Suspending daily monitoring-Daily Potomac flow and demand update (Tuesday 2021-08-17)

Submitted by admin1 on Tue, 08/17/2021 - 09:00

Up to 2 inches of rain fell in some areas of the basin in the past 24 hours. 1 to 2.5 inches of rain is expected in the next 72 hours.

CO-OP is suspending daily drought monitoring because flow at the US Geological Survey’s gage at Point of Rocks, Maryland has risen above the 2000 cfs monitoring threshold. Thank you for your daily submission of withdrawal and reservoir storage data. Although active monitoring has been discontinued, it is still helpful if you submit data on a daily basis to help us maintain, update, and verify our forecast tools.

Daily flows:
Little Falls gage flow 2021-08-16: 1550 MGD (2400 cfs)
Little Falls gage flow 2021-08-17: 1880 MGD (est., based on recently available real time data) (2910 cfs)
Note: Gage flow at Little Falls is measured after water supply withdrawals.
Point of Rocks flow 2021-08-16: 1250 MGD (1940 cfs)
Point of Rocks flow 2021-08-17: 1430 MGD (est., based on recently available real time data) (2210 cfs)

Yesterday's Washington metropolitan area Potomac River withdrawals and discharges (2021-08-16):
Fairfax Water Corbalis withdrawal (Potomac): 94 MGD
WSSC Water Potomac withdrawal: 133 MGD
Washington Aqueduct withdrawal: 126 MGD
Loudoun Water withdrawal: 11 MGD
Loudoun Water Broad Run discharge: 6 MGD
Total Potomac withdrawal: 364 MGD
Total net Potomac withdrawal: 358 MGD

Loudoun Water drought operations protocol river flow values (based on yesterday's flows):
QPR: 1940 cfs
QPR, obs: 1940 cfs
QPR, WS: 0 cfs

Note to Loudoun Water: See NWS ensemble flow forecasts (HEFS, GEFS, NAEFS) for Point of Rocks flow for the next 7 days – see

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