California Code, Public Utilities Code - PUC § 11850

(a) Notwithstanding any other provision of this chapter, in any district formed prior to January 1, 1974, and containing a population of 1,000,000 or more on that date, the number of directors on the district board shall be increased from five to seven as provided in this article.

(b) In any district to which subdivision (a) is applicable and in any district which has owned and operated an electric distribution system for at least eight years and which has a population of 250,000, or more, candidates for the office of director shall be elected by the voters of the ward each represents and shall not be voted upon at large.  Nomination papers may be circulated only within the ward from which the candidate is to be elected, and shall be signed either by 1 percent of the voters within the ward or by 10 voters, whichever is the lesser number, but in no event by more than 20 voters within the ward.  District circulators shall be residents of the ward in which they seek signatures and may obtain signatures only from registered voters residing within that ward.