Cal. Sts. & High. Code § 18031

The city shall not be limited by the provisions of this part to the maintenance or servicing of street lighting systems, or any part thereof, owned only by the city, but the city council may also order such maintenance or service to be furnished upon street lighting systems provided and installed or to be installed by, and remaining the property of, any public utility, public corporation, or other person with whom a contract is entered into for such maintenance or service and may assess the costs and expenses of such maintenance, service, or installation in accordance with the provisions of this part.