Cal. Const. art. IX, § 3.2

Notwithstanding any provision of this Constitution to the contrary, any two or more chartered counties, or nonchartered counties, or any combination thereof, may, by a majority vote of the electors of each such county voting on the proposition at an election called for that purpose in each such county, establish one joint board of education and one joint county superintendent of schools for the counties so uniting. A joint county board of education and a joint county superintendent of schools shall be governed by the general statutes and shall not be governed by the provisions of any county charter.