The Bureau of Environmental Services is planning to restore the banks along the Lower Columbia Slough to improve the habitat for fish and wildlife. The goal is to increase the population of juvenile salmonids along the shoreline areas and provide roosting for birds and bats.
To make the shoreline more habitable to fish, large wood debris structures will be placed along the banks. In addition, non-native plants will be removed and replaced with native shrubs, trees, and grass. Bird and bat houses will also be installed along the shoreline.
The wood debris structures—four logs pinned together and anchored to the bank—will be placed at 35-foot intervals along both the north and south banks of the slough. These structures will be placed above the normal high water level, but below the top of the bank. Installation will be conducted from barges to minimize damage to the shoreline from heavy equipment that would otherwise be required.
The re-vegetation plan includes planting 600 native trees, 1500 native shrubs, and native grass. After planting, the site will be maintained to ensure that invasive non-native plants do not threaten the plantings. Nine bird and bat boxes will be installed along the Slough and under the Lombard Bridge to provide a roosting habitat.
The Bureau of Development Services recently approved the project. The next step for BES is to obtain both state and federal permits. Part of the permit process includes community outreach to the neighborhood association, Friends of Smith & Bybee Lakes, and the tribes associated with the slough.
Design of the project is 90% complete. Once the design is complete and permits have been obtained construction will begin. BES anticipates construction will occur in June, but that depends on water levels in the river. Water levels must be high to install the wood structures at the proper height on the bank. If water levels are too low then construction may be delayed until November when the water levels are higher.
Map courtesy of Columbia Slough Watershed Council
The active work phase will last from 30 to 60 days. Work will begin at the Lombard Bridge and move west to the mouth of the slough at the Willamette River (in the red box above). BES will then monitor the slough for several years to record how fish, wildlife, and vegetation respond to the project.
If you have any questions contact David Helzer at the Bureau of Environmental Services, 503-823-5760
To learn more about the Columbia Slough visit the Columbia Slough Watershed Council.
