Cal. Ed. Code § 16090
The board of supervisors of the county, the county superintendent of which has jurisdiction over any district which under this chapter will have moneys withheld by the Controller from the apportionments to be made to it from the State School Fund during any fiscal year, shall annually at the time the board of supervisors makes the levy of taxes for county purposes, levy a tax upon the property in the district sufficient to raise for the district the amount of money to be withheld by the Controller during the fiscal year in which the tax is levied. Effective July 1, 1988, that tax, when collected, shall be paid into the county treasury of the county, the county superintendent of schools of which has jurisdiction over the district for which the tax was levied, to the credit of a separate fund of the district to be known as the Tax Override Fund.
Ca. Educ. Code § 16090