Franklin County, FL Environmental Rules: Flood Elevation Requirements (2026)

5, handles parcels in flood hazard areas delineated on the Flood Insurance Rate Map where FEMA has not supplied a numeric base flood elevation, commonly called approximate Zone A. The Floodplain Administrator has several options: require the applicant to submit base flood elevation data developed under accepted engineering practice; obtain and hand the applicant elevation and floodway data already available from a federal or state agency; or, where no outside data exists or the available data is unreliable or technically wrong, either demand an engineered elevation study or simply set the base flood elevation at two feet above the highest adjacent grade at the development site, so long as no evidence points to deeper flooding there.

If that data will support a FEMA letter of map change, the applicant's analysis must be signed and sealed by a Florida-licensed engineer in FEMA's required format, and the applicant bears the submittal and processing fees. This default two-foot rule lets small, common projects, an addition, a shed, a rebuilt dock support, move forward without commissioning a full engineering study on the many unincorporated Franklin County parcels along the Apalachicola River and Bay, East Bay, St. George Sound, Alligator Harbor, and the Ochlockonee River and Bay that sit in unnumbered A zones on the county's maps.