The roll certified to the county officers as in this chapter provided, and any modification thereof as provided, shall serve as the base of benefits as to land, buildings and improvements furnished service and benefit by the systems of the district against which valuations dollar rates shall be levied and collected in the same manner as general taxes from time to time for the continuing functioning of the district and its systems. The dollar rate shall be levied in the manner required by law for dollar rate levies by drainage districts.