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 08/05/2011)

Submitted by admin1 on Fri, 08/05/2011 - 09:00

Isolated portions of the basin received approximately a half inch of
rain over the past 24 hours. There is a chance the western portion of
the basin could receive between 0.5 and 1.0 inch of rain over the next
48 hours. The National Weather Service (NWS) quantitative
precipitation forecasts (qpf) predict up to 0.5 inches of rain across
the basin over the next 5-day period.

Daily Potomac flow and demand update (Thursday 08/04/2011)

Submitted by admin1 on Thu, 08/04/2011 - 09:00

Yesterday's scattered showers produced between a 0.01 to a 0.25 of an inch of rain for parts of the basin. Similar scattered showers are expected for today. The 48-hour forecast shows a chance of up to a 0.25 of an inch of rain across the basin. The National Weather Service (NWS) quantitative precipitation forecasts (qpf) indicates the basin could receive accumulated rainfall between 0.5 and 1.25 inches over the next 5 days.

Daily Potomac flow and demand update (Wednesday 08/03/2011)

Submitted by admin1 on Wed, 08/03/2011 - 09:00

Scattered showers producing less than 0.10 inches of rain occurred in
limited parts of the basin yesterday. The 48-hour forecast shows a
chance of up to 0.50 inches of rain across the basin. The National
Weather Service (NWS) quantitative precipitation forecasts (qpf)
indicates the basin could receive accumulated rainfall between 0.75
and 1.50 inches over the next 5 days.

Daily Potomac flow and demand update (Tuesday 08/02/2011)

Submitted by admin1 on Tue, 08/02/2011 - 09:00

Potomac River flows have been steadily decreasing. Current flows at Point of Rocks are at 1890 cfs. National Weather Service (NWS) quantitative precipitation forecasts (qpf) indicate that an accumulation of approximately 0.5 inch of rain is likely for most of the basin over the next 5 days. Some areas have slightly higher or lower qpf totals.

Daily Potomac flow and demand update (Friday 11/05/2010)

Submitted by admin1 on Fri, 11/05/2010 - 09:00

The basin received between 0.25 and 1 inch of rain over the past 24-hour period. The heavier rainfall was seen in the central and
eastern portions of the basin. Zero to trace amounts of precipitation are forecasted to accumulate over the next 5 days.

Given the recent precipitation and low demands, we will not report on conditions over the weekend. A summary of the weekends flows and
demands, along with an assessment of conditions will be sent on Monday with the daily report.

Daily Potomac flow and demand update (Thursday 11/04/2010)

Submitted by admin1 on Thu, 11/04/2010 - 09:00

Over the past 24 hours locations in the basin have seen between 0.25 and 1.5 inches of rain. An isolated area near Paw Paw received 2 inches. The 48-hour forecast predicts 0.5 inches of rain in the western portion of the basin and up to 0.75 inches in the metro area. The 5-day forecast shows a chance of up to 1 inch of accumulated rainfall across the basin.

Daily Potomac flow and demand update (Wednesday 11/03/2010)

Submitted by admin1 on Wed, 11/03/2010 - 09:00

Trace amounts of rain fell upstream of the metro area yesterday. Otherwise, the basin received no precipitation over the last 24 hours. The 48-hour forecast indicates a chance of up to 1 inch of rain in the southern Shenandoah area and between 1/2 and 3/4 of an inch across the rest of the basin. The 5-day forecast predicts accumulations of 1/2 an inch across the basin.

Daily Potomac flow and demand update (Monday 11/01/2010)

Submitted by admin1 on Mon, 11/01/2010 - 09:00

As you may have noticed, for several days the flow at Point of Rocks dropped below the threshold of 2,000 cfs (1293 MGD). When this occurs, daily monitoring and reporting of Potomac River flows and withdrawals are conducted by CO-OP per the Drought Operations Manual of the Water Supply Coordination Agreement. Last Friday we asked that CO-OP utilities begin sending us reports of yesterday's demand, and we will be sending out a daily summary of demands and flows.