Daily Potomac flow and demand update (Sunday 2021-08-15)

Over the past 24 hours, the Potomac Basin received 0.1 to 0.5 inches of rain. Depending on location, some isolated areas saw as much as 2 inches. In the next 72 hours, an additional 0.25 to 1.25 inches of rain is possible.

The National Weather Service's Hazardous Weather Outlook is still in effect for the Maryland portion of the Chesapeake Bay, Tidal Potomac River, and I-95 corridor through central Maryland, northern Virginia, and District of Columbia. The Weather Prediction Center 5 and 7-day precipitation forecasts suggest we may see 1.25 to 4 inches of rain due to periods of heavy rain from the remnants of tropical storm Fred. Another tropical storm, Grace, has not yet been projected to affect the Potomac basin but is following Fred's path with a track toward Florida.

Daily flows:
Little Falls gage flow 2021-08-14: 1590 MGD (2460 cfs)
Little Falls gage flow 2021-08-15: 1467 MGD (est., based on recently available real-time data) (2270 cfs)
Note: Gage flow at Little Falls is measured after water supply withdrawals.
Point of Rocks flow 2021-08-14: 1170 MGD (1810 cfs)
Point of Rocks flow 2021-08-15: 1176 MGD (est., based on recently available real-time data) (1820 cfs)

Yesterday's Washington metropolitan area Potomac River withdrawals and discharges (2021-08-14):
Fairfax Water Corbalis withdrawal (Potomac): 94 MGD
WSSC Water Potomac withdrawal: 123 MGD
Washington Aqueduct withdrawal: 143 MGD
Loudoun Water withdrawal: 11 MGD
Loudoun Water Broad Run discharge: 5 MGD
Total Potomac withdrawal: 371 MGD
Total net Potomac withdrawal: 366 MGD

Loudoun Water drought operations protocol river flow values (based on yesterday's flows):
QPR: 1810 cfs
QPR, obs: 1810 cfs
QPR, WS: 0 cfs