Lake Charles, LA Environmental Rules: Flood Elevation Requirements (2026)

Section 6-487(b) requires that the minimum floor elevation of every enclosed structure be set one foot above whichever of four measurements is highest: the base flood elevation (BFE) from the latest Calcasieu Parish Flood Insurance Study for hazard areas AE and VE (or, for hazard area A, a site-specific value the Army Corps of Engineers determines after the city applies, with a nine-foot floor if the calculated BFE comes in at nine feet or below); the elevation at the centerline of the nearest street facing or adjacent to the structure (using the lower of two streets on a corner lot); the elevation at the top of the nearest sanitary sewer manhole where a community system exists; or the highest recorded historical or modeled 100-year inundation level, if known.

Subsection (c) applies that minimum floor elevation to 'all enclosed residential or commercial structures/buildings, and any substantial improvements related to the same,' and subsection (d) extends the same floor elevation floor to mechanical equipment and sewerage lift stations. Waivers are available under § 6-487(a) where the freeboard calculation produces an unreasonable elevation, or for detached accessory structures of 1,000 square feet or less with no bathroom or kitchen, and no drainage fee attaches to a freeboard waiver; requests are filed under the general waiver procedure in § 6-488, which requires showing good cause and that granting the waiver will not increase flooding risk to others.

The rule is part of the Article X drainage requirements adopted by Ord. No. 18753 in 2020, alongside general drainage, runoff management, and fill mitigation standards for the same developments.