Data Centers Don't Have To Be Water Hogs. But Even In A Record Drought, Some Still Are
With a record drought sweeping the Southwest, the massive amount of water used to cool some data centers has come under increased scrutiny. Critics say the data center industry — and some of the world's largest technology companies — aren't employing the most efficient methods and are using far more water than necessary.
In order to cool their halls filled with thousands of heat-producing servers, all but the newest data centers use massive amounts of water: roughly 3 million to 5 million gallons per day.
Yet despite the strain data centers can place on water resources, data center developers love the desert, where the low humidity reduces wear on computer equipment. More than one-fifth of all data centers draw water from stressed watersheds, according to a May 2021 Virginia Tech study, and cities like Phoenix are among the country’s fastest-growing data center markets.
While many data center operators are now using water-free technologies in their newest data centers, facilities are still being built in desert environments that use water-based cooling. Industry insiders say water sustainability is not being pursued with the same consistency or urgency as efforts to reduce carbon emissions.
Further hampering sustainability efforts has been a lack of transparency among some of the largest data center operators about how much water their facilities use, making the industry's progress difficult to track. But as the record drought forces residents to reduce their own water usage across the Southwest, there are signs that any tolerance for water-guzzling data centers is wearing thin.
“The pressure is up. You have to be paying attention to this issue at this point,” said Jay Dietrich, research director for sustainability at Uptime Institute. "These issues are now at the forefront from a public policy standpoint, and you’re going to have to address it during the permitting process.”
Hyperscale giants like Google, Meta and Microsoft — the companies that have fueled the current data center building boom — are generally regarded as leaders on sustainable energy and emissions, with significant investments in renewables and robust carbon reporting policies. Yet when it comes to water use, sources who spoke with Bisnow said these companies have not taken the same aggressive approach toward water, even compared to others in the data center space.
“Usually, they’re leading on the sustainability fronts, but it feels like the colocation providers are ahead of the big hyperscale companies,” QTS Realty Trust Vice President for Energy and Sustainability Travis Wright said. “For whatever reason, they're a little behind the curve on this.”
One of the largest U.S. data center owners, QTS was acquired by Blackstone last year for $10B.
The American Southwest is amid a 22-year “megadrought” — the worst in 1,200 years, according to a new study in Nature Climate Change. In communities across the region, residents are being asked to dramatically reduce water usage as reservoir levels plunge and wells run dry.
Among the most dramatic demonstrations of the water crisis are the plunging water levels at Lake Mead, which serves as a water source for more than 40 million people. The lake is also a popular fishing destination, yet in recent weeks the water has receded so much that anglers who previously flocked to the lake have been unable to launch their boats.
Jenn Duff is a former pro bass angler herself, although for the past four years she has served on the city council in the Phoenix suburb of Mesa, where she is currently vice mayor.
Last year, Duff was the lone opposing vote to an agreement with social media giant Meta that allowed the hyperscaler to draw 4 million gallons of water each day to cool its data center campus in the city. Meta started construction on an expansion of the campus last month, and the new buildings will also be allowed to draw millions of gallons daily.
“I put the challenge to our government: Should we really have water-cooled data centers in the desert?” Duff told Bisnow.“I really question that based on where we are in our drought. It’s something maybe we have to have a policy on in the city of Mesa.”
A Meta spokesperson, in an emailed statement to Bisnow, said the company has invested in water restoration projects that would restore more than 1 billion gallons of water annually in the U.S., including 200 million gallons in Arizona. The company, formerly known as Facebook, said it has a goal to be “water positive” by 2030, meaning it will replace more clean water than it consumes.
"We are committed to doing our part by continuing to find projects that will restore water to the communities where we operate and will transparently report our progress to our water positive goal," the company said in a statement.
While Mesa City Council approved Meta’s water usage agreement, the past year has seen water emerge as a key cause for data center opponents in the Southwest and beyond.
In Chandler, another Phoenix suburb, city officials passed strict water restrictions on commercial users that effectively halted new data center development. And it is not just desert communities that are pushing back. In Dalles, Oregon, water drawn from the Columbia River for a Google data center was at the heart of a court battle that made headlines across the state.
According to Duff, Meta told city officials in Mesa that water-based cooling was the only viable option in the desert heat, saying alternative cooling methods used excessive amounts of power. But experts tell Bisnow that water-free — or at least more water-efficient — cooling methods are slowly becoming the norm, even in the desert.
Traditionally, most large data centers have been cooled by a method known as evaporative cooling in which air is circulated through a material saturated with cold water. It is an energy-efficient system, and it works particularly well in desert environments with little humidity. Yet these systems require millions of gallons of water to be circulated through a data center each day.
“A big chilled-water evaporative cooling plant is robust, it’s going to be around forever, it’s reasonably efficient, but boy, they use an awful lot of water,” QTS' Wright said.
Alternatives to water-based cooling involve using outside air or conditioning air inside a data center using refrigerants. While these technologies aren’t new, refrigerant-based cooling systems were generally far less energy-efficient than water-based cooling and therefore more expensive to operate, particularly in hot climates.
With cheap water seemingly in abundance even in places like Southern California and Arizona, it made little sense for data center operators to invest in developing alternatives.
But that equation has changed in recent years, as the growth of the data center industry has corresponded with increased water scarcity and public focus on water conservation. Experts say that many current water-free cooling systems have similar energy efficiency to evaporative cooling. And while those systems do perform worse in extreme climates, they have proven viable in desert environments by themselves or in conjunction with a limited water-based system. Experts say it is no longer a choice between saving power and saving water.
Wright says QTS now uses water-free cooling in almost all its new data centers, including its campus currently under construction in Phoenix.
“It used to be that you would either use a water-based system that where you’d get better efficiency or a dry-based system that was not very efficient,” he said. “It’s not that way anymore. You don’t have that trade-off.”
Despite the availability of water-free alternatives, Meta’s current expansion in Mesa stands as evidence that water-based cooling systems are still being built even in the most water-stressed environments.
There is little data on how much water is being used at specific data center sites or by the industry as a whole. Operators have gone to great lengths to prevent transparency into water usage, with Google going so far as to force a lawsuit to prevent journalists from publishing their water consumption in Dalles, Oregon.
Uptime’s Dietrich said the hesitance to share water usage is partially due to concerns about public backlash, but it is also driven by fear of giving competitive insights to rivals. But even if data center operators have legitimate reasons for hiding their water use data from competitors, critics say the lack of transparency is fueling growing ill will toward the industry, particularly in drought-stricken communities where residents are facing restrictions on their own water use.
Facing growing scrutiny, Meta, Microsoft and Google all made separate pledges last year to be “water positive” by 2030. These efforts range from building more efficient data centers to providing clean drinking water in developing countries.
But these promises have been greeted with skepticism from many within the industry and in water-stressed data center markets, who say meeting an artificial water neutrality goal is pulling resources away from the investment needed to make their facilities sustainable.
“Personally, I view them as PR,” Dietrich said. “The bottom line is maximizing the workload delivered per unit of water consumed and unit of energy — those are the two most important metrics — so I want to be investing where I can make a difference in those.”
Google and Microsoft didn't respond to requests to comment for this story.
A Meta spokesperson said that its data centers are 80% more water-efficient than the industry standard, and it has found new ways to reduce humidity in data halls to achieve water savings.
"We continually invest in new ways to make our data centers more water-efficient," the spokesperson said in a statement.
When it comes to renewable energy, tech giants like Meta have routinely partnered with local governments and utilities to build or help finance solar and wind energy projects to power their data centers, efforts that in turn have kick-started renewable energy development in those areas. Critics want to see more of these kinds of partnerships on water efficiency infrastructure beyond the data center walls in places like Arizona.
In Mesa, Duff points to a grey water reclamation pipeline the city has poured millions of dollars into developing, yet the city didn’t have the infrastructure in place to connect Meta’s facility to it. Duff says she would like to see companies like Meta work with municipalities like hers and help develop infrastructure projects that would set the stage for future water-efficient development.
“I love to see these technology companies really help us invest and be innovative, [with] ways that we can use water,” she said.