Conservation Groups Raise Alarm as Potomac River Named Most Endangered in the Nation

The Potomac River, otherwise known as “the nation’s river,” has been named the most endangered river in the country, following a massive sewage spill earlier this year and the ongoing buildout of thirsty data centers across the watershed.

A view of the U.S. Capitol from the Potomac River, March 30, 2026. (Photo by Shannon Heckt/Virginia Mercury)

The ranking comes from the national nonprofit American Rivers, which focuses on conservation of drinking water, wildlife, and other water-related issues. They take into account future risks to water availability, water infrastructure needs, and pollution.

“The Potomac is at an inflection point and cannot continue to sustain the rapid expansion of water-guzzling data centers drawing from its waters,” said Pat Calvert, the Virginia conservation director for American Rivers. “Act now or watch this river be detrimentally redefined for the everyday citizen that depends on it.”

More than six million people live in the Potomac River basin through Virginia, Maryland, West Virginia, Pennsylvania, and Washington, D.C.  It is the main source of drinking water for Washington, D.C., and the surrounding areas.

In January, an aging pipe burst in Maryland and spewed 243-million gallons of sewage into the river. A recreational advisory was issued for 72.5 miles of the Virginia coast, creating public concern over the safety of being around the water even after the advisories were lifted in March.

The disaster highlighted the urgent need for investments in infrastructure that is decades overdue for updates.

“The sewage spill and this ‘most endangered’ designation are a wake-up call that should spark action to fund the major, ongoing investments in infrastructure,” said Allison Hooper Prost with the Chesapeake Bay Foundation.

American Rivers also pointed to Northern Virginia being home to more than 300 data centers that often take hundreds of millions of gallons of water to cool their internal computer systems. With more facilities continuing to be built every day, the group is calling for a watershed-wide analysis of the impacts of water discharge from data centers and what the expansion could mean for future water availability.

“This river, a critically important natural resource for the people and wildlife in our entire region, faces serious threats from unchecked data center development and the Potomac Interceptor pipeline spill,” said Lydia Lawrence, director of conservation for Nature Forward, an environmental nonprofit. “We urge Federal, state, and local legislators to take swift action and pass policies that protect the immediate and future health of the Potomac.”

The Potomac Conservancy reported earlier this year that while data centers account for just 1% of total withdrawals in the Washington metro area, they represent 9% of annual consumptive use and up to 12% of consumptive use in summer. As more centers come online, there are increasing concerns that those numbers could continue to rise.

The groups call on the state and federal governments to invest in wastewater projects and to restore grants through the Clean Water Act that have been halted in recent years.

by Shannon Heckt, Virginia Mercury

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