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 09/27/2017) - DROUGHT EXERCISE

Submitted by admin1 on Wed, 09/27/2017 - 14:00

DROUGHT EXERCISE - Afternoon simulated Potomac flow and demand update (Sunday 09/27/2017) - DROUGHT EXERCISE

Daily Flows (simulated):
Little Falls gage flow 09/26: 190 MGD (300 cfs)
Point of Rocks gage flow 09/26: 420 MGD (650 cfs)
Note: Gage flow at Little Falls is measured after water supply withdrawals.
Little Falls gage flow 09/27: 120 MGD (180 cfs)
Point of Rocks gage flow 09/27: 400 MGD (630 cfs)

Daily Potomac flow and demand update (Wednesday 2017-09-27)

Submitted by admin1 on Wed, 09/27/2017 - 09:00

Forecasts indicate that dry conditions will continue for at least the next 7 days.

Daily Flows:
Little Falls gage flow 2017-09-26: 969 MGD (1500 cfs)
Little Falls gage flow 2017-09-27: 982 MGD (est., based on recently available real time data) (1520 cfs)
Note: Gage flow at Little Falls is measured after water supply withdrawals.

Point of Rocks flow 2017-09-26: 1079 MGD (1670 cfs)
Point of Rocks flow 2017-09-27: 1034 MGD (est., based on recently available real time data) (1600 cfs)

DROUGHT EXERCISE - Afternoon simulated Potomac flow and demand update (Saturday 09/26/2017) - DROUGHT EXERCISE

Submitted by admin1 on Tue, 09/26/2017 - 14:00

DROUGHT EXERCISE - Afternoon simulated Potomac flow and demand update (Saturday 09/26/2017) - DROUGHT EXERCISE

Daily Flows (simulated):
Little Falls gage flow 09/25: 180 MGD (280 cfs)
Point of Rocks gage flow 09/25: 380 MGD (590 cfs)
Note: Gage flow at Little Falls is measured after water supply withdrawals.
Little Falls gage flow 09/26: 130 MGD (190 cfs)
Point of Rocks gage flow 09/26: 370 MGD (580 cfs)

Daily Potomac flow and demand update (Tuesday 2017-09-26)

Submitted by admin1 on Tue, 09/26/2017 - 09:00

Dry conditions are expected to continue over the next week.

Daily Flows:
Little Falls gage flow 2017-09-25: 1021 MGD (1580 cfs)
Little Falls gage flow 2017-09-26: 957 MGD (est., based on recently available real time data) (1480 cfs)
Note: Gage flow at Little Falls is measured after water supply withdrawals.

Point of Rocks flow 2017-09-25: 1028 MGD (1590 cfs)
Point of Rocks flow 2017-09-26: 1125 MGD (est., based on recently available real time data) (1740 cfs)

DROUGHT EXERCISE - Afternoon simulated Potomac flow and demand update (Friday 09/25/2017) - DROUGHT EXERCISE

Submitted by admin1 on Mon, 09/25/2017 - 14:00

DROUGHT EXERCISE - Afternoon simulated Potomac flow and demand update (Friday 09/25/2017) - DROUGHT EXERCISE

Daily Flows (simulated):
Little Falls gage flow 09/24: 130 MGD (210 cfs)
Point of Rocks gage flow 09/24: 550 MGD (850 cfs)
Note: Gage flow at Little Falls is measured after water supply withdrawals.
Little Falls gage flow 09/25: 120 MGD (186 cfs)
Point of Rocks gage flow 09/25: 440 MGD (681 cfs)

Daily Potomac flow and demand update (Monday 2017-09-25)

Submitted by admin1 on Mon, 09/25/2017 - 09:00

Potomac basin stream flows continue to fall. The 7-day forecast indicates that dry conditions will persist.

Daily Flows:
Little Falls gage flow 2017-09-24: 1138 MGD (1760 cfs)
Little Falls gage flow 2017-09-25: 1034 MGD (est., based on recently available real time data) (1600 cfs)
Note: Gage flow at Little Falls is measured after water supply withdrawals.

Point of Rocks flow 2017-09-24: 1021 MGD (1580 cfs)
Point of Rocks flow 2017-09-25: 1021 MGD (est., based on recently available real time data) (1580 cfs)

DROUGHT EXERCISE - Afternoon simulated Potomac flow and demand update (Thursday 09/24/2017) - DROUGHT EXERCISE

Submitted by admin1 on Sun, 09/24/2017 - 14:00

Daily Flows (simulated):
Little Falls gage flow 09/23: 230 MGD (360 cfs)
Point of Rocks gage flow 09/23: 590 MGD (920 cfs)
Note: Gage flow at Little Falls is measured after water supply withdrawals.
Little Falls gage flow 09/24: 250 MGD (380 cfs)
Point of Rocks gage flow 09/24: 730 MGD (1130 cfs)

Today's estimated demand (09/24/17) P.M.:
WSSC P.M. estimated demand: 190 MGD
FW P.M. estimated demand: 185 MGD
Aqueduct P.M. estimated demand: 150 MGD
Total P.M. estimated demand: 525 MGD

Daily Potomac flow and demand update (Sunday, 2017-09-24)

Submitted by admin1 on Sun, 09/24/2017 - 09:00

The Middle Atlantic River Forecast Center (MARFC) predicts no rain in the basin over the next 3 days.

Daily Flows:

Little Falls gage flow 2017-09-23: 1222 MGD (1890 cfs)
Little Falls gage flow 2017-09-24: 1144 MGD (est., based on recently available real time data) (1770 cfs)
Note: Gage flow at Little Falls is measured after water supply withdrawals.

Point of Rocks flow 2017-09-23: 1105 MGD (1710 cfs)
Point of Rocks flow 2017-09-24: 1034 MGD (est., based on recently available real time data) (1600 cfs)

DROUGHT EXERCISE - Afternoon simulated Potomac flow and demand update (Wednesday 09/23/2017

Submitted by admin1 on Sat, 09/23/2017 - 14:00

Daily Flows (simulated):
Little Falls gage flow 09/22: 240 MGD (380 cfs)
Little Falls gage flow 09/23: 240 MGD (est., based on most recently available real time data) (370 cfs)
Note: Gage flow at Little Falls is measured after water supply withdrawals.
Point of Rocks flow 09/22: 490 MGD (760 cfs)
Point of Rocks gage flow 09/23: 580 MGD (est., based on most recently available real time data) (900 cfs)

Daily Potomac flow and demand update (Saturday 2017-09-23)

Submitted by admin1 on Sat, 09/23/2017 - 09:00

Stream flows in the Potomac basin continue to slowly decline. The National Weather Service (NWS) quantitative prediction forecast indicates that less than 1/10 inch of rain will fall in the basin over the next seven day period.

Daily Flows:
Little Falls gage flow 2017-09-22: 1351 MGD (2090 cfs)
Little Falls gage flow 2017-09-23: 1254 MGD (est., based on recently available real time data) (1940 cfs)
Note: Gage flow at Little Falls is measured after water supply withdrawals.