Potomac River Named Most Endangered in U.S. for 2026, Citing Data Center Growth and Water Demands

The Potomac River has been designated the most endangered river in the U.S. for 2026 by American Rivers, with this ranking largely attributed to the unchecked growth of data centers within its watershed and a major sewage spill in January 2026. The Piedmont Environmental Council (PEC) emphasized that this listing highlights the cumulative environmental impacts of data centers, particularly concerning the clean and abundant water supply for the Washington metropolitan area. Loudoun County, a global hub for data centers and bordering the Potomac, accounts for a substantial portion of the basin's water withdrawals, peaking at up to 8% during summer months due to cooling demands. The PEC identified three critical issues: insufficient transparency in data center water usage reporting, a lack of comprehensive cumulative impact assessments for the over 600 data centers in Virginia, and the high consumptive use of water, with 60-80% evaporating rather than returning to the watershed. This exacerbates impacts during multi-year droughts and reduced streamflow. Julie Bolthouse, PEC Director of Land Use, noted that Virginia General Assembly passed SB 553, which will require utilities to report monthly water volumes supplied to data centers to the Department of Environmental Quality starting in 2027. However, she criticized the bill for not requiring details on individual data centers or peak daily usage, underscoring the need for more comprehensive transparency given Virginia's leading position in the data center market. PEC President Chris Miller further elaborated on concerns, highlighting the Potomac River as a crucial drinking water source for millions. He detailed the immense electricity demands, citing Dominion Energy's projections of up to 70 gigawatts of additional demand from data centers, and criticized the state's nearly $2 billion in annual tax incentives for data center operators. Virginia Governor Abigail Spanberger, who received significant contributions from Amazon, has reportedly not supported more aggressive legislation for water-use transparency or the elimination of these tax incentives, which benefit companies like Amazon, Microsoft, QTS, and Iron Mountain. PEC advocates for stronger statewide processes to manage and mitigate these cumulative environmental and resource impacts.