|Document Type:||Contract Report|
|Title:||Studies to determine the effectiveness of extended traveling screens and extended bar screens at McNary Dam, 1991|
|Author/Editor:||Dean A. Brege, Stephen J. Grabowski, William D. Muir, Steven R. Hirtzel, Steven J. Mazur, Benjamin P. Sandford|
|Publisher:||National Marine Fisheries Service|
|Contracting Agency:||U.S. Army Corps of Engineers. Walla Walla, Washington|
McNary Dam, at river mile 292, is operated by the U.S. Army Corps of Engineers and is the fourth hydroelectric project from the mouth of the Columbia River. A juvenile fish bypass system at McNary Dam is used to collect juvenile salmonids either for transport to release sites below the hydrosystem or to bypass and return them to the river below McNary Dam. Submersible traveling screens (STSs) are used to divert juvenile salmonids away from turbines and into the bypass system.
Previous research at McNary Dam indicated that fish guidance efficiency (FGE) for coho salmon Oncorhynchus kisutch, yearling chinook salmon O. tshawytscha, and steelhead O. mykiss was greater than 70%. However, subyearling chinook salmon, with their tendency to migrate deeper in the water column, were more difficult to guide. Tests at McNary Dam indicated that guidance for subyearling chinook salmon ranged from only 33 to 60%, although it was generally less than 50%.
In 1991, we conducted research during the spring and summer juvenile salmonid migrations to assess the effectiveness of newly designed extended length bar screens (ESBS). Concurrently, measurements were made of the smoltification status of the fish. Specific findings research in 1991 are listed below.