California Code, Government Code - GOV § 64120

(a) The issuer may provide for the issuance of bonds for the purpose of refunding any bonds or any series or issue of bonds of the issuer then outstanding, including the payment of any redemption premium thereon and any interest accrued or to accrue to the date of redemption, purchase, or maturity of the bonds.

(b) The proceeds of any bonds issued for the purpose of refunding of outstanding bonds may, in the discretion of the issuer, be applied to the purchase, redemption prior to maturity, or retirement at maturity of any outstanding bonds on their earliest redemption date or dates, upon their purchase or maturity, or paid to a third person to assume the issuer's obligation to make the payments, and may, pending that application, be placed in escrow to be applied to the purchase, retirement at maturity, or redemption on the date or dates determined by the issuer.

(c) Any proceeds placed in escrow may, pending their use, be invested and reinvested in obligations or securities authorized by resolutions of the issuer, payable or maturing at the time or times as are appropriate to ensure the prompt payment of the principal, interest, and redemption premium, if any, of the outstanding bonds to be refunded at maturity or redemption of the bonds to be refunded either at their earliest redemption date or dates or any subsequent redemption date or dates or for payment of interest on the refunding bonds on or prior to the final date of redemption or payment of the bonds to be refunded.  After the terms of the escrow have been fully satisfied and carried out, any balance of the proceeds and interest, income, and profits, if any, earned or realized on the investments thereof may be returned to the issuer for use by the issuer.

(d) All of the refunding bonds are subject to this division in the same manner and to the same extent as other bonds issued pursuant to this division.