Data Centers Use More Water Than California Cities, Study Says
A report by the think tank Ceres indicates that data centers' electricity generation uses an enormous amount of freshwater annually across seven high-concentration states, surpassing California's urban water demand. The study focuses on water withdrawals, a methodology debated by other experts, and highlights the risk to water supplies across the US. The increasing number of data centers, driven by AI, is raising concerns about water consumption in many communities.
The think tank Ceres has released a report titled "The Water Behind the Watts," which states that electric power generation for data centers poses a significant threat to water supplies across the United States, extending beyond traditionally arid regions. The report reveals that data centers in the seven states with the highest concentrations collectively withdraw approximately 3.4 trillion gallons of freshwater annually for electricity generation. This volume surpasses California's average annual urban water demand of 8 million acre-feet and is 12 times the combined annual water use of Los Angeles, Phoenix, and Washington, D.C.
The study highlights specific examples, noting that electric generators powering data centers withdrew 1.4 trillion gallons of water in California and 753 billion gallons in Virginia in 2024. Kristen James, senior program director for water at Ceres, noted that 66% of the power plants using water in these states are exposed to medium to high water stress due to high demand relative to available supply.
Ceres utilized Energy Information Administration data to analyze water use in California, Virginia, Texas, Illinois, Georgia, Ohio, and Arizona, where roughly half of all U.S. data centers are located. The report focuses on water withdrawals, which include water returned to the source, rather than consumptive use, which measures water permanently lost from the system. This methodology has drawn criticism from other experts.
Sarah Porter, director of the Kyle Center for Water Policy at Arizona State University, who was not involved in the Ceres study, argues that consumptive use is a more meaningful metric for assessing the impact of data centers. She pointed to a separate study by Arizona State University researchers, which found data centers' indirect consumptive use, including power generation, to be significantly lower at 650,000 acre-feet nationwide annually. Porter also suggested that counting water through hydropower turbines could lead to an "unrealistically high estimate" and that measuring evaporation and system losses would be more valid for hydropower.