California Code, Government Code - GOV § 24206

Notwithstanding any other law, the Board of Supervisors of the County of Santa Clara may adopt, or a voter of that county may propose by initiative, an ordinance to elect an officer of that county by ranked choice voting.  The ordinance shall specify which county officers shall be elected by this method and whether they shall be elected at large or by or from district, as applicable.  Notwithstanding Section 1300 of the Elections Code or any other law, an ordinance that provides for a ranked choice voting process may hold that election at the statewide primary election at which the election otherwise would be held in accordance with Section 1300 of the Elections Code, the first statewide general election following that statewide primary election, or a combination thereof.  The ordinance may further specify whether ranked choice voting may be used in special elections to fill vacancies in county offices.  Such special elections may be held on any date allowed for such special elections.