UW–Madison expert outlines how counties can regulate data centers and where limits lie

Carl Green, a community planning specialist from the University of Wisconsin–Madison, gave a roughly 20‑minute informational presentation describing the range of data‑center types, their energy and water demands, and the regulatory tools local governments can use.

“Data centers are not all the same,” Green said, explaining the difference between small modular or telecom edge facilities and hyperscale campuses exceeding 100 megawatts. He described how cooling choices — evaporative (water) systems versus compressor cooling — affect both electricity and water use and suggested that water‑use analyses and preliminary engineering reports are typical components of local review. He also noted state incentives such as the 2023 Act 19 sales and use tax exemption for certain large projects and advised that, because some municipalities can annex sites, county moratoriums and zoning only apply to unincorporated areas with county comprehensive zoning.

During Q&A Green emphasized that economic benefits are often concentrated in construction jobs and that operational employment tends to be limited and highly skilled. He recommended that the county review existing zoning definitions and conditional uses and consider development standards (setbacks, screening, noise, backup‑power identification, reclamation bonds) if it wants to exercise regulatory control rather than rely on emergency measures. Green said he would share a developer prospectus and additional resources with county staff.