The basin received negligible rain over the past 24 hours. But the weather forecast shows some potential relief in the coming days. According to the Middle Atlantic River Forecast Center, precipitation totals ranging from 0.25 to 2 inches are expected in the next 72 hours throughout the basin.
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: 0.06 (inches)
Past 3-day cumulative area-weighted average basin precipitation: 0.13 (inches)
Past 7-day cumulative area-weighted average basin precipitation: 0.27 (inches)
Daily flows:
Little Falls gage flow 2023-08-05: 756 MGD (1170 cfs)
Little Falls gage flow 2023-08-06: 737 MGD (est., based on recently available real-time data) (1140 cfs)
Note: Gage flow at Little Falls is measured after water supply withdrawals.
Point of Rocks flow 2023-08-05: 1060 MGD (1640 cfs)
Point of Rocks flow 2023-08-06: 1060 MGD (est., based on recently available real-time data) (1640 cfs)
Yesterday's Washington metropolitan area Potomac River withdrawals and discharges (2023-08-05):
Fairfax Water Corbalis withdrawal (Potomac): 100 MGD
WSSC Water Potomac withdrawal: 114 MGD
Washington Aqueduct withdrawal: 137 MGD
Loudoun Water withdrawal: 13 MGD
Loudoun Water Broad Run discharge: 5 MGD
Total Potomac withdrawal: 364 MGD
Total net Potomac withdrawal: 359 MGD
Loudoun Water Potomac River (PR) flow values for drought operations protocol (based on yesterday's flows):
QPR: 1640 cfs
QPR, obs: 1640 cfs
QPR, WS: 0 cfs
Note to Loudoun Water: See NWS ensemble flow forecasts (HEFS, GEFS, NAEFS) for Point of Rocks flow for the next 7 days – see https://www.weather.gov/erh/mmefs_marfc?id=PORM2&model=NAEFS.
Note: Potomac River flow at Point of Rocks has dropped below the low-flow threshold of 2,000 cfs. When this occurs, per the Water Supply Coordination Agreement of 1982, CO-OP begins daily monitoring and reporting of Potomac flows and withdrawals on behalf of the CO-OP suppliers, Fairfax Water, Washington Aqueduct, and WSSC Water. Suppliers can review data at CO-OP's Data Portal at www.icprbcoop.org. Reports formatted in approved templates should be submitted by email to coop@icprb.org by 8:00 am for automated processing. Published monitoring reports are at http://icprbcoop.org/products/monitoring-reports.