Situational Awareness (Sunday, 2024-07-21)
Rainfall yesterday in the Potomac basin was scattered. Potomac River flows at Point of Rocks have been relatively steady over the past few days. The Middle Atlantic River Forecast Center predicts little rain in the basin over the next day and an average of 0.6 inches over the next three days.
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: 0.16 (inches)
Past 3-day cumulative area-weighted average basin precipitation: 0.23 (inches)
Past 7-day cumulative area-weighted average basin precipitation: 0.54 (inches)
Daily flows:
Little Falls gage flow 2024-07-20: 743 MGD (1150 cfs)
Little Falls gage flow 2024-07-21: 666 MGD (est., based on recently available real-time data) (1030 cfs)
Note: Gage flow at Little Falls is measured after water supply withdrawals.
Point of Rocks flow 2024-07-20: 879 MGD (1360 cfs)
Point of Rocks flow 2024-07-21: 873 MGD (est., based on recently available real-time data) (1350 cfs)
Yesterday's estimated daily flows:
Great Falls estimated flow 2024-07-20: 805 MGD (1245 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 (2024-07-20):
Fairfax Water Corbalis withdrawal - Potomac: 120 MGD
WSSC Water Potomac withdrawal: 141 MGD
Washington Aqueduct withdrawal - Great Falls: 79 MGD
Washington Aqueduct withdrawal - Little Falls: 62 MGD
Loudoun Water withdrawal: 13 MGD
Loudoun Water Broad Run discharge: 7 MGD
Total Potomac withdrawal: 414 MGD
Total net Potomac withdrawal: 408 MGD
Loudoun Water Potomac River (PR) flow values for drought operations protocol (based on yesterday's flows):
QPR: 1360 cfs
QPR, obs: 1360 cfs
QPR, WS: 0 cfs