California Code, Government Code - GOV § 26390

The board may provide for the construction, maintenance and operation of any project upon any lands owned by the county without regard to the manner in which such lands were acquired, and if such lands were acquired other than through the issuance of revenue bonds authorized for the particular project, the board shall fix a reasonable rental for the use of such lands, which rental shall be a charge against the appropriate funds of the project and shall be payable into the general or other appropriate fund of the county.