Oregon Drainage Law

The Engineering Division is responsible for reviewing a variety of private development projects, and projects that impact the County Right-of-Way, for drainage and stormwater issues.  The reviews may apply to required stormwater management plans, Right-of-Way Work permits, building permit applications, and normal roadway drainage issues that occur over time.  The County does not have an established Drainage Ordinance and frequently refers to the City of Hood River's Stormwater Management Design Criteria for design standards within urbanized areas.  For other projects throughout the County, but also applicable to urbanized areas and within the County Right-of-Way, reviews are performed to ensure conformance with accepted drainage design standards and practices, more generally referred to as Oregon Drainage Law.
Oregon has adopted the civil law doctrine of drainage, commonly known as Oregon Drainage Law, which has developed without legislative action and it is embodied in the decisions of the courts. Subsequently, there are no Oregon Revised Statues to cite pertaining to Oregon drainage law.  Under the doctrine of Oregon Drainage Law, adjoining landowners are entitled to have the normal course of natural drainage maintained. A lower landowner must accept water that naturally comes to their land from above, but they are also entitled to not have the normal drainage changed or substantially increased.  Similarly, the lower landowner may not obstruct the runoff from an upper land if the upper landowner is properly discharging the water.  The term "lower landowner" applies not only to the landowner immediately adjacent to the discharge but can also refer to landowners further downstream that may also be impacted by changes in stormwater discharge.  
For a landowner to drain water onto lands of another in the State of Oregon, including onto a public Right-of-Way, the lands must either contain a natural drainage course, or, the landowner must have acquired the right to drain the water onto the land.  This is typically accomplished in the form of a drainage easement.  Additionally, because Oregon has adopted the civil law doctrine of drainage, an upper landowner may not (1) divert water onto adjoining land that would not have otherwise have flowed there, (2) change the place where the water flows onto the lower landowner's land, and (3) accumulate a large quantity of water, then release it, substantially accelerating or increasing the flow onto the lower landowner’s land.
Where certain drainage patterns have been established over long periods of time that are not the original natural drainage, frequently considered to be in excess of over 10 years, a landowner may be able to acquire legal rights which allow the continuance of the altered drainage pattern.
Two commonly asked questions regarding the diversion of stormwater include:
1. Can a  landowner re-direct water onto either a county road road or someone's property to ease their drainage problems?
Depending on the circumstances, the County may have the authority to initiate legal action against a landowner who impairs or damages a road, drain or ditch by re-directing stormwater to a public roadway.  Authority to abate such situations is granted under ORS 368.251.
2. What is a natural channel?
The term "natural channel" has been construed to include all channels through which water flows naturally under existing conditions. However, an artificially created drainage channel, such as an irrigation ditch, may also be construed as "natural" depending on its history of long-time use and acceptance of certain stormwater.
Due to the manner in which Oregon Drainage Law has been established, many standards are complex and may require the assistance of legal advice.  However, the Public Works Department's primary goal when reviewing drainage issues is to apply consistent methodology and applicable rules, and provide for the best interest of the public and individual landowners.  For more information about Oregon drainage standards and design, please review the ODOT Hydraulics Design Manual or seek the assistance of a qualified Hydrologist or Professional Engineer.

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