When a metropolitan district is organized in more than one county, each county shall be represented by a certain number of board members. The distribution of board members shall reflect such factors as the intent and purpose of the district, each county’s interest in the district, each county’s population, each county’s financial contribution to the district, the amount and quality of land dedicated to metropolitan district use in each county, the existing and planned locations of district improvements and organizational efficiency. The board members shall be distributed as follows:

(1) Until January 1, 2012:

(a) Any constitutional charter city not within a county shall appoint three board members;

(b) Any county of the first classification with a charter form of government having a population of more than two hundred ten thousand but less than three hundred thousand inhabitants and any county of the first classification having a population of more than one hundred seventy thousand but less than one hundred seventy-five thousand inhabitants shall each appoint two members;

(c) Any county other than those described in paragraphs (a) and (b) of this subdivision which does not have a population of at least nine hundred thousand inhabitants shall appoint one member;

(d) Any county of the first classification with a charter form of government having a population of at least nine hundred thousand inhabitants shall appoint a number of board members equal to the total number of members appointed by all other political subdivisions with authority to appoint board members in such metropolitan district combined, and no two board members from such county shall be members of the same county council district of such county until one board member has been selected from each county council district;

(e) Any new county entering the metropolitan district shall, along with any county described in paragraph (d) of this subdivision, appoint the appropriate number of new board members pursuant to this subdivision as soon as practicable after the date of entrance of such new county into the metropolitan district, provided that such appointment shall be made on or before the date of the second board of directors’ meeting after such county’s entrance;

(2) As of January 1, 2012, and every ten years thereafter, the allocation of the board of directors shall be determined by the executive of each member county, except that no two board members from any county of the first classification with a charter form of government and having a population of at least nine hundred thousand inhabitants shall be residents of the same county council district of such county until one board member has been selected from each county council district. During the period between September 1, 2011, and January 1, 2012, and during an identical period every ten years after such initial period, the executives of each member county shall meet to determine the appropriate allocation of board members among the counties, including addressing the allocation of staggered terms among the various counties and taking into account the factors set forth in this section. If the executives are unable to agree on an appropriate allocation, then the matter shall be submitted to binding arbitration. Such arbitration shall be conducted by three persons selected by lot from the roster of qualified commercial arbitrators in the eastern district of Missouri maintained by the American Arbitration Association. The decision of the arbitrators shall be rendered before January 1, 2012, or before January first of the appropriate ten-year period thereafter. If, as a result of the reallocation provided by this subdivision, any county loses members on the board, the executive of such county shall designate which board member or members from such county shall resign. If, as a result of the reallocation provided by this subdivision, a county gains members on the board, the executive of such county shall appoint additional board members with the advice and consent of the governing body of such county.