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.

Afternoon Potomac flow and demand update (Friday 09/17/2010)

Submitted by admin1 on Fri, 09/17/2010 - 14:00

Weather conditions and operational recommendations remain the same as this morning.

Daily Flows:
Little Falls gage flow 09/16: 440 MGD (680 cfs)
Little Falls gage flow 09/17: 490 MGD (est., based on most recently available real time data) (759 cfs)
Note: Gage flow at Little Falls is measured after water supply withdrawals.
Point of Rocks flow 09/16: 810 MGD (1260 cfs)
Point of Rocks flow 09/17: 940 MGD (est., based on recently available real time data) (1460 cfs)

Afternoon Potomac flow and demand update (Thursday 09/16/2010)

Submitted by admin1 on Thu, 09/16/2010 - 14:00

Weather conditions and operational recommendations remain the same as
this morning.

Daily Flows:
Little Falls gage flow 09/15: 470 MGD (720 cfs)
Little Falls gage flow 09/16: 350 MGD (est., based on most
recently available real time data) (548 cfs)
Note: Gage flow at Little Falls is measured after water
supply withdrawals.
Point of Rocks flow 09/15: 720 MGD (1110 cfs)
Point of Rocks flow 09/16: 810 MGD (est., based on recently
available real time data) (1250 cfs)

Afternoon Potomac flow and demand update (Wednesday 09/15/2010)

Submitted by admin1 on Wed, 09/15/2010 - 14:00

There has been no change in weather conditions. Operational
recommendations remain the same as in this morning's update.

Daily Flows:
Little Falls gage flow 09/14: 490 MGD (760 cfs)
Little Falls gage flow 09/15: 380 MGD (est., based on most
recently available real time data) (593 cfs)
Note: Gage flow at Little Falls is measured after water
supply withdrawals.
Point of Rocks flow 09/14: 740 MGD (1140 cfs)
Point of Rocks flow 09/15: 720 MGD (est., based on recently
available real time data) (1120 cfs)

Afternoon Potomac flow and demand update (Monday 09/13/2010)

Submitted by admin1 on Mon, 09/13/2010 - 14:00

No change in the weather forecast. Flows at Little Falls have improved temporarily. Utilities should operate per operation preference.

Daily Flows:
Little Falls gage flow 09/12: 460 MGD (710 cfs)
Little Falls gage flow 09/13: 580 MGD (est., based on most recently available real time data) (892 cfs)
Note: Gage flow at Little Falls is measured after water supply withdrawals.
Point of Rocks flow 09/12: 690 MGD (1060 cfs)
Point of Rocks flow 09/13: 720 MGD (est., based on recently available real time data) (1120 cfs)

Afternoon Potomac flow and demand update (Sunday 09/12/2010)

Submitted by admin1 on Sun, 09/12/2010 - 14:00

The rain falling across the basin today is helping to maintain flow
levels and, along with a drop in demands, is keeping utility
operations steady. The releases from the North Branch reservoirs
continue. The leading edge of the release can be seen at the Paw Paw,
WV gage on the mainstem Potomac River.

Washington Aqueduct will go off of the Little Falls pumping station
and back to Great Falls when possible. They were unable to reach the
station earlier in the day due to the triathlon taking place in the
area.

Afternoon Potomac flow and demand update (Saturday 09/11/2010)

Submitted by admin1 on Sat, 09/11/2010 - 14:00

Potomac River flow at the USGS's gage station at Little Falls is now in the vicinity of 300 MGD. There may be some relief from the dry weather this weekend; the National Weather Service predicts accumulations of up to 1/2 inch of rain throughout much of the basin today and tomorrow. The release from the North Branch reservoirs will continue through the weekend.

Afternoon Potomac flow and demand update (Friday 09/10/2010)

Submitted by admin1 on Fri, 09/10/2010 - 14:00

The Jennings Randolph water supply release, which started at 8:30 AM today (September 10), is currently visible at the USGS stream gage in Luke, MD. The USGS did a rating curve adjustment that resulted in an increase of 71 MGD (110 cfs) at Point of Rocks from this morning's reading. We are watching for the arrival of the Little Seneca release at Little Falls. Past tests have indicated that the time of travel is approximately 29 hours, which would imply the arrival to be at 1:00 PM.

Afternoon Potomac flow and demand update (Thursday 09/09/2010)

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

This afternoon we will be requesting concurrence from the general
managers for a release from Jennings Randolph beginning tomorrow
morning. The 50 MGD test release from Little Seneca Reservoir began at
8:00 AM today (September 9) and will continue through 8:00 AM tomorrow
(September 10). The release was observed by Karin Bencala of ICPRB
staff at a location approximately 1 mile downstream of the reservoir.
Flows were observed to be increasing by 9:15 AM. Black Hill Regional
Staff was setting out signs in the park notifying patrons that the