Cal. Educ. Code § 85271

Any warrant drawn on the funds of a district retirement system and issued to the claimant thereof but not presented for payment to the county treasurer within two years after it was issued is void and the proceeds of such warrants shall revert to and become a part of the contributions of the district and shall be applied to reduce the cost to the taxpayers of the district maintaining the retirement system. The county auditor shall each month inform the county superintendent of schools of warrants which have become void during the preceding month, and the county superintendent of schools shall transmit such information to the governing board of the community college district.