Iowa Code § 468.284
Upon the filing of the report of the commissioners to classify lands, fix and assess benefits and apportion costs and expenses, the auditors of the several counties, acting jointly, shall cause notice to be served upon all interested parties of the time when and the place where the boards will meet and consider such report and make a final assessment of benefits and apportionment of costs, which notice shall be the same and served for the time and in the manner and all proceedings thereon shall be the same as provided in subchapter I, parts 1 through 5, in districts wholly within one county, except publication of notice as provided in section 468.15 shall be in each of the counties into which the district extends, and also except that said notice to be published in each of the several counties shall contain only the names of the owners of each tract of land or lot in the district located within the respective county in which said notice is to be published and the total amount of all proposed assessments on the lands located in each of the other counties into which the district extends, and except further that the objections not filed prior to the date of the hearing shall be filed with the boards at the time and place of such hearing.
Iowa Code § 468.284
89 Acts, ch 126, §2