Cal. Education Code § 5205

The governing board of any elementary school district having an average daily attendance of 1,000 or more pupils and an assessed valuation of twenty million dollars ($20,000,000) or more may, and upon petition signed by 25 percent of the heads of families resident in the district, shall order an election to determine whether or not, it shall have the rights, powers, and duties of a city board of education and whether or not the district shall for all purposes be deemed to be a district governed by a city board of education. If the governing board of the district consists of three members, there shall be elected at the election, to take office if the proposal for change in the rights, powers, and duties of the board is approved, two additional members to the board. If the change is approved by a majority of the qualified electors voting on the proposition at the election, the board shall have the rights, powers, and duties of a city board of education, and the district shall for all purposes be deemed to be a district governed by a city board of education. Also, if the change is so approved, the two additional board members shall take office, the one receiving the highest number of votes to serve until the first day of April following the second succeeding regular election at which board members are elected, and the one receiving the next highest number of votes to serve until the first of April following the next such regular election. Thereafter, the governing board of the district shall consist of five members elected in the manner prescribed for other school districts for terms of four years and until their successors are qualified, provided that vacancies shall be filled in the manner provided for unified school districts.