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.

DROUGHT EXERCISE - Afternoon simulated Potomac flow and demand update (Sunday 09/30/2012)

Submitted by admin1 on Sun, 09/30/2012 - 14:00

Drought exercise simulation day: August 25 2022.

Combined water supply storage at Jennings Randolph and Little Seneca reservoirs fell to 60% of capacity this morning. Today's target flow at the Luke USGS gage remains 325 cfs and the Little Seneca release remains at 25 MGD.

DROUGHT EXERCISE - Afternoon simulated Potomac flow and demand update (Friday 09/28/2012)

Submitted by admin1 on Fri, 09/28/2012 - 14:00

Drought exercise simulation day: August 23, 2022.

Water supply releases from the North Branch reservoirs are continuing. Today's target flow at the Luke USGS gage remains at 375 cfs. The Little Seneca release remains at 30 MGD.

Today's estimated demand (08/23/22) P.M.:
ACTUAL WSSC P.M. estimated demand: 170 MGD
ACTUAL FW P.M. estimated demand: 165 MGD
ACTUAL Aqueduct P.M. estimated demand: 155 MGD
SIMULATED LW total estimated demand: 36 MGD
SIMULATED LW WTP estimated demand: 20 MGD

Daily Potomac flow and demand update (Tuesday 09/18/2012)

Submitted by admin1 on Tue, 09/18/2012 - 09:00

Over the past 24 hours the Potomac basin has received between 0.1 and 1 inch of rain; isolated areas in the North Branch received higher amounts closer to 2 inches. The precipitation forecast shows accumulated rainfall estimates between 1.25 and 1.5 inches of rain across the basin over the next 48 hours. ICPRB CO-OP staff will make a determination about the need to continue daily monitoring based on the actual rainfall received and the resultant flow levels. A flow measurement has been taken at Point of Rocks and we are waiting for the rating curve to be revised.

Daily Potomac flow and demand update (Monday 09/17/2012)

Submitted by admin1 on Mon, 09/17/2012 - 09:00

Flow at Point of Rocks dropped below the daily monitoring threshold of 2,000 cfs last Friday. While demand is low right now and there is potential for significant rain in the forecast, daily monitoring has been initiated given that flows continued to drop over the weekend. The Point of Rocks flow is currently below the 25 percentile. The various precipitation forecasts show different accumulated rainfall estimates, but most predict between 1.75 and 2.5 inches of rain across the basin over the next 48 hours.

DROUGHT EXERCISE - Afternoon Potomac flow and demand update (Wednesday 09/21/2011)

Submitted by admin1 on Wed, 09/21/2011 - 14:00

The e-mail report below concludes the 2011 CO-OP Drought Exercise. The exercise focused on use of our daily flow forecast tool and the newly updated OASIS model to inform decisions concerning reservoir releases. This fall we will be testing a variety of new operation procedures using our planning tools, PRRISM and OASIS, in conjunction with Hydrologic's WRF project on climate change. A brief after action report on this year's drought exercise will be forthcoming.

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