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

19 of the Jackson County Zoning Ordinance creates the F- Flood Plain District over land subject to periodic or occasional inundation from stream overflow and tide, based on the base (100-year) flood shown on the Flood Insurance Rate Maps (DFIRMs) the Board of Supervisors adopted in 2009. 19 makes the district permit-only: no use is allowed in the Flood Plain District except one approved through a special use permit, and the Board of Supervisors, after Planning Commission review, can attach conditions covering waste disposal and water supply modifications, limits on periods of use, deed restrictions, channel modifications, dikes and levees, and floodproofing.

Floodproofing measures such as anchoring against flotation, watertight doors and bulkheads, wall reinforcement, water-resistant paints or membranes, added mass to resist flotation, sump pumps, protected water and waste systems, and elevated electrical equipment must be designed consistent with the flood protection elevation for the site, factoring in flood velocities, duration, rate of rise, and hydrostatic and hydrodynamic forces tied to the base flood. Critically, the applicant must submit a plan certified by a registered professional engineer or architect confirming the floodproofing is consistent with the base flood factors for that particular area before the county will approve it.

The ordinance separately defines Regulatory Flood Protection Elevation, or Base Flood Level, as the elevation to which regulated structures and uses must be elevated or floodproofed. 01(q) adds a construction-oversight layer: anyone building in a VE (Velocity) flood zone or floodway must use a licensed contractor to pull a building permit, while self-contractor permits remain available in every other flood zone.