Cal. Sts. & Hy. Code § 35521
Moneys in the fund clearly in excess of the amount necessary to redeem the outstanding bonds as hereinafter provided may be used to pay the costs and expenses referred to in Section 35464. The balance of the fund shall be a trust fund pledged to and held for the benefit of the holders of the outstanding bonds issued pursuant to Chapter 3 (commencing with Section 35400) of this part, and until the bonds and the interest thereon have been fully paid the balance shall be used for no purpose other than the payment of the principal thereof, the interest thereon, and any premiums payable upon the call thereof. If the bonds, or any portion thereof, are to be called for redemption, the city shall immediately give notice of such redemption in the manner and form provided in the ordinance, resolution or indenture under which the bonds were issued, even though the notice may be premature as to time, but if the notice is premature the city shall later give the notice again within the proper time. As soon as the notice, even though premature, has been given and as soon as there are moneys in the fund clearly sufficient to pay the principal of all of the bonds, all interest to maturity or to the call date stated in the notice as the case may be, and all premiums to which bondholders will be entitled by reason of the call, the city is discharged from all obligations under this part or under the ordinance, resolution or indenture to make charges for the use of, or produce revenues from, parking places of the district or parking meters on streets, but the city shall continue to be bound by all other provisions of the ordinance, resolution or indenture.
Ca. Sts. and High. Code § 35521