California Code, Health and Safety Code - HSC § 37648

(a) The local agency may provide for the issuance of the bonds of the local agency for the purpose of refunding any bonds of the local agency then outstanding, including the payment of any redemption premiums thereof and any interest accrued or to accrue to the earliest or subsequent date of redemption, purchase, or maturity of such bonds, and, if deemed advisable by the local agency, for the additional purpose of paying all or any part of the cost of additional historical rehabilitation.

(b) The proceeds of bonds issued for the purpose of refunding any outstanding bonds may, in the discretion of the local agency, be applied to the purchase or retirement at maturity or redemption of such outstanding bonds, either at their earliest or any subsequent redemption date or upon the purchase or retirement at the maturity thereof and may, pending such application, be placed in escrow, to be applied to such purchase or retirement at maturity or redemption on such date as may be determined by the local agency.

(c) Pending use for purchase, retirement at maturity, or redemption of outstanding bonds, any proceeds held in escrow pursuant to subdivision (b) may be invested and reinvested as provided in the resolution authorizing the issuance of the bonds. Any interest or other increment earned or realized on any such investment may also be applied to the payment of the outstanding bonds to be refunded. After the terms of the escrow have been fully satisfied and carried out, any balance of such proceeds and any interest or increment earned or realized from the investment thereof may be returned to the local agency to be used by it for any lawful purpose.

(d) That portion of the proceeds of any such bonds designated for the purpose of paying all or any part of the cost of additional historical rehabilitation pursuant to subdivision (a) may be invested and reinvested in obligations of, or guaranteed by, the United States of America or in certificates of deposit or time deposits secured by obligations of, or guaranteed by, the United States of America, maturing not later than the time or times when such proceeds will be needed for the purpose of paying all or any part of such cost.

(e) All bonds issued pursuant to this section shall be subject to the provisions of this part in the same manner and to the same extent as other bonds issued pursuant to this part.