California Code, Streets and Highways Code - SHC § 9538

Except as otherwise provided in this section and in Sections 9546, 9547, and 9548, assessments originally levied, and all penalties and interest accrued thereon, which are included within the reassessments, shall be deemed superseded and supplanted by the reassessments.If, and to the extent that, the reassessments do not include unpaid installments of assessments originally levied and the penalties and interest thereon, the lien of the original assessments is not superseded and supplanted.

For purposes of this section and Section 9539, “unpaid installments” means those installments which are delinquent and those which are or may be posted to the tax roll for the fiscal year during which the reassessment is confirmed.