Iowa Code § 161A.17: Subdistrict in more than one district.

If the proposed subdistrict lies in more than one soil and water conservation district, the petition may be presented to the commissioners of any one of such districts, and the commissioners of all such districts shall act jointly as a board of commissioners with respect to all matters concerning the subdistrict, including its formation. They shall organize as a single board for such purposes and shall designate its chairperson, vice chairperson, and secretary-treasurer to serve for terms of one year. Such a subdistrict shall be formed in the same manner and has the same powers and duties as a subdistrict formed in one soil and water conservation district.