Iowa Code § 468.633: Lost or incomplete records.

If the records referred to in section 468.632 are incomplete or have been lost, the board may reestablish such records so as to proportion future costs and damages in proportion to the benefits and damages received because of the construction of such mutual drains and improvements thereof, and may order such surveys, engineering reports, reclassification of lands and appraisal of damages as they deem necessary. All costs of such proceedings shall be assessed against the benefited lands.