Cal. Water Code § 43003

The board shall establish equitable rules and regulations for the most economical and efficient distribution and use of water within the district, and pursuant thereto may enter into long-term water service contracts with landowners in the district which contracts may, in the discretion of the board, provide, among other things, that the obligations are a lien on the land with the same force, effect, and priority as an assessment lien if such contract is recorded in the office of the county recorder in the county in which such land is situated. The rules, regulations, and contracts shall recognize and shall be subject to such priorities in the right to water between the different consumers of the water as may legally exist. Among other things the rules and regulations may establish a procedure for fixing tolls and charges authorized by Sections 43006 and 47180 and may provide equitable rules for reapportionment of assessments supplementary to the provisions of Article 8 (commencing with Section 46325) of Chapter 2 of Part 9 of this division.