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 08/21/2010)

Submitted by admin1 on Sat, 08/21/2010 - 09:00

Yesterday there was negligible precipitation in Potomac basin. The Middle Atlantic River Forecast Center predicts up to an inch of rain in the North Branch watershed over the next two days and the National Weather Service 5-day Quantitative Precipitation Forecast indicates a chance of 1/4 to 1 inch of accumulated precipitation across the entire basin.

Daily Potomac flow and demand update (Friday 08/20/2010)

Submitted by admin1 on Fri, 08/20/2010 - 09:00

The Middle Atlantic River Forecast Center shows that there were a few isolated areas of rain yesterday that accumulated up to 0.10 inches of rain. Over the next 48 hours there is a chance of 0.10 inches of rain in the North Branch watershed according to the Forecast Center. The National Weather Service Quantitative Precipitation Forecast shows possible accumulation of 0.10 to 0.50 inches of rain across the basin over the next 5 day period.

Daily Potomac flow and demand update (Thursday 08/19/2010)

Submitted by admin1 on Thu, 08/19/2010 - 09:00

There has been significant rainfall in the DC metropolitan area over the past couple of days, but only approximately 1/4 of an inch in the western portion of the Potomac River basin. The Middle Atlantic River Forecast Center predicts 1/10 to 1/2 of an inch across the southern half of the basin over the next 48 hours, including in the South Branch and Shenandoah areas. The 5-day Quantitative Precipitation Forecast indicates a chance of up to 1 inch of rain across the entire basin.

Daily Potomac flow and demand update (Wednesday 08/18/2010)

Submitted by admin1 on Wed, 08/18/2010 - 09:00

Significant rain fell in the southeastern portion of the Potomac River basin yesterday, with the heaviest accumulations occurring near the DC metropolitan area. More rain is expected today, and the Middle Atlantic River Forecast Center predicts between 1/4 to 3/4 of an inch in the southern basin, including the DC area and parts of the Shenandoah. Though the recent rainfall has caused Potomac River flow at Little Falls to increase significantly, flows remain low in many upstream tributaries.

Daily Potomac flow and demand update (Monday 08/16/2010)

Submitted by admin1 on Mon, 08/16/2010 - 09:00

There were scattered showers and thunderstorms in the basin yesterday, with accumulations of 0.25 to 0.50 inches in few localized areas. The National Weather Service's Middle Atlantic River Forecast Center predicts accumulations of up to 0.25 inches in parts of the basin, including the Shenadoah and Monocacy sub-basins, over the next 48 hours, and up to 0.5 inches in Washington, DC and surrounding areas. The 5-day quantitative precipitation forecast shows a chance of up to 1.5 inches of accumulated rainfall in the southeastern portion of the basin.

Daily Potomac flow and demand update (Sunday 08/15/2010)

Submitted by admin1 on Sun, 08/15/2010 - 09:00

Yesterday there was scattered precipitation across the basin that produced approximately 0.25 to 0.50 inches of rain in the headwaters area, according to the National Weather Service's Middle Atlantic River Forecast Center . Over the next 48 hours, the River Forecast Center predicts an accumulation of up to 0.5 inches of precipitation. The 5-day Quantitative Precipitation Forecast shows a chance of up to 1.5 inches of accumulated rainfall.

Daily Potomac flow and demand update (Saturday 08/14/2010)

Submitted by admin1 on Sat, 08/14/2010 - 09:00

Potomac River flows at Point of Rocks and Little Falls have risen due to the recent storms in the eastern portion of the basin. The National Weather Service's Middle Atlantic River Forecast Center reports 1/2 inch to 3/4 inches of rain in a few locations in the eastern part of the basin over the past 24 hours, and predicts accumulations of between 1/4 and 1/2 inches in the watersheds of the North and South Branches of the Potomac over the next 48 hours.

Daily Potomac flow and demand update (Friday 08/13/2010)

Submitted by admin1 on Fri, 08/13/2010 - 09:00

There was a significant storm over the majority of the basin yesterday. Most locations received 0.75 to 1.5 inches of rain; other locations received as much as 2 to 3 inches of rain. The National Weather Service 48-hour forecast predicts between 0.1 and 0.25 inches of rainfall over much of the basin. The 5-day Quantitative Precipitation Forecast indicates a chance of 0.75 to 1.6 inches of rainfall over much of the basin.

Daily Potomac flow and demand update (Thursday 08/12/2010)

Submitted by admin1 on Thu, 08/12/2010 - 09:00

There was a significant storm over the northeast portion of the basin this morning with up to 2 inches of rain seen in some locations. The National Weather Service 48-hour forecast predicts 0.25 inches in the western areas of the basin and up to 1 inch in the eastern portion. The 5-day quantitative precipitation forecast indicates a chance of over 2 inches of accumulated rainfall over much of the basin. Many of the USGS gages are not currently reporting flow for yesterday and have not been updated with real-time information since around 1:00 am this morning.