Today we are ending daily flow and demand updates due to the arrival of rainfall from tropical storm Nicole. According to the Middle Atlantic River Forecast Center, an inch of rain has already fallen in the southern portion of the basin with more on the way, and 1 to 2 inches are expected throughout the basin upstream of the Little Falls gage over the next 24 hours. This amount of rainfall is predicted to increase flows in the Potomac River at Point of Rocks to between 4,000 and 12,000 cubic feet per second (cfs) over the next several days, well above CO-OP’s daily monitoring threshold of 2,000 cfs.
We very much appreciate the hard work and efforts of water supplier operational staff who make these reports possible by providing us with regular and timely data on water withdrawals.
Stay tuned for next week’s annual Washington metropolitan area drought exercise! The exercise will take place Tuesday, November 15 through Thursday, November 17, and will include twice daily flow and demand updates on simulated drought conditions and simulated operations.
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 (inches)
Past 7-day cumulative area-weighted average basin precipitation: 0.08 (inches)
Daily flows:
Little Falls gage flow 2022-11-10: 1170 MGD (1810 cfs)
Little Falls gage flow 2022-11-11: 1176 MGD (est., based on recently available real-time data) (1820 cfs)
Note: Gage flow at Little Falls is measured after water supply withdrawals.
Point of Rocks flow 2022-11-10: 1176 MGD (1820 cfs)
Point of Rocks flow 2022-11-11: 1293 MGD (est., based on recently available real-time data) (2000 cfs)
Yesterday's Washington metropolitan area Potomac River withdrawals and discharges (2022-11-10):
Fairfax Water Corbalis withdrawal (Potomac): 78 MGD
WSSC Water Potomac withdrawal: 114 MGD
Washington Aqueduct withdrawal: 116 MGD
Loudoun Water withdrawal: 14 MGD
Loudoun Water Broad Run discharge: 6 MGD
Total Potomac withdrawal: 322 MGD
Total net Potomac withdrawal: 316 MGD
Loudoun Water Potomac River (PR) flow values for drought operations protocol (based on yesterday's flows):
QPR: 1820 cfs
QPR, obs: 1820 cfs
QPR, WS: 0 cfs