Cal. Pub. Cont. Code § 21021

Every contract entered into by the district for construction or improvements shall be subject to the provisions of Chapter 303 of the Statutes of 1919, as amended; and the board of supervisors of the district shall require the contractor to file with it good and sufficient bonds conditioned upon the faithful performance of the contract and upon the payment of all claims for labor and material in connection therewith in accordance with the provisions of that act.