The appraisers shall proceed in the same manner and make return of their findings and appraisement the same as when the district is wholly within one county, except that a duplicate thereof shall be filed in the auditor's office of each of the several counties. After the filing of the report of the appraisers, all further proceedings shall be the same as where the district is wholly within one county, except as otherwise provided.
Iowa Code § 468.280
Procedure, §468.24 et seq.