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The Problem
The Cowlitz Falls Hydroelectric Project began operation in the spring of 1994 and was modeled after the Wells Hydroelectric Project on the Columbia River, Washington. A state of the art surface collector and facility, which included attraction, collection, dewatering, bypass, and handling/transport facilities, were completed in 1996. Results at the Cowlitz Falls Project after two full seasons of operation and collection, using mark recaptures, hydro-acoustics, radio telemetry, and evaluation of flow and fish directional vectors using an acoustic Doppler current profiler in the forebay, clearly demonstrated that many salmonid smolts did not readily find their way to the collection system and passed the project through the turbines, either directly or by an induction slot. This project is funded through reimbursable agreement number W68SBV00630772 with the US Army Corps of Engineers (COE). Objectives
Our objective is to improve juvenile salmon guidance efficiency by using induced turbulence to guide fish to the surface collection entrances. Methodology We will use a number of methods to evaluate the effect of induced turbulence. The number of fish collected will be used to compare treatments. An acoustic camera and 3D acoustic telemetry will be used to evaluate fish movements in response to turbulence. An Acoustic Doppler Current Profiler and an Acoustic Doppler Velocimeter will be used to map water currents and turbulence. Highlights and Key Findings Experiments conducted in 2000 at Cowlitz Falls Dam used induced water currents generated by commercial mixers to guide juvenile salmonids to surface collection entrances. Results from flume sampling indicated juvenile chinook salmon responded to the induced water currents. Overall, 18% more juvenile chinook salmon were collected with the large mixers operating and 39% more juvenile chinook salmon were collected with the small mixers operating than during the off test condition. Experiments in 2001 and 2002 focus on modifying the hydraulic signature entering the surface collection flumes, then evaluating the effectiveness of these modifications in improving fish collection efficiency using 3D acoustic telemetry. Where Are We Headed In 2003 To date, we have successfully completed the FY02 field component of this study and data analysis will take place in 2003. Project Contact Dennis Rondorf Email: dennis_rondorf@usgs.gov Publications |
