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

10 lets the Board of County Commissioners, on recommendation of the county engineer, control subdivision development on any property lying within the one-hundred-year floodplain of a river, lake, stream or other drainage course when necessary for public health, safety, welfare or environmental conservation. Subsection A sets the county's own numeric freeboard for flood-prone subdivisions: minimum floor elevations must be at least one foot above the proposed 100-year flood elevation, and garage floor elevations must be at least half a foot above that same elevation. The same subsection sets an interim minimum centerline roadway elevation of six inches above the design high water level, calculated for a one-in-fifty-year storm under the Department of Transportation drainage manual, wherever the county has not yet established a permanent roadway elevation.

Subsection B lets the county commission designate a building restriction line on land found unsuitable for development because of flooding, erosive stream action, or unstabilized slope or fill. 06(E) separately requires all building construction to comply with FEMA regulations and directs applicants to demonstrate on-site containment of a typical 100-year storm's runoff through a licensed engineer's grading plan, with an exception available from the county engineer where existing topography would require extensive re-grading.