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 ...
Cold water released from the Dworshak Reservoir hypolimnion during mid-to late-summer months cools the Clearwater River far below equilibrium temperature. The volume of released cold water augments the Clearwater River, and the combined total discharge is on the order of the Snake River discharge when the two rivers meet at their confluence near the upstream edge of Lower Granite Reservoir. With typical temperature differences between the Clearwater and Snake rivers of 10°C or more during July and August, the density difference between the two rivers during summer flow augmentation periods is sufficient to stratify Lower Granite Reservoir as well as the other three reservoirs downstream.Because cooling of the river is desirable for migrating juvenile fall Chinook salmon (Oncorhynchus tshawytscha) during this same time period, the amount of mixing and cold water entrained into Lower Granite Reservoir's epilimnion at the Clearwater/Snake River confluence is of key biological importance. Data collected during this project indicates the three reservoirs downstream of Lower Granite also stratify as direct result of flow augmentation from Dworshak Reservoir. These four reservoirs are also heavily influenced by wind forcing at the water's surface and during periods of low river discharge often behave like a two-layer lake. During these periods of stratification, lower river discharge, and wind forcing, the water in the upper layer of the reservoir is held in place or moves slightly upstream. This upper layer is also exposed to surface heating and may warm up to temperatures close to equilibrium temperature. The thickness (depth) of this upper warm layer and its direction of travel may be of key biological importance to juvenile fall Chinook salmon.This report describes field data collection, modeling, and analysis of hydrodynamic and temperature conditions in the Lower Granite Reservoir during the summer flow augmentation periods of 2002, 2003, and 2004. Although temperature, and hence density, differences during flow augmentation periods between the Clearwater and Snake rivers were approximately equal (7-12°C) for all four years, the discharge ratio varied which resulted in significant differences in entrainment of cooler Clearwater River water into the Lower Granite Reservoir epilimnion. However, as a direct result of system management, Lower Granite Dam tailrace temperatures were maintained near 20°C during all years. Primary differences in the other three lower Snake River reservoirs were therefore a result of meteorological conditions and dam operations, which produced variations in wind setup and surface heating.Circulation patterns in all four lower Snake River reservoirs were numerically simulated for periods of 2002, 2003, 2004, and 2005 using CE-QUAL-W2. Simulation results show that these models are capable of matching diurnal and long-term temperature and velocity changes in the reservoirs. In addition, the confluence zone of the Clearwater and Snake rivers was modeled using the threedimensional non-hydrost...
Summer temperatures in the Lower Snake River can be altered by releasing cold waters that originate from deep depths within Dworshak Reservoir. These cold releases are used to lower temperatures in the Clearwater and Lower Snake Rivers and to improve hydrodynamic and water quality conditions for migrating aquatic species. This project monitored the complex threedimensional hydrodynamic and thermal conditions at the Clearwater and Snake River confluence and the processes that led to stratification of Lower Granite Reservoir (LGR) during the late spring, summer, and fall of 2002. Hydrodynamic, water quality, and meteorological conditions around the reservoir were monitored at frequent intervals, and this effort is continuing in 2003. Monitoring of the reservoir is a multi-year endeavor, and this report spans only the first year of data collection.
A 42-month investigation from 1996 to 1999 determined that from 211,685 to 576,676 fish were entrained annually at Grand Coulee Dam. Analysis of the entrainment data found that 85% of the total entrainment occurred at the dam's third powerplant. These numbers represent a significant loss to the tribal fisheries upstream of the dam.In response to a suggestion by the NWPPC Independent Scientific Review Panel, the scope of work for the Chief Joseph Kokanee Enhancement Project was expanded to include a multiyear pilot test of a strobe light system to help mitigate fish entrainment. This report details the work conducted during the third year of the strobe light study by researchers of the Colville Confederated Tribes in collaboration with the Pacific Northwest National Laboratory.The objective of the study is to determine the efficacy of a prototype strobe light system to elicit a negative phototactic response in kokanee and rainbow trout under field conditions. The prototype system consists of six strobe lights affixed to an aluminum frame suspended 15 m vertically underwater from a barge secured in the center of the entrance to the third powerplant forebay. The lights, controlled by a computer, illuminate a region directly upstream of the barge.The 2003 study period extended from June 16 through August 1. Three light treatments were used: all six lights on for 24 hours, all lights off for 24 hours, and three of six lights cycled on and off every hour for 24 hours. These three treatment conditions were assigned randomly within a 3-day block throughout the study period.Hydroacoustic technology was used to evaluate the effectiveness of the strobe lights in eliciting a negative phototactic response in fish. The hydroacoustic system in 2003 comprised seven splitbeam transducers arrayed in front of the strobe lights, two multibeam transducers behind the lights, and a mobile splitbeam system. The seven splitbeam transducers were deployed so they tracked fish entering and within the region illuminated by the strobe lights. These transducers were spaced approximately 4 m apart on an aluminum frame floating upstream of the barge and looked vertically downward. The multibeam transducers monitored the distribution of fish directly behind and to both sides of the lights, while the mobile splitbeam system looked at the distribution of fish within the third powerplant forebay.To augment the hydroacoustic data, additional studies were conducted. The hydrodynamic characteristics of the third powerplant forebay were measured, and acoustically tagged juvenile kokanee were released upstream of the strobe lights and tracked within the forebay and downstream of the dam. Strobe Light Deterrent Efficacy Test 2003 Final Report ivAnalysis of the effect of strobe lights on kokanee and rainbow trout focused on the number of fish detected in each of the areas covered by one of the downlooking transducers, the timing of fish arrivals after the status of the strobe lights changed, fish swimming effort (detected velocity minus flow velocity), an...
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