(a) There shall be held an election annually on the first Monday in May in all combination levee and drainage districts where the boundaries of the districts embrace all of the lands within the corporate limits of a city of the first class and no lands situated more than three (3) miles from the corporate limits, for the election of one (1) member of the board of improvement. The judges of the election are to be appointed by the county board of election commissioners.
(b)
(1) The improvement district commissioners shall be elected for terms of three (3) years, one (1) commissioner to be elected each year.
(2)
(A) The commissioners of the districts as constituted on February 6, 1939, shall hold office according to seniority. The oldest commissioner in point of service shall hold office for three (3) years; the next commissioner in point of service shall hold office for two (2) years; and the last elected or appointed commissioner shall serve for one (1) year, or until their successors are elected and qualified.
(B) All of these terms begin from the first Monday in May, 1939.
(c) If for any cause a vacancy occurs on the board of commissioners, then the remaining two (2) commissioners shall fill the vacancy by the appointment of some person qualified to serve.