A water right certificate issued in accordance with the provisions of ORS 537.250 which, after the expiration of three months from the date it is issued, has not been contested and canceled in the manner provided in ORS 537.260, and a water right certificate, when issued under ORS 539.140, shall be conclusive evidence of the priority and extent of the appropriation therein described in any proceeding in any court or tribunal of the state, except in those cases where the rights of appropriation thereby described have been abandoned subsequent to issuance of the certificate.
Oregon Legal Code