California Code, Government Code - GOV § 59670

Unless commenced within 60 days after the confirmation of the reassessment, a person shall not maintain any action or proceeding to cancel, annul, or correct the reassessment, to review any of the acts or determinations made in the proceedings, to question the validity or enjoin the collection of the reassessment or any reassessment of a reassessment made pursuant to this chapter, or to enjoin the issuance of any new bonds to represent them.  Thereafter all persons are barred from any such action or proceeding or any defense of the invalidity of the reassessment or any bonds issued on the reassessment.