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 07/31/2010)

Submitted by admin1 on Sat, 07/31/2010 - 09:00

Little Falls flow is falling from yesterday's higher daily average and is currently at 1480 cfs. Yesterday, the basin received little or no rain. There is a chance of thunderstorms this weekend, and the National Weather Service (NWS) quantitative precipitation forecasts (qpf) indicate that the majority of the basin may receive from 0.01 to 0.5 inch of rain over the next 48 hours.

Daily Potomac flow and demand update (Friday 07/30/2010)

Submitted by admin1 on Fri, 07/30/2010 - 09:00

Yesterday's storms resulted in accumulations of over a half inch of rain in certain localized areas of the basin near the Washington metropolitan area, causing flow at Little Falls to rise slightly. However, most upstream areas of the basin received little or no rain. There is a chance of thunderstorms this weekend, and the National Weather Service (NWS) quantitative precipitation forecasts (qpf) indicate that the majority of the basin may receive from 1/4 to 1 inch of rain over the next 48 hours.

Daily Potomac flow and demand update (Friday 07/23/2010)

Submitted by admin1 on Fri, 07/23/2010 - 09:00

Flow at Point of Rocks is currently 1,660 cfs (1,070 MGD). For the most part, the basin received no rain yesterday. Approximately 0.10 inches were seen in limited western portions of the basin. The National Weather Service (NWS) quantitative precipitation forecasts (qpf) indicate that the majority of the basin will receive 0.0 to 0.1 inches of accumulated rain over the next 5 days.

Daily Potomac flow and demand update (Thursday 07/22/2010)

Submitted by admin1 on Thu, 07/22/2010 - 09:00

Flow at Point of Rocks is currently 1,800 cfs (1,160 MGD). In the past 7 days, the basin has received 0.5 inches of rain with minimal rain accumulation occurring for yesterday. The National Weather Service (NWS) quantitative precipitation forecast (qpf) indicates that 0 to 0.25 inches of rain may occur over the next 5 days.

Daily Potomac flow and demand update (Tuesday 07/13/2010)

Submitted by admin1 on Tue, 07/13/2010 - 09:00

The flow at Point of Rocks is currently above 2,000 cfs and it appears that flow is going to stay above that level for at least a week. Daily monitoring is discontinued until flows drop below the 2,000 cfs threshold. The Washington D.C. area and the eastern portion of the Basin received precipitation totals between 0.5 to 2 inches. However, most of the Basin, particularly in the western portion, received precipitation totals of 0 to 0.1 inches.

Daily Potomac flow and demand update (Saturday 07/10/2010)

Submitted by admin1 on Sat, 07/10/2010 - 09:00

Flow at Little Falls is currently 1520 cfs (980 MGD). The MARFC observed precipitation map shows that much of the western part of the basin received 0.05 to 1 inch of rain in the past 24 hrs. The National Weather Service (NWS) quantitative precipitation forecasts (qpf) indicate a chance of 0.75 to 3.2 inches of accumulated rain across the basin over the next 5 days. Today 0.25 to 0.5 inches of rain is expected for the Washington, D.C. area.

Daily Potomac flow and demand update (Friday 07/09/2010)

Submitted by admin1 on Fri, 07/09/2010 - 09:00

Stream flows continue to fall throughout the basin. Yesterday's daily mean flow at Little Falls was 890 MGD (1370 cfs). The July 4th whitewater release is almost past Point of Rocks, and should be arriving at Little Falls today - producing a short-term uptick in flow.

MARFC's observed precipitation maps indicate that there were scattered thunderstorms in the basin over the past 24 hours, with accumulations
of 1/2 to 1.5 inches in a few localized areas. MARFC predicts accumulations of over an inch throughout much of the basin in the next 48 hours.

Daily Potomac flow and demand update (Thursday 07/08/2010)

Submitted by admin1 on Thu, 07/08/2010 - 09:00

Flow at Point of Rocks is currently 2,070 cfs (1,340 MGD). The increase in Point of Rocks flow is likely due to the 6 hour whitewater release from Savage of 1,000 cfs, which should be recorded sometime today. The basin has received no rain for the month of July, which is 0.7 inches below normal. The National Weather Service (NWS) quantitative precipitation forecasts (qpf) indicate a chance of 0.75 to 1.9 inches of accumulated rain across the basin over the next 5 days.

Daily Potomac flow and demand update (Wednesday 07/07/2010)

Submitted by admin1 on Wed, 07/07/2010 - 09:00

Flow at Point of Rocks is currently 1,910 cfs (1,234 MGD). The basin received no rain yesterday. The National Weather Service (NWS) quantitative precipitation forecasts (qpf) indicate a chance of 0.75 to 1.5 inches of accumulated rain across the basin over the next 5 days. On July 4, there was a 6 hour whitewater release from Savage of 1,000 cfs. The release passed the Hancock gage yesterday.