California Code, Elections Code - ELEC § 17000

(a) The elections official shall preserve all canceled original affidavits of registration for a period of five years, after which they may be destroyed by that officer.

(b) In lieu of preserving the canceled original affidavit of registration, the elections official may, by filming or other suitable method, record the canceled affidavit and destroy the affidavit following the first general election after the date of cancellation.