Oregon Revised Statutes Cities § 224.030

A city, through its council, may divert water and waterways, fill or drain lakes, ponds or other waters, increase or diminish the flow of waters in natural channels or dam channels and do such other acts and things as may be found necessary or essential for the matters provided for in ORS 224.010 to 224.120 and in ORS 224.170. However, no property rights or other vested rights shall be taken without agreement with the owner or a proceeding of condemnation.