Cal. Pub. Util. Code § 12818
(a) No publicly owned utility shall commence the distribution or sale of water for municipal, domestic, industrial or similar purposes for, on, or to, any land within a district already engaged in similar distribution or sale of water and which land is already subject to the lien of a general obligation bonded indebtedness of the district for these purposes. However, a publicly owned utility may commence to provide the service to the land, otherwise prohibited, upon either of the following conditions: