Cal. Gov. Code § 53398.83

The public financing authority may, by majority vote, provide for refunding of bonds issued pursuant to this chapter. However, refunding bonds shall not be issued if the total net interest cost to maturity on the refunding bonds plus the principal amount of the refunding bonds exceeds the total net interest cost to maturity on the bonds to be refunded. The public financing authority may not extend the time to maturity of the bonds.