Basic Floodplain Permitting Requirements
- A state and local floodplain permit is required for all construction activity in the Special Flood Hazard Area (SFHA) or that area inundated by the 1-percent annual chance flood. These SFHAs are designated as A, AE, A1-A30, AH or AO zones on the FIRMs (Flood Insurance Rate Maps). This includes new or substantially improved residential and nonresidential (commercial) structures, filling, excavation and bridges.
- Local floodplain ordinances may be more stringent than state and federal regulations.
- No new residential structures may be constructed in the floodway.
- Nothing may be placed within a floodway that will cause any rise in Base Flood Elevation (BFE). The BFE is defined as the water surface elevation inundated by the 1-percent annual chance flood. An engineering analysis is required.
Residential Development/Substantial Improvement in Special Flood Hazard Areas (A Zones)
- The lowest floor of any new or substantially improved structure (including basement) must be elevated to or above the BFE.
- Fully enclosed areas below the lowest floor require at least a minimum of two openings, having a total net area of not less than 1 square inch per square foot of enclosed area. The bottom of the openings shall be no higher than 1 foot above grade.
- The applicant must submit an Elevation Certificate to the floodplain administrator when the building foundation is complete.
- GENERAL NOTE: No variances granted.
Manufactured Homes in Special Flood Hazard Areas (A Zones)
- For a manufactured home outside of an existing manufactured home park or subdivision, the requirements are the same as for site-built homes. Manufactured homes must be anchored to a permanent foundation.
- Within an existing manufactured home park or subdivision the community has the option of either requiring the home to be elevated at or above the BFE; or have the home elevated on reinforced concrete piers, blocks, etc., to at least 36 inches above grade.
- In the event of substantial damage (over 50 percent of pre-damage value), a replacement manufactured home must be elevated to or above the BFE.
- If a pre-FIRM (Flood Insurance Rate Map) manufactured home is moved at the onset of a flood event and moved back after the water recedes, it may be replaced at the same elevation. NOTE: The manufactured home must be the same home that was previously moved and placed in the original building footprint.
Nonresidential Development in Special Flood Hazard Areas (A Zones)
- The building must be elevated; in lieu of elevation, the building may be floodproofed to a minimum of 1 foot above the BFE.
- If floodproofed, the applicant must submit an "as built" Floodproofing Certificate certified by a professional engineer or architect.
- Variances may be issued for the repair or rehabilitation of historic homes upon determination that the proposed repair or rehabilitation will not preclude the structure's continued designation as a historic structure and the variance is the minimum to preserve the historic character and design of the structure.
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