Franklin County, OH Environmental Rules: Flood Elevation Requirements (2026)
Key Facts
- Freeboard required
- 1 foot above BFE
- Plus
- 0.0-0.5 ft floodway increase
- Certification
- Registered engineer or architect
- Floodway residential building
- Prohibited
Summary
New homes in Franklin County's floodplain must set their lowest floor at least one foot above the base flood elevation, plus any floodway computation increase.
Flood protection shall be achieved by elevating the building. Buildings shall not be permitted with floor levels below the base flood elevation. The lowest floor, including basement, shall be at least one (1) foot above the Base Flood Elevation, plus Floodway computation increases. Floodway computation increases range from 0.0 to 0.5 feet and are listed in the Flood Insurance Study published by FEMA and available at the Franklin County Development Department.
All structural, site and/or grading plans for residential development activities in the floodplain shall be prepared and sealed by a registered professional engineer and/or architect.
The applicant shall obtain and furnish to the Community NFIP Administrator as-built elevations, (certified by a Registered Surveyor), of the basement and first floor, to be maintained on file for public inspection.
No residential buildings and/or structures shall be located in the Floodway portion of the Floodplain.
Full Breakdown
Franklin County Zoning Resolution § 610.081 requires new residential construction in the Regulatory Floodplain District to achieve flood protection by elevation: the lowest floor, including any basement, must sit at least one foot above the Base Flood Elevation, plus floodway computation increases of 0.0 to 0.5 feet from FEMA's Flood Insurance Study. A registered engineer or architect must certify site and grading plans, and no residential structure may be placed in the Floodway itself. The district applies to special flood hazard areas within unincorporated Franklin County.
Violations & Fines
Building a residence with its lowest floor below the required one-foot freeboard, or placing any residential structure in the Floodway, violates § 610.081 and can block issuance of a zoning certificate.
Frequently Asked Questions
How high above the base flood elevation must a new home be built?
Can I build a house in the Floodway?
Sources & Official References
Other rules in Franklin County
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