Walworth County, WI Environmental Rules: Flood Zones (2026)

Section 74-173(a) applies the floodplain overlay to all areas of special flood hazard identified as zones A, AO, AH, A1-30, or AE on the county's Flood Insurance Rate Map, plus any additional areas identified on DNR-approved maps, and requires every city, village, town, and county to obtain necessary permits unless specifically exempted by law. The district itself covers four subdistricts: the Floodway (FW), the Floodfringe (FF), the General Floodplain (GFP), and the Flood Storage District (FSD), each defined by how close it sits to the channel carrying regional floodwaters.

15(3)(b) exception); solid or hazardous waste disposal sites; wells drawn for human consumption; storage of buoyant, flammable, or explosive materials; nearly all new structures and additions, including residential, accessory, agricultural, commercial, and manufactured homes; basements and crawlspaces below grade; public assembly structures; parking and loading areas; mobile homes and mobile home parks; camping units and campgrounds; mineral extraction; repairs or alterations equal to or exceeding 50 percent of a structure's equalized assessed value; replacement of flood-damaged nonconforming structures; and portable latrines. Permitted uses under § 74-173(i) are limited to functionally water-dependent facilities, non-structural agriculture, wetland restoration, nonstructural recreation, and similar low-impact activity, and every permitted use must be built to the flood protection elevation, two feet above the flood profile, without obstructing flow or increasing regional flood height.

Conditional uses under § 74-173(j) require Committee review and approval and include watercourse alterations, driveway maintenance, and repair of nonconforming or historic structures under strict conditions.