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 09/20/2013)

Submitted by admin1 on Fri, 09/20/2013 - 09:00

No significant precipitation fell in the basin yesterday. Over the next 72-hours, the National Weather Service predicts 1 to 2.25 inches of rain throughout the basin with heaviest rain expected around central Maryland.

Due to the expected rainover the weekend, we are temporarily discontinuing daily monitoring on Saturday and Sunday and will resume on Monday.

Daily Potomac flow and demand update (Thursday 09/19/2013)

Submitted by admin1 on Thu, 09/19/2013 - 09:00

Measured flows at Point of Rocks continue to decrease as of this morning. According to USGS, the grasses around the Point of Rocks gage are starting to die off, resulting in less backwater. USGS plans to conduct on-site measurements bi-weekly while low flow conditions persist.

No precipitation fell in the basin yesterday. Over the next 72-hours, the National Weather Service predicts 0.5 to 1.25 inches of rainfall throughout the basin with most areas expecting approximately 0.75 inches.

Daily Potomac flow and demand update (Thursday 09/26/2013)

Submitted by admin1 on Fri, 09/06/2013 - 09:00

Trace amounts to half an inch of rain fell in the central part of the basin over the last 24 hours. No rain is predicted for the next 72 hours.

Daily Flows:
Little Falls gage flow 09/25: 1290 MGD (2000 cfs)
Little Falls gage flow 09/26: 1280 MGD (est., based on recently available real time data) (1980 cfs)
Note: Gage flow at Little Falls is measured after water supply withdrawals.
Point of Rocks flow 09/25: 1200 MGD (1850 cfs)
Point of Rocks flow 09/26: 1160 MGD (est., based on recently available real time data) (1800 cfs)

DROUGHT EXERCISE - Afternoon simulated Potomac flow and demand update (Sunday 08/25/2013)

Submitted by admin1 on Sun, 08/25/2013 - 14:00

(SIMULATED CONDITIONS AND OPERATIONS:) Natural flow in the river has continued to rise, due to the arrival today of the North Branch reservoir release, and flow at Little Falls is currently at 263 cfs (170 MGD). Because of the improvement in flow conditions, Washington Aqueduct will be shifting a portion of its withdrawal back to its Great Falls intake this afternoon.

DROUGHT EXERCISE - Afternoon simulated Potomac flow and demand update (Saturday 08/24/2013)

Submitted by admin1 on Sat, 08/24/2013 - 14:00

The National Weather Service estimates that 0.25 to 2.0 inches of rain fell in some areas in the western portion of the basin this morning. Operational recommendations have changed from this morning's email.

THE FLOWS, DEMANDS, AND DISCHARGES REPORTED BELOW REFLECT ACTUAL CONDITIONS:

DROUGHT EXERCISE - Afternoon simulated Potomac flow and demand update (Friday 08/23/2013)

Submitted by admin1 on Fri, 08/23/2013 - 14:00

The National Weather Service estimates that 1 to 2 inches of rain fell in some areas in the western portion of the basin this morning, and it predicts that the western portion of the basin will receive up to 1/2 inch of additional rain over the coming 24 hours.

An ACTUAL release from Little Seneca Reservoir of 125 MGD was initiated today at approximately 11 AM. The duration of the release will be 12 hours.

THE FLOWS, DEMANDS, AND DISCHARGES REPORTED BELOW REFLECT ACTUAL CONDITIONS:

DROUGHT EXERCISE - Afternoon simulated Potomac flow and demand update (Thursday 08/22/2013)

Submitted by admin1 on Thu, 08/22/2013 - 14:00

There are no significant changes in this afternoon's weather and flow forecasts, and operational recommendations remain the same as reported in this morning's email.

Daily Flows:
Little Falls gage flow 08/21: 1670 MGD (2580 cfs)
Little Falls gage flow 08/22: 1620 MGD (est., based on most recently available real time data) (2500 cfs)
Note: Gage flow at Little Falls is measured after water supply withdrawals.
Point of Rocks flow 08/21: 1740 MGD (2690 cfs)
Point of Rocks flow 08/22: 1860 MGD (est., based on recently available real time data) (2880 cfs)