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The City of Portland, Oregon

Environmental Services

working for clean rivers

Phone: 503-823-7740

Fax: 503-823-6995

MAILING ADDRESS: 1120 SW 5th Ave, Room 1000, Portland, OR 97204

More Contact Info

Oaks Bottom Habitat Enhancement Project Overview

The Oaks Bottom Wildlife Refuge is a 170-acre complex of meadows, woodlands and wetlands on the east bank of the Willamette River just north of the Sellwood Bridge. The refuge is the largest remaining natural area within the lower Willamette River floodplain and provides important habitat for fish and wildlife, including threatened salmon and over 175 bird species.

Overview map of project 

Project Description

Environmental Services, Portland Parks & Recreation, and the U.S Army Corps of Engineers are working together on a large-scale habitat enhancement project to benefit wildlife and people. The project will enhance 75 acres of wetland habitat by:

  • Replacing an existing culvert with a larger box culvert to make it possible for fish to pass between the Willamette River and the wetland refuge, as well as to improve the tidal flow of the Willamette River in and out of the refuge.
  • Excavating tidal slough channels and improving wetland habitats so young fish, including species listed as threatened or endangered, can use the calmer waters of the wetland to rest and find food.
  • Removing invasive vegetation, such as purple loosestrife, and revegetating with native species within the construction footprint.
  • Enhancing opportunities for environmental education and interpretation of the refuge from the Springwater Trail with a new wildlife viewing platform and an overlook for people to observe nature.
  • Download a project fact

Detail of the planned project

Detail map of project


The project will construct a new, bigger culvert underneath the Springwater Trail and excavate new channels between the lagoon and the Willamette river. This will allow for a better exchange of water between the refuge and the river, and allow for salmon to access the refuge to rest and find food. Other wildlife that use the refuge will also greatly benefit from the work, including over 175 bird species, amphibians, reptiles, and mammals including otter and beaver.

schematic diagram of the new culvert

Additionally, the project will enhance opportunities for environmental education and interpretation along the Springwater Trial and provide a new wildlife viewing platform and an overlook for people to observe nature.


The State of Oregon requires that our work occurs during times when it will have the least impact on important fish, wildlife, and habitat resources.


YES!  Oaks Bottom Wildlife Refuge will be open.  You can access the refuge from the parking lot on Milwaukee avenue.  You can also access the refuge from the north or south using Springwater Corridor. Please remember that only pedestrians are allowed on the soft-surface trails!


The trail will be OPEN TO the wildlife refuge but CLOSED AS A THROUGH ROUTE - crews are cutting through the trail and land underneath it during construction and will replace the trail and adjacent railroad tracks upon completion.

Pedestrian, bicycle, and auto access to the Oaks Amusement Park and the Oregon Yacht Club floating home community will be maintained throughout the project. 

About Oaks Bottom

Oaks Bottom supports many wildlife species that are considered “special status” because they are in decline on a regional or statewide scale. These include 44 bird species, three bat species and one amphibian.

Portland Parks & Recreation (PP&R) manages the site as an important habitat area and an inviting place to view wildlife in the heart of the city. The Springwater Corridor, a portion of the region’s trail network, bisects the western edge of the refuge. A hiking trail and one hike/bike trail connect the refuge with two visitor parking lots and the Sellwood neighborhood to the east.

PP&R created the city’s first wildlife refuge at Oaks Bottom in 1988 after a long history of environmental degradation at the site. Now Sellwood residents, schools and colleges, and groups such as Portland Audubon, the Urban Greenspace Institute and Willamette Riverkeeper work with the city to restore habitats at the refuge.

Stay Informed

For more information, Contact: Ronda Fast at 503-823-4921, or email Ronda at Ronda.Fast@PortlandOregon.Gov.