Situational Awareness (Wednesday, 2026-09-23)
Yesterday’s average daily flow at the USGS gage at Point of Rocks was 1,640 cfs, below the 2,000 cfs threshold for CO-OP daily drought monitoring. Flows are increasing, however, due to recent rainfall, with instantaneous flows at Point of Rocks reaching 2,450 cfs this morning. The decision to discontinue daily drought monitoring will be considered if the average daily flow rises above the 2,000 cfs threshold.
According to the Middle Atlantic River Forecast Center, rain is expected across the basin over the next three days. Forecast amounts generally increase from north to south, from trace amounts in the northern basin to as much as an inch in some localized southern areas.
Special Conditions
The U.S. Army Corps of Engineers, Baltimore District, reports that the final scheduled whitewater release from Savage River Dam for 2026 will occur on Saturday, September 26. The 2026 water-quality release schedule for Jennings Randolph and Savage reservoirs is available here: https://water.usace.army.mil/office/nab/releases/north-branch.
Intra-daily flow fluctuations at Potomac River gages, including Point of Rocks, are occurring due to upstream dam operations associated with eel passage.
Daily flows:
Little Falls gage flow 2026-09-22: 1706 MGD (2640 cfs)
Little Falls gage flow 2026-09-23: 2572 MGD (est., based on recently available real-time data) (3980 cfs)
Note: Gage flow at Little Falls is measured after water supply withdrawals.
Point of Rocks flow 2026-09-22: 1060 MGD (1640 cfs)
Point of Rocks flow 2026-09-23: 1583 MGD (est., based on recently available real-time data) (2450 cfs)
Yesterday's estimated daily flows:
Great Falls estimated flow 2026-09-22: 1712 MGD (2649 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 (2026-09-22):
Fairfax Water Corbalis withdrawal - Potomac: 82 MGD
WSSC Water Potomac withdrawal: 128 MGD
Washington Aqueduct withdrawal - Great Falls: 126 MGD
Washington Aqueduct withdrawal - Little Falls: 6 MGD
Loudoun Water withdrawal: 12 MGD
Loudoun Water Broad Run discharge: 7 MGD
Total Potomac withdrawal: 353 MGD
Total net Potomac withdrawal: 346 MGD
Loudoun Water Potomac River (PR) flow values for drought operations protocol (based on yesterday's flows):
QPR: 1640 cfs
QPR, obs: 1640 cfs
QPR, WS: 0 cfs