Brown County, WI Environmental Rules: Flood Elevation Requirements (2026)
Key Facts
- Freeboard
- 2 feet above base flood elevation
- Permit
- Shoreland permit required before construction
- Applies to
- Unincorporated Brown County towns only
- Penalty
- $25–$50 per day forfeiture
- Citation
- Brown County Code § 23.05(2)
Summary
In unincorporated Brown County, Wisconsin, any habitable structure near a mapped floodplain must set its lowest opening at least two feet above the base or regional flood elevation, and obtain a shoreland permit first.
Any structures intended for human habitation adjacent to a floodplain that the Zoning Administrator deems susceptible to flooding must have the lowest opening a minimum of two feet above the area of special flood hazard, regional or base flood elevation. A shoreland permit will be required. If elevations do not exist, it may be required to complete a case by case flood study or to record an affidavit for unmapped floodplain onto the deed of the property.
NOTE: Base flood elevations are derived from the flood profiles in the Flood Insurance Study (FIS) and are shown as AE, A1-30, AH, VE, V1-30, or V Zones on the FIRM. Other regulatory zones are displayed as A and AO zones. Regional Flood Elevations (RFE) may be derived from other studies. If more than one map or revision is referenced, the most restrictive information shall apply.
Full Breakdown
Brown County Code § 23.05(2) requires any structure intended for human habitation adjacent to a floodplain that the Zoning Administrator deems susceptible to flooding to have its lowest opening at least two feet above the area's special flood hazard, regional, or base flood elevation. That two-foot margin is freeboard above FEMA's mapped elevation. A shoreland permit is required before building, and where no elevation data exists the county requires a case-by-case flood study or a recorded affidavit against the property deed. This rule governs Brown County's unincorporated towns; Green Bay, De Pere, Ashwaubenon, and the county's other incorporated villages enforce their own floodplain codes.
Violations & Fines
Building below the required freeboard without a permit is a violation prosecuted by the county attorney, punishable by a $25–$50 forfeiture per day, plus court costs; each day of noncompliance is a separate offense.
Frequently Asked Questions
Does this floodplain rule apply inside Green Bay or De Pere?
What counts as the "lowest opening" for the two-foot rule?
What if my property has no mapped flood elevation?
Sources & Official References
Other rules in Brown County
Compare Brown County to another location·View the Wisconsin environmental rules overview
See something wrong?
Help us keep this page accurate. If you notice an error or outdated information, let us know.