The amount to be disbursed from the vendor payment revolving fund on behalf of an agency electing to utilize such fund shall be deposited therein by the agency on or before the day prior to scheduled disbursement. The deposit shall be made from funds held by the agency outside the state treasury pursuant to law and which are properly chargeable for the disbursement. Disbursements from the revolving fund created by this chapter shall be by warrant in accordance with the provisions of RCW 43.88.160.