Cal. Public Utilities Code § 16409

For the purpose of obtaining and supplying water for domestic, irrigation, and fire protection purposes, a district may cooperate and contract with the United States and borrow or procure money from the United States in the same manner and under the same procedures as irrigation districts under Division 11, Part 6, Chapter 2 of the Water Code. Any district, in order to make payments to the United States under any contract between the district and the United States, may, in lieu, in whole or in part of levying assessments, fix and collect charges for the service of water by the district to any land. A district may charge higher rates for service of water to any landowner in the amount required to pay any interest costs charged to the district on any United States Bureau of Reclamation loan by reason of land held by such owner in excess of 160 acres.