(a) The presidents of the boards of supervisors of each county and the mayors of each city within the region electing to associate as a member of the district, each to serve a term concurrent with their respective elective terms of office. In event of the inability of the president of the board of supervisors or a mayor of a city to attend any meeting, he may designate in writing any other member of the board of supervisors or the governing body of such city to attend such meeting, and to vote for and on behalf of such county or city.

(b) Three members to be appointed by the Governor from qualified electors within the region. The initial appointment of one member shall be for a period of one year, one member for a period of two years, and the third member for a period of three years. Thereafter, all such appointments shall be for a period of four years. Each appointment shall be made from a list of at least three qualified persons submitted to the Governor by the elected official members of the governing body at least thirty days prior to the vacancy.

(c) Four members from the qualified electors in the region to be appointed by a vote of two-thirds (⅔) of the governing body of the district. However, at no time shall the number of appointive members of the district as provided in subsections (b) and (c) of this section be greater than the number of cities and counties then associated with the district. The initial appointment of one member shall be for a period of one year, one member for a period of two years, one member for a period of three years and one member for a period of four years. Thereafter, all such appointments shall be for a period of four years.

(d) The governing body of the district may, in its discretion, designate and appoint ex-officio and nonvoting members to the governing body of the district from such public agencies within the region as the governing body of the district may deem desirable.