Section 10400 Of Chapter 5. Levying And Collecting The Assessment From California Streets And Highways Code >> Division 12. >> Chapter 5.

. The validity of an assessment or supplementary assessment levied under this division shall not be contested in any action or proceeding unless the action or proceeding is commenced within 30 days after the assessment is levied. Any appeal from a final judgment in such an action or proceeding shall be perfected within 30 days after the entry of judgment.