S.C. Code Ann. § 23-21-20: Election of members of board.

The first election may be held at the first meeting of the mayor and aldermen elected to succeed the mayor and aldermen of any such city in office at the time of the decision to establish such board. At such election one member of the board shall be elected to serve one year, one to serve two years, one to serve three years and one to serve four years and thereafter one member of the board shall be elected annually to serve for four years.