Section 72689 Of Article 1. Inclusion Proceedings Initiated By Petition From California Water Code >> Division 20. >> Part 11. >> Chapter 1. >> Article 1.

. Any action or proceeding in which the validity of an annexation to an improvement district pursuant to this article is contested, questioned, or denied shall be commenced within three months after the date of the resolution approving such annexation; otherwise the annexation shall be held to be valid and in every respect legal and incontestable.