Amazon's data centers are more than seven times more water-efficient than the industry average, the company disclosed Thursday, a claim that arrives as Seattle's city council unanimously approved a one-year moratorium on new large data centers inside city limits. The company's global data center operations used 0.12 liters of water per kilowatt-hour in 2025, compared to an industry average of 0.84 L/kWh, according to an announcement from Amazon (About Amazon, Bloomberg). That represents a 52% improvement in water efficiency since 2021.
Air does most of the work. About 90% of the time, AWS data centers use "free air cooling", pulling outside air past server racks and releasing it back outside.
Water-based evaporative cooling only kicks in when ambient temperatures exceed roughly 85 degrees, Amazon said. The company has also engineered its servers to tolerate higher temperatures, reducing the number of hours water is needed.
"The reality of these facilities can differ from public perception," Kerry Person, AWS vice president of Data Center Operations, told GeekWire. "As we've been engaging with our local communities, they've been very pleasantly surprised about how little water we are using."
Amazon's data centers withdrew about 2.5 billion gallons of water worldwide last year, or roughly 5% of what metro Seattle consumes annually (Moneycontrol). The company says it returned 3 gallons for every 4 it used through replenishment projects, putting it 75% of the way toward its goal of being water-positive by 2030.
The disclosure comes as data center water and energy use faces growing political scrutiny. Seattle's city council this week passed an emergency moratorium halting new large data center construction within the city.
Several states and municipalities have considered similar measures amid the AI-driven boom in data center development (GeekWire).
Amazon is also expanding its use of recycled wastewater for cooling from 20 sites to more than 120 locations by 2030, a move the company says will preserve over 530 million gallons of drinking water annually across the US (Data Center Dynamics). It currently operates 26 facilities using 100% reclaimed water sourced from wastewater treatment plants rather than potable supplies.
The efficiency figures cover both Amazon-owned and leased data center space globally and have been verified by outside auditors. Microsoft's water usage effectiveness was 0.27 L/kWh in its most recent fiscal year, while Amazon's own analysis pegs the industry average at 0.84 L/kWh (Moneycontrol).
"We need more transparency," Iris Stewart-Frey, a professor of environmental science at Santa Clara University, told Moneycontrol. "Then communities will actually know what they're getting into and can evaluate the costs and benefits, because the situation is very different from locality to locality."
Amazon's data excludes water required to generate the electricity that powers its facilities and does not include colocation centers where the company rents space. The company has announced more than 50 water replenishment projects expected to return more than 5.8 billion gallons annually once fully implemented.
