If a contract, made and entered into by any irrigation district pursuant to the provisions of section 61-07-29, provides for the payment of the entire purchase price of an annual supply of water, the board, if other revenues are not available for the payment of such purchase price, shall adopt a resolution that assessments be made against the lands within the district sufficient to produce the required amount. Such amount shall be apportioned, assessed, and levied at the time specified in this chapter for the apportionment and levy of assessments.