The reorganized drainage district shall then be subject in all respects to the provisions of this Part, and a plan for reclamation may be prepared as is herein provided, except that the board of commissioners of the reorganized drainage district will not be required to follow the steps or requirements of this Part which are inconsistent with or rendered unnecessary by the work that has already been done prior to reorganization.  The drainage commissioners of any reorganized drainage district may continue the work of reclamation and drainage through any existing sub-drainage district, or sub-drainage districts, or they may if they deem it necessary for the more effective drainage and reclamation of the lands in the reorganized drainage district, consolidate any one or more existing sub-drainage districts with each other, or with other land or lands in the reorganized drainage district, and may cause to be prepared and adopted a plan for reclamation in the manner as provided for by this Part, embracing all or any portion of the lands in the reorganized drainage district, including any one or more existing sub-drainage districts, and may levy taxes against the lands and issue bonds as herein authorized including refunding bonds under La. Rev. Stat. 38:1670 through 38:1673 and, without regard to the boundaries of the previously existing sub-drainage district.  No reorganization of an existing drainage district, or the consolidation of subdrainage districts of a reorganized district, shall have the effect of in any way invalidating any indebtedness, liability, or contract of any nature incurred under the former organization of any reorganized drainage district or any sub-drainage district, but all indebtedness, liability, or contract shall attach to and become the debt and liability of the new organization or of the respective sub-drainage district originally liable, until the indebtedness, liability, or contract is fully paid and discharged.