Cherokee County, SC Environmental Rules: Flood Elevation Requirements (2026)

The lowest-floor rule sits in § 8-142 of the Cherokee County Code, which applies in zones A, AE, AH, AO, A1-30, V and VE where base flood elevation data has been provided. Every new residential structure and every substantial improvement, manufactured homes included, must have its lowest floor elevated no lower than three (3) feet above the base flood elevation. Nonresidential structures follow the same three-foot standard, and no basements are permitted for either type. Nonresidential structures in A-zones can be floodproofed in lieu of elevation if everything below the required elevation is watertight; a registered professional engineer or architect must certify it, and floodproofed structures need an approved maintenance plan with an annual exercise.

The article defines freeboard as a factor of safety expressed in feet above a flood level; the required margin here is the three feet printed in § 8-142. Manufactured homes outside parks, in new parks, in expansions, or in existing parks after substantial flood damage sit on a permanent foundation with the lowest floor three feet above base flood elevation. When the chassis elevation is thirty-six (36) inches or less above grade, reinforced piers or an engineered foundation support it, and above thirty-six inches an engineering certification is required (§ 8-142(3)). Shallow flooding AO zones use the depth number on the flood insurance rate map, in feet, above the highest adjacent grade, or three feet if no depth number is specified (§ 8-145). Fully enclosed areas below the lowest floor need at least two openings on different walls with not less than one (1) square inch of net area for every square foot of enclosed area, and the bottom of each opening no more than one (1) foot above grade (§ 8-142(4)).

Verification happens during construction. Section 8-133(2)(b) requires the permit holder to submit a certification of the as-built lowest floor elevation, in relation to mean sea level, prepared by or under the supervision of a registered land surveyor or professional engineer, as soon as possible after the lowest floor is completed and before any further vertical construction. A substantial improvement is work that equals or exceeds fifty (50) percent of the structure's market value, counted cumulatively over five (5) years (§ 8-134(18)).