Wisconsin Statutes Utilities (Ch. 196 to 201) § 200.31. General duties of the commission

(1) Sewerage system functions. Project, plan, design, construct, maintain and operate a sewerage system for the collection, transmission and disposal of all sewage and drainage of the sewerage service area including, either as an integrated or as a separate feature of the system, the collection, transmission and disposal of storm water and groundwater.

(2) Combined sewer overflow abatement. Abate combined sewer overflows to the extent necessary to comply with federal or state law.