Call for speakers for Potomac River Conference, drought updates, and more, in this week’s Potomac News Reservoir – May 1, 2025 >>>

River Report: Looking at the data on rain, drought, and flow

A lot of yellow, brown, and orange in the graphs this week.

Rain: Since November, the Potomac River basin has received only 12 inches of rain, which is 6 inches below average. Some relief is in the forecast, with 2-4 inches of rain expected over the next week.

Drought: The basin is DRY with 57% of the area in Moderate Drought and 30% in Severe Drought.

Flow: The river’s flow at the USGS gage at Point of Rocks is around 4500 cubic feet per second (cfs). The lowest recorded flow at this time of year is 3000 cfs in 1896.

ICPRB’s Section for Cooperative Water Supply Operations on the Potomac (CO-OP) will be publishing the Water Supply Outlook for May in the coming days. Want to get a notification when the report comes out? Let us know.

As a reminder, the Metropolitan Washington area remains in the Drought Watch declared by the Metropolitan Washington Council of Governments last summer. This means that authorities are asking folks to use water wisely.

Call for Speakers and Posters for upcoming HABs conference

The Interstate Commission on the Potomac River Basin (ICPRB) is calling for speaker and poster abstracts for the 2025 Potomac River Conference: Integrating Science, Policy, and Communications to Combat Harmful Algal Blooms. The conference will take place on Wednesday, October 22, 2025, at George Mason University’s Potomac Environmental Research and Education Center in Woodbridge, VA.

The conference will expound on the science, policy, management, and public communications of freshwater harmful algal blooms (HABs) in the Potomac River basin and beyond. We are seeking presenters to share their expertise in these and related areas. If you are interested in speaking at the conference or presenting a poster, please complete the submission form. Abstracts are due by the end of the day on June 13, 2025.

This is the fourth annual Potomac River Conference produced by ICPRB. Previous conference subjects included PFAS and Invasive Species.

Not interested in speaking but would like to stay informed about the event? Complete the signup form to get notified when conference registration opens. Registration is expected to open at the end of the summer.

Submit an abstract to speak or present a poster at the conference >>>

Please contact ICPRB if you have any questions.

Who declares a drought?, new leader to create resilient water supply in DC, Earth Day events continue, and more, in this week’s Potomac News Reservoir – Apr. 24, 2025 >>>

River Report: Let’s talk about drought

What information is used when declaring a drought? Who are the authorities on drought? Let’s talk…

Federal agencies provide much of the data and expertise that state and local jurisdictions rely on to determine regional droughts. USGS monitors the streams and groundwater. NOAA tracks precipitation. USDA looks at soil moisture. It is truly a team effort.

The National Drought Mitigation Center works with experts across the country to update the U.S. Drought Monitor map on a weekly basis. Rain is an important indicator of drought, but it is not the only one. The parameters they use include:

• Rain/snow
• Reservoir levels
• Streamflow
• Temperature and evaporative demand
• Soil moisture and vegetation health

While some parameters may be showing signs of drought (like a streamflow drought) others might not, but it is the combination of all the data that is important to understand when assessing for drought conditions. Once this data is combined, the map is populated with drought categories based on a color-coded system ranging from Normal Conditions to Exceptional Drought.

Some states have their own drought declaration processes and websites, including Maryland, Virginia, and Pennsylvania. Unlike the Federal maps, the state maps are segmented into drought evaluation regions. Authorities look at precipitation, groundwater levels, streamflow, and reservoir levels on a regional level. The language used at the state level is also different. The conditions range from Normal to Drought Watch to Drought Warning to Drought Emergency. Each status declaration is paired with activities required by the state agencies.

More regionally, local jurisdictions — in coordination with their water utilities — are responsible for declaring water restrictions, whether voluntary or mandatory. Last summer we saw jurisdictions throughout the region declare voluntary and mandatory water restrictions.

The Metropolitan Washington Council of Governments Drought Coordination Technical Committee monitors drought in the D.C. Metro region. They met earlier this month to discuss the situation. After receiving presentations by ICPRB as well as Federal and state agencies, the members agreed to continue the Drought Watch that was originally declared last summer. Authorities are encouraging wise water use, which includes shorter showers, only run a full dishwasher, and turn off the faucet while not in use.

ICPRB in the community

Please join us at one of our upcoming events:

• Apr. 27 – Rockville Science Day (MD)
• May 3 – Walk in the Woods: Mussel Power with Anacostia Watershed Society (DC)
• May 10 – Walk in the Woods: Frederick Municipal Forest (MD)

• May 17 – Anacostia Festival (DC)

• May 31 – Earth Fest 2025 (Frederick, MD)
• June 14 – Walk in the Woods: Potomac Fever (Chevy Chase, MD)
• Jul. 11 – RiverPalooza: Shenandoah Snorkel, Mussel & Paddle Trip (Bentonville, VA

Water Supply Outlook released, more intense rainstorms, spring events, and more, in this week’s Potomac News Reservoir >>>

River Report: Water Supply Outlook

The first Water Supply Outlook reports for the year 2025 has been published by ICPRB’s CO-OP staff. This report provides an update on the possibility of water supply releases from the area’s reservoirs based on the best available data.

The probability of water supply releases from backup reservoirs in the Washington metropolitan area during the summer and fall seasons of 2025 is currently above normal.

As of early April, streamflow is below normal, and groundwater levels are mostly below normal across the Potomac basin.

The Metropolitan Washington Council of Governments’ drought watch, along with state-level drought watches and warnings in Maryland, Virginia, and Pennsylvania, remains in effect. Nonetheless, the region is well-prepared for drought conditions, with well-established contingency plans designed to safeguard the reliability of the Washington metropolitan area’s water supply.

Contact us if you would like to receive an email notification when the monthly Water Supply Outlook is published.

Field Trip for ICPRB Staff

Staff from ICPRB and Virginia Department of Environmental Quality recently toured the Broad Run watershed in Northern Virginia as part of a stressor analysis project. In addition to inspecting the streams, the group walked the site at Loudoun Water’s Broad Run Reclamation Facility and received a presentation on Broad Run monitoring data analysis by Dr. Stanley Grant at the Occoquan Watershed Monitoring Laboratory. Thank you to Loudoun Water for hosting us!

See the photos on our Facebook page >>>

Projects likes these identify factors the in a watershed that are impacting water quality. When officials are aware of what is creating the problem, they are better able to address it.

Learn more about ICPRB’s water quality reports throughout the basin >>>

ICPRB’s annual report explores the river in 2024, road salt sweeping, where is the rain?, and more, in this week’s Potomac News Reservoir – Mar. 27, 2025 >>>

We are proud to share our 2024 Annual Report, highlighting a year of impactful work protecting and enhancing the Potomac River watershed.

Inside the report:

💦 The 2024 Full River Report
🌿 Tackling climate challenges & drought resilience
🐟 Fighting aquatic invasive species
📉 Tracking water use & conservation efforts
🏘 Partnering with communities for sustainable water use
🔬 Advancing science for a cleaner, healthier Potomac

The Potomac River is a vital resource for millions. Through science, collaboration, and education, ICPRB is ensuring its health for future generations.

Excerpt from the “River Report” section of the 2024 Annual Report:

Records were broken. The D.C. region experienced its longest dry streak of 38 days without significant rain. According to NOAA, October was one of the warmest and driest on record for the entire United States. The Potomac basin upstream of Washington, D.C. received only 0.8 inches of rain during that month, which is 2.2 inches below normal.

Scientists are seeing a trend in increasing average temperatures year after year. Heat-induced moisture loss could lead to longer, more widespread, drought conditions.

These increases are not limited to the ambient (air) temperature. Recent data analysis by ICPRB has seen an increase in water temperatures over the past century. Average water temperatures are increasing across all seasons with winter months seeing the fastest climb.