Problem Plants and Animals

Do you need information about nuisance species such as Japanese knotweed or nutria? You'll find many answers in the Integrated Vegetation and Animal Management Guidance document (PDF, 3MB).

Learn more about nuisance plants on our invasive plants page.

Portland Audubon Society also has lots of great tips on Living with Urban Wildlife.

Beaver and Nutria

Because Clean Water Services' staff does so much work in stream corridors, we are often asked what to do about beaver and nutria. We do not disturb beaver unless their activity is flooding a structure or damaging the public drainage system. Nutria are an invasive, non-native species that we may have trapped if they are damaging stream enhancement projects, water quality facilities or drainage systems.

If you observe beaver or nutria activity that is flooding a structure or damaging the public drainage system, please report it to our Field Operations staff at (503) 547-8100.

If wildlife activity on your property is creating a health or safety threat, you may contact USDA Wildlife Services at (503) 604-4699 and leave a detailed message for assistance.