Streets and Highways Code § 25120

Immediately following the organization of the district, the several boards of supervisors of the counties composing the district shall provide the district with a sufficient contingent fund to enable the district and its officers to perform their prescribed functions and duties. The proportionate contributions of the several counties within the district may be suggested to the several boards of supervisors thereof by the board of directors of the district and the board of directors shall from time to time report to the said boards of supervisors its requirements and in general its expenditures.