TL;DR · 30-second read
The Short Version
Amazon says the buildings that run its websites, apps and artificial intelligence services use about one-seventh the water of a typical facility of their kind.
The main trick is letting the computers run warmer. Outside air cools the buildings about 90% of the time. Water is used only when it is hotter than about 85 degrees Fahrenheit outside.
This matters because these buildings are multiplying, and their neighbors want to know how much local water they take. The open question is whether the newest artificial intelligence chips, which Amazon says needed a new kind of liquid cooling, will let that approach last.
Amazon said in a June 11, 2026 post on its About Amazon site that its global data center operations used 0.12 liters of water per kilowatt-hour (L/kWh) in 2025. The company puts that at more than seven times better than an industry average of 0.84 L/kWh and says it is a 52% improvement since 2021. It withdrew about 2.5 billion gallons of water across its global data center footprint in 2025.
Amazon credits two things for the result. The first is free-air cooling, which it uses about 90% of the time. The second is higher server temperature limits, so that evaporative cooling runs only when outside air is above roughly 85°F. The company also said it is 75% of the way to its 2030 water-positive goal and that it runs 26 facilities on 100% reclaimed water, with 130 more contracted.
Executive Summary
Amazon has published a headline water-efficiency figure for its data centers: 0.12 liters of water for every kilowatt-hour of energy in 2025. It set that against an industry average of 0.84. The company explains how it got there. It relies on outside air for most cooling, uses evaporative cooling only in the hottest hours, and has spent several years raising the temperatures its servers are allowed to run at. It says this cut water use without raising hardware failure rates.
The figure matters because water has become one of the main local questions asked of new data center campuses. Amazon’s explanation also shows that water efficiency is a set of engineering trade-offs, not a fixed property of a building. The company chose to use some water on hot days rather than run chillers, which it says need 25% to 35% more electricity at the moments the grid is most stressed.
Two things are harder to assess. One is the comparison itself: Amazon did not publish how the 0.84 average was built or on what basis each peer’s figure is measured. The other is the future. Amazon says denser AI chips already required a custom liquid cooling system, so the air-first approach behind the 7x figure now has to hold up as AI capacity grows.
The Water Number Is Really a Temperature Number
Amazon’s 0.12 liters per kilowatt-hour did not come from a new water technology. It came from deciding how rarely to use water at all. About 90% of the time, Amazon says, its data centers use free-air cooling. Outside air is drawn past the servers and pushed back out, with no water involved. Water comes into play only through evaporative cooling. In that process, hot air passes through a water-soaked medium and cools by five to 10 degrees as the water evaporates. Amazon now switches that on only when outside air exceeds roughly 85°F.
That threshold is the lever. Every degree of heat the servers can tolerate removes hours from the evaporative season, so raising operating temperatures cuts water use directly. Amazon’s own evidence is specific:
- Two identical data centers on the same campus, one running hotter, differed by about 50% in water use.
- Northern Virginia, its largest region by IT load (the power drawn by the computing equipment itself), cut water use 42% year over year while demand grew.
- Thousands of hours of campus data showed no increase in failure rates at the higher temperatures.
Those results fit the 52% efficiency improvement Amazon reports since 2021.
The same logic is why this is a test for AI-era cooling. The approach depends on air being able to carry heat away from the servers. Amazon itself says denser, more powerful AI chips required a completely custom liquid cooling system. It has not said how much of its fleet now runs that way, whether those systems rely on evaporative water on hot days, or how a growing share of AI capacity will move the 0.12 figure. The air-first playbook behind the 7x gap was proven on the fleet Amazon has run since 2021. Whether it carries over to high-density AI halls is the next data point to watch.
Water or Watts: The Trade Behind the Ratio
Amazon is explicit that a low water number is partly a choice about electricity. The alternative it names is chillers, which work like giant air conditioners and, by Amazon’s figures, typically need 25% to 35% more electricity. The timing of that extra load is the problem. It arrives in the hottest hours, when household air conditioning is already straining the grid. Amazon concluded it is better to spend some water on those days than to add power demand at the peak.
That is a defensible engineering position, and it cuts against a simple reading of water metrics. An operator could report a lower water ratio by running chillers, which shifts the burden onto the grid and, depending on how that electricity is generated, onto water used off site. Conversely, a site that uses more water may be sparing a stressed grid. For utilities and local planners, the useful question is how much water and how much power a campus uses together at the peak hour, not either one in isolation.
Amazon did not quantify the grid side of its trade. It has not said how much peak demand evaporative cooling avoids across its fleet, or how many hours a year its sites in hot regions exceed 85°F. Without those figures, the argument rests on the chiller penalty range alone.
Why 0.12 and 0.84 Are Hard to Line Up
Liters per kilowatt-hour is the industry’s standard water-efficiency ratio, often called water usage effectiveness. It divides the water used for cooling by the energy consumed by the IT equipment. Amazon describes it as water per unit of compute, but the denominator is energy, not work done. A fleet running more efficient chips gets more computing out of each kilowatt-hour, and the metric does not capture that in either direction.
The 7x claim depends entirely on the 0.84 industry average. Amazon’s chart cites sustainability reports and blogs from Microsoft, Google and Meta alongside its own report. The company did not publish how 0.84 was derived: which operators it covers, how they were weighted, or whether each figure measures water withdrawn (taken from a source) or water consumed (evaporated and not returned). Large operators do not all report water the same way, so a like-for-like reading requires knowing which basis each number uses.
Scope matters too. Amazon’s absolute figure, about 2.5 billion gallons in 2025, is a withdrawal number for its global data center footprint. The 2% year-over-year decline it cites applies only to sites it owns and operates directly. The company did not say whether the 0.12 ratio is based on withdrawal or consumption, or whether leased facilities are included. None of that makes the claim wrong. It does mean the 7x multiple is Amazon’s own calculation rather than a figure a reader can reproduce from peers’ reports.
Replenishment and Reclaimed Water Carry the Local Story
Efficiency is only half of Amazon’s water case. The company has committed to being water positive by 2030, meaning it returns more water to communities than its data center operations use. It says it is 75% of the way there, returning 3 gallons for every 4 used in 2025. It has announced more than 50 projects that are expected to return over 5.8 billion gallons a year once fully implemented, which is more than twice its 2025 withdrawals. Examples include:
- storing Columbia River winter flows in an aquifer in Hermiston, Oregon;
- a runoff pipeline in Pina del Ebro, Spain;
- watershed restoration near Guadalajara, Mexico.
Replenishment is an accounting balance. Its value to a given town depends on whether the returned water lands in the same basin the data center draws from. Reclaimed water addresses the local question more directly, because it replaces drinking water with treated wastewater at the site itself. Amazon says 26 facilities already run on 100% reclaimed water, more than any other cloud provider, and 130 more are contracted. It has also funded infrastructure and helped with permitting for programs in Mississippi, Hong Kong and Indonesia. If those 130 facilities come online, reclaimed supply may matter as much to neighbors as the headline efficiency ratio.
Background
Amazon operates one of the world’s largest data center fleets, mostly to run Amazon Web Services (AWS), its cloud computing business. Data centers convert nearly all the electricity they use into heat, and removing that heat is where most of their water goes. The industry commonly measures water efficiency as liters of water per kilowatt-hour of IT energy, a ratio known as water usage effectiveness, or WUE.
Amazon has committed to being water positive by 2030 and has expanded its use of reclaimed water from wastewater treatment plants. Amazon says data centers account for less than 0.5% of global industrial water use. Still, where a campus draws its water matters to the surrounding community, and Amazon says its water team is particularly focused on water-scarce areas. Source: Amazon’s data centers are 7x more water-efficient than the industry average. Here’s how we do it. (About Amazon): Amazon’s account of its 2025 data center water efficiency, cooling methods, and progress toward its water-positive goal.Sources