Chicagoland data center boom raises new questions about Lake Michigan water use
The data center boom in Chicagoland is raising concerns among residents and farmers regarding its potential impact on Lake Michigan water levels and aquifer depletion. While experts say data centers are unlikely to affect Lake Michigan's overall level, Illinois operates under a Supreme Court decree limiting water diversion, making efficient usage crucial. Local communities like Joliet are planning their water allocation from Lake Michigan, including for data center campuses, while state-level bills are being proposed to mandate water use reporting.
The rapid expansion of data centers in the Chicagoland area has sparked apprehension among residents and farmers over potential strains on water supplies, including Lake Michigan and local aquifers. While the Alliance for the Great Lakes President and CEO Joel Brammeier clarifies that data center water use is unlikely to directly impact Lake Michigan's overall level, Illinois faces a strict daily diversion limit from the lake imposed by a 1967 U.S. Supreme Court ruling known as the Lake Michigan Diversion Consent Decree. This historical decree limits Illinois to just over 2 billion gallons of water diversion daily into the Mississippi River Basin, meaning large-scale users like data centers, farms, and residential customers could conflict over the finite supply.
Joliet, for instance, is transitioning from an unsustainable aquifer to Lake Michigan water by 2030, purchasing treated water from Chicago. The city's Public Utilities Department projects about 1% of its 15.6 million gallons daily allotment will go to its 795-acre data center campus, which plans to use closed-loop cooling. However, Robert Hirschfeld, director of water policy at Prairie Rivers Network, points out that outside the Lake Michigan decree area, Illinois's outdated English common law framework for water rights leads to an inefficient system where landowners can withdraw water as long as they don't impede another's "reasonable use." Philip Nelson, president of the Illinois Farm Bureau, highlighted farmers' concerns about water usage and the conversion of prime farmland for data center development.
Currently, data centers are not required to report their water or electricity usage, nor their cooling systems, making it difficult for agencies like the Chicago Metropolitan Agency for Planning (CMAP) to forecast future demand accurately. Nora Beck, a policy analyst at CMAP, emphasizes the need for more data to protect the state's water allocation. State-level bills have been introduced to address these reporting gaps, and the Illinois Farm Bureau has developed guidelines for data center projects in rural areas. Despite the concerns, residents like Jeremy Brzycki worry that data centers, with their significant financial and political influence, will ultimately prevail in any water use conflicts with communities, underscoring the urgency for smarter planning and regulatory reforms.