Cal. Sts. & High. Code § 8626

If the assessment was levied under the Municipal Improvement Act of 1913 or other law, the proceeds of the sale of the bonds shall be paid into the fund of the proceeding to represent the assessments for which the bonds were issued. If the bonds are sold for an amount in excess of par, the excess shall be paid into the fund specified in Section 10424 or other special fund specified in the law pursuant to which the assessment was levied to finance the acquisitions or improvements.