To improve server efficiency, data centers employ cooling systems that consume enormous volumes of water.
Most frequently, data centers use evaporative cooling, where water circulates through cooling towers and evaporates to dissipate heat.
A single large hyperscale facility can consume up to 5 million gallons of water per day - equivalent to the daily water use of a city of 50,000 people, or as much as 1.8 billion gallons per year from a single building (Coakley, 2025).
More advanced techniques - including direct-to-chip (D2C) liquid cooling and full immersion cooling, in which entire server racks are submerged in non-conductive liquid - are more water-efficient but remain deeply water-intensive at scale. Neither technique eliminates the water footprint; they simply redistribute it (Coakley, 2025).
Evaporative cooling system schematic server racks
Water consumption in data centers is poorly regulated. Privette, Barros, and Cai (2026) argue in a study published in AGU Advances that data center water footprints urgently require greater transparency, noting that current reporting frameworks are inadequate to capture the scale or geographic distribution of water use. Communities near major data centers often lack basic information about how much water is being withdrawn from shared aquifers.
Approximately two-thirds of all data centers globally are built in water-stressed regions (Walker & Goldsmith, 2026). This is intentional. Data center siting decisions are driven by land cost, energy access, tax incentives, and regulatory environments - not by water availability. The consequence is that facilities consuming millions of gallons per day are being constructed in areas where water scarcity is already a pressing crisis.
Phoenix, Arizona, is the most prominent US example. Already grappling with one of the most severe water crises in American history - its primary source, Lake Mead, has reached historic lows - the Phoenix metro continues to attract AI infrastructure investment at a rapid pace (Grist, 2026). Aquifer depletion is accelerating, and local communities, particularly lower-income and indigenous communities that rely on groundwater, bear the greatest risk.
Arizona's Sedona region - part of the water-stressed American Southwest where data center development is accelerating despite severe aquifer depletion.
As Gorey (2025) documents in Land Lines, the land and water impacts of the AI boom extend well beyond Phoenix. Rural communities across the American West are experiencing aquifer depletion, sediment contamination of local waterways, and conflict over industrial water rights - often without access to the data they would need to understand or challenge what is happening.
One reason water consumption receives less public attention than carbon emissions is that water lacks a standardized unit of moral legibility. "Metric tons of CO₂" has achieved cultural understanding through decades of climate communication; "gallons per query" has not. Making data center water consumption comprehensible requires contextualized measurements - comparing facility consumption to household use, local aquifer capacity, or the daily water needs of surrounding communities.
When five million gallons per day is expressed as the water use of 50,000 people, the number becomes a community - not an abstraction.