St. Johns County, FL Hurricane Preparedness: Flood Elevation (2026)

A requires any site plan or construction document for development in a Flood Hazard Area to delineate flood zones, floodway boundaries, and base flood elevations, plus ground elevations where needed for review. 4, new buildings proposed in Coastal High Hazard Areas and Coastal A Zones must be located landward of the reach of mean high tide. B requires the applicant to supply elevation data prepared under currently accepted engineering practices, or the Floodplain Administrator obtains that data from a federal or state source. C imposes engineer-certified numeric caps on elevation impact: a Floodway Encroachment Analysis for development in a Regulatory Floodway must show the project causes no increase at all in base flood elevations, and if an applicant instead proposes an increase, the analysis must go to FEMA for a Conditional Letter of Map Revision before development proceeds.

2 caps the cumulative effect of the proposed development, combined with all other existing and anticipated encroachments, at no more than one foot of base flood elevation increase anywhere in the community; that cap does not apply in isolated flood areas unconnected to a riverine system or in Zone AO or Zone AH. D makes the applicant responsible for FEMA's submittal requirements and processing fees if the elevation data is used to seek a Letter of Map Change.