At the first regular election of any such irrigation district held after the passage of this act [73-10-8, 73-10-9 N.M. Stat. Ann.], directors from odd-numbered divisions of any such district shall be elected for a term of two years each, and directors from even-numbered divisions for a term of four years each. At each succeeding biannual [biennial] election for directors, after the first held hereafter, successors to the directors whose terms expire that year shall be elected for a term of four years each.