Cal. Sts. & Hy. Code § 5170
If the work proposed to be done includes the laying of conduits, pipes, hydrants, or any appliance for the supplying or distributing of a domestic water supply, and the distribution of such domestic water supply in the territory in which the work is contemplated is under the management and control of a municipal water district, a municipal utility district, a public utility district, a metropolitan water district, or any public agency other than the city ordering the work done, the conduits, pipes, hydrants, or other appurtenances for supplying or distributing such domestic water supply shall be installed under the proceedings specified in this chapter, which must be taken prior to the adoption of the resolution of intention.
Ca. Sts. and High. Code § 5170