Cal. Water Code - WAT § 540. Section 540.
Notwithstanding any other provision of law, a water district, as defined in Section 20200, may serve as an aggregator to facilitate direct transactions within the boundaries of the district in accordance with Chapter 2.3 (commencing with Section 330) of Part 1 of Division 1 of the Public Utilities Code and charge a fee that is equal to the district’s cost for providing that service.