DESCRIPTION
This project restored fish passage to 2 miles of spawning and rearing habitat for chum, Chinook, Coho, and steelhead, on tributary channel 15.0187, in the Curley Creek watershed. Funds were utilized to remove the fishway/barrier, remove accumulated sediment behand the dam, restore the stream channel and replace the road crossing with a 40' bridge.
The 20 foot high earthen dam impounding the tributary channel 15.0187 at the confluence with Curley Creek was removed. A four-foot wide concrete weir-pool fishway which provided fish passage was failing and was also removed and a stream channel was constructed under the new bridge. Fish no longer have to navigate 12 weirs that averaged about 12 inches high each. A roadway crossed the channel atop the fishway and earthen embankment was removed. To establish a stream channel upstream of the dam, some of the sediment that had accumulated behind the dam was removed and approximately 300 feet of stream channel was formed. The stream was contoured and LWD installed to provide channel structure in otherwise fine substrate and to provide salmon habitat.
Construction of the bridge and stream channel resulted in the removal of several barriers... a drop barrier at the outfall pool, the dam acting as a hydraulic control, and the total blockage of sediment transport and disconnection of stream morphology. The WDFW fishway assessment report notes the concrete weir had an excessive outfall drop of approximately 18 inches and an undersized low flow notch classifying the fishway as a partial passage barrier with an estimated pass ability of 67%. The concrete fish weir and associated pond and water control bypass we're in poor condition and failure could result in flows that further restrict fish passage or render the structure impassable. Also, the dam bypass was not screened and fish passage likely leads to mortality.
Now salmon can navigate the entrance of this tributary with out any manmade barriers. The riparian area will continue to improve with establishment of the native trees and shrubs that were planted. KCD produced a project video and the landowners have provided several public viewing opportunities.