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.

Daily Potomac flow and demand update (Saturday, 2026-02-07)

Submitted by admin1 on Sat, 02/07/2026 - 14:06

Situational Awareness (Saturday, 2026-02-07)
According to information from the Middle Atlantic River Forecast Center, there was light precipitation in the Potomac watershed above Little Falls yesterday, ranging from 0.01 to 0.10 inches water equivalent in most areas.  No precipitation is in the forecast for the next 3 days.

Special Conditions

Daily Potomac flow and demand update (Wednesday, 2026-02-04)

Submitted by admin1 on Wed, 02/04/2026 - 12:51

Situational Awareness (Wednesday, 2026-02-04)
According to information from the Middle Atlantic River Forecast Center, there were scattered areas of light precipitation in the Potomac watershed over the past 24 hours. Over the next 3 days, 0.01-0.10 inches is expected throughout the portion of the watershed above Little Falls, with higher amounts predicted in the far northwestern corner. 

Special Conditions

Daily Potomac flow and demand update (Tuesday, 2026-02-03) hmoltz Tue, 02/03/2026 - 13:21

Situational Awareness (Tuesday, 2026-02-03)
According to the Middle Atlantic River Forecast Center, no appreciable precipitation fell in the basin over the past 24 hours. Over the next 3 days, 0-0.25 inches of precipitation is possible, with the higher amounts expected in the southern portions of the basin. 

Daily Potomac flow and demand update (Monday, 2026-01-26)

Submitted by hmoltz on Mon, 01/26/2026 - 13:20

Situational Awareness (Monday, 2026-01-26)
According to the Middle Atlantic River Forecast Center, 0.5-2.0 inches of liquid-equivalent precipitation fell in the basin over the past 24 hours. Up to 0.1 inches of additional precipitation is forecast in the far western portion of the basin over the next 3 days.  No precipitation is expected in the rest of the basin over that same 3-day period.

Special Conditions
None

Daily Potomac flow and demand update (Sunday, 2026-01-25)

Submitted by snummer on Sun, 01/25/2026 - 14:01

Situational Awareness (Sunday, 2026-01-25)
According to the Middle Atlantic River Forecast Center, the past 24 hours saw between 0.25 and 1 inch of precipitation. Over the next 3 days, the average basin liquid-equivalent precipitation may be around 1 inch, with the most upstream regions of the watershed seeing between 1.25 and 1.75 inches of precipitation.

Special Conditions
None

Daily Potomac flow and demand update (Saturday, 2026-01-24)

Submitted by admin1 on Sat, 01/24/2026 - 13:45

Situational Awareness (Saturday, 2026-01-24)
No precipitation fell in the Potomac basin yesterday. A cumulative average of 1 to 1 1/2 inches is expected in the portion of the watershed above Little Falls over the next 3 days according to information from the Mid-Atlantic River Forecast Center.

Special Conditions
None

Daily flows:
Little Falls gage flow 2026-01-23: 1364 MGD (2110 cfs)