California Code, Water Code - WAT § 74650

(a) A district may act by ordinance in exercising its powers under this division over lands, structures, and facilities in which the district has a real property interest. All ordinances shall be enacted only by rollcall vote entered into the proceedings of the board.

(b) It is the policy of the Legislature to avoid duplication of authority of local districts to regulate upon the same subjects in the same area. Accordingly, this chapter shall not apply to a district lying within another district having and exercising, in accordance with the governing statute of the overlying district, the authority to adopt and enforce, upon civil or penal sanction, ordinances for the same purposes.