If a proposal for formation of a district is approved and the proposal specifies an appointed district board of commissioners, the county court shall appoint three persons with the qualifications described in ORS 371.338 (1) to be the first commissioners of the district and shall designate the term of office of each. [Amended by 1961 c.681 §2; 1965 c.498 §6; 1971 c.727 §102; 1999 c.764 §3]