Ouachita Parish, LA Environmental Rules: Flood Zones (2026)

Article III of Chapter 21, Storm Drainage and Flood Control, applies to all areas of special flood hazard in Ouachita Parish that fall within the police jury's jurisdiction and outside the corporate limits of incorporated municipalities (Sec. 21-75); Monroe, West Monroe and Sterlington administer their own flood ordinances. Sec. 21-102(a) requires a development permit before any construction or development begins in an area of special flood hazard identified on the parish's FEMA maps, and the application must show the site's elevations, existing and proposed structures, watercourses, fill and drainage facilities, plus the lowest-floor elevation of every structure and, for floodproofed buildings, an engineer's certification.

The program administrator, appointed under Sec. 21-101, checks each application against factors listed in Sec. 21-102(d), including the danger to life and property from flooding, whether materials could wash onto other land, and the safety of emergency access, and Sec. 21-101(b)(10) bars new construction, fill or substantial improvement in an undesignated Zone A1-30 or AE floodway unless it is shown the cumulative effect will not raise the base flood elevation more than one foot. Encroachment into a mapped floodway is flatly prohibited under Sec. 21-119 unless a technical study proves no increase in flood levels, and mobile homes may never be placed in a floodway. Variances go to the program administrator first, with appeals to the Ouachita Parish Police Jury and, beyond that, to the courts (Sec. 21-103).