Cal. EDC § 5227

In those cases in which the boundaries of the school district, high school district, or community college district, governed by a city board of education, are not coterminous with the boundaries of the city, and where elections, either primary, general, or recall, of members of the board of education are by the provisions of the laws governing the cities held at times other than on the day of municipal elections, general or special, the cost and expense of the district elections shall be a legal charge against the funds of the district or districts governed by the board of education. The city shall be reimbursed by the district or districts for its actual cost and expense incurred in the conduct of the election or elections. The cost and expense of conducting the election in territory common to two or more districts shall be borne by the districts in equal shares. In territory within a single district the cost shall be borne by the district.

In those cases in which the school district, high school district, or community college district is governed by a city board of education, and elections, either primary, general, or recall, of members of the board of education are by the provisions of the laws governing the cities held on the same day as municipal elections, general or special, a proportionate part of the actual cost and expense of the election shall be a legal charge against the school districts governed by the board of education. The city shall be reimbursed for the proportionate cost and expense incurred in the conduct of the election. The cost and expense of the elections within the boundaries of the city shall be apportioned between the city and the districts in the ratio that the total number of offices to be filled and propositions to be voted upon by the electors of the city and the school district or districts, respectively, bears to the total number of offices to be filled and propositions submitted. The cost and expense of the election in territory outside of the municipal boundaries shall be borne by the districts affected. As between the districts, costs and expense shall be apportioned as follows: In territory common to two or more districts the cost of conducting the election shall be borne in equal shares, and in territory within a single district the cost shall be borne by the district.