At first glance, data centers might seem like just warehouses packed with servers. But inside, they’re using up surprising amounts of resources to stay online. Water is a big one—it keeps all that equipment from overheating.
A single large data center can go through hundreds of thousands of gallons of water in a single day. That’s a lot of water for what looks like a bunch of computers in a building.
These numbers add up fast. For instance, a hyperscale facility might use 200 million gallons every year. Even smaller centers run through millions.
Companies like Google and Microsoft? They sometimes report water usage in the billions of gallons across all their sites worldwide. This scale makes you wonder—where does all this water come from, and where does it go?
Not every data center has the same impact. Facilities in dry places put more strain on already limited water supplies. Others are trying to get creative, using recycled or reclaimed water to ease the demand.
As more of our lives move to the cloud, it’s getting more important to know how much water data centers really use, and what companies are doing about it.
Key Takeaways
- Data centers need lots of water to keep cool
- Water use depends on size, location, and how they cool things down
- Companies are starting to look for ways to use less water over time
How Data Centers Use Water
Data centers use water in a few ways. Mainly, it’s for cooling the servers, but there’s more to it than that.
There’s direct water use—like actually running water through the cooling systems. Then there’s indirect use, such as the water needed to generate all the electricity these places burn through.
Direct Water Consumption for Cooling
Most of the water goes into cooling systems. Servers and other equipment are running all day, every day, and they get hot.
To keep things from overheating, facilities use chilled water, cooling towers, and heat exchangers. In a chilled water setup, water gets cooled in a central unit, then pumped through coils and out to a cooling tower.
Some of that water evaporates, and that’s where the permanent loss happens. The rest is reused, but you can’t avoid losing water this way.
Big “hyperscale” data centers—the kind that power cloud services or AI—can use hundreds of thousands of gallons daily. Google’s big sites, for example, average about 550,000 gallons a day.
Smaller data centers use less, but even then, it adds up to millions of gallons each year.
Indirect Water Consumption via Electricity
Water use doesn’t stop at cooling. Data centers also use water indirectly, through the power they consume.
Electricity usually comes from power plants, and a lot of those plants need water to cool turbines or manage steam. So, even if a data center switches to air cooling, it still has a water footprint because of the electricity it uses.
The total water footprint includes on-site water, water used by power plants, and even water used in making the hardware. The Environmental and Energy Study Institute says this gives a more accurate picture of indirect water consumption.
With AI workloads growing, electricity demand is rising. That, in turn, means more water gets used at power plants. If a data center is in a region where water is already scarce, this can be a big problem.
Water Use in Humidification and Maintenance
There are other uses for water in data centers, too. Humidity control is a big one—if the air gets too dry, static electricity can build up and damage the hardware.
These systems keep humidity between 40% and 60%. Water also goes into fire suppression, cleaning, and even landscaping around the facility.
These uses don’t compare to cooling, but they do add up. Some operators try to cut down by using greywater or reclaimed water for things like humidification.
Google, for instance, says over 25% of its campuses use alternative water sources for humidification and cooling. That takes the pressure off city water supplies and is a step toward sustainability.
Cooling Systems and Water Demand
Cooling is at the heart of water demand in data centers. The system you pick changes everything—from how much water you need to how much power you use.
Cooling design is a huge part of a data center’s environmental footprint. Sometimes it feels like a never-ending balancing act.
Evaporative Cooling Systems
Evaporative cooling systems use water to absorb heat from servers, then release it through cooling towers. They’re really efficient—up to 90% better than old-school air conditioning.
But that efficiency comes at a cost: water. A 1-megawatt data center with evaporative cooling might use about 18,500 gallons a day. Scale that up, and hyperscale facilities use much more.
Facilities usually mix and match—chillers, pumps, heat exchangers, condensers—to move heat around. This setup saves energy but means a steady need for water.
In dry regions, this can put a real strain on communities. Some data centers try to use greywater or rainwater instead of drinking water, which definitely helps.
Closed-Loop Cooling Systems
Closed-loop cooling systems are a bit different. They recycle the same water over and over, instead of always drawing more from the outside.
Water moves through chillers and heat exchangers, picking up heat and dropping it off without much evaporation. This can save millions of gallons each year compared to open systems.
However, there’s a catch. Since the water isn’t evaporating, you need more mechanical cooling—like air-cooled chillers or dry coolers—which bumps up your electricity use.
Some companies are testing hybrid models, mixing closed-loop systems with a bit of evaporative cooling during peak times. It’s all about finding a balance that works.
Air Cooling and Air-Cooled Data Centers
Air cooling skips water entirely and relies on outside air or mechanical refrigeration. If you’re in a cooler climate, you can use free cooling—just bring in filtered outdoor air.
In warmer places, air-cooled chillers are more common. They use refrigerants and fans, so there’s no big water draw, but they do need more electricity, especially when it’s hot outside.
Air-cooled data centers use computer room air handlers (CRAH) or computer room air conditioners (CRAC) to keep air moving around the servers. This cuts out water use but makes the facility more dependent on the power grid.
Operators have to weigh what’s more important—saving water or saving energy. Air cooling cuts water use almost to zero, but it can mean higher greenhouse gas emissions if the power isn’t green.
It really comes down to local conditions: how much water is available, the climate, and what electricity costs. There’s no one-size-fits-all answer here.
Measuring and Reporting Data Center Water Usage
Data centers track water use in a few different ways. Some focus on efficiency, others just report total use, and some do a bit of both.
It all depends on what they’re trying to show—whether it’s for internal goals or public sustainability reports.
Water Usage Effectiveness (WUE) Metric
The Water Usage Effectiveness (WUE) metric is a popular way to measure efficiency. It tells you how much water is used for every kilowatt-hour of IT energy (L/kWh). Lower is better.
Say a data center uses 100,000 liters of water and 50,000 kWh of energy—its WUE is 2.0 L/kWh. The industry average is about 1.8 L/kWh, but some big players, like Amazon, report even lower numbers.
WUE is helpful, but it doesn’t tell you where the water comes from. Two centers with the same WUE could have very different effects on their local water supply.
Tracking WUE helps data centers spot ways to improve cooling systems. If you want to dig deeper, check out this guide to WUE.
Corporate Sustainability Reports
A lot of tech companies publish corporate sustainability reports with their water usage numbers. These usually show both total water use and efficiency. Google and Microsoft, for example, report billions of liters used each year.
Reports will often mention year-over-year changes, regional differences, and any progress toward using less water. Sometimes they’ll talk about investments in recycled water or plans to return water to the community.
But reporting isn’t always consistent. Some companies share detailed, site-level data, while others just give big-picture totals. It’s tough to compare across the whole industry. According to The Conversation, most companies don’t reveal exact numbers for each data center.
Even with these gaps, sustainability reports are still one of the few ways the public can see how much water big tech is really using.
Water Footprint and Withdrawal
Looking beyond efficiency, analysts also check a data center’s water footprint and water withdrawal. The water footprint includes onsite use, water used at power plants, and water needed to make IT hardware.
Water withdrawal is just the total water taken from local sources, no matter if it gets returned or not. For example, a data center in Iowa reportedly used nearly a billion gallons in one year, which made locals worry about competition with homes.
In areas where water is scarce, understanding both footprint and withdrawal is crucial. Heavy reliance on groundwater can put extra pressure on aquifers. The Environmental and Energy Study Institute has more on how these calculations give a fuller view of data center water consumption.
Combining WUE, sustainability reports, and footprint analysis gives everyone a clearer idea of just how much water data centers are using—and what that means for the environment.
Key Sources of Water for Data Centers
Data centers have a few options for water sources. Most use treated municipal water, but some also tap into surface water, groundwater, or even recycled water if they can get it.
Municipal Water Systems
Most data centers stick with municipal water systems. It’s treated to be safe for drinking, so it’s reliable and has a consistent quality. Cooling systems need that reliability to avoid equipment issues.
Big facilities can use hundreds of thousands of gallons every day. Hyperscale centers might go through millions each year, often supplied by city or regional utilities.
Municipal water isn’t just for cooling. It’s also used for humidification and fire safety. Since it’s regulated and easy to get, it’s the go-to for operators, big or small.
Surface Water and Groundwater
Some data centers, depending on where they are, use surface water from lakes or rivers, or groundwater from wells. These sources can provide a lot, but they need extra treatment to meet cooling system needs.
Surface water might have organic stuff or sediment that can clog pipes. Groundwater can be high in minerals, leading to scaling in cooling towers.
Operators have to weigh the cost and availability, but also the risk of overusing local water. Taking too much from lakes or wells can hurt local ecosystems, especially where water is already limited. Some facilities keep a close eye on their withdrawals to limit environmental impact.
Use of Non-Potable and Recycled Water
To cut down on using drinking water, some data centers have started using non-potable water—think reclaimed wastewater, greywater, or even stormwater. Sure, you can’t drink it, but after a bit of treatment, it’s fine for cooling systems.
Google’s jumped on board with reclaimed water at several campuses. Over 25% of its facilities now use it for cooling.
According to Dgtl Infra, recycled water usually covers less than 5% of the total supply, but it’s slowly becoming a bigger deal.
Using recycled water takes some pressure off city systems and gives regions in drought a more sustainable option. There’s a catch, though—it needs extra infrastructure for treatment and delivery, so smaller data centers might not be able to pull it off.
Regional and Environmental Impacts
Data centers use a lot of water for cooling, which can strain local supplies, especially in dry places. Their energy use also links water demand to power generation, so you’ve got freshwater stress and carbon emissions tied together.
Location, infrastructure, and the energy source all play into how big these impacts get.
Water Stress and Scarcity
A lot of data centers end up in areas that are already dealing with water stress. In the U.S., about 20% of them pull water from watersheds facing moderate to high drought risk.
This means more competition for water between industries, homes, and farms.
Big data centers can use up to 5 million gallons a day—that’s about what a small city might need. Pulling that much water can drain aquifers and lower stream levels.
Since just 0.5% of Earth’s water is actually usable for people, heavy withdrawals in dry regions are a long-term problem. Cooling systems like evaporative air setups are even thirstier in hot climates, right where water’s already tight.
Impact on Local Communities
When data centers ramp up water use, nearby residents can feel the pinch. In Northern Virginia, which is basically the world’s biggest data center hub, these facilities used almost 2 billion gallons in 2023—up 63% since 2019.
Most of that came from drinking water, not reclaimed sources.
Local utilities sometimes have to upgrade their systems just to keep up. Smaller towns might not be ready for that, especially if their water setup was built for homes, not giant server farms.
Communities in water-stressed regions sometimes find themselves competing with data centers for the same supply, raising questions about who should get priority.
There’s also the issue of wastewater. About 80% of the water data centers take in just evaporates, but the rest gets dumped into city systems. Municipal treatment plants aren’t always built for that extra load, which can drive up costs and stress local infrastructure.
Great Lakes Region as a Data Center Hub
The Great Lakes area is drawing in new data centers because there’s lots of freshwater and the climate’s cooler. Unlike places hit by drought, this region can handle evaporative cooling without as much worry about running dry.
But even here, big withdrawals can matter. If data centers take out more water than nature puts back, ecosystems could feel it.
Building new facilities means planning carefully to avoid messing up local balance.
Economic perks are tempting companies to set up shop in the Midwest. Still, whether this stays sustainable depends a lot on if they use closed-loop cooling or reclaimed water.
Balancing tech growth and ecosystem health is a real challenge for the region’s future as a data center hotspot.
Carbon Emissions and Energy Sources
Water use isn’t just about on-site cooling. A big chunk comes from the power plants making the electricity. In 2023, U.S. data centers used 176 terawatt-hours of electricity, much of it from fossil fuels.
Steam-based coal and gas plants are thirsty—coal plants need almost 19,000 gallons per megawatt-hour. Gas plants use less but still draw heavily. These plants also pump out carbon, so water stress and climate change are tangled together.
Switching to renewables like wind and solar helps cut both water use and emissions. Since they don’t need water for cooling, expanding clean energy could shrink data centers’ water and carbon footprints.
Major Companies and Industry Practices
The world’s biggest data centers are run by large tech companies, and their water use varies a lot. Some share detailed reports, others hardly say a word—so comparing them isn’t easy.
Amazon, Google, Microsoft, and Meta
Google is probably the most open about water use. In 2023, it used 6.4 billion gallons, and 95% of that went to data centers. One Iowa facility alone used 1 billion gallons in 2024—enough to supply every home in Iowa for five days (The Conversation).
Meta said its global operations used 813 million gallons in 2023, again with 95% for data centers. Microsoft and Amazon report total water use but don’t often break out data center numbers.
Amazon’s sustainability reports don’t give exact water figures, and Microsoft just gives overall totals.
With such uneven reporting, it’s tough to line up these companies side by side. Still, it’s clear that data centers make up nearly all their water use, which shows just how big the challenge is.
Digital Realty and Equinix
Digital Realty and Equinix are two of the biggest colocation providers. Unlike cloud giants who own their own data centers, these guys lease space to lots of clients. Their water use is big, but even less transparent.
Researchers have found a lot of variability in what they disclose. Some sustainability reports give totals, but you rarely see details by site or cooling method.
That makes it hard for locals to know how much water is being pulled from their area.
Since they run hundreds of centers worldwide, their total water footprint is probably massive. But without consistent reporting, it’s nearly impossible for the public to compare them to Amazon, Google, or the rest.
Sustainability Strategies and Innovations
Companies are trying out different cooling methods, which changes how much water they need. Evaporative cooling uses more water but less energy. Closed-loop systems recycle water but need more power.
Google mixes and matches depending on location—some sites use air cooling to save water, like at their Pflugerville, Texas site.
Some firms are investing in water replenishment, hoping to return more water than they use in stressed areas. Microsoft wants to be “water positive” by 2030, and Google’s working on offsetting withdrawals with local watershed projects.
Even so, gaps in reporting and different ways of measuring make it hard to see how much progress is being made.
Water Efficiency and Future Solutions
Data centers are under more pressure to use less water without sacrificing cooling. They’re looking at new cooling tech, tighter water policies, and better efficiency tracking to help guide improvements.
Innovative Cooling Technologies
Cooling eats up most of the water in big data centers. Many still use evaporative cooling, which drains a lot of freshwater.
To fix this, operators are trying out air cooling, liquid immersion, and hybrid systems.
Some companies now use water-free cooling designs that can save tens of millions of gallons each year by using outside air or closed-loop setups. Facilities using these can get their Water Usage Effectiveness (WUE) close to zero, as QTS Freedom Design data centers have shown.
Immersion cooling is another interesting idea—it dunks servers in non-conductive liquid, pulling heat away without needing much water. It’s still pricey, but it cuts both water and energy use.
Benefits of advanced cooling systems:
- Lower water bills
- Less stress on local supplies
- Better energy efficiency, especially with renewables
Regulatory Policies and Water Law
Water law and policy shape how data centers operate, especially where water is tight. Regulators often require companies to report usage and adopt conservation steps.
Local governments might even limit withdrawals during droughts, so operators have to switch up their cooling methods.
The Lawrence Berkeley National Laboratory found that stricter rules push companies toward more sustainable cooling.
Policies are all over the map. Some U.S. states need environmental reviews before new data centers are approved. Others encourage using recycled water for cooling.
As water competition heats up, following water laws will matter as much as energy efficiency rules. Companies that see this coming can plan better and keep the community on their side.
Trends in Water Efficiency
Tracking water use is becoming the norm. The Water Usage Effectiveness (WUE) metric compares liters of water to kilowatt-hours of IT power. The industry average is about 1.8 L/kWh, but some, like Amazon, report much lower numbers.
Operators are starting to monitor water use in real time, tying it to temperature and power data. This lets them dial back withdrawals when it’s cooler out.
Using recycled or reclaimed water for cooling is catching on. It might not always improve WUE, but it does take pressure off city systems and helps with sustainability.
U.S. data centers have used hundreds of billions of liters a year, but efficiency steps are finally starting to slow the growth. Studies like Data Centers and Water Consumption point out that both direct and indirect water use matter, including what’s tied to power generation.
Water management is quickly becoming as important to data center design as power optimization.
Frequently Asked Questions
Data centers use a ton of water for cooling, but how much really depends on size, design, and location. Companies are trying new ways to cut back, reuse water, and adjust to local limits.
What are the typical water usage rates for cooling in large-scale data centers?
Big hyperscale data centers can use about 550,000 gallons a day—that’s around 200 million gallons a year. Smaller centers might use closer to 18,000 gallons daily. The gap between giant cloud facilities and smaller ones is huge (Dgtl Infra).
How do data centers implement water conservation measures?
Operators are switching to recycled or non-potable water, making cooling more efficient, and tracking water usage effectiveness (WUE). For instance, Amazon Web Services aims to be water positive by 2030, using reclaimed water and supporting replenishment projects (Dgtl Infra).
Can the water used in data center cooling be recycled or reused?
Yes, definitely. Many centers recirculate water through cooling towers and heat exchangers. Some also treat and reuse stormwater or wastewater for non-drinking uses.
Google says reusing water for cooling can cut demand by up to 50% compared to once-through systems (Dgtl Infra).
What impact does the local climate have on a data center’s water consumption?
Hot, dry climates mean cooling systems have to work harder, so water use goes up. Cooler regions can use more air cooling, which saves water.
Where a data center is built really shapes whether it uses millions of gallons or much less (The Conversation).
Are there any innovative technologies aimed at reducing water use in data centers?
There are! New ideas include direct evaporative cooling, free-air cooling, and liquid immersion cooling. Some companies are also putting money into advanced water treatment to reuse water longer and cut down on waste.
All these approaches try to keep performance high but shrink the water footprint (Dgtl Infra).
How does water usage in data centers compare to other industrial water usage?
A 100-megawatt U.S. data center uses about as much water as 2,600 households. That’s quite a bit, honestly.
Still, it’s not as much as some heavy hitters like agriculture or paper production.
But with cloud computing growing so fast, people are starting to worry more about how much water these data centers are actually using (Congress.gov).