Constitution of the State of California 1879 Art. XII, § 8

Sec. 8.  A city, county, or other public body may not regulate matters over which the Legislature grants regulatory power to the Commission.  This section does not affect power over public utilities relating to the making and enforcement of police, sanitary, and other regulations concerning municipal affairs pursuant to a city charter existing on October 10, 1911, unless that power has been revoked by the city's electors, or the right of any city to grant franchises for public utilities or other businesses on terms, conditions, and in the manner prescribed by law.