California Code, Public Utilities Code - PUC § 90070

(a) A petition calling for the formation of the district is filed with the board of supervisors from each of the seven cities specified in Section 90050.  Each of the petitions from the seven respective cities shall be signed by a number of signers equal to at least five percent (5%) of the voters registered for the last municipal election in each particular city.  A petition may be on separate papers, but each paper shall contain the affidavit of the person who circulated it, certifying that each name signed thereto is a true signature of the person whose name it purports to be.

(b) A resolution of consent calling for the formation of the district is filed with the board of supervisors from each of the city councils of the seven cities specified in Section 90050;  provided, that the requirements of this section shall be deemed to have been met if a combination of petitions and resolutions of consent have been filed with the board of supervisors, so long as each of the seven cities specified in Section 90050, either through a petition or by a vote of the city council, has authorized the calling of an election for the formation of the district.