Cal. Gov't Code § 56129
(a) If a public utility has been granted a certificate of public convenience and necessity authorizing and requiring it to furnish gas or electric service within a certain service area and, as a result of a change of organization or a reorganization, territory consisting of all, or any part, of that service area becomes a part of, or is formed into, a district authorized by its principal act to furnish gas or electric service, the district shall not furnish that service within the territory except upon approval by both of the following: