Cal. HSC § 2006

(a) Any action to determine the validity of either the organization, or any action, of a district shall be brought pursuant to Chapter 9 (commencing with Section 860) of Title 10 of Part 2 of the Code of Civil Procedure. (b) Any judicial review of an action taken pursuant to this chapter shall be conducted pursuant to Chapter 2 (commencing with Section 1084) of Title 1 of Part 3 of the Code of Civil Procedure.