Cal. Gov. Code § 43775

During the time the city owns any district bonds payable from taxes or assessments levied wholly or partially in accordance with the assessed value of the land within the district, the legislative body may omit any sum for the payment of principal and interest past due and unpaid because of delinquencies from the amount of the annual tax or assessment to be levied for the payment of principal and interest of such bonds. It may also limit or omit any sum for anticipated delinquencies. The legislative body may exercise its discretion as to such omission each year. The tax or assessment shall be levied pursuant to the statute under which the bonds acquired were issued, but the total amount of the annual levy may be limited as provided in this section.