Concurrent Sessions A: Emerging Engineering Solutions for Downstream Fish Passage at Big Dams - Cowlitz Falls North Shore Collector - Downstream Fish Passage Project
Completion of the Cowlitz River Project in the 1960s effectively blocked historical Cowlitz River runs of coho, spring and fall Chinook salmon, steelhead and sea-run cutthroat trout from volitional migration to about 80% of their former spawning habitat. Tacoma Power unsuccessfully attempted to maintain the runs through trap and haul of out-migrants upstream from Mossyrock Dam until 1973. Then, in the mid-1990s, Bonneville Power Administration (BPA) began reintroduction of salmon and trout upstream from the Cowlitz Falls Dam and added juvenile fish collection facilities at the dam called the Cowlitz Falls Fish Facility (CFFF). The CFFF was installed during dam construction in 1996 and was modeled after a surface collection concept at the Wells Dam Hydroproject in eastern Washington. This facility has never performed as well as intended for a number of reasons. As part of Tacoma Power’s 35-year federal license for its Cowlitz River Hydroelectric Project issued in 2003, Tacoma Power agreed to improve downstream fish passage on the Cowlitz River and has been working with the Cowlitz Fisheries Technical Committee (FTC) including representation from Tacoma Power, Lewis County PUD, resource agencies, and regional stakeholders to improve fish passage performance at the Dam. This presentation will provide an overview of the history of the project, the original fish passage facilities, and a summary of Tacoma Power’s efforts since 2003 that included creation of a Fish Passage Design Team as a subcommittee to the FTC. The process the Design utilized to develop conceptual designs will be presented, along with their recommendations that helped Tacoma Power decide to move forward with a new North Shore Collector. Additionally, the presentation will provide an overview of the investigations and design efforts underway since 2011 to refine the design concepts and converge on a final design layout that is planned for construction in 2015
