Cal. Water Code § 12003

Any person may co-operate and contract with the United States, under the Federal Reclamation Act of June 17, 1902, and all acts amendatory thereof or supplementary thereto or under any other act of Congress heretofore or hereafter enacted permitting co-operation or contracts for any or all of the purposes set forth in Section 12004, whether under said federal reclamation laws, or otherwise.