Oregon Revised Statutes Water Resources: Irrigation, Drainage, Flood Control, Reclamation § 540.560

(1) If the Water Resources Commission considers that a certificate of water right does not identify the lands to which the right is appurtenant with sufficient specificity for management, delivery or transfer of that right, the commission may issue an order clarifying and refining the description of the land to which the water right is appurtenant.

(2) An order issued under this section may not reduce the rate, duty or number of acres stated in the certificate of water right. The sole purpose of an addendum to a water right certificate is to better define the location of acreage to which the water right is appurtenant, where the certificate states only that the use is limited to a number of acres within a larger tract.

(3) Any order issued under this section shall be served on the legal owner of the land to which the water right is appurtenant and on the occupant of the land, by certified mail, return receipt requested. If the owner or occupant files a written request for a hearing within 30 days after service of the order, the commission shall conduct a hearing of the matter under ORS 183.413 to 183.484.

(4) A final order under this section shall become an addendum to and shall be filed with the certificate of water right that the order clarifies. For all purposes, the final order shall constitute the description of the land to which the water right is appurtenant.