Illinois Lawmakers Push for Water Use Transparency Requirements for Data Centers
Why It Matters
Illinois lawmakers are pressing for greater transparency around water consumption by data centers, raising questions about how the state manages its water resources as the data center industry expands rapidly. The debate has direct implications for communities near large facilities, as well as for agriculture, residential users, and industries that draw from the same watersheds.
Water use by data centers — particularly hyperscale facilities that support artificial intelligence operations — has emerged as one of the most significant regulatory concerns in Illinois. A single large facility can consume as much water in a day as a small city, yet current state regulations require little in the way of reporting or pre-approval review.
What Happened
The Illinois House Executive Committee held the final in a series of three hearings focused on data center regulation on Wednesday, with water resource management as the central topic. Lawmakers have used these hearings to conduct a deep-dive review of data center policy before any legislative action moves forward.
State Rep. Ann Williams, a Chicago Democrat who chaired the committee, emphasized that water planning must receive the same serious attention that energy resource planning has garnered. “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,” Williams said during the hearing.
Lawmakers heard testimony from water resource advocates who support a pending measure known as the POWER Act, as well as from a data center industry representative who opposed it. The hearing did not result in a vote, but members indicated that conversations about water management would continue.
By the Numbers
1 — The number of data center facilities that can use as much water in a single day as a small city, according to testimony presented at the hearing.
4 — The number of times per year the POWER Act would require data centers to report water usage, both to the Illinois Power Agency and to a publicly accessible website.
3 — The number of House committee hearings focused on data center regulation that have now concluded, with the Senate having separately held hearings on groundwater supplies and resource management.
Multiple industries — Agriculture, certain manufacturing sectors, and golf courses were cited by the data center industry as comparable high-volume water users not subject to the same proposed scrutiny.
The Debate: Industry vs. Transparency Advocates
Helena Volzer of the Alliance for the Great Lakes and Andrew Rehn of the Prairie Rivers Network both testified in support of the POWER Act. Volzer described current state water regulations as “haphazard,” noting there is little mechanism to evaluate whether a watershed can support a proposed water use before it begins. She also cited climate-driven pressures — including hotter, drier summers and increased drought — as compounding the challenge.
The POWER Act, as described during testimony, would require data centers to produce water use and sustainability plans, adopt the most water-efficient cooling methods using closed-loop cooling as a baseline, and submit those plans for review by the Illinois Water Survey, a nongovernmental body that monitors the state’s water supplies.
Brad Tietz, Midwest policy director for the Data Center Coalition, pushed back on the legislation. He argued that data centers already coordinate with utilities and municipalities on water planning, and that the industry is more water-efficient than agriculture and other large-scale users. Tietz also noted that cooling technology is evolving, with options including air cooling during cooler months, non-potable water use, and recycled water systems — though he acknowledged those alternatives involve tradeoffs between energy and water consumption.
“Cooling data centers involves inherent tradeoffs,” Tietz said. “Air cooling tends towards higher energy use, while liquid and evaporative methods typically require more water.”
Rep. Theresa Mah, a Chicago Democrat, questioned why the industry would object to making project water use plans publicly available, signaling that lawmakers across the committee remain skeptical of arguments against basic disclosure requirements.
Zoom Out
Illinois is not alone in grappling with the water footprint of the data center boom. As artificial intelligence infrastructure accelerates nationally, states across the country are beginning to scrutinize how large facilities interact with local water supplies. The tension between economic development and resource stewardship is a policy challenge that extends well beyond Illinois, and the regulatory frameworks developed here could influence how other states approach the issue.
What’s Next
With three House hearings now concluded, the focus is expected to shift toward whether legislation such as the POWER Act advances through the General Assembly. The Senate has already held separate hearings on groundwater and resource management, suggesting both chambers are actively examining the issue. Lawmakers indicated Wednesday that further conversations on water management policy are forthcoming, though no vote timeline was announced.