Any claimant who, prior to entry of the order of determination by the board, had no actual knowledge or notice of the pendency of the proceedings may, at least 10 days prior to the date set for hearing by the court or within such further time prior to the decree as the court may allow, intervene in the proceedings by filing with the court an exception to the order of determination and a proof of claim which shall contain all the matters required by this chapter of claimants who have been served with notice of the proceeding.
Ca. Water Code § 2780