Artificial intelligence runs on chips made in factories and on servers housed in data centres. Both use water. In Arizona, a desert state with limited river and groundwater supplies, that demand has turned into an argument about how its water is shared.
The subject in brief
The phrase “AI has come for Arizona’s water” refers to the pressure that new digital infrastructure puts on water supplies in an arid state. Two kinds of facility are involved. The first is the semiconductor fabrication plant, or fab, where chips are made. The second is the data centre, where those chips are packed into servers that run search engines, streaming services, cloud software and AI chatbots.
The Verge has published a feature on the subject. It describes a vast grey industrial complex in the Arizona desert, low and spread out against the surrounding mountains, where engineers make the components behind phones, computers, appliances, online services and AI tools. The article’s web address points to TSMC, the Taiwanese contract chipmaker that is building manufacturing capacity in Arizona.
The question underneath is a simple one. The state’s water is already shared between cities, farms, industry and the natural environment, so adding large and thirsty industrial users means deciding who gives something up.
Origins of the boom
Arizona has drawn chipmakers for decades. It has plenty of land, a business-friendly regulatory approach, an existing semiconductor workforce and state and local governments keen to attract manufacturing. More recently, governments in the United States have encouraged companies to make advanced chips at home rather than rely only on factories in Asia. That policy push brought new fab projects to the Phoenix area.
Data centres arrived for related reasons. Large sites can be bought in the Phoenix metropolitan area, natural disasters such as hurricanes and earthquakes are comparatively rare there, and the region is close to major West Coast markets. Demand for computing power rose sharply once generative AI became popular, and developers looked for places where they could build quickly.
All this happened while Arizona’s water supply was getting less secure. The state takes much of its surface water from the Colorado River, which serves several states and has been under strain from long-term drought and over-allocation. Arizona also relies heavily on groundwater, which in many places is being pumped faster than it naturally refills. The arrival of water-hungry industry on top of that has made the subject politically sensitive.
Water use today
Chip fabs need very large amounts of ultrapure water. Wafers are rinsed repeatedly during manufacturing to remove tiny particles and chemical residues, and the water used must be treated far beyond drinking standards. Fabs also use water in cooling systems and to control air quality. Modern plants treat and reuse a large share of their water on site, but they still draw fresh supplies and send wastewater away for treatment.
Data centres use water mainly for cooling. Servers produce heat, and in a hot climate many facilities rely on evaporative cooling, in which water absorbs heat as it evaporates. This method uses relatively little electricity but consumes water, because the evaporated water leaves the local system. Other designs use closed-loop liquid cooling or air cooling, which need less water but more energy. Some of that energy comes from power stations that themselves use water, so a data centre’s water footprint includes a hidden, indirect part.
How much individual facilities in Arizona use is often not known in public. Companies do not always disclose site-level water figures, and the figures they do publish are not always calculated in the same way. Local governments and utilities negotiate supply agreements, and the details vary from project to project.
Common misconceptions
One frequent mistake is to treat all water use as the same. Water withdrawn is taken from a source and may be returned after treatment. Water consumed is lost to the local system, mostly through evaporation. A fab that recycles heavily and a data centre that cools by evaporation can affect a region very differently even if their withdrawal figures look alike.
A second misconception is that technology companies are the largest water users in Arizona. Historically, agriculture has accounted for most of the state’s water use. That does not settle the debate, because new industrial demand is concentrated, long-term and often located in fast-growing urban areas where supplies are already committed. But it does matter for any honest comparison.
A third is that “AI uses water” describes a single activity. Making the chips, training models and answering everyday queries each have different water and energy profiles. They often happen in different places too, so the water cost of a single chatbot request cannot simply be read off a facility in Arizona.
Finally, it is sometimes assumed that switching to waterless cooling solves the problem. It reduces direct water use but usually raises electricity demand, which brings its own environmental and grid pressures.
Where to look next
Readers who want to follow the subject should start with The Verge’s feature, which gives a ground-level account of the industrial landscape. State water agencies publish material on groundwater management and Colorado River allocations. Federal bodies that manage the river release reports on reservoir levels and shortage planning. Universities in the region carry out research on desert water policy and urban growth.
Corporate sustainability reports from chipmakers and cloud companies can be useful, but they deserve careful reading. Check whether figures cover withdrawal or consumption, and whether they are reported per site or across a whole company. Local council and utility meeting records often hold the most specific information about individual supply agreements.
Frequently asked questions
Why do chip factories need so much water?
Chip manufacturing involves many cleaning steps in which silicon wafers are rinsed to remove microscopic particles and chemical residues. The water has to be ultrapure, treated well beyond drinking standards, so even small impurities do not damage circuits. Fabs also use water for cooling equipment and controlling air conditions. Modern plants recycle much of this water, but they still need a substantial, reliable supply of fresh water to operate.
How do data centres use water?
Data centres use water mainly to remove heat produced by servers. Many facilities in hot climates use evaporative cooling, where water absorbs heat as it evaporates, which saves electricity but consumes water. Others use closed-loop or air-based cooling, which uses less water but more energy. Data centres also have an indirect water footprint through the power stations that supply their electricity, some of which use water for cooling.
Where does Arizona get its water?
Arizona relies on a mix of sources. Much of its surface water comes from the Colorado River, which is shared among several states and has been strained by drought and over-allocation. The state also depends heavily on groundwater, which in many areas is being pumped faster than it naturally refills. Smaller rivers within the state and recycled wastewater add further supply for cities, farms and industry.
Is AI the biggest water user in Arizona?
No. Historically, agriculture has accounted for most of Arizona’s water use. The concern about chip plants and data centres is less about their share of the total than about the fact that they are new, long-term, concentrated demands. Many of them sit in growing urban areas where water is already committed to other users, and they arrive at a time when overall supplies are shrinking.
Can data centres run without using water?
Data centres can reduce direct water use by using closed-loop liquid cooling or air cooling instead of evaporative systems. These approaches usually need more electricity, however, and generating that electricity can itself consume water at power stations. So cutting on-site water use often means trading it for higher energy demand. Which option is better depends on the local climate, the electricity supply and the water situation.
Sources and further reading
- The Verge: a feature on Arizona’s water, chip manufacturing and data centres
- State water management agencies: background on groundwater rules and Colorado River allocations
- Federal water and reservoir authorities: reports on Colorado River conditions and shortage planning
- University research centres on water policy in the American Southwest: analysis of desert water use and urban growth
Surfaced from the rss:verge signal “AI and desert water”. AI-assisted draft, editorially reviewed.
