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 (Sunday, 2026-08-09)

Submitted by snummer on Sun, 08/09/2026 - 12:41

Situational Awareness (Sunday, 2026-08-09)
Flows at the Point of Rocks gage has stayed above 2,000 cfs and are predicted to remain so through at least the beginning of this week. Additionally, according to the Middle Atlantic River Forecast Center predictions, the next 3 days are forecasted to see between 0.1 and 0.5 inches of rain.  As such, CO-OP is suspending its daily drought monitoring and reporting. This phase of CO-OP's drought response is triggered when daily flows at USGS's Point of Rocks gage fall below 2,000 cfs. 

Daily Potomac flow and demand update (Saturday, 2026-08-08)

Submitted by hmoltz on Sat, 08/08/2026 - 12:34

Situational Awareness (Saturday, 2026-08-08)
Flows continue to hover around 2,000 cfs, the CO-OP threshold for daily drought monitoring. Over the past 24 hours, most portions of the basin have received trace amounts to 0.5 inches of rain. According to the Middle Atlantic River Forecast Center predictions, little rain is expected over the next 3 days. The 10-day outlook expects a total of about one inch of rain in the basin.

Daily Potomac flow and demand update (Wednesday, 2026-08-05)

Submitted by snummer on Wed, 08/05/2026 - 12:34

Situational Awareness (Wednesday, 2026-08-05)
According to the Middle Atlantic River Forecast Center predictions, the next 24 hours may see 0.01 to 0.25 inches of rain. Over the next 3 days, the average basin rainfall may be between 0.25 and 1 inch. The week-long outlook expects a total of approximately 0.25 to 1.25 inches of rain in the basin.

Special Conditions
None

Daily Potomac flow and demand update (Tuesday, 2026-08-04)

Submitted by snummer on Tue, 08/04/2026 - 12:43

Situational Awareness (Tuesday, 2026-08-04)
River flow at the USGS Point of Rocks gage remains fairly steady at around 1750 cfs. The past 24 hours saw trace amounts of rainfall, mostly in the southern portions of the basin. According to the Middle Atlantic River Forecast Center predictions, the basin will receive between 0.1 and 0.5 inches of rain over the next 72 hours.  The week-long outlook expects a total of approximately 0.5 to 1.0 inches of rain in the basin.

Special Conditions
None

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.