Cal. Water Code - WAT § 43730. Section 43730.
An action to determine the validity of bonds, assessments, contracts, including contracts with the state, the department, any other district, or the United States, the adoption of a project or the taking of any other action by the district or by the board under the provisions of this division may be brought pursuant to Chapter 9 (commencing with Section 860) of Title 10 of Part 2 of the Code of Civil Procedure.