1.    Only a landowner experiencing flooding or adverse effects from an unauthorized drain constructed before January 1, 1975, may file a complaint with the water resource board. Any person may file a complaint about an unauthorized drain constructed after     January 1, 1975. Upon receipt of a complaint of unauthorized drainage, the water resource board shall promptly investigate and make a determination of the facts with respect to the complaint. If the board determines that a drain, lateral drain, or ditch has been opened or established by a landowner or tenant contrary to this title or any rules adopted by the board, the board shall notify the landowner by certified mail at the landowner’s post-office address of record. A copy of the notice must also be sent to the tenant, if known. The notice must specify the nature and extent of the noncompliance and must state that if the drain, lateral drain, or ditch is not closed or filled within a reasonable time as the board determines, but not less than fifteen days, the board shall procure the closing or filling of the drain, lateral drain, or ditch and assess the cost of the closing or filling, or the portion the board determines, against the property of the landowner responsible. The notice must also state that the affected landowner, within fifteen days of the date the notice is mailed, may demand, in writing, a hearing on the matter. Upon receipt of the demand, the board shall set a hearing date within fifteen days from the date the demand is received. In the event of an emergency, the board may immediately apply to the appropriate district court for an injunction prohibiting the landowner or tenant from constructing or maintaining the drain, lateral drain, or ditch and ordering the closure of the illegal drain. Assessments levied under this section must be collected in the same manner as assessments authorized by chapter 61-16.1. If, in the opinion of the board, more than one landowner or tenant has been responsible, the costs may be assessed on a pro rata basis in proportion to the responsibility of the landowners. If a complaint is frivolous in the discretion of the board, the board may assess the costs of the frivolous complaint against the complainant.

2.    Following the closing or filling of an unauthorized drain, either by a water resource board or by a party complying with an order of a water resource board, the board may assess its costs against the property of the responsible landowner.