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 (Monday 08/15/2011)

Submitted by admin1 on Mon, 08/15/2011 - 09:00

Over the past 24 hours, the basin received between 0.10 and 3.0 inches of rain. The heaviest rain in the region fell outside of the basin to the south and north east. MARFC's 48-hour forecast shows a chance of a 0.25 of an inch of rain across most of the basin. The 5-day forecast shows that the basin could receive between 0.5 and 1.00 inch of rain.

Point of Rocks flow is currently above the 2,000 cfs threshold. We will track flows and the weather forecast to see if this is sustainable. Daily monitoring remains active.

Daily Potomac flow and demand update (Sunday 08/14/2011)

Submitted by admin1 on Sun, 08/14/2011 - 09:00

Yesterday, a limited area in the southern portion of the basin
received between 1.0 and 4.0 inches of rain. Most areas received
between 0.10 and 0.50 inches. The heaviest rain in the region fell
outside of the basin to the south and north east. MARFC's 48-hour
forecast shows a chance of up to 1.0 inch of rain across the basin.
The 5-day forecast shows most of the basin could receive up to 1.50
inches of rain, with the downstream area receiving up to 1.75 inches.

Daily Potomac flow and demand update (Saturday 08/13/2011)

Submitted by admin1 on Sat, 08/13/2011 - 09:00

Near zero amounts of rainfall were experienced over the last 24 hours. Over the next 48-hour period, MARFC forecasts between 1.0 and 2.0 inches of rain to occur throughout the basin. This rain is expected to arrive mostly in the form of thunderstorms. The 5-day forecast shows between 1.25 and 2.00 inches of accumulated precipitation across the basin.

Daily Potomac flow and demand update (Friday 08/12/2011)

Submitted by admin1 on Fri, 08/12/2011 - 09:00

Negligible amounts of rainfall were experienced over the last 24
hours. Over the next 48-hour period, MARFC forecasts between 0.25 and
1.0 inch of rain. The heaviest rainfall is predicted in the western
portion of the basin. The 5-day forecast shows between 1.25 and 2.00
inches of accumulated precipitation across the basin.

Daily Potomac flow and demand update (Thursday 08/11/2011)

Submitted by admin1 on Thu, 08/11/2011 - 09:00

In the past 24 hours, the Middle Atlantic River Forecast Center (MARFC) measured zero precipitation in the basin. The 48-hour forecast shows no chances of precipitation across the basin. The 5-day forecast indicates that the basin may receive between 0.75 to 2.3 inches of accumulated precipitation. MARFC does not forecast precipitation around the basin until possibly this Saturday or Sunday.

The lack of precipitation has caused Point of Rocks flow to drop below the 2,000 cfs threshold again.

Daily Potomac flow and demand update (Wednesday 08/10/2011)

Submitted by admin1 on Wed, 08/10/2011 - 09:00

In the past 24 hours, trace amounts of precipitation were measured
across the basin. Limited areas in the northern portion received up to
0.75 inches. The 48-hour forecast shows no precipitation over most of
the basin, though there is a chance of trace amounts east of the
Monocacy River. The 5-day forecast indicates the basin may receive
between 0.5 to 1.0 inches of accumulated precipitation.

Daily Potomac flow and demand update (Monday 08/08/2011)

Submitted by admin1 on Mon, 08/08/2011 - 09:00

Most of the basin received between 0.10 and 0.50 inches of rain
yesterday. The forecast for the next 48 hours indicates a chance of up
to 0.25 inches of rain across the majority of the basin. The western
portion may receive up to 0.50 inches. The 5-day forecast shows a
chance of 0.25 to 0.50 inches of accumulated precipitation.

Daily Potomac flow and demand update (Saturday 08/06/2011)

Submitted by admin1 on Sat, 08/06/2011 - 09:00

Minor precipitation events have kept flows relatively steady over the past 5 days. The Middle Atlantic River Forecast Center (MARFC) quantitative precipitation forecast indicates that over 1/2 inch of rain will fall throughout the basin over the next 48 hours. MARFC's new ensemble forecasts, available at www.erh.noaa.gov/mmefs/, indicate that flow at Point of Rocks has a good chance of rising above 2000 cfs sometime in the next 7 days.