WARRENTON, Va. (April 16, 2026) -This week, American Rivers released its 2026 list of most endangered rivers, and the Potomac River leads the list, due in large part to uncontrolled data center growth throughout the watershed.

The Potomac River borders and serves Loudoun County, a major suburb of the Washington Metropolitan Area (WMA) and home to the data center capital of the world. Loudoun County’s data center water usage alone represents about 2–3% of the total water withdrawals from the basin but can reach up to 8% during peak summer months when cooling demand is highest. 

“This report comes at a time when our legislators need to seriously consider and mitigate the cumulative impacts of data centers on every aspect of our life. It underscores what PEC and our coalition partners have been highlighting for years. Beyond rising energy costs, data centers threaten all of our natural resources, including access to clean, abundant water,” says Chris Miller, president of The Piedmont Environmental Council. “We need to pause data center development, so our leaders can make a plan. Until then, Virginia is allowing big tech demand, which was never anticipated or analyzed with adequate transparency, to break every system it has, including draining a primary source of drinking water for the nation’s capital.” 

Three main issues are at play with data center water usage:

• First, transparency around their daily usage and consumption is insufficient. As of now, in Virginia, data centers are not required to report water usage, and municipalities are not required to consider water use when approving new projects. The substantial surge in demand is in the summer when drought conditions can be extreme and other water uses increase, with monthly use close to three times the average annual demand and peak daily use as much as ten times average demand. 
• Second, there’s currently no way to assess the cumulative impact of data center water usage across the state. The annual demand of one data center is not necessarily the problem; it’s the cumulative impact of 600+ data centers in Viriginia and their increasing peak daily usage in the late summer months when conditions are drier and the water level is lower. Data center approvals are regional, but their water demand, like electricity demand, affects communities well beyond the jurisdiction of the approving locality. No statewide process exists to track, manage and mitigate data center water usage so the state can effectively assess how to plan for the water needs of Virginia’s households, hospitals, schools and farms. 
• Third, data center water usage can be hugely consumptive, meaning most of the water is evaporated instead of being returned to the watershed through groundwater absorption. Data centers represent 9% of annual consumptive use of water and up to 12% of consumptive use in the summer. In a recent report, Google reported that evaporation loss is 60-80% of its water withdrawal. Virginia is already drought prone. The lack of precipitation over the past couple of years has led to decreased streamflow and groundwater levels throughout central Virginia. Ongoing, uncontrolled and unmitigated data center expansion will only exacerbate this.

“This spring, the General Assembly passed SB 553, a bill that will require utilities to report monthly water usage by data centers to the Department of Environmental Quality. This is an important first step, but it’s not enough. It will not provide detailed information about individual data centers or peak daily usage, nor will it require disclosure of planned water usage by proposed data centers,” says Julie Bolthouse, director of land use at The Piedmont Environmental Council. “Water usage, consumption and wastewater discharge by data centers is complex. Different companies have very different cooling systems, and therefore very different impacts, which is why we need more transparency. As the state with the largest data center market in the world, our lawmakers and regulators must set the bar higher by proactively planning and ensuring that communities and the resources of the state are not exploited and endangered.”

Media Contact: Mike Doble, [email protected]

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