Gov. Code, § 50797

All revenues received from the operation of the project acquired, constructed or completed by the board shall be paid into the treasury of the local agency to the credit of the revenue fund which the treasurer is hereby directed to establish for the particular project for which the bonds were authorized. The moneys in the revenue fund shall be paid out and disbursed for the payment of the principal and interest on all bonds issued by the board for the particular project producing the revenue as and when such principal and interest shall become due and for the creation of any reserve fund or other special fund provided by the board in the proceedings for the issuance of said bonds and also for the payment of all costs and expenses for the maintenance, operation and insurance of the project, engineering and administrative costs and for all repairs and replacements and other costs and expenses incurred in connection with such project.