Cal. Wat. Code § 50978
Without limiting the generality of Section 50971, when a contract has been executed with the United States under this chapter, the board may, by resolution, provide for an assessment upon the land to be benefited by such contract to pay all or any portion of the amounts to become due under the contract. Such assessment may be levied and collected in the same manner as any other district assessment might be levied and collected, as deemed appropriate by the board.
As an alternative to such levy of an assessment, or in addition thereto, the board may derive all or a portion of the amounts to be paid to the United States under the contract by the collection of charges from the persons to or for whom the water was furnished, under the provisions of Section 50911.
Ca. Water Code § 50978