Monitoring Reports

During periods of drought, the Cooperative Water Supply Operations on the Potomac (CO-OP) helps manage the Washington metropolitan area water supply system by coordinating withdrawals from the Potomac River and off-river reservoirs and recommending releases from upstream reservoirs when forecasted flow in the river is not sufficient to meet expected needs. These needs include water demands and an environmental flow-by of 100 million gallons per day (MGD) on the Potomac River at Little Falls dam near Washington, D.C.
SUSPENDING DAILY DROUGHT MONITORING; Daily Potomac flow and demand update (Thursday, 2026-02-19) snummer Thu, 02/19/2026 - 14:03

Situational Awareness (Thursday, 2026-02-19)

Daily Potomac flow and demand update (Monday, 2026-02-16)

Submitted by snummer on Mon, 02/16/2026 - 13:59

Situational Awareness (Monday, 2026-02-16)
Between 0.1 and 1.0 inches of rain fell in the basin over the past 24 hours, with greater accumulation occurring in southern portions of the basin. According to the Middle Atlantic River Forecast Center, trace amounts of precipitation are expected over the next 3 days. The week-long outlook can expect to see approximately 0.75 inches of precipitation. 

Daily Potomac flow and demand update (Saturday, 2026-02-14)

Submitted by admin1 on Sat, 02/14/2026 - 13:24

Situational Awareness (Saturday, 2026-02-14)
No precipitation was observed within the last 24 hours. Over the next three days, the basin may receive approximately 0.1 to 0.5 inches of precipitation (higher totals below Little Falls). This three-day forecast also includes much-needed rainfall across Virginia in areas outside of the basin, with totals on Sunday potentially exceeding 1 inch in southern Virginia.

Daily Potomac flow and demand update (Friday, 2026-02-13)

Submitted by hmoltz on Fri, 02/13/2026 - 13:25

Situational Awareness (Friday, 2026-02-13)
According to the Middle Atlantic River Forecast Center, no appreciable precipitation fell in the basin over the past 24 hours. Over the next three days, precipitation is expected to range from 0.01 to 0.75 inches, increasing from north to south, with the highest totals in southern areas.  

Daily Potomac flow and demand update (Thursday, 2026-02-12)

Submitted by snummer on Thu, 02/12/2026 - 19:34

Situational Awareness (Thursday, 2026-02-12)
According to the Middle Atlantic River Forecast Center, nonappreciable precipitation fell in the basin over the past 24 hours. Additionally, no appreciable precipitation is expected over the next 3 days. The 5-day forecast can expect to see between 0.1 and 0.5 inches of liquid-equivalent precipitation. 

Daily Potomac flow and demand update (Tuesday, 2026-02-10)

Submitted by admin1 on Tue, 02/10/2026 - 15:38

Situational Awareness (Tuesday, 2026-02-10)
The NWS Weather Prediction Center 7-day forecast indicates that significant precipitation may be on the way, though according to the Middle Atlantic River Forecast Center (MARFC), negligible precipitation is expected in the basin over the next 3 days and no precipitation fell during the past 24 hours. 

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