Whenever any municipality pursuant to an act of the legislature has adopted an ordinance for any of the purposes covered in R.S. 33:4721 through R.S. 33:4729, the ordinance shall be deemed to have been adopted under R.S. 33:4721 through R.S. 33:4729, and it shall not be necessary in such cases for the local legislative body to appoint a zoning commission as herein provided. All such ordinances shall remain in effect, except so far as they are inconsistent with R.S. 33:4721 through R.S. 33:4729, until they shall have been amended, altered or repealed by the legislative body.
La. R.S. § 33:4730