CA Pub Util Code Section 240306

(a)

The commission, subject to the approval of the voters, may impose a maximum tax rate of one-half of 1 percent under this division and Part 1.6 (commencing with Section 7251) of Division 2 of the Revenue and Taxation Code, and the commission may state the maximum tax rate in terms of not to exceed one-half of 1 percent, or any lesser percentage thereof. Neither this division nor the ordinance shall affect any tax otherwise authorized.

(b)

The tax rate adopted pursuant to this chapter, unless otherwise prohibited, may be increased by the commission by ordinance adopted in the manner and by the vote stated in Section 240301 and approved by a majority of the electors voting on the measure at an election called for that purpose by the commission.