California Code, Government Code - GOV § 26907

(a) Notwithstanding Section 26201, 26202, or 26205, the auditor or ex officio auditor may destroy any county, school, or special district claim, warrant, or any other paper issued as a warrant voucher that is more than five years old, or at any time after the document has been photographed, microphotographed, reproduced by electronically recorded video images on magnetic surfaces, or recorded on optical disk or reproduced on any other medium that does not permit additions, deletions, or changes to the original document and is produced in compliance with Section 12168.7 for recording of permanent records or nonpermanent records if the copy is kept or maintained for five years from the date of the document.A duplicate copy of any record reproduced in compliance with Section 12168.7 for recording of permanent or nonpermanent records, whichever applies, shall be deemed an original.

(b) The auditor may make a photographic record of an index or warrant register and may provide for the destruction of the index or warrant register. Any index or warrant register that is over five years old may be destroyed without being photographically or microphotographically reproduced.