Illinois lawmakers are taking a closer look at how the rapid expansion of data centers—particularly large “hyperscale” facilities driven by artificial intelligence—could affect the state’s water resources. During a House Executive Committee subject matter hearing on April 22, 2026, policymakers and stakeholders explored how water is used, monitored, and regulated in connection with these high-demand facilities, with a particular emphasis on long-term sustainability and transparency.
A central theme of the hearing was the complex relationship between water and energy use. Witnesses emphasized that while some data centers may appear to use little or no water onsite, significant water consumption often occurs indirectly through electricity generation. In regions like the Great Lakes basin, energy production, particularly nuclear and fossil fuel generation, remains one of the largest users of water. As a result, policymakers were cautioned against evaluating data center water impacts in isolation, as shifting cooling methods can create tradeoffs between direct water use and increased energy demand.
The discussion also highlighted the growing scale of modern data centers. Witnesses noted that today’s hyperscale facilities are substantially larger than earlier generations, often spanning hundreds of acres and requiring significant infrastructure to support advanced computing needs. This shift has intensified concerns about cumulative water impacts, particularly as multiple facilities cluster in certain regions.
A key area of concern for lawmakers was groundwater sustainability, especially in communities that rely heavily on aquifers. Testimony underscored that aquifer recharge rates vary widely and are not fully understood, making it difficult to predict how quickly water sources can recover from heavy withdrawals. Changing precipitation patterns, more frequent droughts, and increased land development—such as large expanses of impermeable surfaces associated with data centers—can further hinder recharge. These factors make siting decisions critically important, as the same facility could have vastly different impacts depending on local water conditions.
At the same time, witnesses described Illinois’ current groundwater regulatory framework as fragmented and limited in scope. While the state does require certain large withdrawals to be reported under the Illinois Water Use Act, compliance rates have been described as low, and enforcement authority is limited. Moreover, because most data centers connect to municipal water systems rather than drawing directly from groundwater, their usage is often not captured in existing reporting requirements. This has created a significant information gap, leaving policymakers and communities without a clear understanding of how much water these facilities consume.
The issue of transparency emerged as a recurring concern throughout the hearing. Lawmakers questioned whether communities have sufficient access to information about proposed data center projects, particularly regarding water sourcing, consumption levels, and potential impacts during periods of scarcity. While industry representatives noted that detailed information is typically shared with local utilities and municipalities, they expressed reservations about public disclosure at the individual facility level, suggesting that aggregated or anonymized reporting could strike a balance.
Several witnesses pointed to the proposed “Power Act” (HB 5513 and SB 4016) as a potential framework to address these concerns. The legislation would establish new water-use reporting requirements, require analysis of water-efficient cooling technologies, and mandate planning for drought or water-scarcity scenarios. It would also involve state agencies, including the Illinois Environmental Protection Agency and the State Water Survey, in evaluating whether proposed facilities could adversely impact local water resources before receiving approval.
Importantly, the hearing also touched on emerging practices aimed at reducing freshwater demand, including the use of treated wastewater for industrial cooling. While this approach is already being implemented in other parts of the country and is permissible under Illinois law, witnesses noted that it may be more feasible for large hyperscale facilities than for smaller data centers.
For county governments, the issues raised during the hearing carry significant implications. Counties often play a central role in land use decisions, infrastructure planning, and coordination with local water utilities. The lack of consistent statewide data on water usage and aquifer capacity can make it more difficult for county officials to evaluate proposals and communicate impacts to residents. At the same time, large-scale developments may place additional strain on local water systems, requiring infrastructure upgrades or long-term resource planning.
As lawmakers continue to evaluate the appropriate policy response, the hearing made clear that Illinois is at an inflection point. With data center development accelerating, particularly in regions with access to water and energy infrastructure, policymakers are weighing how to balance economic growth with the protection of critical natural resources. The conversation is expected to continue as legislation advances and additional hearings are held.