Walworth County, WI Environmental Rules: Flood Elevation Requirements (2026)

Code § 74-131 defines "flood protection elevation" as an elevation two feet of freeboard above the water surface profile elevation designated for the regional flood, a safety margin meant to cover unknown factors such as ice jams, debris accumulation, wave action, bridge-opening obstructions, and the effects of watershed urbanization that can push actual flood heights above computed levels. That two-foot freeboard standard governs construction throughout the Floodplain Overlay District created under § 74-173, pursuant to Wis. 30 and NFIP regulations. Under § 74-173(j)(7), any structure or building intended for seasonal or permanent human habitation that is erected, constructed, reconstructed, structurally altered, or moved into a Flood Storage District must be placed on fill with the finished surface of the lowest floor, excluding basement or crawlway, at or above the flood protection elevation.

That fill must be at least one foot above the regional flood elevation and must extend at that elevation for at least 15 feet beyond the structure's limits, with dryland access provided. If the structure has a basement or crawlway, the floor of that space must sit at or above the regional flood elevation itself and be floodproofed up to the flood protection elevation in accordance with Wis. Admin. 16. The Zoning Administrator, who administers the floodplain ordinance under § 74-116, reviews all such applications, and the ordinance flatly states that no variance may be granted to allow any floor below the regional flood elevation, closing off the most common route property owners elsewhere use to avoid an elevation standard.