California Code, Streets and Highways Code - SHC § 6468.4

The treasurer shall keep a separate redemption fund, properly designated, into which he shall place all sums received by him from the collection of the assessments against public property for bonds issued under the provisions of this chapter and for interest and penalties thereon and from which fund he shall disburse and pay the bonds and the interest due thereon upon presentation of the proper bonds and coupons.  Under no circumstances shall the bonds or the interest thereon be paid out of any other fund.