** 8/20/25 - WTTW - Mega Data Centers Could Drain Water Supplies in Great Lakes Region if Protections Aren’t Put in Place: Report + As Data Centers Proliferate Across Illinois, Communities Grapple with How to Supply the Necessary Water
Buzz Sawyer
New Alliance for the Great Lakes Report Sounds Alarm Over Lack of Planning and Oversight
"The company would prefer to use reclaimed water, according to Michelle Lindeman, a spokesperson for Equinix, and a law passed in May by state legislators explicitly permits that.
The Illinois Environmental Protection Agency already allowed reclaimed water to be used for industrial purposes in certain circumstances, but the agency has only permitted one facility to use treated wastewater discharge. The new law clarifies that companies can apply for permits to use treated municipal wastewater for industrial purposes, and the agency said it will apply existing regulations to approve or deny those applications.
“Where the data centers want to set up is not where we have great water resources [in Illinois], but we do have water reclamation facilities that generate water every day,” said Tim Gualandri, president of the Illinois section of the WateReuse Association. The trade group, which focuses on “recycled water” policy, is working with municipalities and state agencies to develop regulations"
Mega Data Centers Could Drain Water Supplies in Great Lakes Region if Protections Aren’t Put in Place: Report
It’s easy for residents of the Great Lakes to look at thirsty states like Colorado, Nevada and Arizona and feel smug about water.
The Great Lakes is a water-rich region, holding some 20% of the planet’s surface freshwater, a gift from departing glaciers as they retreated and melted thousands of years ago.
But that doesn’t mean cities across Illinois, Indiana, Wisconsin, Michigan, Ohio, Minnesota, Pennsylvania and New York couldn’t turn into the next Phoenix.
Just ask Joliet, where the aquifer the city draws its water from is expected to run dry by 2030.
Some 20% to 40% of water flowing into and out of the Great Lakes originates as groundwater.
“Which is not something that people think about — the water that’s under their feet,” said Helena Volzer, senior source water policy manager with the Alliance for the Great Lakes, a nonpartisan nonprofit working to protect the Great Lakes.
Volzer is the author of a new report that explores how unprecedented levels of consumption by heavy water users — namely “hyperscale” data centers — could lead to conflicts over and even shortages of a resource that’s largely been taken for granted.
In some places, that future is already playing out.
“There is a need for speed,” Volzer said, when it comes to drafting policies that ensure Great Lakes states don’t squander their Ice Age legacy.
The Great Lakes Compact, signed into law in 2008, prohibits diversions of Great Lakes surface and groundwater outside the basin.
In short, “our water is staying here at home,” said Volzer.
While the average Chicagoan might think that translates into an unending supply of tap water, bathwater or dishwater, such household use is a drop in the proverbial bucket.
Officials in Great Lakes states have touted the region’s “blue economy,” and lured data centers to locate in the region, offering tax breaks and other incentives on top of the promise of all the water these centers need to cool their energy-intensive computing equipment.
In essence, the water can’t leave the basin, so bring the users to the basin.
The ploy worked.
Illinois and Ohio rank fourth and fifth in the nation behind Virginia, Texas and California in terms of the number of data centers they house, whether that purpose is crypto mining, cloud computing or generative artificial intelligence.
In the past year or two, as the AI arms race has heated up, the size and scope of these centers has mushroomed, as has the pace at which these behemoths are being built, Volzer said.
A single hyperscale center of the sort operated by tech giants such as Meta or Microsoft — 10,000 square feet or more, with 5,000-plus servers — can consume 1 million to 5 million gallons of water each day. That’s 365 million gallons of water a year, Volzer said, or as much as 12,000 Americans’ annual use put together.
Not a single Great Lakes state currently has water management mechanisms in place to curb over-extraction, or what could be termed “de-watering,” before it happens, she said. The first step could be revising state groundwater management laws.
Otherwise, scenarios like the one playing out in rural Georgia — “Their Water Taps Ran Dry When Meta Built Next Door” — aren’t outside the realm of possibility.
“We’re just on this cusp,” Volzer said. “Those are the kinds of impacts we will begin to see.”
Layer on other water guzzling uses such as extractive mining for the metals needed to fuel the transition to electric vehicles, or the increased need for irrigation as climate change wreaks havoc with rainfall patterns, and the future begins to appear more than a little dystopian, Volzer said.
Which is why, she said, it’s important to put protections in place while there’s still time to conserve resources.
“From my perspective, I try to focus on the proactive long-term things that states could change now to be better prepared for this increasing demand,” Volzer said.
In the report, Volzer identifies a number of vulnerabilities and outlines solutions, some of which are already being enacted in one state or another but require broader region-wide adoption.
For starters, she said, there’s a need for greater transparency from data centers about their water consumption, both when centers are still in the proposal phase and then later when they’re operating at full capacity.
Currently, this usage is either buried in larger consumption reports or hidden behind non-disclosure agreements.
“There’s a lot more that we don’t know than we do,” Volzer said.
But access to such information is crucial if state and local officials are to be able to accurately assess the potential impact of a data center or other large user, such as a semi-conductor chip manufacturer, on water resources.
To that end, Volzer said states should be mapping their groundwater — showing where water is available, and how much — and using this data in tandem with a large user’s anticipated water needs to determine whether a given site is appropriate for certain types of development.
Any assessment of water availability and water demands, she added, should take into account ecosystem impacts, a factor that is often ignored.
“What kind of water level is needed to sustain a fish population? Make that part of the demand study,” Volzer said.
She also recommended that states not only reverse course on offering incentives to data centers — a stance Ohio’s legislature adopted, but Gov. Mike DeWine vetoed — but also negotiate benefits for communities, including mandating water conservation and efficiency standards.
“I’m hopeful this report prompts states to take a look at this issue because there’s been so much energy and attention focused on the electricity side of the equation when it comes to data centers,” Volzer said.
The water side demands no less attention, she argued.
“We’re blessed with this resource,” Volzer said of the Great Lakes, "but it’s something that requires constant managing.”
Read the complete report: A Finite Resource: Managing the Growing Water Needs of Data Centers, Critical Minerals Mining, and Agriculture in the Great Lakes Region
Contact Patty Wetli: pwe...@wttw.com
As Data Centers Proliferate Across Illinois, Communities Grapple with How to Supply the Necessary Water
Computing facilities require lots of water to operate, putting the burden of allocating resources on municipalities.
Once they’re online, data centers require a lot of electricity, which is helping drive rates up around the country and grabbing headlines. What gets less attention is how much water they need, both to generate that electricity and dissipate the heat from the servers powering cloud computing, storage and artificial intelligence.
A high-volume “hyperscale” data center uses the same amount of water in a year as 12,000 to 60,000 people, said Helena Volzer, a senior source water policy manager for the environmental nonprofit Alliance for the Great Lakes.
Increasingly, residents, legislators and freshwater advocacy groups are calling for municipalities to more carefully consider where the water that supplies these data centers will come from and how it will be managed. Even in the water-rich Great Lakes region, those are important questions as erratic weather patterns fueled by climate change affect water resources.
When it comes to siting data centers, “we don’t see a lot of coordination or long-term thinking about water,” said Michelle Stockness, executive director of Freshwater Society, a nonprofit focused on water preservation. Some places cannot support data centers, she said, “and you’ll have water-use conflicts if you put them there.”
Illinois already has more than 220 data centers, and a growing number of communities interested in the attendant tax revenue are trying to entice companies to build even more. Many states in the Great Lakes region—Illinois, Indiana, Michigan and Minnesota among them—are offering tax credits and incentives for data center developments. The Illinois Department of Commerce and Economic Opportunity has approved tax breaks for more than 20 data centers since 2020.
“Hyperscale data centers are the really large data centers that are being built now for [generative] AI, which is really driving a lot of the growth in this sector because it requires vast data processing capabilities,” said Volzer. “The trend is larger and bigger centers to feed this demand for AI.”
Much of the water used in data centers never gets back into the watershed, particularly if the data center uses a method called evaporative cooling. Even if that water does go back into the ecosystem, deep bedrock aquifers, like the Mahomet in central Illinois, can take centuries to recharge. In the Great Lakes, just 1 percent of the water is renewed each year from rain, runoff and groundwater.
“You have to think of [water] as a bank account. What is the input? What is the output? What is your nest egg in there? And how fast are you drawing it down?” said Carrie Jennings, the research and policy director at Freshwater Society. “That’s where groundwater governance, your Illinois State Water Survey and your empowered local groups that have the right data to work with can think about managing this system.”
In Illinois, 40 percent of the population gets its water from aquifers. In some places, like Chicago’s southwest suburbs in Will and Kendall counties, the amount of water in those aquifers is dwindling.
To ensure that they can supply citizens with safe drinking water, officials from six suburbs southwest of Chicago—Joliet, Channahon, Crest Hill, Minooka, Romeoville and Shorewood—made an agreement with the city two years ago to buy millions of gallons of water a day from Lake Michigan. They are currently building a $1.5 billion pipeline to transport the water, which is expected to be completed by 2030.
Illinois is unique among the Great Lakes states when it comes to water. The Great Lakes Compact each state signed in 2008 bans diversions of water from the lakes to communities outside the basin, but it makes an exception for Illinois thanks to a 1967 Supreme Court ruling allowing Chicago to sell water to farther-flung municipalities.
“We are concerned about the planning of the explosion of data centers, and if these far-out suburbs are actually accounting for that,” said Iyana Simba, city government affairs director for the Illinois Environmental Council. “How much of that was taken into account when they did their initial planning to purchase water from the city of Chicago? This isn’t reused wastewater. This is drinking water.”
The Chicago skyline is seen across Lake Michigan from Whiting, Ind. Credit: Scott Olson/Getty ImagesLast year, Equinix Inc. proposed building a data center in Minooka. If it’s approved, it could use 30 percent of the drinking water allocated to that municipality from the new pipeline.
The company would prefer to use reclaimed water, according to Michelle Lindeman, a spokesperson for Equinix, and a law passed in May by state legislators explicitly permits that.
The Illinois Environmental Protection Agency already allowed reclaimed water to be used for industrial purposes in certain circumstances, but the agency has only permitted one facility to use treated wastewater discharge. The new law clarifies that companies can apply for permits to use treated municipal wastewater for industrial purposes, and the agency said it will apply existing regulations to approve or deny those applications.
“Where the data centers want to set up is not where we have great water resources [in Illinois], but we do have water reclamation facilities that generate water every day,” said Tim Gualandri, president of the Illinois section of the WateReuse Association. The trade group, which focuses on “recycled water” policy, is working with municipalities and state agencies to develop regulations.
“We just want to tap into that resource so that we can attract industries, grow our jobs and continue to grow economic development here,” Gualandri added.
In Minooka, the village would still have to develop the infrastructure to get reclaimed water to the data center.
Non-disclosure agreements that companies ask municipalities to sign when they propose a data center further obscure how much water is needed and where it would come from, making it difficult to determine whether municipalities have enough supply, said Volzer, with Alliance for the Great Lakes.
To help combat that, some states in the region like Ohio and Indiana are now conducting regional water-demand studies, which would help communities determine where water is available before approving a data center. Some water managers are also conducting those studies in Illinois, but they are not required.
A bill proposed in February by Illinois state Sen. Steve Stadelman would have required data centers to disclose how much electricity and water they use, but lawmakers failed to vote on it before the legislative session ended May 31.
“The Great Lakes region is seen as water-rich. And it’s true, we have a lot of water here, but there’s an important detail not to be missed: Water abundance requires proper management to ensure that it’s available going forward,” Volzer said. “Our surface water is connected to our groundwater supply.”
Ordinances in other Great Lakes states could serve as a model for how to regulate water diverted to data centers, she added. In Michigan, for example, companies proposing data centers must show that there is enough existing water supply to support the facility in order to get the state tax incentive.
“With all of this demand, and with climate change, it seems prudent to start making these legislative changes now,” said Volzer.