Situational Awareness (Saturday, 2024-08-03)
According to the Middle Atlantic River Forecast Center predictions, the next 24 hours may see 0.4 inches of rain. Over the next 3 days, the average basin rainfall may be around 0.7 inches. The week-long outlook expects a total of approximately 1.4 inches of rain in the basin.
Special Conditions
The USGS made field visits yesterday to both the Point of Rocks and Little Falls stream gages. The stage discharge curve for Point of Rocks was revised due to increased presence of grass in the river in the vicinity of the gage.
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: 0.1 (inches)
Past 3-day cumulative area-weighted average basin precipitation: 0.23 (inches)
Past 7-day cumulative area-weighted average basin precipitation: 0.58 (inches)
Daily flows:
Little Falls gage flow 2024-08-02: 834 MGD (1290 cfs)
Little Falls gage flow 2024-08-03: 885 MGD (est., based on recently available real-time data) (1370 cfs)
Note: Gage flow at Little Falls is measured after water supply withdrawals.
Point of Rocks flow 2024-08-02: 1105 MGD (1710 cfs)
Point of Rocks flow 2024-08-03: 1163 MGD (est., based on recently available real-time data) (1800 cfs)
Yesterday's estimated daily flows:
Great Falls estimated flow 2024-08-02: 902 MGD (1395 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 (2024-08-02):
Fairfax Water Corbalis withdrawal - Potomac: 147 MGD
WSSC Water Potomac withdrawal: 135 MGD
Washington Aqueduct withdrawal - Great Falls: 90 MGD
Washington Aqueduct withdrawal - Little Falls: 68 MGD
Loudoun Water withdrawal: 13 MGD
Loudoun Water Broad Run discharge: 4 MGD
Total Potomac withdrawal: 452 MGD
Total net Potomac withdrawal: 448 MGD
Loudoun Water Potomac River (PR) flow values for drought operations protocol (based on yesterday's flows):
QPR: 1710 cfs
QPR, obs: 1710 cfs
QPR, WS: 0 cfs
Interstate Commission on the Potomac River Basin