Cal. Water Code § 35180

Directors of the district shall be elected on an at-large basis. Newly elected directors shall take office on the last Friday in November next following the general district election. The term of office of each director shall be four years and each director shall hold office until his successor qualifies and takes office. The terms of office of directors shall continue to be staggered to keep as nearly equal as practicable the number of directors to be elected at each subsequent general district election.