St. Tammany Parish, LA Hurricane Preparedness: Flood Elevation (2026)

The parish's Unified Development Code ties minimum floor height to the FEMA flood zone printed on the property's panel. In an unnumbered "X" or "D" zone, the lowest habitable floor must sit at least 12 inches above the centerline of the street or the top of curb fronting the lot, whichever reading is higher. In an unnumbered "A" or "AO" zone the floor must clear the base flood elevation set by the Parish Flood Plain Administrator by 12 inches, and in a numbered "A," "AE," or "AH" zone it must clear the base flood elevation from the Flood Insurance Study by the same 12 inches. Coastal "V" and "VE" zones are measured differently: the bottom of the lowest horizontal structural member, not the floor, must clear the base flood elevation by 12 inches. Commercial buildings that choose dry floodproofing instead of elevating must add a full additional foot on top of whichever zone standard applies.

Fill has its own ceiling. On a residential lot narrower than 90 feet in an A, AE, AO, AH, X, or D zone, a builder may raise the pad with fill up to 24 inches; anything higher requires piers, posts, piles, or a stem wall instead. Fill is barred outright for elevating a structure in a V, VE, or VO zone. Elevations are referenced to the NAVD88 vertical datum.

Compliance is checked three separate times under Sec. 300-5.4: a "construction drawing" elevation certificate before the Permitting Department issues the building permit, a "Building Under Construction" certificate after the foundation forms are set but before the pour (or before framing on an elevated home), and a "Finished Construction" certificate after the structure is complete but before a certificate of occupancy is issued. The Director of the Permitting Department can approve a lower elevation where existing topography makes matching the street grade impractical or would harm neighboring drainage, or approve fill above 24 inches where a subdivision has an approved fill plan.