Willamette River Elk Rock Island Side Channel

This project includes placement of key pieces of large wood in the back channel alcove, management of invasive riparian plants, and restoration of native riparian plant communities. This project will enhance winter rearing habitat for coho, fall & spring Chinook, Pacific lamprey, and steelhead. There are very few opportunities for back channel enhancements on the Lower Willamette River due to geological constraints and this project offers a unique opportunity to improve much needed winter refuge habitat for outmigrating juvenile anadromous fish. The majority of this property is owned by the City of Milwaukie and managed by NCPRD.

The project is located at Elk Rock Island in the Mainstem Willamette River. Partners are the Clackamas Partnership and its member organizations, the City of Milwaukie, and the North Clackamas Parks and Recreation District.

Migrating adult salmon and steelhead likely use the Elk Rock Island side channel & alcove as high water refugia rearing habitat. Juvenile salmon and steelhead from both the Clackamas River and the Upper Willamette River populations are likely present during much of the year. For example, beach seining studies in the Lower Willamette River have noted juvenile Chinook salmon in every month of the year, with peak densities between January and April when river levels are high. Improving habitat complexity at this key location will provide habitat, including highwater refuge habitat, for these juvenile salmon. Monitoring observations indicate a large number of juvenile Chinook are present in Rinearson Natural Areas restored off-channel habitats just upriver on the Willamette from the site.

Currently, the site has minimal habitat complexity: A few pieces of large wood have been installed by the North Clackamas Parks and Recreation District (NCPRD) at the head of the back channel. The Council and NCPRD (North Clackamas Parks and Recreation District) annually attach Christmas trees to these large wood pieces with volunteers, to enhance the complexity and increase stakeholder understanding of the role of cover, complexity, and woody debris. There are no large pieces or accumulations consisting of multiple pieces of wood. Adding large wood and encouraging pool development at the site will improve hiding and feeding habitat for Upper Willamette juvenile Chinook, coho, and other salmonids during those winter and spring months when they are in high abundance, and during upstream migration.