Cal. Pub. Util. Code § 12815.3
Before circulating the petition, its proponents shall publish a notice of intention to do so. The notice shall be accompanied by a printed statement, not exceeding 500 words in length, stating the reasons for the petition. The notice and statement shall be published at least once in a newspaper of general circulation which is published in the district.
Within 10 days after notice is published, the proponents shall file a copy of such notice and the accompanying statement, and an affidavit as to the publishing thereof, with the secretary. The petition may be circulated among the voters of the district twenty-one days after notice is published. The petition shall bear a copy of the printed notice of intention and its accompanying statement. Signatures shall be secured and the petition shall be presented to the secretary for filing within 180 days from the date of the first publication of the notice of intention.
Ca. Pub. Util. Code § 12815.3