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 (Tuesday 09/30/2014)

Submitted by admin1 on Tue, 09/30/2014 - 09:00

Daily Potomac flow and demand update (Tuesday 09/30/2014)

Only trace amounts of precipitation fell in the Potomac basin over the past 24 hours. The Middle Atlantic River Forecast Center forecasts accumulations ranging from 0 to 3/4 inches in the basin over the next 72 hours. The National Weather Service's Weather Prediction Center forecasts over an inch of rain in the western portion of the basin over the next 5 days.

Daily Potomac flow and demand update (Sunday 09/28/2014)

Submitted by admin1 on Sun, 09/28/2014 - 09:00

The National Weather Service reports that trace amounts of rain fell in small, isolated areas of the basin over the last 24 hours. Their 48-hour forecast shows no rain in the basin. Trace amounts may fall in the western portion of the basin over the next five days.

A scheduled artificially varied flow release of 1,000 cfs from Jennings Randolph Reservoir began yesterday at 10 am and will end today at 4 pm.

Daily Potomac flow and demand update (Wednesday 09/24/2014)

Submitted by admin1 on Wed, 09/24/2014 - 09:00

Over the last 24 hours up to half an inch of rain fell around and upstream of the metro area. The National Weather Service indicates a chance of rain across the entire basin over the next 24 hours. The western areas can expect between trace amounts and half an inch. The predicted totals increase to the east, with up to 1.25 inches expected in the metro area. There is also a chance of a small amount of additional rain on Thursday.

Daily Potomac flow and demand update (Tuesday 09/23/2014)

Submitted by admin1 on Tue, 09/23/2014 - 09:00

Over the last 24 hours 0.1 to 0.75 inches of rain fell in the central portion of the basin, with the most falling along the border between Fairfax and Prince William counties. The National Weather Service indicates a chance of rain across the basin beginning Wednesday night through Thursday afternoon. Total rainfall amounts are predicted between 0.1 and 1.0 inch. The heaviest rainfall is forecast in the metro area and areas to the east.

Daily Potomac flow and demand update (Monday 09/22/2014)

Submitted by admin1 on Mon, 09/22/2014 - 09:00

Scattered rain, ranging from trace amounts to almost half an inch, occurred in localized portions of the basin over the last 24 hours according to the National Weather Service. The Middle Atlantic River Forecast Center predicts that less than 0.1 inch of rain may fall in a small area of the far western portion of the basin over the next 72 hours. No precipitation is expected across the rest of the basin during that period.

Daily Potomac flow and demand update (Sunday 09/21/2014)

Submitted by admin1 on Sun, 09/21/2014 - 09:00

Trace amounts of rain fell in a limited area between the USGS gage at Point of Rocks, MD and Washington, D.C. over the last 24 hours. The National Weather Service indicates there is a chance of 0.03 to 0.10 inches of rain over the next 72 hours and 0 to 0.5 inches over the next 7 days.

Thank you again to those sending in weekend daily withdrawal numbers.