Gulfport, MS Environmental Rules: Flood Zones (2026)

Gulfport sits on the Mississippi Gulf Coast and is one of the most flood-exposed cities in the state. Hurricane Katrina (Aug. 29, 2005) produced a record 28-foot storm surge that pushed the floodplain inland past the historic 100-year and 500-year boundaries. After Katrina the city adopted the revised DFIRM and overhauled Appendix B - Flood Damage Prevention of the Code of Ordinances, which is the city's stand-alone floodplain management chapter. Appendix B requires a floodplain development permit for any construction, fill, or substantial improvement in a Special Flood Hazard Area (SFHA). For new construction and substantial improvements in A-zones (riverine/inland) the top of the lowest floor must be at or above Base Flood Elevation plus the city's freeboard (Gulfport applies at minimum 1 foot of freeboard, consistent with neighboring Mississippi Gulf Coast jurisdictions and Harrison County's post-Katrina 2-foot freeboard for the unincorporated areas). In V-zones (coastal high-hazard, subject to wave action) the bottom of the lowest horizontal structural member must be at or above BFE plus the city's freeboard, and structures must be on open piles or columns with breakaway walls below. The substantial improvement / substantial damage threshold (50% of pre-improvement market value) under 44 CFR §59.1 / §60.3 triggers full compliance with current elevation rules. Elevation Certificates (FEMA Form 086-0-33) are required at permit application and post-construction. Fill is restricted in floodways. New structures in V zones may not be constructed seaward of mean high tide. Flood damage repairs require a permit, and post-FIRM elevated structures must also obtain a permit before repair work. Permit review and floodplain administration are handled by the Gulfport Urban Development Department / Building Code Services, (228) 868-5700, 311@gulfport-ms.gov. Federal law: National Flood Insurance Act, 42 U.S.C. §4001 et seq.; 44 CFR Parts 59-60. State enabling: Miss. Code Ann. §17-1-1 et seq. (zoning) and §17-2-1 et seq. (building codes).