The boundaries of the subdistricts shall be drawn in such a manner that each shall contain approximately an equal number of voters, except that no municipality shall contain more than two (2) subdistricts, nor shall any municipality be divided unless it shall comprise more than one (1) subdistrict. Should the district as finally constituted comprise a smaller area than originally proposed because of the failure of one or more election units or municipalities to approve the district at the election, then at the first meeting of the board of directors the boundaries of the subdistricts shall be redetermined so as to conform to the terms hereof.