California Code, Water Code - WAT § 35050

If the number of signatures is not sufficient, a supplemental petition, in the form of a duplicate petition, but bearing additional signatures, may be filed with the county elections official of the principal county within 10 days from the date on which the county elections official of the principal county certified the results of the examination.  The supplemental petition shall be verified in the same manner as the original petition.  If the signatures on the petition are still insufficient, no action shall be taken thereon.  The petition shall remain on file as a public record and failure to secure sufficient signatures shall not prejudice the later filing of an entirely new petition.