Situational Awareness (Friday, 2024-08-02)
Scattered rainfall occurred over the Potomac basin yesterday. Potomac River flow at the USGS’s Point of Rocks gage briefly rose above 2000 cfs yesterday, CO-OP’s trigger for Drought Monitoring, but is now again below that level, National Weather Service forecasts call for heavy rainfall to the east of the basin over the next week. The 7-day cumulative basin-wide precipitation average above the Little Falls gage is predicted to be 0.9 inches.
Special Conditions
None
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: 0.05 (inches)
Past 3-day cumulative area-weighted average basin precipitation: 0.39 (inches)
Past 7-day cumulative area-weighted average basin precipitation: 0.51 (inches)
Daily flows:
Little Falls gage flow 2024-08-01: 782 MGD (1210 cfs)
Little Falls gage flow 2024-08-02: 840 MGD (est., based on recently available real-time data) (1300 cfs)
Note: Gage flow at Little Falls is measured after water supply withdrawals.
Point of Rocks flow 2024-08-01: 1325 MGD (2050 cfs)
Point of Rocks flow 2024-08-02: 1234 MGD (est., based on recently available real-time data) (1910 cfs)
Yesterday's estimated daily flows:
Great Falls estimated flow 2024-08-01: 828 MGD (1281 cfs)
Note: Estimated flow below Great Falls intake is flow at Little Falls plus Little Falls water supply withdrawal.
Yesterday's Washington metropolitan area Potomac River withdrawals and discharges (2024-08-01):
Fairfax Water Corbalis withdrawal - Potomac: 119 MGD
WSSC Water Potomac withdrawal: 134 MGD
Washington Aqueduct withdrawal - Great Falls: 114 MGD
Washington Aqueduct withdrawal - Little Falls: 46 MGD
Loudoun Water withdrawal: 13 MGD
Loudoun Water Broad Run discharge: 5 MGD
Total Potomac withdrawal: 426 MGD
Total net Potomac withdrawal: 422 MGD
Loudoun Water Potomac River (PR) flow values for drought operations protocol (based on yesterday's flows):
QPR: 2050 cfs
QPR, obs: 2050 cfs
QPR, WS: 0 cfs
Interstate Commission on the Potomac River Basin