Ala. Code § 11-43B-27

All laws relating to the school board, library board, hospital board, airport board, industrial development boards or authorities, housing authorities, medical clinic boards, plumbers or electricians boards or other technical boards, planning commission, board of adjustment, any municipally owned service enterprise, and any board, authority, agency, etc., given such independent status, as the same may apply and be in effect at the time when the municipality shall elect to be governed by the provisions of this chapter, shall continue in full force and effect and without interruption or change as to the establishment or conduct of any such authority, board, or agency until otherwise provided by law.