Prior to the expenditure of any funds for the bus transit and water transportation system of the district, the board shall determine:
(a) The amount which the counties, and the transit districts therein, served by the system shall contribute to the operation of the system for benefits derived from intracounty operation connected with, or related to, the system. The method of computing and receiving such amount shall be the method provided for in the district’s Resolution No. 7030, adopted May 8, 1970.
(b) That the board of supervisors of these counties, and the transit districts therein, have made a commitment to contribute the amount specified in subdivision (a).