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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

 Project Description

Environmental Services, Portland Parks & Recreation, and the U.S Army Corps of Engineers worked together on a large-scale habitat enhancement project to benefit wildlife and people. The project restored 75 acres of wetland habitat in 2018 by:

  • Replacing an existing culvert with a larger 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

Details of the project

Detail map of project

schematic diagram of the new culvert

WILL SALMON USE HABITAT IN THE WILDLIFE REFUGE?

Generally, when the right kind of habitat is available, it gets used.  In Crystal Springs - when we removed barriers, salmon were immediately visible.  We expect that salmon will immediately use the refuge now that they can get there.  Salmon seek out cooler, calmer water and the new channels are now ideal for baby salmon to hide from predators, find food, and rest.  Because the habitat is primarily for young salmon on their way to the Ocean, their presence may not be as visible, but BES scientists will regularly survey for fish, and when we have news, we’ll share it! 

THE SITE LOOKS BARE – WILL IT BE PLANTED?

Yes, in February 2019, BES crews will install thousands of seedling- and cutting-sized trees and shrubs.  The small-sized plantings will take a while to fill in, but eventually, we expect that the entire project area to be covered with native vegetation.

WILL THIS PROJECT HELP CONTROL PURPLE LOOSESTRIFE?

With the water control structure gone, and a better culvert installed, purple loosestrife may not thrive like it did, but time will tell.  But, PP&R and BES will continue to work with Oregon Department of Agriculture, and other partners to control purple loosestrife in the refuge while also continuing to work on establishing native vegetation in the refuge. 

WHAT ARE THOSE SLASH PILES? WILL THOSE BE CLEANED UP?

As much as possible, vegetation that needed to be cleared was re-used on the site.  Rather than haul excess woody material offsite, the contractor used the material to construct brush piles for birds, reptiles, salamanders, and small mammals to use for nesting and cover.  Trees were also re-purposed as large woody debris in the channels. 

WHAT IS THE DIFFERENCE BETWEEN THE VIEWING PLATFORM AND THE OVERLOOK?

Construction of the overlook is complete – it is the wide section of the trail near the new channels and culvert.  The viewing platform is an elevated, wood deck that will be constructed closer to Oaks Amusement Park.  It will be ideal for wildlife viewing over the open water area.  We anticipate construction to begin in Spring 2019. 

DID THE SPRINGWATER CORRIDOR TRAIL CLOSE DURING THE PROJECT?

The trail was open to the wildlife refuge but closed as a through route as crews cut through the trail, railroad tracks and berm during construction.  To view construction photos and videos, visit BES's Flickr Page and a timelapse video of the construction.

Contact Info

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