Smyrna, GA Environmental Rules: Flood Elevation Requirements (2026)

The elevation rule sits in Sec. 54-62, Specific standards, in Article III of Chapter 54. Wherever base flood elevation data are available in an area of special flood hazard, new construction or substantial improvement of any structure or manufactured home must have the lowest floor, including basement, elevated no lower than three feet above the base flood elevation. The Code defines base flood as the flood with a one percent chance of being equaled or exceeded in any given year, so the three-foot freeboard margin sits on top of that flood level.

Nonresidential buildings in A1-30, AE or AH zones have an alternative: flood-proofing in lieu of elevation. The structure and its utility and sanitary facilities must be designed water tight to three feet above the base flood elevation, and a registered professional engineer or architect must certify the design (Sec. 54-62(2)). Manufactured homes get the same three-foot rule under Sec. 54-62(3). In an existing manufactured home park, a home can instead sit with its chassis supported by reinforced piers of no less than 36 inches in height above grade. Recreational vehicles must be licensed and ready for highway use, or meet the new-construction anchoring and elevation requirements.

The paperwork tracks the number. The permit application must show the elevation of the lowest floor in relation to mean sea level or highest adjacent grade (Sec. 54-37(1)), and once the lowest floor is complete the permit holder must provide an as-built certification prepared by a registered land surveyor or professional engineer. The city engineer verifies and records the actual elevation (Sec. 54-38(4)).

Fully enclosed space below the lowest floor needs at least two openings with a total net area of not less than one square inch for every square foot of enclosed area, with the bottom of every opening no higher than one foot above grade. That space is limited to parking of vehicles, limited storage of maintenance equipment, or entry to the elevated area, and it cannot be partitioned or finished into rooms (Sec. 54-61(4)).