Lawmakers eye water use transparency requirements for data centers
[April 24, 2026]
By Nikoel Hytrek and UIS Public Affairs Reporting (PAR)
SPRINGFIELD — Lawmakers emphasized the need for transparency about how
much water data centers use to cool their facilities at the final of
three data center-focused hearings in the House Executive Committee.
Undisclosed water use is one of the most common complaints about data
centers, particularly for the large, hyperscale facilities that support
artificial intelligence that are proliferating across Illinois.
“We talk a lot about energy, and people express concerns about, ‘Are we
utilizing energy? Are we going to have enough resources there?’ We have
a plan,” said Democratic Rep. Ann Williams of Chicago, who chaired the
committee on Wednesday. “I think that same process needs to happen with
water and how much of it already exists versus what we need to put in
place with the influx of users.”
The amount of water a data center uses can vary widely and depends on
factors like its size, outside temperatures and how it cools its
servers, but one facility can use as much as a small city in a day.
Helena Volzer, senior source water policy manager for the Alliance for
the Great Lakes, and Andrew Rehn, the climate policy director of the
Prairie Rivers Network touted the POWER Act, a regulation bill currently
under consideration in the General Assembly, as the best mechanism to
manage water use by data centers.
Volzer said one of the major benefits of the POWER Act is that it begins
to address what she described as haphazard water management planning in
Illinois.
“There’s really not much in the way of water use reporting or evaluating
whether or not the watershed can handle a proposed water use before that
water use occurs,” she said of current state regulations.
Climate change, Volzer added, is threatening water sources with hotter,
drier summers and more droughts.
“The connection between groundwater and surface water means that surface
water resources can become stressed if groundwater becomes depleted,”
she said. “With simultaneously competing demand for water from
agriculture, industry, data centers and residential use, communities in
Illinois are facing complex tradeoffs in managing primary water
supplies.”
The POWER Act requires data centers to produce plans for water use,
scarcity and sustainability. It also requires data centers to use the
most water efficient cooling method — using closed loop cooling as a
baseline for efficiency — and to report that usage four times a year to
the Illinois Power Agency and to a publicly accessible website.
The POWER Act also requires data centers to submit their plans for
review from the Illinois Water Survey, a nongovernment group that
monitors water supplies across the state.
Rehn said the frameworks in the POWER Act will give residents more
clarity on how much water data centers use and assuage fears if that
amount is lower than they expected.
“We are asking for a plan that’s just a document that says, ‘here’s what
we’re going to do,’” he said. “I personally think transparency will shed
daylight and let folks be more comfortable if the water usage is indeed
that low. That seems like an easy thing to do.”
[to top of second column]
|
State Rep. Ann Williams, D-Chicago, speaks in favor of a
megaprojects bill on the Illinois House floor on Aprill 22, 2026.
(Capitol News Illinois photo by Jerry Nowicki)
Pushback
Brad Tietz, the Midwest policy director for the Data Center Coalition,
pushed back on the planning requirements, arguing that data center
developers already work closely with utilities and municipalities to
make plans and ensure the facilities will have the cooling resources
they need.
The data center industry opposes the POWER Act on the grounds that it
singles out one industry when there are others that use a lot of water
and aren’t under the same scrutiny.
Compared to agriculture, some manufacturing and golf courses, he said,
data centers are much more water efficient.
Tietz also said data center cooling methods are constantly evolving, and
innovations include building near water treatment plants or using
cooling methods that involve non-potable water, recycled water or air.
He said those methods are possible in Illinois, especially given its
cooler temperatures, which could allow data centers to use air cooling
outside of summer months. He acknowledged that some of those methods
require more energy, and the choice depends on the hardware in the
facility.
“Cooling data centers involves inherent tradeoffs,” Tietz said. “Air
cooling tends towards higher energy use, while liquid and evaporative
methods typically require more water. Selecting a cooling technology
therefore becomes a matter of balancing energy consumption and water
usage.”
Lawmakers said those developments don’t change the need for transparency
about how data centers operate in communities.
Rep. Theresa Mah, D- Chicago, said she didn’t understand why the
industry objected to making project plans public.
“I live in a community where there’s a data center nearby and it’s been
important for my constituents and myself to know what’s happening there
and to have that transparency,” she said. “It seems like it just makes
sense for everywhere else in the state as well.”
Williams said managing water needs in Illinois requires information
about large water users to be available for everyone and data centers
are a good place to start.
“I know every data center company is different, but what’s the objection
to providing that upfront transparency?” Williams asked. “This is a new
large user. I get what you’re saying. There are other users out there,
certainly that there have been for some time, but with this influx of
new users, it seems like planning would be helpful.”
Democrats in the Senate have held hearings about statewide groundwater
management and are considering how to approach the issue.
Capitol News Illinois is
a nonprofit, nonpartisan news service that distributes state government
coverage to hundreds of news outlets statewide. It is funded primarily
by the Illinois Press Foundation and the Robert R. McCormick Foundation. |
