La. Stat. tit. 38 § 1802
The provisions of this Part shall apply to gravity drainage or sub-drainage districts authorized to be created under Article XIV of the Constitution of 1921, and created or reorganized under its provisions; and shall not apply to any drainage district created under Article XV of the Constitution of 1921, except as herein otherwise provided in R.S. 38:1801. This Part shall be considered as the general law governing gravity drainage districts or gravity sub-drainage districts under which they must organize in the future. But all laws or parts of laws, general or special, appertaining to drainage or subdrainage districts shall remain in force as to the drainage or subdrainage districts now existing, which are not reorganized under the provisions of this Part.
La. R.S. § 38:1802