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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

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Oaks Bottom Habitat Enhancement Project

Oaks Bottom project mapThe 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.

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.

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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.

Project Description

Environmental Services, PP&R 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.


Construction is scheduled for summer 2018.

Oaks Bottom

Short-Term Impacts, Long-Term Benefits

The Springwater Trail will close for up to 120 days in summer 2018. Bicyclists and pedestrians will detour to surface streets.  Pedestrian and bicycle access to the Oregon Yacht Club floating home community and Oaks Amusement Park will be maintained throughout the project.  When the project is completed, trail improvements will include two new wildlife viewing platforms.

Oaks Bottom photo courtesy Mike HouckFunding

  • U.S. Army Corp of Engineers
  • City of Portland Environmental Services Capital Improvement Program
  • Lower Columbia Estuary Partnership
  • U.S. Fish & Wildlife Service


To get involved with volunteer stewardship activities at the refuge or for information about PP&R:

Download the project fact sheet.