Cal. Elec. Code § 12284

Upon request of the elections official, state-owned buildings, parking lots, and other facilities shall be made available free of charge for use as polling places and vote centers, except that the Department of General Services may exclude from use as polling places or vote centers state facilities at which access to confidential materials cannot be reasonably safeguarded, which are inaccessible to the public, the use of which would disrupt state business, or which are otherwise impractical for use as polling places.