🎃 Halloween forecast; 🗺️ drought update; 🏢 data centers in the news; and more, in today’s Potomac News Reservoir – Oct. 30, 2025 >>>

River Report: Soggy end to October

🎃 Happy Halloween 🎃

🍬 Good news to report—It looks like the rain will let up just in time for kids to get their free candy tomorrow.

🌧️ According to the Middle Atlantic River Forecast Center, between 0.25 and 1.5 inches of rain fell in the basin over the past 24 hours with most of the basin seeing around 1 inch of rain.

🔮 Over the next 3 days, the average basin rainfall may be between 0.25 and 1.5 inches.

🌊 The USGS Point of Rocks gage is 1820 cubic feet per second (cfs) and climbing. Historical median for today is 2525 cfs.

🗺️The U.S. Drought Monitor released this morning shows stronger drought conditions spreading further east since last week’s map. The data is valid through last Tuesday, so it doesn’t include the recent rain.

That’s a Wrap on the 2025 Potomac River Conference

The 2025 Potomac River Conference: Integrating Science, Policy & Management to Combat Harmful Algal Blooms was held on October 22, 2025, at the George Mason University Potomac Environmental Research and Education Center (PEREC) in Woodbridge, Virginia.

ICPRB’s annual conferences highlight important issues facing the Potomac River watershed. Previous topics included PFAS and invasive species.

The most recent conference, organized and hosted by the Interstate Commission on the Potomac River Basin (ICPRB), focused on research and management of harmful algal blooms (HABs) in the Potomac River basin and beyond. The event opened with remarks from ICPRB and PEREC leaders, followed by three main sessions highlighting research, local, and government responses to HABs. Session 1 presented scientific studies on cyanobacteria ecology, toxin production, and environmental drivers. Session 2 explored local monitoring, response strategies, and societal impacts, including the use of remote sensing and community management practices. Session 3 featured a government panel discussing multi-state coordination and detection of algal toxins, complemented by a poster session showcasing emerging research and management innovations.

Presentations, speaker information, and more, can be found on ICPRB’s website >>>

ICPRB staff will start planning for the 2026 Potomac River Conference soon. Want to see a specific subject highlighted? Let us know >>>

River ups and downs; what the winter holds; data center regulations in discussion; and more, in this week’s Potomac News Reservoir – Oct. 23, 2025 >>>

River Report: Remaining Steady(ish)

Ups and downs

Notice something interesting about the flow at the Point of Rocks gage?

The daily fluctuations are a result of upstream hydroelectric dam operations to protect American eels. The dams are turned off at night during the annual American eel migration downstream (September to December). This keeps the slippery little fish from getting caught up in dam machinery as they make their way to sea to spawn. As a result, the flows downstream fluctuate in this predictable daily pattern.

Join ICPRB’s upcoming webinar on November 18, Unsung Heroes of the Potomac River: American Eels, to learn more about American Eels. The event is just one of a series of webinars celebrating ICPRB’s 85th anniversary.

Drought Report

📝 No rainfall occurred in the basin over the past 24 hours, according to the Middle Atlantic River Forecast Center.

🔮No rainfall is expected in the next 3 days. The week-long outlook expects a total of approximately 0.75 to 1.5 inches of rain in the basin, with localized areas predicted to see up to 2 inches of rain.

🗺️The U.S Drought Monitor map released this morning shows a 6% increase in moderate drought conditions (light orange) over last week while the severe and extreme drought conditions remain steady.

Welcoming new members to the ICPRB team!

Please join us in welcoming new members to the ICPRB team.

Mary Stack recently joined the ICPRB team as the Water Quality Data Manager at the Chesapeake Bay Program, bringing a B.S. in Geology from Boston College and an M.S. in Environmental Science from the University of Virginia.

She manages the water quality datasets housed in the Chesapeake Environmental Data Repository (CEDR), ensuring that the data is accessible, accurate, and actionable for decision-making.

Prior to joining our team, Mary directed watershed monitoring initiatives at the Shaw Institute in Maine, conducted water quality data collection and management at Hot Springs National Park, and supported coastal monitoring projects with the Virginia Coast Reserve Long-Term Ecological Research (LTER). She also contributed to geospatial watershed studies in Arctic environments at Toolik Field Station in Alaska and led climate research on coastal Antarctic storm and sea ice dynamics with the Palmer LTER.

Garett Pignotti has joined ICPRB as an Environmental Scientist. He holds a doctorate from Purdue University in Ecological Sciences and Engineering and has previously worked at Washington State University Vancouver and as an ORISE Fellow at the U.S. Forest Service.

Garett has experience working in agricultural, forested, and urban systems to evaluate the effects of climate and land use change on water quantity and quality at the watershed scale. He uses a combination of sensor data, modeling, and satellite observations to understand how water, energy, and nutrient cycles are changing and the implications for their management.

Originally from Orlando, Florida, Garett is excited to support ICPRB’s efforts in improving and securing the basin’s natural resources and, hopefully, escaping his Florida man label.

Mary took over for Mike Mallonee, who managed vital data at the Chesapeake Bay Program for the past 17 years until his retirement last month. Garett has stepped into the shoes of Andrea Nagel, who retired this summer after 24 years at ICPRB. We wish them both a Happy Retirement! 🎊

ICPRB in the community

Please join ICPRB for our webinar series highlighting the past, present, and future of our nation’s river in celebration of our 85th anniversary.

• Oct. 30: Webinar: Who Owns the Potomac? (Speaker: Michael Nardolilli, Executive Director of ICPRB)

• Nov. 1 – Walk in the Woods: Let’s be Smart About Winter Salt – Sligo Creek (Takoma Park, MD)

• Nov. 6: Webinar: Water Impacts from Data Centers (Speaker: Dr. Alimatou Seck, Senior Water Resources Scientist of ICPRB)

• Nov. 18: Webinar: Unsung Heroes of the Potomac River: American Eels (Gordon “Mike” Selckmann, Associate Director of Aquatic Biology, ICPRB)

• Dec. 2: Webinar: Reconsidering Connectivity: A North Branch Potomac Case Study (Gordon “Mike” Selckmann, Associate Director of Aquatic Biology, ICPRB)

• Dec. 9: Webinar: The Future of Water in the DC Metro Area (Speaker: Dr. Cherie Schultz, Director, CO-OP Operations of ICPRB)

The Interstate Commission on the Potomac River Basin is celebrating 85 years of protecting and preserving the Potomac River watershed. Much has happened since ICPRB was authorized by Congress in 1940, so please join us for this webinar series highlighting the past, present, and future of our nation’s river.

A recording of the webinar will be posted to ICPRB’s YouTube page after the event.

Webinars

Who Owns the Potomac?

Click here for the recording >>>

Thursday, October 30, 11:00am
Speaker: Michael Nardolilli, Executive Director of ICPRB

Why are the state boundary lines along the Potomac River so irregular? Why doesn’t the line run neatly down the middle of the river, as it does in many other states? Join ICPRB to learn about the fascinating story behind the Potomac’s peculiar borders involves colonial land grants, centuries-old legal disputes, and evolving interpretations of land and water rights. This webinar was funded by ICPRB’s Clean Water Act Section 106 grant from the EPA.*

Water Impacts from Data Centers

Click here for the recording >>>

Speaker: Dr. Alimatou Seck, Senior Water Resources Scientist of ICPRB
Thursday, November 6, 11:00am

Data centers are rapidly expanding across the Potomac watershed and beyond, raising important questions about their impacts on regional water resources. This webinar will share the Interstate Commission on the Potomac River Basin’s research on data center consumptive use under different growth scenarios through 2050, evaluating implications for regional water supply reliability and long-term planning. The findings provide insights to help decision-makers and stakeholders navigate the intersection of water, energy, technology, and infrastructure in support of regional resilience. This webinar was funded by ICPRB.

Unsung Heroes of the Potomac River: American Eels

Click here for the recording >>>

Speaker: Gordon “Mike” Selckmann, Associate Director of Aquatic Biology and Megan McClaugherty, Ecological Technician and GIS Specialist both from ICPRB
Tuesday, November 18, 11:00am 

American eels have a long and important history in the Potomac River basin. Join ICPRB to learn about their historical importance to the region, their fascinating life cycle, and their importance to both water quality and the ecosystem. Also hear about ICPRB’s work to help restore these fish (yes, they are fish!) to their native range. This webinar was funded by ICPRB’s Clean Water Act Section 106 grant from the EPA.*

ICPRB Land Use Webinar: Land Prioritization Mapping to Protect Drinking Water Quality (2025)

Click here for the recording >>>

Speaker:  Renee Thompson, Water Resources Planner and Megan McClaugherty, Ecological Technician and GIS Specialist both from ICPRB
Friday, December 5, 12:00 pm

The Land Prioritization Mapping to Protect Drinking Water Quality (2025 Update) ranks land parcels in specific Mid-Atlantic states to protect drinking water quality and their potential to degrade long-term water quality.

The question asked in this five-year update remains the same as the original 2020 project, “Which parcels of land should be conserved to be most beneficial to drinking water?” However, the scope of this updated tool is much larger. Instead of focusing just on the Potomac River basin as the 2020 tool had done, the 2025 map was expanded to include the entirety of the states in which the basin sits—the District of Columbia, Maryland, Pennsylvania, Virginia, and West Virginia.

This project provides a robust, data-driven framework for identifying parcels critical to drinking water source protection. By integrating multiple geospatial metrics and offering flexible visualization options, the tool supports informed land conservation decisions. High priority areas were identified across the study area and for individual counties for better usability. Users across the region can combine this drinking water perspective with other conservation priorities to identify win-win opportunities to achieve multiple protection objectives. This webinar was funded by ICPRB’s Clean Water Act Section 106 grant from the EPA.*

The Future of Water in the DC Metro Area

Click here for the recording >>>

Speaker: Dr. Cherie Schultz, Director, CO-OP Operations of ICPRB
Tuesday, December 9, 11am

What does the future hold for our region’s water supply? Every 5 years ICPRB publishes a report on the reliability of our water supply, forecasting decades into the future.

From extreme droughts to booming data centers, join the Interstate Commission on the Potomac River Basin for a webinar as we break down the key findings of the upcoming 2025 Water Supply Reliability Study — a once-every-5-years report that looks decades into the future to ensure safe, reliable drinking water for the DC Metro area. This webinar was funded by ICPRB.

Reconsidering Connectivity: A North Branch Potomac Case Study

Click here for the recording >>>

Speaker: Gordon “Mike” Selckmann, Associate Director of Aquatic Biology, ICPRB
Tuesday December 18, 11:00am

The North Branch of the Potomac River has come a long way. Arguably best known for its industrial recent past, this webinar puts the current state of the western-most Potomac region into perspective. Starting with the geological formation of the mountains, we will then tour the North Branch watershed through time and space, describing the pre-colonial period, the industrialized period, and ending at the current state of the region. Given all discussed we ask “what’s next for this region?” This webinar was funded by ICPRB’s Clean Water Act Section 106 grant from the EPA.*

BONUS WEBINARS: Winter Salt Week

Join ICPRB and our partners in the D.C. Metro Region for two mini-webinar events to learn how you can take action around your community to stay safe and reduce salt impacts to the Potomac and other DC area water sources:

Safe Sidewalks, Clean Water: Smart Salting for Residents

January 21, 2026 | 1 – 1:30 pm 

This webinar explains how winter salt impacts our environment, why it’s a growing regional concern, and the simple steps you can take at home—before, during, and after storms—to apply just the right amount of salt to maintain safety in the winter. Learn application tips, alternatives to salt, and other ways you can be #wintersaltsmart while protecting the environment. This webinar was funded by ICPRB’s Clean Water Act Section 106 grant from the EPA.*

Register

Community Winter Salt Management in Action

January 23, 2026 | 1 – 1:30 pm 

This session is tailored for HOA and other community association residents, board members, community managers, and maintenance team members. Gain best practices and resources for efficient winter salt use, contractor coordination, and strategies to reduce environmental damage while maintaining profitability and setting winter maintenance expectations. Hear from the Reston Association and Columbia Association on ways that they are taking action to improve winter salt management in their communities. This webinar was funded by ICPRB’s Clean Water Act Section 106 grant from the EPA.*

###

A note on funding for the webinars marked with an asterisk (*):

*This project has been funded wholly or in part by the United States Environmental Protection Agency under assistance agreement 98339418 to the Interstate Commission on the Potomac River Basin. The contents of this document do not necessarily reflect the views and policies of the Environmental Protection Agency, nor does the Environmental Protection Agency endorse trade names or recommend the use of commercial products mentioned in this document, as well as any images, video, text, or other content created by generative artificial intelligence tools, nor does any such content necessarily reflect the views and policies of the Environmental Protection Agency.

Shutdown impacts ; ghostly haunts ; bill to fight river pollution ; and more, in this week’s Potomac News Reservoir – Sept. 25, 2025 >>>

River Report: Impacts from Shutdown

Today, an urgent message greets the visitors to the US Geological Survey (USGS) Point of Rocks and Little Falls monitoring websites, “Due to a lapse in government funding, this website will not be updated except to provide important public safety information.”

The Federal government has shutdown.

ICPRB relies on accurate data from Federal organizations to predict drought conditions in the region. For example, ICPRB’s Section for Cooperative Water Supply Operations on the Potomac (CO-OP) is currently conducting daily drought monitoring. This is a daily email to water suppliers and other partners with information on the river’s flow, DC metro area water use, and weather. This is vital operational intelligence for water utilities, especially as forecasts are looking dry. Just to compile this one daily email, CO-OP staff access data from a myriad of Federal agencies, including USGS, NOAA, National Weather Service (NWS), US National Weather Service Middle Atlantic River Forecast Center (MARFC), U.S. Army Corp of Engineers/Washington Aqueduct, and others.

Having up-to-date Potomac River flow information is essential for ICPRB during drought. The river’s flow determines our region’s stage of drought response, informs our decisions on use of reserve water supply storage, and helps us make sure that when we turn on the tap, water comes out.

As of now, streamgages are still operating through automated systems as part of critical activities to protect life and property. However, it is unclear how long this data will remain available before disruptions occur, or whether we will be able to contact our USGS partners to check station status, report issues, or ask questions.

This just emphasizes the importance of our Federal partners which are already stretched thin. They are vital to the stability of water resources in the DC Metro area and beyond.

As for current conditions, Abnormally Dry and Moderately Dry conditions have inched up a couple percentage points since last week, while the area in Extreme and Exceptional Drought has stayed roughly the same, according to today’s U.S. Drought Monitor map.

The USGS gage at Point of Rocks has consistently hovered around 2,000 cubic feet per second for several days.

Dry conditions are predicted to persist in the watershed for at least the next five days, according to forecasts from MARFC and NWS.

It’s Source Water Protection Week… Do you know where your water comes from?

This week ICPRB and staff are celebrating Source Water Protection Week. The best way to ensure high quality drinking water at the tap is to protect the water that goes into it. Throughout the week, we will be sharing tips, information, and photos using #sourcewaterprotectionweek and #ProtectthePotomac across social media.

Today (Thursday), is a special day because it is #sourcewaterselfie day! We are encouraging our readers to share a picture of themselves with the source of their drinking water. Not sure where you water comes from? Check out your water utilities’ website or EPA’s How’s My Waterway, then post a selfie and tag ICPRB!

ICPRB in the Community

Join us at one of our upcoming events:

• Oct. 4 – Walk in the Woods: Let’s be Smart About Winter Salt (Rockville, MD)

• Oct. 5 – Walk in the Woods: Tomorrow’s Trees (Lorton, VA)

• Oct. 11 – Walk in the Woods: Frederick Municipal Forest (Frederick, MD)

• Nov. 1 – Walk in the Woods: Let’s be Smart About Winter Salt – Sligo Creek (Takoma Park, MD)