ORS § 541.220
In any stream system where construction is contemplated by the United States under the Act of Congress approved June 17, 1902, 32 Stat. 388 to 390, and known as the Reclamation Act, the Water Resources Commission shall make a hydrographic survey of the stream system, and shall deliver an abstract thereof together with an abstract of all data necessary for the determination of all rights for the use of the waters of such system, to the Attorney General. The Attorney General, together with the district attorneys of the districts affected by the stream system shall, at the request of the Secretary of the Interior, enter suit on behalf of the State of Oregon, in the name of the state, for the determination of all rights for the use of the water, and shall diligently prosecute the same to a final adjudication.
ORS 541.220