Bear Creek restoration could improve salmon spawning habitat
from the U.S. Army Corps of Engineers, Seattle District
No bears wander through Bear Creek today, but fish do. The creek produces the greatest number of sockeye salmon in the Sammamish basin.
With the support of local sponsors--the city of Redmond and King County--some planned changes could greatly improve the fish and wildlife habitat in the Bear Creek basin.
In the early 1900s, the Sammamish River, with its tributaries and side sloughs, provided a nursery for fish and wildlife. The Sammamish River and its floodplain also supported a cedar swamp and agricultural lands which flooded seasonally.
In 1960, help was sought from the Corps of Engineers to provide flood protection for nearby farmlands. The lower mile of Bear Creek was channeled and riprapped as part of the Sammamish River Channel Improvement Project for flood control.
But the changes to the river affected the fish and wildlife habitat. Improved flood control encouraged development in the former agricultural lands, and today, lower Bear Creek is squeezed on both sides, by Highway 520 and by the new Town Center mall in Redmond. Because the lower mile of Bear Creek now is a narrow, fast-flowing channel, it is no longer suitable for salmon spawning, rearing, or winter refuge.
At the request of the city of Redmond and King County, the Corps is evaluating restoration of the channel section to a natural stream and floodplain by carving meanders into the lower two-thirds-of-a-mile and excavating up to 10 acres of valley floor to reestablish wetlands and provide some additional flood storage. This restoration will be cost-shared by the city of Redmond and would implement a key part of the Master Plan for Bear Creek.
Bear Creek flows are controlled largely by groundwater sources upstream. There are extensive bogs, swamps, and lakes in the upper reaches of Bear Creek and Cottage Lake Creek. Because of this valuable upstream habitat, the water temperatures in Bear Creek are much lower than in the Sammamish River. Salmon and trout use Bear Creek to escape the hot water in the Sammamish River during the summer.
To further help both juvenile and adult salmon, the Corps has proposed to plant trees and shrubs in the wetland and streamside areas to provide shade to cool the stream water. The proposed meanders in the stream will reduce velocities to allow juvenile salmon to feed and hide in the lower part of Bear Creek, even during high flows.
The Washington Department of Transportation is also proposing a "sister" project immediately upstream to restore an additional two-thirds mile. This will involve moving a small portion of the stream farther from Highway 520 for water quality and habitat improvements.
All four government agencies are working together to improve lower Bear Creek and keep the fish and wildlife healthy.