Cal. Water Code - WAT § 71680. Section 71680.
(a)
A district may exercise any of the powers, functions, and duties which are vested in, or imposed upon, a fire protection district pursuant to the Fire Protection District Law of 1987, Part 3 (commencing with Section 13800) of Division 12 of the Health and Safety Code.
(b)
If the district includes any part of any local agency which provides fire protection service to any territory in the district, the district shall have no authority regarding the prevention or suppression of fires, in that territory unless the district has obtained the consent of the other local agency.