Iowa Code Title IX. Local Government [Chs. 331-420] § 357.30. Additional territory

If a district is under the control of trustees, the trustees are empowered to deal with parties without the district who desire to be taken into the district or to obtain water from the district. The trustees shall determine the amount to be assessed against the territory to be taken in or connected with the district. The trustees shall have power in such cases to make agreements for the district, and may, with the consent of the board of supervisors, alter the district boundaries to take in the additional territory. If an owner of a lot or parcel has paid any assessment to a district, the lot or parcel of land shall not be put out of the district without the consent of the owner.