Daily Potomac flow and demand update (Monday, 2026-01-26)

Submitted by hmoltz on Mon, 01/26/2026 - 13:20

Situational Awareness (Monday, 2026-01-26)
According to the Middle Atlantic River Forecast Center, 0.5-2.0 inches of liquid-equivalent precipitation fell in the basin over the past 24 hours. Up to 0.1 inches of additional precipitation is forecast in the far western portion of the basin over the next 3 days.  No precipitation is expected in the rest of the basin over that same 3-day period.

Special Conditions
None

Daily flows:
Little Falls gage flow 2026-01-25: 879 MGD (1360 cfs)
Little Falls gage flow 2026-01-26: 475 MGD (est., based on recently available real-time data) (735 cfs)
Note: Gage flow at Little Falls is measured after water supply withdrawals.
Point of Rocks flow 2026-01-25: 834 MGD (1290 cfs)
Point of Rocks flow 2026-01-26: 1125 MGD (est., based on recently available real-time data) (1740 cfs)

Yesterday's estimated daily flows:
Great Falls estimated flow 2026-01-25: 879 MGD (1360 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 (2026-01-25):
Fairfax Water Corbalis withdrawal - Potomac: 86 MGD
WSSC Water Potomac withdrawal: 157 MGD
Washington Aqueduct withdrawal - Great Falls: 134 MGD
Washington Aqueduct withdrawal - Little Falls: 0 MGD
Loudoun Water withdrawal: 8 MGD
Loudoun Water Broad Run discharge: 10 MGD
Total Potomac withdrawal: 384 MGD
Total net Potomac withdrawal: 375 MGD

Loudoun Water Potomac River (PR) flow values for drought operations protocol (based on yesterday's flows):
QPR: 1290 cfs
QPR, obs: 1290 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 – https://www.weather.gov/erh/mmefs_marfc?id=PORM2&model=NAEFS. See US Army Corps of Engineers Potomac River Basin page for observed releases from Savage and Jennings Randolph reservoirs - https://water.usace.army.mil/office/nab/; See US Army Corps of Engineers North Branch Potomac River and Savage River page for scheduled releases - https://water.usace.army.mil/office/nab/releases/north-branch.

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.

Tags
AM Report
Daily Monitoring