CA Elec Code Section 17300

(a)

The elections official shall preserve all rosters of voters or combined rosters and indexes as provided for in Section 14109, if applicable, until five years after the date of the election, after which they may be destroyed by that official.

(b)

In lieu of preserving the original roster of voters, the elections official may, by filming or other suitable method, record the original roster of voters and destroy the roster following the next subsequent general election.