Iowa Code § 161A.14
When the landowners in a proposed subdistrict desire that a subdistrict be organized, they shall file a petition with the commissioners of the soil and water conservation district. The area must be contiguous and in the same watershed but it shall not include any area located within the boundaries of an incorporated city. The petition shall set forth an intelligible description by congressional subdivision, or otherwise, of the land suggested for inclusion in the subdistrict and shall state whether the special annual tax or special benefit assessments will be used, or whether the use of both is contemplated. The petition shall contain a brief statement giving the reasons for organization, and requesting that the proposed area be organized as a subdistrict, and must be signed by sixty-five percent of the landowners in the proposed subdistrict. Land already in one subdistrict cannot be included in another. The soil and water conservation district commissioners shall review the petition and if it is found adequate shall arrange for a hearing on it.
Iowa Code § 161A.14
87 Acts, ch 23, §23