Stream flows in the Potomac basin continue to slowly decline. According to the National Weather Service’s 7-day cumulative precipitation forecast, little rain is expected over the next week. There was a data gap in real-time flow at the USGS’s Point of Rocks gage yesterday, so yesterday’s daily average flow is estimated
CO-OP daily drought monitoring and reporting will continue over the weekend.
Recent basin-wide average precipitation (above Little Falls):
(based on CO-OP's Low Flow Forecast System analysis of Middle Atlantic River Forecast Center (MARFC) gridded multisensor precipitation estimates)
Yesterday's area-weighted average basin precipitation: 0 (inches)
Past 3-day cumulative area-weighted average basin precipitation: 0.12 (inches)
Past 7-day cumulative area-weighted average basin precipitation: 0.19 (inches)
Daily flows:
Little Falls gage flow 2022-10-27: 1273 MGD (1970 cfs)
Little Falls gage flow 2022-10-28: 1234 MGD (est., based on recently available real-time data) (1910 cfs)
Note: Gage flow at Little Falls is measured after water supply withdrawals.
Point of Rocks flow 2022-10-27: 1228 MGD - estimated (1900 cfs – estimated value)
Point of Rocks flow 2022-10-28: 1163 MGD (est., based on recently available real-time data) (1800 cfs)
Yesterday's Washington metropolitan area Potomac River withdrawals and discharges (2022-10-27):
Fairfax Water Corbalis withdrawal (Potomac): 75 MGD
WSSC Water Potomac withdrawal: 99 MGD
Washington Aqueduct withdrawal: 131 MGD
Loudoun Water withdrawal: 11 MGD
Loudoun Water Broad Run discharge: 5 MGD
Total Potomac withdrawal: 315 MGD
Total net Potomac withdrawal: 310 MGD
Loudoun Water Potomac River (PR) flow values for drought operations protocol (based on yesterday's flows):
QPR: 1900 cfs (estimated from available Point of Rocks real-time data)
QPR, obs: 1900 cfs
QPR, WS: 0 cfs