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 fish-passage studies at Bonneville Dam using hydroacoustic evaluation methods. 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 conducted in 2001 at Bonneville Dam in an extensive summary, in the main body of the report, and in appendices. Appendix E on the accompanying compact disk includes hourly estimates of forebay elevation and route-specific water discharge, fish passage, and associated variances and covariances. One study was a project-wide evaluation of fish-passage efficiency, and the other was a more narrowly focused study of 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 baseline 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.

Hydroacoustic Evaluation of Fish Passage Through Bonneville Dam in 2002

“…This was the third consecutive year of full-project hydroacoustic sampling and passage estimation. The first was conducted in 2000 (Ploskey et al 2002a and b) and the second in 2001 (Ploskey et al 2002c).…”

Re-Analysis of Hydroacoustic Fish-Passage Data from Bonneville Dam after Spill-Discharge Corrections

“…Routes of interest included the spillway, Powerhouse 1 (B1) turbines, Powerhouse 2 (B2) turbines, B1 sluiceway relative to B1, B2 Corner Collector (B2CC) relative to B2, and all non-turbine routes combined (i.e., fish-passage efficiency). For a detailed description of sampling methods by year, we refer readers to the original technical reports (Ploskey et al 2002a(Ploskey et al , 2002b(Ploskey et al , 2003(Ploskey et al , 2005(Ploskey et al , and 2006. During the re-analysis, we took the opportunity to adjust spatial expansions of spillway-passed fish to compensate for reduced hydroacoustic detectability that occurs when spill discharge through individual bays increases, something that was done for the first time in the 2006 report on 2005 data.…”

“…The first study was conducted in 2000 by the Engineer Research and Development Center, U.S. Army Corps of Engineers, Vicksburg, Mississippi (Ploskey et al 2002a). Subsequent studies in 2001 (Ploskey et al 2002b), 2002(Ploskey et al 2003), 2004(Ploskey et al 2005, and 2005 (Ploskey et al 2006) were conducted by PNNL, Richland, Washington.…”

“…The two most obvious determinants of dam operations are water availability in the reservoir and the demand for hydropower generation. The drought of 2001 was an extreme case wherein discharge was only 48% of the ten-year average annual discharge from 1996-2005 (Figure 1.2), which, combined with very high generation demand, led to unusually low spill volumes over a curtailed spill season (Ploskey et al 2002b). In 2001, the project spilled 16% of the total discharge in spring and 11% in summer, down from 31% and 50%, respectively, in 2000.…”

“…For study years from 2000 through 2004, hydroacoustic detectability for all passage routes, except the spillway, remained the same as described in the original technical reports (Ploskey et al 2002a, Ploskey et al 2002b, Ploskey et al 2003, Ploskey et al 2005. However, spatial expansions for spillway passage for 2000, 2001, 2002, and 2004 were scaled upward to account for decreasing detectability with increasing discharge through individual spill bays, similar to what was done to 2005 spillway data (Ploskey et al 2006).…”