Olive Branch, MS Environmental Rules: Flood Zones (2026)

Olive Branch enforces floodplain rules through Chapter 30 - Floods of the Code of Ordinances, administered alongside Appendix A Zoning and the 2018 IBC/IRC. The applicable maps are FEMA's countywide DeSoto County, Mississippi Digital Flood Insurance Rate Maps and Flood Insurance Study, with effective date May 5, 2014, replacing the prior September 2005 study. The city is in northern DeSoto County with the Coldwater River, Cow Pen Creek, and Camp Creek as the principal drainages. Chapter 30 implements the federal minimum standards in 44 CFR §60.3: a floodplain development permit is required for any development (including filling, grading, paving, mining, drilling, and structures) in a Special Flood Hazard Area (SFHA, Zone A/AE/AH/AO); new residential construction and substantial improvements must elevate the lowest floor to or above Base Flood Elevation (BFE); non-residential structures may be elevated or floodproofed; manufactured homes in SFHAs require permanent foundations and elevation; encroachments in regulatory floodways are barred unless a no-rise certification is provided. The substantial improvement / substantial damage threshold under 44 CFR §59.1 is 50 percent of pre-improvement market value, which triggers full compliance for repairs or remodels. Elevation Certificates (FEMA Form 086-0-33) are required at permit application and post-construction. The Floodplain Administrator function is housed in the Building Department (662-892-9333) / Planning and Development (662-892-9339). Federal law: National Flood Insurance Act, 42 U.S.C. §4001 et seq.; 44 CFR Parts 59-60. State enabling: Miss. Code Ann. §17-1-3 et seq. (zoning) and §17-25-21 (drainage districts). Mississippi Emergency Management Agency (MEMA) is the state NFIP coordinator; FEMA Region 4 oversees Mississippi.