California Code, Government Code - GOV § 29962

During the time the county 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 board of supervisors may each year omit from the amount of the annual tax or assessment to be levied for the payment of principal and interest of the bonds any sum for the payment of principal and interest due and unpaid because of delinquencies, and may limit or omit any sum for anticipated delinquencies.  The tax or assessment shall be levied in accordance with the statute under which the bonds acquired were issued, but the total amount of any annual levy may be limited as provided in this article.