Interstate Commission on the Potomac River Basin - ICPRB

09/03/2026

It is a mixed bag in today’s River Report.

While the drought status across the region on today’s National Drought Mitigation Center map (see below) holds steady from last week, the flow at the USGS Point of Rocks gage hovers around 2,020 cubic feet per second (cfs). While this is not unusual for this time of year — the median is 2220 cfs — at 2,000 cfs, ICPRB begins Drought Monitoring activities, which means a daily email to water suppliers and other stakeholders with information on flow, water use, and weather forecasts. It’s essentially an extra set of eyes on the data when the flow gets low.

Due to last year’s dry winter, we are still in a rain deficit of 7.6 inches for the past calendar year. However, year to date for 2026 has seen closer to average. (National Oceanic and Atmospheric Administration (NOAA))

While some rain is expected in the region, it appears NOAA’s 7-day forecast doesn’t have more than an inch across the watershed.

Find more links and graphs from today's newsletter at www.potomacriver.org.

09/01/2026

The ICPRB 4th Quarter FY2026 Business Meeting will be held on Tuesday, September 22, 2026, at AlexRenew in Alexandria, Virginia. Commissioners will be presented with Virginia House Resolution No. 371, Commending the Interstate Commission on the Potomac River Basin, which was introduced by Delegate Tran (District 18). Also on the agenda, Commissioners will get updates on the “Secure the Source” Study, data center developments, the Potomac Interceptor, and the development of a new Strategic Plan for ICPRB. After the meeting, Commissioners and guests will enjoy a tour of AlexRenew’s wastewater treatment facility.

The public is invited to attend or provide public comment. Please contact us by Friday, September 18 to register.

The ICPRB 4th Quarter FY2026 Business Meeting will be held on Tuesday, September 22, 2026, at AlexRenew in Alexandria, Virginia. Commissioners will be presented with Virginia House Resolution No. 371, Commending the Interstate Commission on the Potomac River Basin, which was introduced by Delegate T...

08/28/2026

Freshwater Friday is a thing, right!? 👀

Enjoy this quiet underwater moment from our recent snorkel in the Shenandoah River with Potomac Riverkeeper Network.

08/27/2026

The Week’s River Report: Improvements Continue

Drought conditions continue to improve across the watershed, but as one news article says, it’s still pretty droughty out there.

Today’s U.S. Drought Monitor map remains similar to last week, with a swath of Moderate Drought conditions across the center of the watershed and much of the remaining area Abnormally Dry.

Flow at the USGS Point of Rocks gage is Above Normal (in the 75-90th percentile).

Average rain still remains in a deficit though, at 8 inches below average for the past year.

Find more graphs and links in today's newsletter >>> https://mailchi.mp/6c5ba4b3e52a/potomac-news-reservoir-4793313

08/26/2026

39 years of Chesapeake Bay stream health mapped, modeled, and changing fast.

Streams are the lifeblood of the Chesapeake Bay watershed but tracking their health over time and across such a vast area has always been a challenge. Not anymore.

In a new study from the USGS Eastern Ecological Science Center, researchers used machine learning to predict the biological condition of 360,893 small streams across the watershed, going all the way back to 1985. By combining decades of real-world insect (macroinvertebrate) data with landscape, land-use, and climate information, they built a detailed 39-year picture of stream health.

The results paint a complex and sobering picture. Streams near Washington, D.C. and Baltimore are in worse shape and getting worse, a clear signal of urbanization's toll on waterways.

But the story isn't the same everywhere.

Many southern streams are actually improving in overall biological integrity, while northern streams are heading in the opposite direction. Meanwhile, pollution-sensitive insect groups like mayflies, stoneflies, and caddisflies are declining watershed-wide, with the Southeastern Plains region standing out as a rare exception to that trend.

Perhaps most striking is this: by 2021, only about 1% of stream length showed real improvement, falling well short of the region's restoration goals.

These findings matter because they give scientists and resource managers something they've long lacked: a long-term, high-resolution view of where streams are struggling most, and where conservation efforts could make the biggest difference.

Read the study here https://ow.ly/ix4z50ZC6Zg

📸: Benthic macroinvertebrate taxa collected from Straight Run, Tioga County, Pennsylvania, USA. Credit: Kelly Maloney, USGS Public Domain.

08/21/2026

We are officially knocking on fall's door ✊ and excited to announce the first hike in ICPRB's free fall Walk in the Woods series!

Learn with us about one of the sneakier pollutants out there: salt! 🧂❄️

Together, we'll do some environmental detective work by testing our local streams and adding some data to the national hub, which is coordinated by the Izaak Walton League of America's Salt Watch Program🔍

Reserve your spot soon, as space is limited! https://www.eventbrite.com/e/1996757104250?aff=oddtdtcreator

08/21/2026

Looking a bit better, but we are still drier than usual this year. Rain is in the forecast soon for some parts of the Potomac watershed 🤞

Thank you WTOP News for speaking with us and giving folks the update! For more information, you can sign up for our weekly newsletter: https://www.potomacriver.org/resources/publications/newsletter-subscription-management/

The rain the D.C. region has experienced recently is helping improve drought conditions across the Potomac watershed — but there is still a long ways to go to officially end the watershed's two-year drought.

Read more on our website: https://wtop.com/weather-news/2026/08/drought-conditions-improve-across-potomac-watershed-after-weeks-of-rain/

(📸: Getty Images/Kevin Carter)

08/20/2026

Today we are discussing salt and chloride pollution in the Potomac basin with landscape professionals doing the good work on the ground. While we often talk about the impacts to wildlife in the watershed, excess salt can be a killer for landscaping and long-term soil quality. 😔

Thank you to the Northern Virginia Native Plants for Landscape Professionals Conference organizers, Plant NOVA Natives and Northern Virginia Bird Alliance, for inviting us and our partners: Arlington County Virginia – Government, Fairfax County Department of Public Works and Environmental Services, Northern Virginia Soil and Water Conservation District, and Only Rain Nova for tabling with us!

08/14/2026

Self serve kayaks?! Sign us up!

App-based bike and scooter rentals have become ubiquitous in many cities. Now that concept of self-serve access is being extended to kayaks at select

08/13/2026

The Week’s River Report: August Water Supply Outlook

The August Water Supply Outlook was published yesterday. This monthly report provides an update on the possibility of water supply releases from the area’s reservoirs and gives an overall look at drought in the watershed.

Yesterday’s report shows improvement over earlier this summer. While the July report calculated the chance of needing to release water from upstream reservoirs was up to 48%, the August has up to a 16% chance, which is a more positive outlook for the rest of the year. However, some drought conditions remain.

Here is the full summary:

There is a near-normal probability of releases from the Washington metropolitan area’s back-up water supply reservoirs for the 2026 summer and fall seasons. Typically, the use of the Jennings Randolph and Little Seneca reservoirs is triggered by low river flows resulting from a combination of low summer precipitation and low groundwater levels.

The Potomac basin upstream of Washington, D.C., received 3.9 inches of precipitation in July, 0.1 inches above average; as of August 1, the 12-month cumulative total was 29.2 inches, 10.9 inches below average.

Groundwater conditions are generally near normal basin-wide, though above- and below-normal readings occur at individual wells.

Recent rainfall has increased Potomac River streamflow, prompting ICPRB to suspend daily drought monitoring on August 9 after initiating it on August 3 in response to declining flows.

The Climate Prediction Center’s seasonal outlook indicates drought conditions across much of the Mid-Atlantic should improve or be removed by the end of October. A Drought Watch for the metropolitan Washington region remains in effect. Reservoirs remain near full.

At present, Potomac River flow is sufficient to meet metropolitan area water demands without upstream reservoir augmentation. The region remains well protected by established contingency plans should conditions worsen.

Read the full report >>> https://bit.ly/water_supply_outlook

Drought conditions remain across portions of the basin with only a slight improvement over last week. As of August 11, about 12 percent was in severe drought (D2), 44 percent in moderate drought (D1), and 37 percent abnormally dry (D0), with no area in extreme drought (D3).