Situational Awareness (Thursday, 2025-10-02)
No rainfall fell in the Potomac watershed yesterday according to Middle Atlantic River Forecast Center (MARFC) estimates. Dry conditions are predicted to persist in the watershed for the next five days, according to forecasts from MARFC and from the National Weather Service’s Weather Prediction Center.
Special Conditions
Messages have been posted on USGS stream gage website pages reporting that they will not be updated due to the lapse in federal funding. However, at this time updated streamflow data continues to be available. Mary K. Foley, Director of the USGS’s MD-DE-DC Water Science Center, sent out a message yesterday saying that "During this period, USGS will continue critical activities necessary to protect life and property, such as the operation and maintenance of streamgages and other essential monitoring systems. These vital functions are being maintained to ensure the uninterrupted delivery of public safety information."
Daily flows:
Little Falls gage flow 2025-10-01: 1183 MGD (1830 cfs)
Little Falls gage flow 2025-10-02: 1118 MGD (est., based on recently available real-time data) (1730 cfs)
Note: Gage flow at Little Falls is measured after water supply withdrawals.
Point of Rocks flow 2025-10-01: 1306 MGD (2020 cfs)
Point of Rocks flow 2025-10-02: 1306 MGD (est., based on recently available real-time data) (2020 cfs)
Yesterday's estimated daily flows:
Great Falls estimated flow 2025-10-01: 1183 MGD (1830 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 (2025-10-01):
Fairfax Water Corbalis withdrawal - Potomac: 109 MGD
WSSC Water Potomac withdrawal: 135 MGD
Washington Aqueduct withdrawal - Great Falls: 132 MGD
Washington Aqueduct withdrawal - Little Falls: 0 MGD
Loudoun Water withdrawal: 12 MGD
Loudoun Water Broad Run discharge: 7 MGD
Total Potomac withdrawal: 387 MGD
Total net Potomac withdrawal: 380 MGD
Loudoun Water Potomac River (PR) flow values for drought operations protocol (based on yesterday's flows):
QPR: 2020 cfs
QPR, obs: 2020 cfs
QPR, WS: 0 cfs
Interstate Commission on the Potomac River Basin