When an assessment for improvements as provided in section 468.126, exceeds twenty-five percent of the original assessment and the original or subsequent assessment or report of the benefit commission as confirmed did not designate separately the amount each tract should pay for the main ditch and tile lateral drains then the board shall order a reclassification in accordance with the principles and rules set forth in section 468.41.
Iowa Code § 468.131
89 Acts, ch 126, §2