Data centers use a combination of energy intensive air cooling and water intensive evaporative cooling to remove heat from servers.
Up to 85% of the water data centers use evaporates and does not return to the water supply.
Higher temperatures and concentrations of dissolved solids in water returned to the supply impact drinking water, crops, and aquatic life.
Data centers are facilities that contain servers and computers that run online services, like cloud storage, cryptocurrency mining, and Artificial Intelligence (AI) programs (Leppert 2025, Offutt & Zhu 2025). As of April 2026, the U.S. has more than 4,000 data centers, 37% of the world’s total (Data Center Map n.d.). As AI and other operations require more processing power, data centers use more electricity and create more heat (Singer et al. 2024, Kim & Lee 2024).
Data centers directly consume water during cooling, and indirectly by using electricity (Ahmad 2024). Indirect water use depends on the type of fuel used for electricity and the power plant’s efficiency. Direct water use depends on how the facility approaches cooling. Some facilities use air cooling, where air conditioners blow cold air through the servers to carry the heat away (Shehabi et al. 2024). Others use evaporative cooling, where hot air from the server room is passed through a cooling tower containing water. The evaporating water absorbs heat, which lowers electricity used for cooling. However, the water vapor is lost in the process, creating a tradeoff between electricity-intensive air cooling and water-intensive evaporative cooling (Hershberg et al. 2025, Vertiv 2020). Data centers choose cooling systems based on factors including climate and resource availability.
Withdrawal refers to the total amount of water used by a facility, while consumption is the amount of water not returned to the system. Data centers in the U.S. directly consumed 17.4 billion gallons of water in 2023, equivalent to roughly 160,000 American households (U.S. Environmental Protection Agency 2025, Shehabi et al. 2024). Annual direct consumption is projected to increase to between 38 and 73 billion gallons by 2028. Hyperscale data centers are expected to account for half of that water consumption. While definitions for hyperscale data centers vary, they typically contain at least 5,000 servers, take up more than 10,000 square feet of space, and can require more than 100 MW of power (Powell & Smalley n.d.). These projections vary based on expected developments in processing and cooling technologies, as well as construction and demand for data center services.
Some data center companies have published data on their water usage, though few have released information on individual data center consumption. Equinix, which operated 268 data centers worldwide in 2024, reported withdrawing 1.4 billion gallons and consuming 1.2 billion gallons, or 85% (Equinix 2025a, Equinix 2025b). Google reported their data center water consumption increased from 4.3 billion gallons in 2021 to 6.1 billion gallons in 2024 (Google 2025, Hölzle 2022). In total, the company withdrew 7.8 billion gallons of water in 2024, consuming 78%. Of 24 individual data centers in the U.S. and Canada, Google reported that nine withdrew less than 500,000 gallons per day, and three withdrew more than 2 million gallons per day (Google 2025, Figure 1). Their largest data center, located in Council Bluffs, IA, withdrew an average of 3.9 million gallons of water and consumed 2.8 million gallons per day.
Research on how data center cooling affects water quality is limited. However, data center cooling systems are similar to those found in industrial facilities such as power plants and refineries, which can affect discharged water (Brown et al. 2025). Cooling water that returns to the water supply has a higher concentration of dissolved solids, such as calcium, chloride, and silica (Ahmad 2024). These can affect the taste of drinking water, lower crop yields, and be toxic to aquatic life (U.S. Geological Survey 2019, World Health Organization 2003). Increased salinity and temperature in discharge water may lower oxygen solubility and affect metabolism in freshwater wildlife (Khatib et al. 2025, Vengopalan et al. 2012). Legionella bacteria, which can cause Legionnaires’ disease in humans, can grow in improperly maintained cooling towers and spread through released water vapor (Centers for Disease Control 2025, Cejudo 2023).
See the Data Center Power Requirements and Addressing AI Energy Demands Science Notes for more information.
Figure 1. Distribution of water usage reported by Google data centers in the U.S. and Canada in 2024. The company reported water usage for 24 data centers. Sixteen of these withdrew fewer than 1 million gallons per day, while three used more than 2 million gallons per day. Out of the 7.8 billion gallons of water the company’s data centers withdrew in 2024, 78% was consumed due to evaporation during cooling and was not returned to the water system. Data from Google 2025.
References
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