Fish Rescue Efforts Associated with the Hemlock Dam Removal and Trout Creek Restoration Project

This presentation and paper will discuss the recent removal of Hemlock Dam, an aging power/irrigation facility on National Forest land, as well as the fish rescue efforts associated with this project. Hemlock Dam was a 26-foot high, 180-foot long dam located on Trout Creek, a major tributary to the Wind River, on the Gifford Pinchot National Forest in southwest Washington.  The dam was built in 1935 and it continued to impact the wild steelhead trout and other fish of this watershed for 75 years before it was removed in summer 2009.  

The Wind River, including Trout Creek, supports Lower Columbia River steelhead, a Distinct Population Segment which is federally-listed as threatened under the Endangered Species Act. For the past two decades, this drainage has been managed as a wild steelhead stronghold. The recovery of Lower Columbia River steelhead here is heavily reliant on habitat improvement within the watershed because there is no hatchery supplementation occurring.    

Prior to its removal in 2009, Hemlock Dam impaired fish migration, water quality, and aquatic habitat in lower Trout Creek.  The mechanical demolition and removal of the dam was preceded by the removal of some 50,000 cubic yards of sediment from the reservoir area and the construction of two stream channels through the impacted reach. The decision to undertake a large-scale fish removal effort and to remove the impounded reservoir sediments, rather than breaching or notching the dam and allowing the sediments to erode downstream, was arrived at after consideration of the low numbers of returning steelhead adults to Trout Creek, particularly during the prior fifteen years. 

The fish removal effort, the removal of Hemlock Dam, and the stream and riparian restoration were the culmination of fifteen years of planning and partnerships between the U.S. Forest Service and many other federal, state, tribal, and private entities. This presentation and paper will describe these three components of the project, with particular emphasis on the partnerships, planning, and techniques used to capture and transport over 2,700 steelhead trout prior to the dewatering of Trout Creek and the implementation of the Hemlock Dam Removal.