Memphis, TN Environmental Rules: Flood Elevation Requirements (2026)

Sub-Section 8.8.5.B.1.a of the Memphis and Shelby County Unified Development Code sets the local freeboard standard for residential buildings: "Where base flood elevation data is available, new construction or substantial improvement of any residential building (or manufactured home) shall have the lowest floor, including basement, elevated no lower than 24 inches above the base flood elevation." That two-foot freeboard applies on top of the mapped BFE, and if solid perimeter walls are used to elevate the structure, the code requires flood-vent openings sized to equalize hydrostatic pressure on both sides of the walls.

Nonresidential buildings face the identical 24-inch standard under Sub-Section 8.8.5.B.2.a, though owners may flood-proof rather than elevate if a registered engineer or architect certifies the design meets accepted watertight construction standards. Where the property sits in an unnumbered A zone and no BFE has been established, Sub-Section 8.8.5.B.1.b shifts the benchmark: the Administrator must require the lowest floor elevated or floodproofed to at least three feet above the highest adjacent grade, with "lowest floor" and "highest adjacent grade" defined in Section 12.3.3. Manufactured homes placed in existing manufactured-home parks follow the same split standard under Sub-Section 8.8.5.B.4.b: 24 inches above BFE where available, or three feet above the highest adjacent grade on reinforced piers where it is not.

All elevation or floodproofing certifications must be prepared by a registered land surveyor, engineer or architect and recorded with the Administrator under Sub-Section 8.8.4.B before further work can proceed.