Iowa Code § 468.123
When proceedings have been instituted for the establishment of a drainage district or for any change or repair thereof, or the change of a natural watercourse, and the establishment thereof has failed for any reason either before or after the improvement is completed, the board shall have power to reestablish such district or improvement and any new improvement in connection therewith as recommended by the report of the engineer. As to all lands benefited by such reestablishment, repair, or improvement, the board shall proceed in the same manner as in the establishment of an original district, using as a basis for assessment the entire cost of the proceedings, improvement, and maintenance from the beginning; but in awarding damages and in the assessment of benefits account shall be taken of the amount of damages and taxes, if any, theretofore paid by those benefited, and credit therefor given accordingly. All other proceedings shall be the same as for the original establishment of the district, making of improvements, and assessment of benefits.
Iowa Code § 468.123
89 Acts, ch 126, §2