Winnebago County, WI Environmental Rules: Flood Elevation Requirements (2026)
Key Facts
- Freeboard required
- 2 feet above regional flood
- Fill height
- 1+ foot above regional flood
- Fill extent
- 15 feet beyond structure
- Applies in
- Floodfringe district, unincorporated towns
- Governing section
- Ch. 26 § 26.5-23(b)
Summary
Winnebago County requires new and substantially improved homes in the floodfringe district to sit at or above the flood protection elevation, the regional flood elevation plus 2 feet of freeboard, with fill extending at least 15 feet past the structure.
The elevation of the lowest floor shall be at or above the flood protection elevation on fill unless the requirements in subsection (b)(2) can be met. The fill shall be one foot or more above the regional flood elevation extending at least 15 feet beyond the limits of the structure.
(2) The basement or crawlway floor may be placed at the regional flood elevation if it is flood proofed to the flood protection elevation. No basement or crawlway floor is allowed below the regional flood elevation.
(3) Contiguous dryland access shall be provided from the structure to land outside of the floodplain, except that in developments where existing street or sewer lineelevations
05/20/14 5-5
Full Breakdown
Chapter 26 defines flood protection elevation as 2 feet of freeboard above the regional flood elevation. In the floodfringe district, Section 26.5-23(b) requires the lowest floor of any new or substantially improved habitable structure, including manufactured homes, to be built on fill at or above that elevation, with the fill at least 1 foot above the regional flood elevation and extending 15 feet beyond the structure; a basement floor may instead be flood-proofed to the flood protection elevation but never placed below the regional flood elevation.
Violations & Fines
Building below the required flood protection elevation is a Chapter 26 violation, prosecuted by the county corporation counsel; conviction forfeits $10 to $50 per day, each day a separate offense, and the county may sue to abate it as a nuisance.
Frequently Asked Questions
Can a basement go below the flood protection elevation?
Does this elevation rule apply outside the floodfringe district?
Sources & Official References
Other rules in Winnebago County
Compare Winnebago County to another location·View the Wisconsin environmental rules overview
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