Water on County Roads is Prohibited per Oregon Revised Statute
368.256 Creation of Road Hazard Prohibited. (1) Except as authorized by the county governing body, an owner or lawful occupant of land shall not allow:
(a) Any water to overflow, seep or otherwise discharge from that land onto a public road under county jurisdiction including, but not limited to, water that is passing over the land, diverted from the land by an obstruction on the land, flowing from the land because of rainfall or discharged from an irrigation sprinkler or other device.
(b) Any structure, tree, drainage way, soil deposit or other natural or man-made thing on that land to present a danger to or create a hazard for the public traveling on a public road or facilities within the right of way of the public road by obstructing, hanging over or otherwise encroaching or threatening to encroach in any manner on a public road that is under county jurisdiction.
(2) A person is not in violation of this section if there is no reasonable method for the person to control, stop or remove the cause of the violation. [1981 c.153 §27]
Click the link below to review the entire Oregon Revised Statute 368 regarding : General Provisions for County Roads, Highways, Bridges & Ferries