To levy and collect special assessments upon lands under Class C as herein provided, the board shall make contracts for water service with each of the petitioning irrigation districts within the district in the manner as hereinafter provided and shall fix and determine the rate or rates per acre-foot and terms at and upon which water service shall be supplied to such irrigation district; Provided, that such rates shall be equitable although not necessarily equal or uniform for like classes of services throughout the district. In the event any irrigation district shall desire to obtain the beneficial water service from the district, the board of such irrigation district shall by resolution authorize and direct its president and secretary to petition the board for water service, upon terms prescribed by the board, which petition shall contain inter alia, the following: (1) Name of irrigation district; (2) quantity of water to be furnished; (3) the terms of years such service is to be supplied; (4) price per acre-foot to be paid; (5) whether payments are to be made in cash or annual installments; and (6) an agreement by such irrigation district to make payments for such water service, together with annual maintenance and operating charges, and to be bound by the provisions of sections 46-501 to 46-573 and the rules and regulations of the board.