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Environmental Services

working for clean rivers

Phone: 503-823-7740

Fax: 503-823-6995

1120 SW 5th Avenue, 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.

Portland Parks & Recreation manages the site as an important habitat area and an inviting place to enjoy wildlife viewing 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

Portland Parks & Recreation and Environmental Services are working together on design of a large scale habitat enhancement project to benefit wildlife and people. The project will enhance 75 acres of wetland habitat by:

  • Replacing the existing culvert with a larger box culvert to enhance fish passage and significantly improve the flow of Willamette River water in and out of the refuge
  • Excavating tidal slough channels and enhancing wetland habitats at the southern end of the refuge to provide off-channel refuge for ESA-listed salmon
  • Removing invasive vegetation, such as purple loosestrife, and revegetating with native species to improve wildlife habitat
  • Enhancing opportunities for environmental education and interpretation of the refuge from the Springwater on the Willamette Trail


  • Design: 2009-2016
  • Construction: 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.The closure will create heavier use on other Oaks Bottoms trails in sensitive wildlife areas. Trail users are required to stay on trails, leash dogs and respect Oaks Bottom wildlife. 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 River Estuary Partnership
  • US Fish & Wildlife Service


To get involved with volunteer stewardship activities at the refuge or for information about the Portland Parks & Recreation Environmental Stewardship Program:

Project Partners

  • City of Portland Parks & Recreation
  • City of Portland Environmental Services
  • U.S. Army Corps of Engineers
  • Willamette Riverkeeper
  • Audubon Society of Portland
  • Urban Greenspaces Institute
  • Neighbors and users of Oaks Bottom Wildlife Refuge
  • Metro