La. Stat. tit. 38 § 1605
No drainage district shall be created until the Department of Public Works shall have first approved the formation of the district with respect to the body of land to be included therein, and shall have furnished the police jury a map approved by the Department of Public Works showing the lands which in the opinion of the department should be included in the drainage district. If in the opinion of the Department of Public Works it is necessary to include in the district any high lands for the purpose of reclaiming the body of unreclaimed lands, the inclusion shall not invalidate the creation of the district or any proceeding taken in connection therewith, but the high lands shall be taxed only in the proportion, if any, as they shall be benefited by the reclamation and drainage works constructed in the district. The department of public works shall examine into and report its opinion or findings, and furnish all maps required to be given, made or furnished by it under the provisions of this Part.
La. R.S. § 38:1605