LANL expansion could double water use, deepen New Mexico drought worries

Los Alamos National Laboratory’s next phase of growth is colliding with a shrinking water supply in a county already living with contamination, drought and cleanup pressures. Recent reporting says AI and nuclear operations at the lab could require about 1.4 million gallons of water a day, a demand that would land on top of a local system Los Alamos County says is already strained.

The U.S. Department of Energy and the National Nuclear Security Administration issued the Final Site-Wide Environmental Impact Statement for Continued Operation of Los Alamos National Laboratory in March 2026, covering operations through about 2038. The agency selected an Expanded Operations Alternative that would allow new facilities and broader mission growth, including an additional supercomputing complex and a new X-ray-free electron laser facility. One estimate tied to that buildout puts the lab at as much as 705,000 square feet of new facilities by 2038.

Los Alamos County says its Long-Range Water Supply Plan is being updated in 2025 and 2026 because it shut down its highest-producing water well after groundwater contamination was found. The county’s Department of Public Utilities does not just serve homes and businesses in Los Alamos and White Rock; it also provides wholesale water service to LANL. County planners are now working on a new exploratory well at Overlook Park in White Rock after Pajarito Well No. 3 was taken offline because of groundwater contamination.

The scale of the lab’s thirst is not new, but the pressure is sharper now. A 2001 report found LANL used 393 million gallons of water that year, about 27% of all water used in Los Alamos. At the same time, the Department of Energy’s Office of Environmental Management said protecting water supplies remained a key priority in the lab’s legacy cleanup mission, and that a pump-and-treat system for the chromium plume had treated almost 460 million gallons of groundwater since May 2018.

Public hearings on the draft SWEIS were held in Santa Fe, Española and Los Alamos in February 2025, and the comment period was extended to April 10, 2025. For Los Alamos County and northern New Mexico, the fight is no longer abstract: every new building, every contaminated well and every gallon pulled from the system now carries direct consequences for local infrastructure, environmental cleanup and trust in how much water the region can spare.