Waukesha, WI Environmental Rules: Flood Zones (2026)

Wisconsin's floodplain management framework is set by Wis. Stat. Sec. 30, which directs every county, city, and village within or with land in a floodplain to adopt a reasonable and effective floodplain zoning ordinance. Implementation standards are in Wis. Admin. Code Chapter NR 116 (Wisconsin's Floodplain Management Program), which the Wisconsin DNR enforces. NR 116 requires local ordinances to meet or exceed the National Flood Insurance Program minimums in 44 CFR Parts 59-72. The City of Waukesha adopted its current Floodplain Ordinance in 2023, mapping the Fox River corridor and other SFHAs to three districts: Floodway District (where development is most strictly limited), Flood-Fringe District (the area outside the floodway but within the 1% annual chance floodplain), and General Floodplain District (used where detailed studies are unavailable).

13, residential structures in the flood-fringe must be elevated with the lowest floor (including basement) at or above the flood protection elevation, which is at least 2 feet above the base flood elevation (BFE) - Wisconsin requires 2 feet of freeboard, more than the federal minimum. Substantial improvements (repairs or upgrades equaling 50% or more of pre-improvement market value) must bring the entire structure into compliance. Floodway development is prohibited for residential structures. Permits are issued by the City Zoning Administrator before any building permit. gov) and the Wisconsin DNR Surface Water Data Viewer for their parcel.