Iowa Code § 161A.19: Governing body.

The commissioners of a soil and water conservation district in which the subdistrict is formed are the governing body of the subdistrict. When a subdistrict lies in more than one soil and water conservation district, the combined board of commissioners is the governing body. The governing body of the subdistrict shall appoint three trustees living within the subdistrict to assist with the administration of the subdistrict.