California Code, Harbors and Navigation Code - HNC § 6020

At the time and place specified in the notice, the board of supervisors shall consider the petition and may continue the hearing from time to time, not exceeding a period of 90 days.

At the hearing by the board of supervisors a certificate issued by the assessor of the county and filed with the clerk of the board of supervisors in the proceedings stating that the name of any signer of the petition appears upon the last equalized assessment roll of the county for land assessed to that signer and located within the boundaries of the proposed district, is prima facie evidence that the signer is a freeholder within the proposed district.

A certificate signed by the county elections official that the name of any signer of the petition is a registered and uncanceled voter of the county, residing within the boundaries of the proposed district, is prima facie evidence that the signer is a registered voter within the boundaries of the proposed district.