Cal. Rev. & Tax. Code § 7285
The board of supervisors of any county may levy, increase, or extend a transactions and use tax throughout the entire county or within the unincorporated area of the county for general purposes at a rate of 0.125 percent or a multiple thereof, if the ordinance proposing that tax is approved by a two-thirds vote of all members of the board of supervisors and the tax is approved by a majority vote of the qualified voters of the entire county if levied on the entire county or the unincorporated area of the county if levied on the unincorporated area of the county, voting in an election on the issue. The board of supervisors may levy, increase, or extend more than one transaction and use tax under this section, if the adoption of each tax is in the manner prescribed in this section. The transactions and use tax shall conform to Part 1.6 (commencing with Section 7251). The revenues derived from the imposition of a tax pursuant to this section shall only be used for general purposes within the area for which the tax was approved by the qualified voters.
Ca. Rev. and Tax. Code § 7285