Vacancies shall be filled in the same manner in which regular appointments are required to be made. If the ninth member resigns prior to the expiration of the term, the individual appointed to fill the vacancy shall meet the requirements for the ninth member specified in section 262.1. Other vacancies occurring prior to the expiration of the ninth member's term shall be filled in the same manner as the original appointments for those vacancies.
Iowa Code § 262.6
88 Acts, ch 1260, §2