When the Reclamation Board has approved, modified, or rejected any reclamation plan after a hearing as provided in this article, such action shall be final, and the sufficiency of the plan shall not be subject to attack before the reclamation board or in any court, but nothing in this section shall prevent the board from filing with the county clerk any amendatory, additional or supplemental plan of reclamation at any time.
Ca. Water Code § 51028