CHICAGO — Mayor Brandon Johnson signed an executive order Tuesday directing city departments to intensify scrutiny of new data centers in Chicago — a politically potent move that doesn’t unilaterally impose new limits on the fast-growing industry, but could slow its growth.

The order directs his administration to toughen air pollution evaluations, add noise restrictions and expand city bureaucrats’ authority to review water and electricity usage at data center facilities. But it does not cap or ban new construction. That harder step would require approval from the City Council, which Johnson urged Tuesday to pass a moratorium on new data center projects while the city develops more comprehensive rules.

“This is a newer phenomenon, and we want to get as out front of this matter as fast as we possibly can,” Johnson said. “A temporary moratorium is critical because it will ensure that new data centers do not move forward while the City Council contemplates the deliberate, comprehensive process of developing the protections Chicagoans have called for and deserve.”

During a news conference announcing the order, the mayor said “Chicagoans must come first” as the city intends to set its own terms for the industry as artificial intelligence drives a nationwide boom in data center construction.

“Chicago will not be passively shaped by this new industry. We will lead and actively set the terms for how this technological development occurs,” Johnson said. “Chicagoans have been absolutely clear: They do not want data centers expanding across our city without strong protection.”

The order marks the city’s strongest response yet to the controversial facilities known for their noise, pollution and intense water and electricity usage. It comes as aldermen prepare to consider an ordinance next month, proposed in July by City Council Environmental Chair Ald. Maria Harden, that would require data centers to report their electricity and water usage. Hadden said her measure “works with” the mayor’s new order.

“There’s plenty of work to do,” Hadden, 49th, said when asked whether Johnson had overstepped into aldermanic territory. “We started with something really straightforward that I just wanted to take some action on, that we knew we could get going right away. I think it’s great to see the mayor move on what he can do.”

Across the nation, more than 530 counties and municipalities have blocked or severely restricted data centers, according to Heatmap Pro, a clean energy news service. More than 200 additional towns are considering similar restrictions, according to a Heatmap report last month, including six Illinois towns where data centers have been canceled since last year and 13 that have enacted moratoriums or restrictive ordinances, according to Robinson Meyer, Heatmap’s executive editor.

Several progressive aldermen stood behind Johnson during the announcement — a visible show of support that belied the mayor’s often rocky relationship with the council. That tension surfaced in a lighter moment when Ald. Lamont Robinson, 4th, held out his chair for Johnson as he sat down at a wooden desk for the ceremonial signing.

“Finally, I’ve got an alderman that has my back,” Johnson joked.

With his relationship with aldermen strained most notably following a bruising budget fight, casting himself as a check on an industry increasingly blamed for rising utility bills could give Johnson a rare point of common ground with his council critics — and a message that could resonate with voters as he looks toward reelection.

In his remarks, the mayor also called on state legislators to pass the POWER Act, a bill aimed at regulating massive “hyper-scale” data centers more likely to be built outside city limits.

Pressed on whether the order could hurt businesses or slow the city’s economy, Johnson argued that protecting the city’s access to the Great Lakes, one of the largest bodies of fresh water in the world, takes priority.

“This is the best place to do business, and the proof is in how we have produced, but again, development cannot happen at the expense of working people,” he said.

Chicago currently has 39 data centers, with more likely as demand grows. One recent proposal would place a center inside 300 W. Adams St., a 12-story terra-cotta Loop building designed by Jens Jensen and landmarked in 2009.

Johnson’s order follows a series of recommendations published in July by the city’s Sustainable Data Centers Working Group, a city panel formed last year that includes department leaders, environmental activists and data center industry leaders. Panel leaders warned aldermen during a hearing last month that the buildings, central to the ongoing boom in cloud computing and artificial intelligence, can drive up electricity costs and jeopardize the city’s climate goals.

“Our electric bills have already gone up because of data centers and will continue to do so unless policymakers at multiple levels take action,” said Sarah Moskowitz, executive director of the Citizens Utility Board. “Our clean energy targets were set before data centers were really a thing, and now data centers have come on the scene and have thrown all of those goals into question.”

Johnson’s move won quick praise from environmental activists, including Iyana Simba, city programs director for the Illinois Environmental Council.

“We are hearing horror stories across the state, across the city, across the country about AI data centers driving up bills, threatening the reliability of our grid, polluting our air, straining our water supply and frankly jeopardizing the health of communities,” Simba said. “That’s why action on all levels is needed.”

Johnson held the news conference on Northerly Island, the same site where then-Mayor Richard M. Daley shocked Chicagoans in 2003 by bulldozing X-shaped gashes into the Meigs Field runway overnight, a move that killed the downtown airport and cleared the way for the land’s conversion into a public park and nature sanctuary.

The symbolism wasn’t lost on Angela Tovar, commissioner of the Department of Environment, which Johnson reestablished in his first budget.

“That’s exactly the spirit we’re bringing to the work we are here to talk about,” Tovar told the crowd.

“This is a place the city reclaimed and reimagined, a place where we chose to prioritize green space, nature and the health of Lake Michigan over what was built here prior,” she said. “It’s a reminder that Chicago has always had the ability to make deliberate choices about how we grow and who that growth serves.”

_____

©2026 Chicago Tribune. Visit chicagotribune.com. Distributed by Tribune Content Agency, LLC.