Wisconsin Statewide Rule

Wisconsin Floodplain Zoning Mandate Under NR 116

Heavy RestrictionsApplies statewide across Wisconsin (2026)

Key Facts

Code: NR 116 / Wis. Stat. 87.30
Floodway homes: Prohibited
Freeboard: 2 feet above BFE
Substantial improvement: 50% market value

Last verified: September 5, 2026Source: Wisconsin State Legislature

Summary

Wisconsin requires every county, city, and village with mapped floodplains to adopt floodplain zoning meeting NR 116 minimums. Local ordinances must be approved by the DNR and cannot weaken state baselines.

If any county, city or village does not adopt a reasonable and effective floodplain zoning ordinance within one year after hydraulic and engineering data adequate to formulate the ordinance becomes available, the department shall, upon petition of an interested state agency or a municipality or upon its own motion as soon as practicable and after public hearing, determine and fix by order the limits of any or all floodplains within a county, city or village within which serious damage may occur.

Source: Wisconsin State LegislatureView official code

Full Breakdown

Under Wis. Stat. section 87.30 and Wis. Admin. Code NR 116, all communities with FEMA-mapped floodplains must adopt and enforce floodplain zoning ordinances. New residential structures are prohibited in floodways, and structures in flood fringe areas must have lowest floors elevated at least two feet above the base flood elevation. Substantial improvements (50 percent or more of market value) trigger full code compliance. The DNR reviews and approves all local floodplain ordinances and amendments. Failure to adopt compliant zoning can result in suspension from the National Flood Insurance Program, eliminating federally backed flood insurance for residents.

Violations & Penalties

Unpermitted construction in a floodplain may require removal, daily forfeitures, NFIP suspension for the community, and personal liability for damages caused to neighboring properties.

Frequently Asked Questions

Can I build a house in a Wisconsin floodway?

No. NR 116 prohibits new residential structures in mapped floodways. Limited accessory and water-dependent uses may be allowed with strict conditions.

How high must my home be in the flood fringe?

The lowest floor, including basement, must be at least two feet above the base flood elevation. Fill placement and openings must also meet NR 116 requirements.

What is a substantial improvement?

Any repair, reconstruction, or addition costing 50 percent or more of the structure's market value. It triggers full floodplain code compliance for the entire structure.

Sources

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