La. Stat. tit. 38 § 1668
When any existing drainage district or districts have been reorganized, and a board of commissioners has been appointed and qualified, the board shall employ a chief engineer, and thereafter all proceedings relative to the reclamation, assessment, taxation, and maintenance of the lands of the reorganized drainage district shall be had as provided in this Part in the case of a new district. The engineer of the reorganized drainage district in preparing the plan for reclamation thereof, or of any sub-district thereof, shall prepare a plan that will afford complete and entire reclamation and drainage of the district or sub-district, and which will provide for the completion of any work of reclamation or drainage undertaken prior to reorganization, as well as the restoration, enlargement or improvement of any works theretofore constructed, or the construction of new works.
La. R.S. § 38:1668