Written by Kevin Seifert & Susan Ortiz
 
Rain and more rain. The past two winters in Oregon have far exceeded historical rainfall averages. The extra water pools, ponds, and courses across the land, but most of it still needs to drain to our streams and rivers. As we alter our land uses, building house, roads, and other structures, new problems and concerns arise regarding drainage of surface water. These problems and concerns have become more prevalent by the encroachment of urbanization on our rural lands. Recently, several problems have arisen in the urban/rural interface; in one instance, considerable fill soil was brought in before new housing was constructed causing flooding of an existing house. Attention needs to be given to the potential effect the additional fill will have on the natural drainage course. Whose problem is this? How do we come to a resolution? Was there a problem in the first place? Drainage issues can lead to property damage and civil suits. In order to avoid problems we need to understand our drainage rights in Oregon.
 
The State of Oregon observes the Modified Civil Rule when it comes to assessing liability for flooding, erosion and drainage alterations. Under this rule, adjoining landowners are entitled to have the normal or historical course of natural drainage maintained. This means that a down-gradient owner must accept the surface water that naturally drains onto his land from an up-gradient neighbor. However, the up-gradient owner may not do anything to change the natural system of drainage so as to increase the natural burden across the down-gradient property. The down-gradient owner may not obstruct the run-off from the upper land, if the upper landowner is properly discharging the water.
 
For a landowner to drain water onto lands of another in the State of Oregon, two conditions must be satisfied initially; first, the lands must contain a natural drainage course; and secondly, the landowner must have acquired the right of drainage supported by consideration.
 
In addition, because Oregon has adopted the modified civil rule regarding drainage, these basic elements must be followed:

• A landowner may not divert water onto adjoining land that would not otherwisehave flowed there. “Divert water” includes but is not necessarily limited to:
  • water diverted from one drainage area to another; and
  • water collected and discharged which normally would infiltrate into the ground, pond, and/or evaporate.

• The upper landowner may not change the place where the water flows onto the lower owner's land. (Most of the diversions not in compliance with this element result from grading and paving work and/or improvements to water collection systems.)

• The upper landowner may not accumulate large quantities of water, and then release it, greatly accelerating the flow onto the lower owner's land. This does not mean that the upper landowner can not accelerate the flow of water at all; experience has found drainage to be improper only when acceleration and concentration of the water were substantially increased.

If you are concerned that your drainage has been changed by an adjacent property try to document the changes with pictures; historical aerial photos of drainages may also be available. Generally, working with your neighbor is the best way to resolve drainage issues.
 
Please note that the information in this article is provided as general information and not intended as legal advice.