Iowa Code Title XI. Natural Resources [Chs. 455-485] § 468.573. Parties--notice--service

The board of supervisors of such county or counties wherein the drainage district is located, shall be notified of the proceeding and hearing by original notice served in the same manner as in civil actions; notice of said hearing shall be served upon all owners of each tract of land or lot within such drainage district, as shown by the transfer books in the county auditor's office, upon each lienholder or encumbrancer of any land within the said drainage district as shown by the county records, and upon all persons holding claims against said drainage district, as shown by the county records, and also upon all other persons whom it may concern, including bondholders and actual occupants of the land within said drainage district, without naming individuals, by publication thereof, once each week for two consecutive weeks, in some newspaper of general circulation in the county or counties where said drainage district is located, the last of which publications shall be not less than twenty days prior to the date set for hearing on the said petition and a copy of such notice shall also be sent by ordinary mail to the person's last known address unless there is on file an affidavit of one of the petitioners or the petitioner's attorney stating that no mailing address is known and that diligent inquiry has been made to ascertain it. Such copy of notice shall be mailed not less than twenty days prior to the date set for hearing. Proof of publication and mailing shall be by affidavit and shall be included in the records of the proceedings.