-12-08: 1364 MGD (2110 cfs)
Little Falls gage flow 2025-12-09: 1396 MGD (est., based on recently available real-time data) (2160 cfs)
Note: Gage flow at Little Falls is measured after water supply withdrawals.
Point of Rocks flow 2025-12-08: 1183 MGD (1830 cfs)
Point of Rocks flow 2025-12-09: 1306 MGD (est., based on recently available real-time data) (2020 cfs)
Yesterday's estimated daily flows:
Great Falls estimated flow 2025-12-08: 1364 MGD (2110 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 (2025-12-08):
Fairfax Water Corbalis withdrawal - Potomac: 76 MGD
WSSC Water Potomac withdrawal: 156 MGD
Washington Aqueduct withdrawal - Great Falls: 126 MGD
Washington Aqueduct withdrawal - Little Falls: 0 MGD
Loudoun Water withdrawal: 9 MGD
Loudoun Water Broad Run discharge: 9 MGD
Total Potomac withdrawal: 367 MGD
Total net Potomac withdrawal: 358 MGD
Loudoun Water Potomac River (PR) flow values for drought operations protocol (based on yesterday's flows):
QPR: 1830 cfs
QPR, obs: 1830 cfs
QPR, WS: 0 cfs
Interstate Commission on the Potomac River Basin