The members of the Commission shall be appointed by the Mayor and confirmed (four affirmative votes) by Council. Three of the members first appointed under this section shall serve for terms of one year, three for terms of three years, and three for terms of five years, respectively, from the date of the approval of this section and until their respective successors have been duly appointed. Appointments of successors, in each case, will be for a period of five years. Any vacancy occurring otherwise than by expiration of term shall be filled for the unexpired term in the same manner as original appointments. An ex-officio member representing the Public Works Department will be designated by the Mayor and an ex-officio member representing Council will be appointed via resolution.