Steigerwald Floodplain Reconnection Project Enters Final Year of Construction
- June 15, 2021
- John Harrison
Work on a major habitat improvement and restoration project along the lower Columbia River about 10 miles east of the Portland/Vancouver area is in the third and final year of construction in 2021, reconnecting historic floodplain to the river for the benefit of fish and wildlife, particularly juvenile salmon and steelhead migrating to the ocean.
The Steigerwald Habitat Restoration and Flood Control Project involves removing 2.2 miles of an existing flood-control levee, building two new levees to protect adjacent properties from flooding and, as a result, reconnecting 965 acres of floodplain habitat to the river. The project also will expand the size of the existing 1,049-acre Steigerwald Lake National Wildlife Refuge, which is managed by the U.S. Fish and Wildlife Service, and increase recreational opportunities.
The Steigerwald project involves a collaboration of numerous entities including the Lower Columbia Estuary Partnership, Bonneville Power Administration, U.S. Fish and Wildlife Service, Friends of the Columbia Gorge, and six others. Elaine Placido, executive director of the Lower Columbia Estuary Partnership, provided an update on the project to the Council’s Fish and Wildlife Committee at its June meeting.
“Our focus is on recovery of salmon, steelhead, and lamprey habitat and restoring unobstructed passage,” she said. In early June, work began on regrading the bed of Gibbons Creek. This involved trapping and relocating fish, including almost 5,000 lamprey. “That’s pretty impressive,” she said.
Currently, the levee system, constructed in the mid-1960s, partially blocks Gibbons Creek from flowing into the Columbia, causing occasional flooding. The levee also blocks access to important potential resting and rearing habitat for migrating fish. In addition to removing a portion of the levee, the project will remove a water-diversion structure on Gibbons Creek, enhance approximately two miles of wetland channels, and plant new trees in 225 acres of forest along the shoreline, Placido said. By reducing the potential for Gibbons Creek to flood, the project also will reduce pumping costs at a wastewater treatment facility operated by the Port of Camas-Washougal adjacent to the western boundary of the refuge.
The Steigerwald refuge was created in the early 1980s as partial mitigation for the fish and wildlife impacts of the construction of the second powerhouse at Bonneville Dam about 25 miles upriver. Expanding the refuge will increase habitat and restore natural ecosystem processes for the benefit of Winter Steelhead, Cutthroat Trout, Chinook, Coho, and Chum salmon, and Pacific and Western Brook Lamprey.
As part of its work monitoring ecosystem conditions in the lower Columbia and estuary, the Estuary Partnership is working to identify where fish are vulnerable to climate change impacts, Placido said. Currently there is a 57-mile stretch of the river, from the mouth of the Lewis River to Bonneville Dam, where there are few or no places for migrating juvenile fish to pull out of the Columbia and rest in cooler water, and this problem will be exacerbated as river temperatures warm in the future, particularly in the late spring and summer when many juvenile salmon and steelhead migrate, she said.
This makes the Steigerwald reconnection project, located about half way between the Lewis River and Bonneville, extremely important to the survival of juvenile fish. The project also will improve Gibbons Creek as a place for adult salmon and steelhead to spawn. The two new levees, one at the east side of the refuge and the other on the west side, will have “living shorelines” of trees and vegetation as opposed to the traditional rock riprap. The project also involves raising a portion of State Highway 14 above the 500-year flood level, reconstructing the existing trail system through the refuge, and building a new parking lot and restroom at the new trailhead, which will be a short distance west of the old one.