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 (Friday, 2024-07-19)

Submitted by admin1 on Fri, 07/19/2024 - 12:49

Situational Awareness (Friday, 2024-07-19)
Dry conditions continue and Potomac basin stream flows continue to decline. According to the Middle Atlantic River Forecast Center, the Potomac watershed above Little Falls is expected to receive no precipitation over the next day, 0.2 inches over the next 3 days, and 1.1 inches over the next week.

Special Conditions

Daily Potomac flow and demand update (Wednesday, 2024-07-17)

Submitted by admin1 on Wed, 07/17/2024 - 08:19

Situational Awareness (Wednesday, 2024-07-17)
Stream flows throughout the Potomac basin are continuing to decline. Flows in some major Potomac River tributaries have fallen below historic minimums for this day of the year – notably in the South Branch Potomac River near Springfield, WV, and the Shenandoah River at Millville, WV. According to the Middle Atlantic River Forecast Center predictions, 0.4 inches of rain is expected in the basin over the next day and 0.6 inches over the next 3 days.

Daily Potomac flow and demand update (Sunday, 2024-07-14)

Submitted by admin1 on Sun, 07/14/2024 - 08:20

Situational Awareness (Sunday, 2024-07-14)
Small amounts of rain fell in the basin over the past 24 hours mainly in the eastern and northwestern areas. Potomac River flows are continuing to decline following a temporary increase from the combined effects of localized storms and the whitewater release from Savage Reservoir. The Middle Atlantic River Forecast Center predicts no rain in the next 24 hours and a basin rainfall average of 0.5 inches over the next 7 days.

Daily Potomac flow and demand update (Saturday, 2024-07-13)

Submitted by admin1 on Sat, 07/13/2024 - 08:22

Situational Awareness (Saturday, 2024-07-13)
Significant rainfall occurred in the eastern parts of the basin over the past 24 hours, with local amounts reaching up to 1.5 inches. This has led to a notable increase in river flow at Little Falls, while upstream gages continue to show low levels. According to the Middle Atlantic River Forecast Center, a basin average of 0.1 inches of rain is anticipated over the next three days. The weekly forecast suggests a total of approximately 1.2 inches of rain for the basin..

Daily Potomac flow and demand update (Friday, 2024-07-12)

Submitted by snummer on Fri, 07/12/2024 - 12:24

Situational Awareness (Friday, 2024-07-12)
According to the Middle Atlantic River Forecast Center predictions, the next 3 days may see 0.2 inches of rain. The week-long outlook expects a total of approximately 0.8 inches of rain in the basin.

Special Conditions
The effects of the whitewater release from Savage Reservoir last Sunday (2024-07-07) are currently visible at the USGS streamflow gage on the Potomac River at Point of Rocks, MD.

Daily Potomac flow and demand update (Thursday, 2024-07-11)

Submitted by admin1 on Thu, 07/11/2024 - 08:24

Situational Awareness (Thursday, 2024-07-11)
Scattered thunderstorms occurred throughout the basin over the past 24 hours. Over the next 3 days, 0.1 to 0.5 inches of rain are expected, mainly in the eastern parts of the basin.  

Special Conditions
The effects of the whitewater release from Savage Reservoir last Sunday (2024-07-07) are currently visible at the USGS streamflow gage on the Potomac River at Shepherdstown.

Daily Potomac flow and demand update (Wednesday, 2024-07-10)

Submitted by admin1 on Wed, 07/10/2024 - 12:13

Situational Awareness (Wednesday, 2024-07-10)
The Middle Atlantic River Forecast Center expects some rain with localized thunderstorms starting today. According to their predictions, the next 24 hours may see 0.1 inches of rain. Over the next 3 days, the average basin rainfall may be around 0.4 inches. The week-long outlook expects a total of approximately 0.6 inches of rain in the basin. Any rainfall will be combating the impacts of evaporation and the increased demand from outdoor watering due to the excessive heat currently affecting the Potomac Basin.