Tenn. Code Ann. § 7-1-110

Any city or county office, department, board, commission, agency or function established by private act prior to the adoption of a metropolitan form of government may be altered, consolidated or abolished by ordinance of the chief legislative body of the metropolitan government if the charter of the metropolitan government does not otherwise provide for the office, department, board, commission, agency or function, and such alteration, consolidation or abolition is not otherwise prohibited by chapters 1-6 of this title or the Constitution of Tennessee.