Jackson, MS Environmental Rules: Flood Elevation Requirements (2026)

Chapter 62's flood-damage-prevention ordinance, most recently amended by Ord. No. 2025-36(6) on October 7, 2025, layers elevation standards by flood-zone type. The city-wide baseline comes from § 62-42, which requires new construction and substantial improvement of residential and non-residential buildings in mapped AE zones to keep the lowest floor at or above the base flood elevation shown on the Hinds County and Rankin County flood insurance rate maps adopted by reference at § 62-12. For the shallow-flooding AO/AH zones addressed at § 62-44, where 'flood hazards [are] associated with base flood depths of one to three feet' and 'a clearly defined channel does not exist,' the ordinance adds a specific freeboard formula: the lowest floor, including any basement, must sit at or above the highest adjacent grade at least as high as the FIRM's printed depth number plus a minimum of two feet, or, if the map shows no depth number, no less than three feet six inches above the highest adjacent grade. The same standard applies to non-residential buildings, which may instead be completely floodproofed to that elevation with engineer certification.

A floodplain development permit is required under § 62-14 before any development activity begins in a special flood hazard area, and § 62-42(3) separately bars fill or structures in AE zones without a floodway if a registered engineer cannot certify the project will not raise the base flood water surface more than one foot anywhere in the community. The floodplain administrator verifies and records each building's actual lowest-floor elevation on a FEMA elevation certificate form.