Situational Awareness (Friday, 2024-06-28)
Dry conditions persist. According to the Middle Atlantic River Forecast Center predictions, average rainfall in the portion of the Potomac basin above Little Falls will total 0.3 inches over the next 24 hours and 0.5 inches over the next 3 days. The week-long outlook expects a total of approximately 0.7 inches.
Special conditions:
The river flow fluctuations caused by the National Park Service bathymetric survey project at Dams 4 and 5 are now visible at the USGS’s gage at Little Falls.
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: 0.07 (inches)
Past 3-day cumulative area-weighted average basin precipitation: 0.17 (inches)
Past 7-day cumulative area-weighted average basin precipitation: 0.23 (inches)
Daily flows:
Little Falls gage flow 2024-06-27: 1234 MGD (1910 cfs)
Little Falls gage flow 2024-06-28: 1066 MGD (est., based on recently available real-time data) (1650 cfs)
Note: Gage flow at Little Falls is measured after water supply withdrawals.
Point of Rocks flow 2024-06-27: 1202 MGD (1860 cfs)
Point of Rocks flow 2024-06-28: 1202 MGD (est., based on recently available real-time data) (1860 cfs)
Yesterday's estimated daily flows:
Great Falls estimated flow 2024-06-27: 1378 MGD (2132 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 (2024-06-27):
Fairfax Water Corbalis withdrawal - Potomac: 103 MGD
WSSC Water Potomac withdrawal: 129 MGD
Washington Aqueduct withdrawal - Great Falls: 0 MGD
Washington Aqueduct withdrawal - Little Falls: 144 MGD
Loudoun Water withdrawal: 13 MGD
Loudoun Water Broad Run discharge: 7 MGD
Total Potomac withdrawal: 390 MGD
Total net Potomac withdrawal: 383 MGD
Loudoun Water Potomac River (PR) flow values for drought operations protocol (based on yesterday's flows):
QPR: 1860 cfs
QPR, obs: 1860 cfs
QPR, WS: 0 cfs