How much water does Microsoft use for AI?

Microsoft doesn't sell a frontier model of its own so much as it sells the floor the frontier runs on: Azure is OpenAI's compute provider, and Copilot rides on OpenAI models. That makes Microsoft's environmental reports the closest thing to a fleet-level measurement of AI's water cost.

The headline figure: in 2022, the year GPT-4 trained and ChatGPT launched, Microsoft's global water consumption rose 34% to roughly 1.7 billion gallons. Researchers connected the dots to specific places; local reporting put the West Des Moines, Iowa campuses where GPT-4 trained at 68.5 million gallons in 2024, drawn from the same watershed that supplies the city.

Microsoft has since promised 'water positive by 2030' and publishes replenishment numbers alongside consumption. Replenishment is real but happens in different watersheds than the withdrawals. The almond grower's question ('whose water, where?') applies to data centers too.

For your own Copilot or ChatGPT share, the calculator's frontier class covers it; Microsoft's contribution is the data center, not a separate model.1,3,2,4