To levy and collect special assessments under Class B as herein provided, the board shall make contracts for water service with each petitioning municipality in the district in the manner hereinafter provided and shall fix and determine the rate or rates per acre-foot and terms at and upon which water service shall be furnished for use by such municipalities; Provided, that such rates shall be equitable although not necessarily equal or uniform for like classes of service throughout the district. In the event any city shall desire to obtain water service from the district for domestic or irrigation purposes, the legislative body of such municipality shall by ordinance authorize and direct its mayor and clerk to petition the board for water service upon terms prescribed by the board, which petition shall contain inter alia, the following: (1) Name of municipality; (2) quantity of water to be supplied; (3) the term of years such service is to be supplied; (4) price per acre-foot to be paid for water service; (5) whether payments are to be in cash or annual installments; and (6) an agreement by the municipality 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.