Hydroacoustic Evaluation of Fish-Passage Efficiency at Bonneville Dam in 2001

Abstract

The Portland District of the U.S. Army Corps of Engineers requested that scientists with the Pacific Northwest National Laboratory (PNNL) and the U.S. Army Engineer Research and Development Center (ERDC) conduct the hydroacoustic fish-passage studies described in this report. The ERDC also contracted with MEVATEC Corporation and Dyntel to provide staff ranging from scientists to technicians for the study. This study supports the Portland-District goal of maximizing fish passage efficiency (FPE) and obtaining 95% survival for juvenile salmon passing the Bonneville Project. This report presents results of two hydroacoustic studies of juvenile salmonids. One was a Project-wide study of fish-passage efficiency, and the other was more narrowly focused upon the approach, vertical distribution, and fish-guidance efficiency (FGE) of fish at Unit 15, where the Portland District extensively modified the gatewell and vertical barrier screen to improve gatewell flow and FGE. The goal of the larger of the two studies was to provide project-wide estimates of FPE, spill efficiency, and spill effectiveness for run-of-river fish passing the Bonneville Project during the 2001 out-migration. This type of study also provides estimates of the horizontal, vertical, and diel distributions of fish passage and FGE by turbine unit. These data will provide a baselinemore » for evaluating the performance of future management efforts to improve juvenile fish passage. The goal of the second study was to assess the effect of gatewell and vertical-barrier-screen modifications on the FGE of Unit 15.« less