Plymouth, MN Environmental Rules: Flood Elevation Requirements (2026)
Key Facts
- Governing sections
- §21660.06, Subd. 1(b)(1); §21005.02 (definition)
- Freeboard required
- At least 2 feet above the regional flood elevation
- Fill extent
- Extends 15 feet beyond structure's outside limits
- Accessory structure alternative
- FP1-FP4 floodproofing, under 576 sq ft
- Enforcing office
- Zoning Administrator
- Penalty
- Misdemeanor, no variance below elevation (§21660.10)
Summary
In the City of Plymouth, the Zoning Ordinance's Floodplain Overlay District requires new and substantially improved structures in the Flood Fringe District to sit on fill so the lowest floor is at or above the 'regulatory flood protection elevation,' defined in Section 21005.02 as at least two feet above the regional flood elevation. Fill must extend that height at least 15 feet beyond the structure's outside limits.
(s)Regulatory Flood Protection Elevation: The elevation to which uses regulated by this Chapter are required to be elevated or floodproofed. The regulatory flood protection elevation shall be an elevation not less than two feet above the elevation of the regional flood. ... All structures, including accessory structures, shall be elevated on fill so that the lowest floor, as defined, is at or above the regulatory flood protection elevation. The finished fill elevation for structures shall be no lower than one foot below the regulatory flood protection elevation and the fill shall extend at the same elevation at least 15 feet beyond the outside limits of the structure.
Full Breakdown
Plymouth's Floodplain Overlay District, codified at Section 21660 of the Zoning Ordinance and adopted to keep the City eligible for the National Flood Insurance Program, sets the elevation a building must reach to be built in a mapped flood area. 02, defines the 'regulatory flood protection elevation' as at least two feet of freeboard above the regional (one-percent-annual-chance) flood elevation, a margin used throughout the floodplain regulations. 06, Subd. 1(b)(1) requires all structures, including accessory structures, to be elevated on fill so the lowest floor sits at or above that regulatory flood protection elevation, with the fill's finished elevation no lower than one foot below that same elevation and extending at least 15 feet beyond the structure's outside limits.
Accessory structures may floodproof instead of filling, using FP1 through FP4 classifications in the Minnesota State Building Code, provided they stay under 576 square feet. 04, Subd. 5 and 6. 08 and requires certification by a registered engineer, architect or surveyor that finished fill and building elevations comply with the ordinance. 08, Subd. 3(b). 10.
Violations & Fines
Building or substantially improving a structure in Plymouth's Flood Fringe District with its lowest floor below the regulatory flood protection elevation, at least two feet above the regional flood, violates Section 21660.06, Subd. 1(b)(1). The Zoning Administrator enforces the Floodplain Overlay District, and any violation, including an elevation shortfall, is a misdemeanor under Section 21660.10; no variance may authorize a lower elevation.
Frequently Asked Questions
How high above flood level must a Plymouth home be built?
Can an accessory structure skip the fill requirement in Plymouth's floodplain?
Can I get a variance to build below the required flood elevation?
Sources & Official References
Other rules in Plymouth
Compare Plymouth to another location·View the Minnesota environmental rules overview
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Flood Elevation Requirements in Nearby Cities
How other cities in Hennepin County handle flood elevation requirements.