We compiled every disclosed AI data-center water figure: the tracker

A northern Oregon city sued its own newspaper to keep one of the figures below secret. Another came out of an Iowa utility's records 1 2.

Epoch AI, the research organization whose database counts large AI data centers from satellite imagery, permits and public documents, currently tracks 93 sites totaling 13.5 gigawatts of IT power across every major operator 3. The Federation of American Scientists, which documented the satellite-census method in a May 2026 report, states the core problem directly: public information on data center facilities is often incomplete or opaque 4. Operators publish company-wide water totals: Google's latest accounting says its stewardship projects replenished roughly 7.7 billion gallons in 2025, about 78 percent of its freshwater consumption, which by our arithmetic puts that consumption near 9.9 billion gallons 5. Meta's sustainability site offers a downloadable environmental data index beside its 2030 water-positive goal 6. Microsoft disclosed a 34 percent jump in global water consumption in 2022, to nearly 1.7 billion gallons 2.

Why the famous water numbers never actually contradict each other

The headline claims look irreconcilable because each answers a different question with a different denominator. Tagged by scope:

• Training and prompts. The paper that anchored the debate, by Pengfei Li, Shaolei Ren and co-authors, estimates training GPT-3 directly evaporated 700,000 liters of clean freshwater, and projects global AI demand at 4.2 to 6.6 billion cubic meters of water withdrawal in 2027, four to six Denmarks' annual withdrawal 7. The same team's ChatGPT estimate is 500 milliliters per 5 to 50 prompts, and it includes off-site water to cool the power plants feeding the data center, usage the operators do not measure 2. The popular shorthand, a bottle per prompt, claims 5 to 50 times what the researchers actually wrote.
• The national aggregate. NVIDIA, citing the Manhattan Institute, has promoted the figure that data centers use 0.2 percent of daily water usage in the United States 8. That is a share of a national total. It is not the share of one town's supply that one campus draws on a July afternoon.
• The campus reality. Google's campuses in The Dalles, Oregon consumed nearly 550 million gallons in 2025, close to 40 percent of all the water consumed in the entire city 9 10.

Same resource, three incompatible units. Nobody is lying; nobody is comparable, either.

Where these campus figures come from: one lawsuit, one utility's records, one projection

The disclosure ledger behind those headlines is short, and Google tops it: since late 2022 the company has published annual water consumption for its data center locations, city by city, and the environmental report Latitude reviewed lists data centers across 36 cities in 2024, 23 of them in the United States 10 11. Meta is the only other operator on it: trade coverage of Amazon's first company-wide water disclosure counts Google and Meta as the only companies reporting water withdrawal for every municipality they operate in 12. That ledger is the context for this section: its three dated figures reached the public through a courtroom settlement in Oregon, a utility's filings in Iowa and, for the largest campus in the census, a projection.

The city of The Dalles sued The Oregonian in 2022 to shield Google's water records as trade secrets, then settled that December and released Google's annual local use for 2012 through 2021. Within the settlement, Google told the Associated Press it would stop treating site-level water-use numbers as trade secrets at any of its data centers nationwide 1. Those records are the only reason the public knows Google's use there nearly tripled in five years, hitting 355.1 million gallons in 2021, more than a quarter of the city's water 13 1. In West Des Moines, utility records showed Microsoft's Iowa cluster pumped about 11.5 million gallons in July 2022, roughly 6 percent of the district's water, in the month before OpenAI says it completed its training of GPT-4 2. Another dated campus-scale number in this record is a projection, not a measurement: xAI's Memphis supercomputer, the census's largest site at 946 megawatts, carried a projected cooling demand of at least one million gallons a day in Protect Our Aquifer's initial estimate, and the group's current page puts expected water demand at more than five million gallons per day 14 3.

The 2030 water pledges predate most of the campuses

Microsoft's water-positive 2030 goal 15 and Meta's water-positive 2030 goal 16 both predate most of the campuses the census now tracks 3.

The trajectory to watch: in December 2022, Google dropped site-level secrecy nationwide 1. In June 2026, it announced new water stewardship commitments for its data center communities, backed by 17 million dollars across seven states 17 18. Google's own framing of the problem, in that same announcement: "Water use shouldn't be a 'black box.'" 17

The metric to watch in the 2027 report season is a second per-city table; until one appears, a measured campus figure still arrives the way the ones in this record did, out of a settlement or a utility's filings.