La. Stat. tit. 38 § 1992
Nothing in this Part shall be construed as abridging or affecting in any respect and there is hereby specially reserved to the parishes of Ouachita, Morehouse, and Richland and the property owners and the resident landowners of the parishes, and any part thereof, the right to organize, create, and maintain drainage districts and subdrainage districts, with all the privileges, powers, authority, and functions provided and conferred by the Constitution and general laws of Louisiana on the subject. Nothing in this Part shall be construed as abridging or affecting in any respect the right of either of the parishes acting in the interest of the property owners of the parish to refuse to join in and become a part of the levee and drainage district.
La. R.S. § 38:1992