Iowa Code § 468.206: Notice and hearing.

If upon consideration of the plan or amended plan and the report or reports of the engineer and the commitments involved in the adoption of the plan the board finds that the district will benefit therefrom or the purposes for which the district was established will be promoted thereby, the board shall adopt the same as a tentative plan, enter an order to that effect, and fix a date for hearing thereon not less than thirty days thereafter and direct the auditor to cause notice to be given of such hearing as provided in section 468.207.