SummaryThe U.S. Army Corps of Engineers Portland District engaged the Pacific Northwest National Laboratory to evaluate fish passage at The Dalles Dam in 2004. The goal of the study was to provide information on smolt passage at The Dalles Dam that will inform decisions on long-term measures and operations to enhance sluiceway and spill passage and reduce turbine passage in order to improve smolt survival at the dam. The study addressed two of the main programs dedicated to improving juvenile salmonid survival at The Dalles Dam: Spillway Improvements and Surface Flow Bypass.The study objectives (see below) were met using a combination of hydroacoustic and hydraulic data. The study incorporated fixed-location hydroacoustic methods across the entire project, with especially intense sampling at the sluiceway and spillway using multiple split-beam transducers at selected locations. At the sluiceway nearfield, we used an acoustic camera to track fish. The fish data were interpreted and integrated with hydraulic data from a computational fluid dynamics (CFD) model and in-field acoustic Doppler current profiler (ADCP) measurements. Data were collected in the framework of an "experiment" to compare two sluiceway operations: West only (Sluice 1 [SL 1]) vs. West+East (SL 1 + SL 18). The 2004 study was divided into two periods: spring (April 19 to June 5) and summer (June 6 to July 17).During the study, daily outflow at TDA ranged from 124 to 289 kcfs. Mean daily outflow was 209 kcfs in spring and 189 kcfs in summer. Outflow peaked in early June. During the 2004 study, total project outflow was 76% of the 10-year average for spring and 77% of the 10-year average for summer. Daily powerhouse discharge averaged 122 kcfs in spring and 110 kcfs in summer. Spill for fish protection commenced on April 12. Daily spill flow during our study ranged from 49 to 119 kcfs, with a mean of 82 kcfs (39% of total) in spring and 74 kcfs (39% of total) in summer. Daily sluice flow ranged from about 3.0 to 4.6 kcfs, depending on experimental treatment and forebay elevation. In spring and summer, mean sluice discharge was 2.2% and 2.4% of total project discharge, respectively.Our study encompassed the majority of the migration period for yearling (stream-type) Chinook (Oncorhyncus tshawytscha), coho (O. kisutch), and sockeye (O. nerka) salmon as well as steelhead (O. mykiss) trout and subyearling (ocean-type) Chinook salmon. Passage of yearling fish peaked in mid-to late May. Passage of subyearling Chinook salmon, the most abundant salmonid fish migrating downstream through The Dalles Dam, peaked at the end of June. During the spring study period, species composition was: yearling Chinook salmon (60%); steelhead (16%); sockeye (11%); and coho (9%). During the summer study period, subyearling Chinook salmon comprised 89% of the outmigration.The findings, summarized by objective, were as follows:Estimate spill passage efficiency 1 and effectiveness, sluice passage efficiency and effectiveness, and fish passage efficiency on a seasonal and daily ...

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 2004iii AbstractThe Portland District of the U.S. Army Corps of Engineers requested that the Pacific Northwest National Laboratory (PNNL) conduct fish-passage studies at Bonneville Dam in 2004. These studies support the Portland District's goal of maximizing fish-passage efficiency (FPE) and obtaining 95% survival for juvenile salmon passing Bonneville Dam. Major passage routes include 10 turbines and a sluiceway at Powerhouse 1 (B1), an 18-bay spillway, and eight turbines and a sluiceway at Powerhouse 2 (B2).In this report, we present results of four studies related to juvenile salmonid passage at Bonneville Dam. The studies were conducted between April 15 and July 15, 2004, encompassing most of the spring and summer migrations. Studies included evaluations of 1) project fish passage efficiency and other major passage metrics, 2) B2 fish guidance efficiency and gap loss, 3) smolt approach and fate at the B2 Corner Collector (B2CC), and 4) B2 vertical barrier screen head differential. Appendices A through I are presented on the accompanying compact disk (CD). Most are in an Adobe Acrobat portable document format (PDF) and six large tables in Appendix E (E3-E8) are presented only as comma-separated-variable files. The CD also includes a PDF version of the report.

No abstract

In spring and summer 2003, the Pacific Northwest National Laboratory led a team that conducted mobile and fixed hydroacoustic surveys in the forebay of The Dalles Dam for the U.S. Army Corps of Engineers-Portland District. This research was part of the Corps' Anadromous Fish Evaluation Program. The surveys provided information on the distribution and movement of smolt-sized fish relative to ambient factors such as flow, bathymetry, or diel cycle in the forebay at The Dalles Dam. A proposal for the use of a guidance structure in the forebay at The Dalles Dam, a modified version of a similar structure located at Lower Granite Dam, has recently been suggested by the U.S. Army Corps of Engineers and regional resource managers as a potential approach to improve the passage survival of juvenile salmon at the dam. The structure would be designed to divert fish from the powerhouse to the spillway. This project provided baseline data for the development of a behavioral guidance structure and surface bypass alternatives for juvenile salmon at The Dalles Dam. We sampled the forebay of The Dalles Dam one day and night each week for six weeks in the spring and another six weeks in the summer. Two research vessels were used. Each pushed a raft outfitted with sampling gear consisting of two split-beam transducers, four single-beam transducers, one acoustic Doppler current profiler (ADCP), a pitch-roll-heading indicator, and a differential global positioning system (GPS). The split-beam transducers provided information on the location, size, and movement of fish. The ADCP sampled the flow environment in which each fish was detected. One 12° split-beam transducer was aimed downward. The other split-beam transducers and the four single-beam transducers were all forward-looking 6° beams that were aimed to provide intensive sampling in the upper 9 m of the water column. The rafts were secured 7.5 m forward of the bow of the research vessels (15 m from the vessel's outboard motor) to minimize fish avoidance behavior. Mobile sampling was conducted from a research vessel and raft moving in a zigzag pattern extending from 180 m above the spillway to 1.8 km upstream of the spillway along 26 transects during each sampling period. A second research vessel sampled at 15 fixed-point locations for ten minutes at each point. From the fixed sampling we determined the rate and the direction of fish movement past those points (flux). Using the combined mobile and fixed sampling methods we were able to determine the distribution of smolt-sized fish and their movement patterns in the forebay. Smolt-sized fish were defined as those with a return signal of greater than-56 dB re||1µPa and less than-34 dB for spring fish (90-320 mm) or less than-45 dB for summer fish (90-105 mm). The species of smolt-sized fish that were targeted for springtime samples were juvenile steelhead trout (Oncorhynchus mykiss), juvenile yearling Chinook salmon (O. tshawytscha), juvenile coho salmon (O. kisutch), and juvenile sockeye salmon (O. nerka). Summertime samples were ...