Back in Drought Monitoring; record dry August; mixed water quality results from CBP; and more, in this week’s Potomac News Reservoir – Sept. 4, 2025 >>>
River Report: CO-OP Initiates Drought Monitoring; September Water Supply Outlook
Due to low flows on the Potomac River, staff in ICPRB’s Section for Cooperative Water Supply Operations on the Potomac (CO-OP) began daily drought monitoring on Tuesday.
During active Drought Monitoring, CO-OP staff provide a daily email to stakeholders summarizing flow, weather, and demand conditions.
Join the conversation and find the daily drought monitoring information on Facebook using #droughtmonitoring.
Today’s US Drought Monitor Map shows 80% of the watershed in abnormally dry conditions.
The river’s flow at Point of Rocks USGS gage is 1860 cubic feet per second (cfs). Median for today is 2265 cfs.
Water Supply Outlook
The September Water Supply Outlook was published yesterday. This monthly report looks at the possibility of water supply releases from the area’s reservoirs based on data from current precipitation, river flow, forecasts, and more.
According to the report, despite a record dry August, there is a below-normal probability of needing releases from the Washington metropolitan area’s back-up water supply reservoirs for the remainder of the year.
Since last month’s Water Supply Outlook, the portion of the basin classified as abnormally dry has expanded from 0 to 38.5 percent (and has since jumped to 80%). The 12-month rainfall average is back in the negative at 1.5 inches below normal.
The Climate Prediction Center forecasts warmer-than-normal temperatures for September through November but noted no clear signal for precipitation amounts either way.
All that being said, the cooler, fall-like temperatures decrease evaporation as well as reduces the demand for water by both plants and people. This provides some relief from drought pressures when things get dry.
ICPRB will continue to monitor the situation and provide timely updates.
Registration Open for 2025 Potomac Conference on Harmful Algal Blooms
Join the Interstate Commission on the Potomac River Basin (ICPRB) on October 22 for a conference that will expound on the latest research, policy, and management of freshwater harmful algal blooms in the Potomac basin and beyond.
Click here for the full agenda >>>
The one-day conference will include sessions on HAB detection, benthic algal communities, case studies from local jurisdictions, and response strategies from different levels of government. A poster session will highlight additional research on the subject.
Watersheds Highlighted at Regional Park
We’re excited to share that the City of Manassas will be using an ICPRB map in their Stormwater Education Trail at Dean Park, which is one of the largest parks in the city.
The sign, highlighting the Potomac River basin within the Chesapeake Bay Watershed, will be one of 11 other signs installed this fall.