U.S. data centers use as much water in a year as almond farms use in four days
Closed-loop cooling sharply cuts water withdrawals, though some water still evaporates.
Lightspeed Venture Partners · The 7 Layers of the AI Data Center Stack ft. Guru Chahal | LightworkA ChatGPT prompt does not use a bottle of water.
American data centers use about 17 billion gallons of water a year, in the comparison offered by Guru Chahal, a partner at the venture firm Lightspeed. By his rough math, California almond farming uses about that much in four days.
Chahal says the closed-loop design is what matters most. Once a data center is running, water circulates inside to absorb heat, rather than drawing continuously from a nearby river and discharging hot water. Closed-loop systems cut withdrawals sharply, though some water is still lost to evaporation in cooling towers and at the power plants that supply the electricity.
Questions people ask
If the water recirculates, why do data centers need water at all?
Mostly evaporation. Data centers reject heat through cooling towers where some water evaporates, and the power plants that supply their electricity also evaporate water. Recirculating the rest keeps total withdrawals much lower than a system that constantly takes in fresh water.
Where did the bottle-of-water-per-prompt claim come from?
The image came from a 2023 study that estimated the water used to train and run large AI models, including cooling and power generation, and divided it down to a per-query amount. The broader point about scale was fair, but a bottle per prompt makes it sound like water vanishes with each question, which is not how shared cooling works.