Appendix E-6C. Fish Entrainment - Eugene Water & Electric Board

Fish Entrainmentat the Carmen-Smith Hydroelectric Project,Upper McKenzie River Basin, OregonFinal ReportPrepared forEugene Water & Electric BoardEugene, OregonPrepared byStillwater SciencesArcata, CaliforniaJanuary 2006

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical ReportFish Entrainmentat the Carmen-Smith Hydroelectric Project,Upper McKenzie River Basin, OregonExecutive SummaryIntroductionThe Carmen-Smith Hydroelectric Project (Project) (FERC No. 2242) is a 114.5-megawatt (MW)facility owned and operated by the Eugene Water & Electric Board (EWEB). The Project’s existinglicense, issued by the Federal Energy Regulatory Commission (FERC), expires on 30 November2008. To obtain a new license for operating the Project, EWEB prepared and distributed an InitialConsultation Package (ICP) (EWEB 2003). Following issuance of the ICP, public meetings andstudy scoping sessions were held in Fall 2003 to discuss the Project’s operations and potentialenvironmental effects.During the ICP review, an Aquatics Technical Subgroup (ATS) was formed and worked together todevelop a study plan for the Fish Entrainment study (Stillwater Sciences 2004). This report describesthe results of the Fish Entrainment study, portions of which were implemented by EWEB through anorder issued by FERC (FERC 2003). This technical report describes the methods used in this studyand the results of the analysis. Details on the methods used for installing, monitoring, and analyzinghydroacoustic transducer data are described in Fixed-Aspect Hydroacoustic Evaluation of FishPassage at Trail Bridge Dam (2004-2005) (Exhibit 3). Outcomes of the technical studies that pertainto management decisions or actions will be addressed in the License Application, due to FERC inNovember 2006.In this study, “entrainment” is considered the movement of fish, volitional or otherwise, from areservoir through various water conveyances at a dam to downstream exit locations. The purpose ofthis study is to: (1) document and evaluate entrainment through Project facilities, and (2) evaluate thepotential for delay or injury associated with Project tailraces.MethodsStudies were developed to evaluate the species composition, magnitude, and timing of entrainment atProject facilities.• To estimate the species and numbers of fish entrained at the Trail Bridge turbine intake andspillway, and to determine the rate of injury or mortality for salmonids entrained throughTrail Bridge Powerhouse, monitoring was conducted with hydroacoustic transducers, remotevideo cameras, passive integrated transponder (PIT) tag antennas, and a rotary screw trap.• To determine the risk of entrainment of resident trout at the Smith intake (the intake forCarmen Powerhouse), spillway information from field surveys (sonar and speciescomposition) and data in the scientific literature were assessed.• To estimate the numbers and species composition of fish entrained into the Carmen Diversiontunnel, an underwater camera was used to monitor entrainment.• To determine the species composition and relative numbers of fish entrained at CarmenDiversion spillway, snorkel surveys, fyke trapping, and electrofishing methods were used.• To assess the risk of fish entrainment into draft tubes at the Carmen Powerhouse and TrailBridge Powerhouse tailraces, direct observation surveys were conducted (snorkel and video)and PIT tag antennas were installed and monitored.20 January 2006 Stillwater SciencesCopyright © 2006 Eugene Water & Electric Board- i -

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical Report• To determine the susceptibility for juvenile or adult fish to move into draft tubes and beinjured or killed, Project operations and associated velocities at the tailraces and in theturbines were evaluated.ResultsAccurate enumerations of the number of fish entrained (an original objective of the study) were notpossible. The hydroacoustic estimates of passage represent a relative index rather than an absoluteestimate because of filtering of data and false detections from debris. Based on hydroacoustic datacollected at Trail Bridge turbine and spillway, fish are entrained at both locations. Video footageindicated that hydroacoustic detections (or simply detections) at the turbine included both fish anddebris. In addition, PIT-tagged fish detected on the spillway and downstream either passed over thespillway or through the turbine. Chinook salmon (Oncorhynchus tschawytscha) smolts (progeny ofhatchery adult spring Chinook released into Trail Bridge Reservoir) were captured at the rotary screwtrap in Trail Bridge tailrace, dead, alive, or injured. Injuries appeared consistent with what would beexpected in a turbine. The proportion of fish injured or killed passing through the turbine was notestimated, and although many analogous Kaplan systems result in less than 5% mortality (Skalski etal. 2002), the turbine mortality at Trail Bridge turbine is assumed to be greater than 10%.Based on hydroacoustic data, passage at Trail Bridge Dam peaked from November through February.Passage was higher at the Trail Bridge turbine during the night than during the day, and the oppositewas observed at the spillway. Based on hydroacoustic data, fish are more likely to pass downstreamvia the spillway, even though the Project spilled water less than 10% of the time during the study.At the Smith intake, resident trout could be entrained. No direct data on entrainment at the Smithintake were collected. A literature review and field surveys of fish distribution indicates that fewnative species are present in Smith Reservoir; those that are present are not in the vicinity of theSmith intake, and the intake is deeper than the depths occupied by species present in the reservoir.However, the literature does indicate that if fish were entrained at the Smith intake, injury andmortality rates would be expected to be high (> 10%).No direct data on entrainment at the Smith spillway were collected. The spillway is a “flip bucket”freefall to a bedrock pool, with a relatively high head, making the likelihood of injury and mortalityof any fish traversing the spillway high. However, because of the species composition anddistribution in the reservoir, and because of the low frequency of spills at the spillway, few native fishare expected to be entrained at the Smith spillway.At Carmen Diversion, fish are entrained into the diversion tunnel or over the spillway. The risk ofentrainment is primarily to brook trout (Salvelinus fontinalis) and hatchery rainbow trout, given thelow abundance of native cutthroat in Carmen Diversion Reservoir, and absence in field surveysconducted below Carmen Diversion Dam following spills.Bull trout (Salvelinus confluentus) or Chinook salmon could, in theory, enter the draft tubes at theTrail Bridge and Carmen powerhouses when turbines are not operational, and be injured or killedwith the turbines are turned on. For the Trail Bridge Powerhouse, risk is mitigated by the partialeffectiveness of the tailrace barrier, infrequent off-line turbine periods, and the hydraulics in the drafttubes. Although turbines at the Carmen Powerhouse are cycled on and off daily, snorkel surveys andexamination of adult Chinook salmon (live and carcasses) for injuries provided no evidence that fishenter the draft tubes and suffer injury or mortality. Furthermore, water at the draft tube exit and in thevicinity of the draft tubes is remarkably clear, allowing thorough examination of the tail water.20 January 2006 Stillwater SciencesCopyright © 2006 Eugene Water & Electric Board- ii -

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical ReportAdult hatchery Chinook salmon released into Trail Bridge Reservoir could be delayed at thedischarge from the Carmen Powerhouse prior to spawning in the Carmen Bypass Reach or SmithBypass Reach. However, patterns of upstream fish migration suggest there is no delay fromdischarge at the Carmen Powerhouse tailrace. Habitat conditions in the vicinity of the CarmenPowerhouse (e.g., deep water, structure, intersection of water from the bypass reach and reservoir) aresuitable for salmonids when the powerhouse is operating and when it is off.20 January 2006 Stillwater SciencesCopyright © 2006 Eugene Water & Electric Board- iii -

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical ReportTable of Contents1 INTRODUCTION ....................................................................................................................11.1 Background ......................................................................................................................11.2 Purpose and Relationship to Other Studies......................................................................21.3 Key Questions..................................................................................................................31.4 Study Area .......................................................................................................................42 METHODS................................................................................................................................52.1 Literature Review.............................................................................................................52.2 Entrainment through Project Turbines.............................................................................52.2.1 Hydroacoustics at Trail Bridge turbine intake.........................................................52.2.2 Video monitoring at Trail Bridge turbine intake.....................................................72.2.3 Rotary screw trap in Trail Bridge Powerhouse tailrace...........................................72.2.4 PIT tag antennas downstream of Trail Bridge Dam................................................82.2.5 Entrainment at Smith intake....................................................................................92.3 Entrainment at Project Spillways.....................................................................................92.3.1 Hydroacoustics at Trail Bridge spillway .................................................................92.3.2 PIT tag antenna at Trail Bridge spillway...............................................................102.3.3 Entrainment at Smith spillway ..............................................................................112.3.4 Fyke trap and electrofishing at Carmen Diversion spillway .................................112.4 Entrainment at Carmen Diversion Tunnel .....................................................................122.5 Risk at Project Tailraces ................................................................................................132.5.1 Direct observation surveys in Trail Bridge and Carmen powerhouse tailraces.....132.5.2 PIT tag antennas in Project tailraces .....................................................................142.5.3 Vaki Riverwatcher and video in Carmen Bypass Reach.......................................153 RESULTS................................................................................................................................163.1 Trail Bridge Turbine ......................................................................................................163.1.1 Entrainment rates...................................................................................................163.1.2 Entrainment effects................................................................................................193.2 Trail Bridge Spillway.....................................................................................................213.2.1 Spill frequency ......................................................................................................213.2.3 Entrainment effects................................................................................................273.3 Effects of Project Operations on Entrainment at Trail Bridge Dam ..............................283.4 Smith Intake ...................................................................................................................283.5 Smith Spillway...............................................................................................................293.6 Carmen Diversion Spillway...........................................................................................303.7 Carmen Diversion Tunnel Intake...................................................................................323.8 Project Tailraces.............................................................................................................323.8.1 Trail Bridge Powerhouse tailrace ..........................................................................323.8.2 Carmen Powerhouse tailrace.................................................................................344 LITERATURE CITED ..........................................................................................................3620 January 2006 Stillwater SciencesCopyright © 2006 Eugene Water & Electric Board- iv -

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical ReportTablesTable 1-1. Key questions and report sections in which they are addressed........................................3Table 2-1. Fish-equivalent length classes. ..........................................................................................6Table 2-2. Trail Bridge Powerhouse tailrace rotary screw trap location, and sampling duration andfrequency. ..........................................................................................................................7Table 2-3. PIT tag antennas downstream of Trail Bridge Dam and dates of operation......................8Table 2-4. Underwater video camera sampling dates and duration at Carmen Diversion tunnel in2004. ................................................................................................................................12Table 2-5. Locations and sampling periods for direct observation surveys at Trail Bridge andCarmen powerhouse tailraces..........................................................................................14Table 3-1. Summary of hydroacoustic mean hourly detection rates at the Trail Bridge turbine from10 May 2004 to 17 May 2005. ........................................................................................17Table 3-2. Summary of Trail Bridge turbine intake video observations, based on over 250 hours offootage during daylight hours..........................................................................................18Table 3-3. Summary of bull trout and Chinook salmon detections downstream of Trail Bridge Damin 2004 and 2005. Based on 191 PIT tagged bull trout, 141 Chinook salmon adults, and71 other trout species. ....................................................................................................19Table 3-4. Summary of Trail Bridge Powerhouse tailrace rotary screw trap captures from April2004 to July 2005, based on 145 days of trapping. .........................................................20Table 3-5. Summary of hydroacoustic mean hourly detection rates at the Trail Bridge spillway, 10May 2004 to 17 May 2005 (522 hours of spill)...............................................................22Table 3-6. Summary of weekly detections at Trail Bridge spillway during periods of spill, May2004 to May 2005............................................................................................................23Table 3-7. PIT tag detections of fish passing over Trail Bridge Dam and detected at Carmen-SmithSpawning Channel. Based on 191 PIT tagged bull trout, 141 Chinook salmon adults,and 71 other trout species. ...............................................................................................25Table 3-8. PIT tag detections of fish detected at Trail Bridge spillway. Antenna was operationalfrom 20 April to 20 July 2005, and from 10 September to 1 November 2005. Based on191 PIT tagged bull trout, 141 Chinook salmon adults, and 71 other trout species. .......27Table 3-9. Fish captured directly downstream of Carmen Diversion Dam during 2004 and 2005spill events.......................................................................................................................30Table 3-10. Typical velocities in draft tubes at the Trail Bridge Powerhouse tailrace when power isbeing generated. (See Figure 3-9 for velocity locations.)...............................................33Table 3-11. Typical velocities in draft tubes at Carmen Powerhouse tailrace when power is beinggenerated. (See Figure 3-10 for velocity locations.).......................................................34FiguresFigure 1-1. Study Area.Figure 1-2. Relationship of the Fish Entrainment study to other Carmen-Smith HydroelectricProject relicensing studies.Figure 2-1. Rotary screw trap in Trail Bridge tailrace.Figure 2-2. Trail Bridge tailrace helical antenna.Figure 2-3. Trail Bridge tailrace, with the square-shaped antenna represented in red.Figure 2-4. Carmen-Smith Spawning Channel antenna.Figure 2-5. Trail Bridge Velocity Barrier antennas.Figure 2-6. Smith intake.Figure 2-7. Trail Bridge spillway (from the reservoir facing downstream).Figure 2-8. Trail Bridge spillway construction drawing.20 January 2006 Stillwater SciencesCopyright © 2006 Eugene Water & Electric Board- v -

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical ReportFigure 2-9. Trail Bridge spillway antenna, facing up the spillway (upper image) with the antennahighlighted in red, and facing perpendicular to the spillway (lower image).Figure 2-10. Smith spillway.Figure 2-11. Smith spillway, facing downstream.Figure 2-12. Smith spillway construction drawing.Figure 2-13. Smith spillway scour hole, two-foot contours.Figure 2-14. Carmen Diversion spillway.Figure 2-15. Fyke trap in 2004, shown at 80 cfs.Figure 2-16. Fyke trap in 2005, shown at 1 cfs.Figure 2-17. Carmen Diversion tunnel intake.Figure 2-18. Carmen Powerhouse tailrace, with antenna represented in red.Figure 2-19. Underwater view of lower Carmen Bypass Reach Vaki Riverwatcher and weir.Highlighted box shows the passage of an adult Chinook salmon.Figure 2-20. Lower Carmen Bypass Reach Vaki Riverwatcher and weir.Figure 3-1. Trail Bridge tailrace rotary screw trap captures of Chinook salmon fry and juveniles.Data was averaged by month from 12 April–7 August 2004 and 26 January–10 June2005.Figure 3-2. Trail Bridge spillway at a high-magnitude spill (

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical Report1 INTRODUCTION1.1 BackgroundThe Carmen-Smith Hydroelectric Project (Project) (FERC No. 2242) is a 114.5-megawatt (MW)facility owned and operated by the Eugene Water & Electric Board (EWEB). The Project’sexisting license, issued by the Federal Energy Regulatory Commission (FERC) under the FederalPower Act (FPA), expires 30 November 2008. To obtain a new license for operating the Project,EWEB is using the traditional three-stage licensing process. During the first stage, EWEBprepared and distributed an Initial Consultation Package (ICP) (EWEB 2003). Followingissuance of the ICP, public meetings and study scoping sessions were held in fall 2003 to discussthe operations and potential environmental effects of the Project. Study scoping sessions wereattended by representatives of non-governmental organizations (NGOs), tribes, and manygovernmental agencies, including the United States Fish and Wildlife Service (USFWS), OregonDepartment of Fish and Wildlife (ODFW), National Oceanic and Atmospheric Administration(NOAA) Fisheries, and United States Department of Agriculture Forest Service (USFS). AnAquatics Technical Subgroup (ATS) was formed with representatives from these groups, andworked together to develop a study plan for the Fish Entrainment study (Stillwater Sciences2004).Bull trout and spring Chinook salmon are two species of ecological and regulatory interest. TheProject is within the range of two bull trout local populations, one in the mainstem and tributariesof the McKenzie River downstream of Trail Bridge Dam, and the other in the mainstem andtributaries of the McKenzie River upstream of Trail Bridge Dam (USFWS 1998). On June 10,1998, the USFWS issued a final rule listing the Columbia River and Klamath River populationsof bull trout as threatened under the authority of the Endangered Species Act (ESA) of 1973. TheWillamette Basin was excluded from the final rule designating critical habitat in October 2004(USFWS 2004).Spring Chinook salmon are native to the McKenzie River basin and belong to the UpperWillamette River (UWR) Evolutionary Significant Unit (ESU). Spring Chinook salmon in thisESU are listed as threatened under the Endangered Species Act (ESA), and includes all naturallyspawned spring Chinook salmon populations in the Clackamas River and in the Willamette Riverand its tributaries above Willamette Falls (NMFS 2005a). Seven artificial propagation programsare considered part of this ESU, including spring Chinook salmon produced by the McKenzieRiver Hatchery (NMFS 2005a). NMFS designated critical habitat for this ESU that includesstream channels within the designated reaches, extending laterally to the ordinary high-water line(NMFS 2005b). The upstream extent of designated critical habitat on the McKenzie Riverincludes Trail Bridge Reservoir and the Smith Bypass Reach to just above its confluence withTrail Bridge Reservoir, and the Carmen Bypass Reach to Tamolitch Falls (NMFS 2005b). Adultspring Chinook salmon originating from the McKenzie Hatchery are currently released into TrailBridge Reservoir, and NMFS is considering whether unmarked adult Chinook salmon that reachthe base of Trail Bridge Dam of their own accord should be reintroduced upstream of TrailBridge Dam. Historical spawning habitat for spring Chinook salmon was acknowledged in the1958 agreement between EWEB and the Oregon Fish and Game Commission and includedmitigation for loss of spawning habitat in the form of the spawning channel (Federal PowerCommission 1959, Stillwater Sciences 2005a)20 January 2006 Stillwater SciencesCopyright © 2006 Eugene Water & Electric Board1

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical ReportIn 2002, EWEB submitted a plan to FERC for improvements at the Carmen-Smith Project’s TrailBridge Development saddle dike. EWEB also prepared a draft Biological Assessment (BA)covering both the effect of the work at the saddle dike and the continued operation of theCarmen-Smith Project on species listed under the Endangered Species Act (ESA) and includingproposed conservation measures for two of the listed species. FERC adopted the BA and sent itto USFWS and NOAA Fisheries. In 2003, USFWS and NOAA Fisheries each filed BiologicalOpinions with FERC addressing the saddle dike work, continued operation of the Project and theproposed conservation measures (USFWS 2003, NOAA Fisheries 2003). Also in 2003, FERCauthorized the saddle dike work and issued an order approving the conservation measures fromthe Biological Opinions.USFWS and NOAA Fisheries’ Biological Opinions evaluated the effects of the continuedoperation of the Project under its existing license on listed species including bull trout and springChinook salmon. These Biological Opinions determined that the continued Project operation andsaddle dike work along with the proposed conservation measures would not likely jeopardize thecontinued existence of the Columbia River bull trout DPS or Upper Willamette River Chinooksalmon ESU. Many of the conservation measures called for studies that will provide informationuseful for Project relicensing.This report describes the results of the Fish Entrainment study, sections of which wereimplemented by EWEB through an order issued by FERC (FERC 2003). This technical reportdescribes the methods used in this study and the results of the analysis. Details on the methodsused for installing, monitoring, and analyzing hydroacoustic transducer data are described inFixed-Aspect Hydroacoustic Evaluation of Fish Passage at Trail Bridge Dam (2004-2005)(Exhibit 3). Outcomes of the technical studies that pertain to management decisions or actionswill be addressed in the License Application, due to FERC in November 2006.1.2 Purpose and Relationship to Other StudiesIn this study, “entrainment” is considered the movement of fish, volitional or otherwise, from areservoir through various water conveyances at a dam to downstream exit locations. TheCarmen-Smith Hydroelectric Project has three impoundments: Carmen Diversion and TrailBridge reservoirs on the mainstem McKenzie River, and Smith Reservoir on the Smith River(Figure 1-1). There is a potential for entrainment at the following locations:• Fish entrainment from Trail Bridge Reservoir to the McKenzie River below Trail BridgeDam may occur through the intake to the Trail Bridge Powerhouse. Entrainment fromthe Trail Bridge Reservoir to the McKenzie River may also occur during spills from theTrail Bridge spillway.• Entrainment of resident fish from Smith Reservoir to Trail Bridge Reservoir may occurthrough the intake to the Carmen Powerhouse (called the Smith intake), but entrainmentto the Smith Bypass Reach (and ultimately to Trail Bridge Reservoir) may also occurduring spills from the Smith spillway.• Fish residing in Carmen Diversion Reservoir may be entrained at either the CarmenDiversion tunnel to the Smith Reservoir or over the Carmen Diversion spillway to theupper Carmen Bypass Reach.Bull trout and spring Chinook salmon are the primary analysis species in this entrainment study.Juvenile spring Chinook salmon (progeny of adults transported from the McKenzie RiverHatchery to Trail Bridge Reservoir) must pass through the Trail Bridge Powerhouse turbine, the20 January 2006 Stillwater SciencesCopyright © 2006 Eugene Water & Electric Board2

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical ReportTrail Bridge spillway, or the Trail Bridge Howell-Bunger bypass valve, to migrate downstreampast the dam. In addition to the analysis fish species, native coastal cutthroat trout(Oncorhynchus clarki clarki), resident rainbow trout (Oncorhynchus mykiss) (both hatchery andnative stocks), and non-native brook trout may be entrained at Project facilities.The objectives of this study are two fold: (1) to document and evaluate entrainment throughProject turbine intakes, diversions tunnels, and spillways and (2) to assess the potential for delayor injury associated with the tailraces of Carmen and Trail Bridge powerhouses. Entrainment atthe Trail Bridge facilities was the primary focus of this study because of the documented presenceof ESA listed species.This study is related to other relicensing studies (Figure 1-2). The Fish Population Distributionand Abundance study (Stillwater Sciences 2005a) addresses the species composition anddistribution in Project reservoirs, and the Hydrologic Regimes study (Stillwater Sciences 2005b)assesses spill magnitudes and frequency at Project spillways. Entrainment effects examined inthis study are considered in models describing population dynamics of bull trout and springChinook salmon upstream of Trail Bridge Dam, as well as in the development of the AquaticProtection, Mitigation, and Enhancement Opportunities study (Stillwater Sciences 2005c).1.3 Key QuestionsKey questions were identified by the ATS during the development of the Fish Entrainment studyplan. The questions are answered throughout this report (Table 1-1), as well as in Exhibits 1, 2,and 3- which are major components of this report. During the development of the study plan itwas a stated objective of this study to estimate the magnitude of entrainment at Trail Bridge Dam(Table 1-1). However, even with the use of the state-of-the-art technology, it was not possible toenumerate how many fish were entrained at Trail Bridge Dam, but it was possible to documentthe relative magnitude of entrainment for analysis species and life stages (i.e., adults versusjuveniles), seasonal entrainment patterns, and passage routes (i.e., spillway versus turbine).Limited time and available technology prevented accurate estimates of entrainment magnitude atCarmen Diversion Tunnel, Smith intake, or Smith spillway.Table 1-1. Key questions and report sections in which they are addressed.Key question from study plan1. Can fish injury and mortality rates from studies at facilitiessimilar to the Trail Bridge and Smith developments be used inlieu of conducting site-specific entrainment and turbine/spillmortality studies at the Carmen-Smith Project?2. What species, and numbers of fish are currently beingentrained at the Trail Bridge turbine intake and spillway gate, theSmith intake or spillway, and the Carmen Diversion spillway andDiversion tunnel intake?Relevant report section(s)Exhibits 1 and 2Sections:• 3.1.1• 3.2.1• 3.3• 3.4• 3.5• 3.6Exhibits 1, 2, and 320 January 2006 Stillwater SciencesCopyright © 2006 Eugene Water & Electric Board3

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical ReportKey question from study plan3. What is the rate of injury or mortality for entrained salmonidsthrough Trail Bridge Powerhouse and spillway, and CarmenPowerhouse and Smith spillway?4. What is the potential for delay, injury or mortality of juvenileand adult salmonids at the Trail Bridge and Carmen Powerhousetailraces and draft tubes?Relevant report section(s)Sections:• 3.1.2• 3.2.2• 3.3• 3.4• 3.5• 3.6Exhibits 1 and 2Section:• 3.71.4 Study AreaThe Study Area included Carmen Diversion, Smith, and Trail Bridge dams and reservoirs, andthe McKenzie River downstream of Trail Bridge Dam (Figure 1-1). The sampling areasincluded:• Trail Bridge spillway, turbine, and tailrace (including draft tubes)• Smith spillway and Smith intake• Carmen Powerhouse tailrace (including draft tubes)• Carmen Diversion spillway and Carmen Diversion tunnel intake20 January 2006 Stillwater SciencesCopyright © 2006 Eugene Water & Electric Board4

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical Report2 METHODSThe implementation of this study was conducted in collaboration with the ATS. Pursuant to theFish Entrainment study plan (Stillwater Sciences 2004), “Periodic Updates” and “DecisionPoints” were used to inform and collaborate on decisions affecting the study. Decision Pointswere identified in the study plan to indicate circumstances that lead to the re-convening of theATS. At each Decision Point, EWEB participated in collaborative decision-making regardinghow to proceed (e.g., changes in study areas, sampling methods, seasonal timing, or cessation orextension of a given field effort). Decision Points were also triggered by unforeseencircumstances, such as unexpected operational constraints.2.1 Literature ReviewAs a first step in evaluating the relative risk of fish entrainment at the Project, the scientificliterature on entrainment at other hydroelectric projects was reviewed to assess general patterns ofentrainment for the analysis species. This literature review resulted in a report, Literature Reviewof Fish Entrainment Risk at Hydroelectric Facilities (Exhibit 1). This report was followed by theInformation on Entrainment at Spillways report (Exhibit 2), which focused on entrainment risk atspillways, especially as it pertains to the Trail Bridge spillway.The literature reviews presented in Exhibits 1 and 2 were the primary methods for assessingentrainment effects at Project facilities. In addition, based in part on the results of the literaturereviews, several field studies were developed to evaluate the species composition, magnitude, andtiming of entrainment at Project facilities.2.2 Entrainment through Project TurbinesTo estimate the species and relative rate of fish entrained at the Trail Bridge turbine intake,monitoring was conducted with hydroacoustics transducers, remote video cameras, passiveintegrated transponder (PIT) tag antennas, and a rotary screw trap, as described below. Althoughan original objective of the study was to enumerate the number of fish entrained at Projectfacilities, available technology limited the ability to determine the precise magnitude ofentrainment. The Trail Bridge intake structure is located approximately 60 feet underwater andseveral hundred feet from the shoreline. Installation, adjustment and/or maintenance of allinstrumentation required the use of hard hat divers during power plant outages.2.2.1 Hydroacoustics at Trail Bridge turbine intakeThe specific objectives of monitoring with hydroacoustic transducers were to:• determine whether fish entrainment occurs at the Trail Bridge turbine intake,• describe fish behavior and distribution in the vicinity of the turbine intake,• characterize seasonal patterns of fish entrainment, and• estimate fish entrainment rates at the turbine intake under current Project operations, inorder to evaluate potential structural or operational changes that could be implemented toreduce entrainment.20 January 2006 Stillwater SciencesCopyright © 2006 Eugene Water & Electric Board5

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical ReportTo determine the extent of entrainment of all fish species at the Trail Bridge turbine, the PacificNorthwest Division, Battelle Incorporated (Battelle), was contracted to conduct an independentanalysis. The methods used by Battelle are described in detail in Fixed-Aspect HydroacousticEvaluation of Fish Passage at Trail Bridge Dam (2004-2005) (Exhibit 3). An understanding ofBattelles’ methods is critical to interpreting the results that follow. A summary of the generalapproach used by Battelle is provided here.Battelle installed two split-beam transducers in the Trail Bridge turbine entrance just downstreamof the trash racks on 10 May 2004. Transducers sampled continuously from installation until 17May 2005, except when data were downloaded from the acquisition computer (about 30 minutesevery 3–4 days), when the turbine was off, or when equipment problems occurred.Hydroacoustic transducers record echoes from objects passing through an acoustic beam. Themean target strengths of echo traces were categorized into fish-equivalent length classes tointerpret detected objects consistent with the fish species and life stages in the Study Area (Table2-1). The use of fish-equivalent length classes provides finer resolution of entrainment thanpooled estimates for all length classes.Table 2-1. Fish-equivalent length classes.Detection length class38–100 mm (1.5–3.9 in)> 100–200 mm (> 3.9–7.9 in)> 200–350 mm (> 7.9–13.8 in)> 350 mm (> 13.8 in)Potential fish equivalentsChinook salmon, mountain whitefish, nativerainbow, cutthroat, brook, or bull trout fryChinook salmon smolts, mountain whitefish,native rainbow, cutthroat, brook, or bull troutjuveniles, and hatchery released rainbowtroutNative rainbow, cutthroat, or bull troutjuveniles and subadults, brook trout,mountain whitefish, and hatchery releasedrainbow troutNative rainbow, brook, cutthroat, or bulltrout adults, hatchery released rainbow trout,and Chinook salmon adultsThe hydroacoustic estimates of passage represent a relative index to entrainment rather than anabsolute estimate because of false detections from debris, and the necessity of data filtering. Theprobability that a target is a fish is much higher for targets moving more slowly than the medianspeed of the smallest targets, since most fish swim against an entraining flow. Filters used toseparate non-fish targets from fish are described in detail in Exhibit 3; in general, speed, numberof echoes per trace, and direction of targets were used as discriminating variables. Most non-fishtargets such as bubbles and sticks are small (< 100 mm [3.9 in] long) and are easy to filter,whereas large debris is more difficult to filter out.A detailed description of the methods, analysis, and uncertainties of hydroacoustic transducerdata are described in Fixed-Aspect Hydroacoustic Evaluation of Fish Passage at Trail BridgeDam (2004-2005) (Exhibit 3).20 January 2006 Stillwater SciencesCopyright © 2006 Eugene Water & Electric Board6

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical Report2.2.2 Video monitoring at Trail Bridge turbine intakeThe specific objectives of the video monitoring were to:• determine the species composition of fish being entrained, and• compare species identification with results from the fixed hydroacoustic arrays.Two IR Tuffcam underwater cameras were deployed on the Trail Bridge turbine intake trashrack facing across and down the trash rack bars. The field of view of the video camerasoverlapped partially with that of the hydroacoustic transducers, so that hydroacoustic detectionscould be compared with video observations. Infrared lights were installed to illuminate the fieldof view for nocturnal observations, but the lights did not project far enough in the water to beeffective. A time-lapse video recorder was used to record camera images of entrained fish (andother objects). Footage was initially collected 24 hours per day, but based on review of datacollected between May 10 and 25 October 2004, was thereafter collected from 0830 to 1130,which generally overlapped with peak detections at the hydroacoustic transducers. Video footagewas not available for the period of 21 July to 9 September 2004, and 18 March to 17 May 2005,when algal growth covered the lens.All footage was reviewed, and a description and time were noted for all objects (e.g., plants,sticks, trash, fish) passing through trash rack. All footage showing fish entering or in the vicinityof the penstock was digitized for species determination (when possible), and description ofbehavior.2.2.3 Rotary screw trap in Trail Bridge Powerhouse tailraceTo assess migration timing and entrainment effects on juvenile fish through the Trail Bridgeturbines or over the spillway, a 2.4-m (8-ft) rotary screw trap was installed downstream of TrailBridge Dam on 12 April 2004 (Figure 2-1). For most of Summer 2004, the trap was located atriver right (on the west side of the channel), in line with the turbine discharge (Table 2-2).During Fall 2004, the trap was moved to river left, in line with the Trail Bridge spillway.However, during the time the trap was in this location, the trash drum became loose, and the livebox could not effectively hold fish, so trap efficiency declined sharply (for both live or dead fish).The trap was subsequently fixed and moved back to its original position. In general, the trapoperated 4 or more days per week (Table 2-2). Crews identified and measured each captured fish,and documented any injuries or mortalities.Table 2-2. Trail Bridge Powerhouse tailrace rotary screw trap location, and sampling durationand frequency.Trap locationApproximately 40 m (130 ft)downstream of Trail Bridge Dam,in line with turbine dischargeApproximately 60 m (200 ft)downstream of Trail Bridge Damand near left bank, in line withspillwayApproximately 40 m (130 ft)downstream of Trail Bridge Dam,in line with turbine dischargeSamplingdates12 April to 17August 20047 September2004 to 21January 200526 January to10 June 2005Sampling frequency(average)3–4 days/wk>4 days/wk>4 days/wkCommentsRemoved on 18 August 2004to repair live box.Reinstalled downstream ofspillway to capture fishduring spills. Live box wasineffective during this time.Moved to downstream of theturbine discharge to capturefish entrained in turbine.20 January 2006 Stillwater SciencesCopyright © 2006 Eugene Water & Electric Board7

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical ReportTrap efficiencies were measured at the trap using marked, 60–70 mm fork length (2.4–2.8 in)hatchery spring Chinook salmon. In April 2004, 100 live and 100 dead hatchery Chinook salmonfrom McKenzie River Salmon Hatchery, were marked with a dye indicating whether they werealive or dead, and released just below the turbine draft tubes at Trail Bridge Dam via a conduitpipe. In June 2005, a second test was conducted with 100 live and 67 dead hatchery springChinook salmon. After both trials, 10 live and 10 dead Chinook salmon were given a caudal finclip and placed in the live box overnight to estimate loss from within the live box.2.2.4 PIT tag antennas downstream of Trail Bridge DamThe specific objective of the PIT tag monitoring below Trail Bridge Dam was to documententrainment of PIT-tagged bull trout, brook trout, adult Chinook salmon, and cutthroat troutthrough the Trail Bridge turbine or spillway. As described in detail in the Fish PopulationDistribution and Abundance technical report (Stillwater Sciences 2005a), by summer 2005 244bull trout, 197 adult hatchery spring Chinook salmon, 67 cutthroat trout, and 11 brook trout werePIT tagged in the Study Area upstream of Trail Bridge Dam in Trail Bridge Reservoir, CarmenBypass Reach, and Sweetwater Creek.Antennas designed to detect fish tagged with 23-mm (0.9-in) half-duplex PIT tags were installedin the Trail Bridge Powerhouse tailrace, on the velocity barrier downstream of the tailrace, and atthe entrance to the Carmen-Smith Spawning Channel (Table 2-3). All fish detected at these siteswere assumed to have moved through the powerhouse or over the spillway.Table 2-3. PIT tag antennas downstream of Trail Bridge Dam and dates of operation.GenerallocationTrail BridgePowerhousetailraceCarmen-SmithSpawningChannelMainstemMcKenzieRiverSpecificlocationBetween thespillway andturbine drafttubesBetweenHowell-Bunger valveand turbinedraft tubesLower-mostweirVelocitybarrierPeriod ofoperation3 March 2004to 2September20042 September2004 to 3October 20043 July 2004 toPresent10 November2004 to 15April 2005Design typehelical cableattached towooden framestructureSingle cable loopattached to aPVC frameSingle cable loopmounted tochannel outfallwallTwo singlesynchronizedcable loops, eachcovering halfchannel for fullchannel coverageDetectordimensionsRead-range m,(at 10 scans/sec)(m) Vertical Horizontal4-m helix 0.6–2.4 1.5–3.00.9 m x 0.9 m 0.9 0.51.2 m long1.0 m highEach antenna:15.2 m length1.0 m high1.1 0.40.7–0.8 0.1–0.2The first antenna installed in the Trail Bridge Powerhouse tailrace was constructed of a 4-m (8-ft)helical antenna cable attached to a wooden frame structure, and anchored by ropes onto the20 January 2006 Stillwater SciencesCopyright © 2006 Eugene Water & Electric Board8

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical Reportcement wall adjacent to the tailrace turbine between the Howell-Bunger valve and the turbinedischarge (Figure 2-2). A second antenna frame was constructed after the first frame wasdamaged from a spill event, causing the antenna cable to snap. This second smaller antennastructure was constructed using polyvinyl chloride (PVC) pipe with single cable loop runningthough a square (0.9 m x 0.9 m [3 ft x 3 ft]) frame. This frame was mounted to the center cementwall facing downstream (Figure 2-3). This antenna loop was frequently baited with cannedsalmon to attract tagged bull trout.To monitor fish movement in and out of the spawning channel, a third single loop antenna wasmounted to the outfall wall at the base of the spawning channel (Figure 2-4). The spawningchannel antenna provided an opportunity to detect fish that were entrained at Trail Bridge Dam, ifthey subsequently moved into the spawning channel. This antenna consisted of a single loop,measuring 1.2 m (4 ft) long and 1 m (3.5 ft) high, which provided full coverage of PIT-taggedfish passage in and out of the spawning channel.The fourth and fifth antennas were single loop, synchronized antennas that were installed on thevelocity barrier on the mainstem McKenzie River adjacent to the spawning channel; their purposewas to monitor upstream and downstream movement below Trail Bridge Dam. These twoantennas measured 15.2 m (50 ft) long and 1.0 m (3.5 ft) high, and provided full coverage of thechannel (Figure 2-5).Details of the methods used for installing, monitoring, and analyzing PIT tag data are described inthe Fish Population Distribution and Abundance technical report (Stillwater Sciences 2005a).2.2.5 Entrainment at Smith intakeThe unscreened intake for Carmen Powerhouse (Smith intake) is located approximately 34 m(110 ft) beneath the average water surface of Smith Reservoir (Figure 2-6). Under normaloperating conditions the seasonal range of reservoir elevations includes a minimum water depthabove the intake entrance of approximately 29 m (95 ft), and 36 m (118 ft) at maximum poollevel. The risk of entrainment for resident trout at the Smith intake was assessed based oninformation from field surveys (sonar and species composition) and a review of the scientificliterature (Exhibit 1). The sonar survey methods and the methods for determining speciescomposition are provided in the Fish Population Distribution and Abundance technical report(Stillwater Sciences 2005a).2.3 Entrainment at Project SpillwaysTo determine the species and relative rate of fish entrained at Trail Bridge and Carmen Diversionspillways, and to determine the rate of injury or mortality for entrained salmonids throughspillways, monitoring was conducted using a combination of hydroacoustic transducers, videocameras, PIT tag antennas, and fyke traps, as described below. Although an objective of thestudy was to enumerate the number of fish entrained at Project facilities, available technologylimited the ability to determine the precise magnitude of entrainment.2.3.1 Hydroacoustics at Trail Bridge spillwayTrail Bridge Dam has one concrete spillway, located on the left (eastern) abutment of TrailBridge Dam (Figure 2-7). The spillway is 9 m (30 ft) wide and has a radial gate to allow20 January 2006 Stillwater SciencesCopyright © 2006 Eugene Water & Electric Board9

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical Reportcontrolled flow releases. The flip bucket type spillway narrows to a 6-m (20-ft) wide chutesection of 34% slope (Figure 2-8). The chute section intersects the flip section at a horizontalsegment, which then inclines into a 10% slope along the “flip”, leading to the flip bucketdeflector. The length of the spillway, from radial gate opening to flip bucket deflector, isapproximately 61 m (200 ft).The specific objectives of monitoring with hydroacoustic transducers were to:• determine whether fish entrainment occurs at the Trail Bridge spillway,• characterize seasonal patterns of fish entrainment as they coincide with spillway operationunder normal conditions, and• estimate fish entrainment rates at the spillway under existing Project operations, in order toevaluate the potential structural or operational changes that could be implemented toreduce entrainment.To determine the extent of entrainment of all fish species at the Trail Bridge spillway, Battellewas contracted to conduct an independent analysis. The methods used by Battelle are describedin detail in Fixed-Aspect Hydroacoustic Evaluation of Fish Passage at Trail Bridge Dam (2004-2005) (Exhibit 3), an understanding of which is critical to interpreting the results that follow. Asummary of the general approach used by Battelle is provided here.Battelle installed two split-beam transducers just upstream of the gate at the Trail Bridge spillwayon 10 May 2004. Transducers sampled continuously from installation until 17 May 2005, exceptwhen data were downloaded from the acquisition computer (about 30 minutes every 3–4 days),when the spillway was closed, or when equipment problems were encountered. Mean targetstrengths of echo traces, which are correlated to fish lengths, were used to categorize detectedtargets into fish-equivalent length classes, and data were filtered to exclude non-fish targets, asdescribed in Section 2.1.1. Video cameras were also deployed at the spillway to confirmhydroacoustic detections, but the conditions were too poor to discern fish from debris. Details onthe methods used for installing, monitoring, and analyzing hydroacoustic transducer data aredescribed in Exhibit 3.2.3.2 PIT tag antenna at Trail Bridge spillwayThe specific objective of the PIT tag antenna at the Trail Bridge spillway was to documententrainment of PIT-tagged bull trout, cutthroat trout, brook trout, and adult Chinook salmon overthe Trail Bridge spillway.An antenna designed to detect PIT-tagged fish was installed at the Trail Bridge spillway on 7January 2005, although the unit was not fully operational until 20 April 2005 due to challengesresulting from the antenna length. The antenna was also offline from 20 July 2005 to 10September 2005 during a construction outage on the spillway, and due to continued challengesresulting from the antenna length. The spillway antenna consists of two 8-cm (3/8-in) steelcables, each 9.2 m (30 ft) in length, anchored approximately 0.9 m (3 ft) upstream of the spillwaygate (Figure 2-9). One steel cable was anchored to the cement of the spillway structure, the otherwas attached to eye bolts 0.6 m (2 ft) above and parallel to the lower cable (Figure 2-9). Therubber-sheathed copper wire antenna was secured to the cables creating a 9.2-m (30-ft) long, 0.6-m (2-ft) high antenna. Additional details on the methods used for installing, monitoring, andanalyzing PIT tag data are described in the Fish Population Distribution and Abundancetechnical report (Stillwater Sciences 2005a). All fish that were detected at the spillway antennawhile the spillway gate was open were presumed entrained (voluntarily or otherwise).20 January 2006 Stillwater SciencesCopyright © 2006 Eugene Water & Electric Board10

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical Report2.3.3 Entrainment at Smith spillwayThe spillway on Smith Dam is a radial gate Ogee crest weir that is 6.1 m (20 ft) wide, and islocated on the right (western) abutment of Smith Dam (Figure 2-10). The radial gate allows forcontrolled flow releases, which enter a concrete chute section before free-fall into a bedrock pool(Figure 2-11). The spillway chute section has a slope of 15%, is 4.6 m (15 ft) wide andapproximately 104 m (340 ft) long, and has a deflector structure at the tip (Figure 2-12). Oncewater passes over the deflector, there is roughly 46 m (150 ft) of free-fall prior to contact with a 3m (10 ft) deep bedrock pool (Figure 2-13). The Smith spillway has a 15,513 cfs rated capacity.Direct observations of entrainment were not conducted at Smith spillway. The risk ofentrainment for resident trout at the Smith spillway was assessed based on information from fieldsurveys of the fish species composition and distribution in the Smith Reservoir and Smith Riverupstream of the reservoir conducted as part of the Fish Population Distribution and Abundancestudy (Stillwater Sciences 2005a) and a review of the scientific literature (Exhibit 2).2.3.4 Fyke trap and electrofishing at Carmen Diversion spillwayThe Carmen Diversion spillway is a 19-m (63-ft) long free-flowing concrete weir with two 2.6-m(8.5-ft) long concrete stop-log sluiceways (Figure 2-14). To determine the species compositionand relative number of fish that are entrained at Carmen Diversion spillway, snorkel surveys, fyketrapping, and electrofishing methods were used. Different techniques were used to sample duringlow (1–50 cfs) and high-magnitude (> 50 cfs) spills that occurred during Spring 2004 and 2005,as described below.2.3.4.1 Low-magnitude spill eventsDuring low-magnitude spill events, downstream migrant fyke traps were placed in the upperCarmen Bypass Reach approximately 50 m (164 ft) downstream of the Carmen Diversionspillway, to capture all age classes of resident trout (cutthroat trout, brook trout, and rainbowtrout) entrained over the spillway. The first fyke trap was installed in April 2004; this trap hadone opening, with dimensions of 1.2 x 1.2 x 3.0 m (4 x 4 x 10 ft) (length x height x width) andfive baffles. On each side of the trap, the wing lead heights and lengths were 1.5 m (5 ft) and 7 m(23 ft), respectively; the net was made of 0.64 cm (1/4 in) mesh (Figure 2-15). The fyke trap wasfitted with a fish holding box, located at the downstream end of the trap. The box dimensionswere 0.6 x 0.5 x 0.6 m (2 x 1.5 x 2.0 ft).In 2005, a second, larger fyke trap was installed to increase the capture efficiency at higher flows(> 25 cfs); it consisted of two openings joined side by side (Figure 2-16). Each opening was 1.8m (6 ft) wide and 1.8 m (6 ft) tall. Each net was 5.5 m (18 ft) long and made of three baffles, andeach lead wing was 2 m (6 ft) tall and 12.2 m (40 ft) long. The fyke net used in 2005 was madeof 0.6-cm (1/4-in) mesh except for the outer 6 m (20 ft) of each wing, which was 1.3-cm (1/2-in)mesh. The fyke net was fitted with two fish holding boxes, each located at the downstream endof the nets. The box dimensions were 1.2 x 0.6 x 0.6 m (4 x 2 x 2 ft). Fyke traps were installedin Spring 2004 and Spring 2005, and were monitored daily during spill events.20 January 2006 Stillwater SciencesCopyright © 2006 Eugene Water & Electric Board11

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical Report2.3.4.2 High-magnitude spill eventsThe fyke traps were not sufficiently strong for high magnitude spill events (> 50 cfs); therefore,the channel below the Carmen Diversion Dam was also sampled using electrofishing, minnowtrapping, and snorkel surveys.During or directly after each planned or unplanned spill, electrofishing surveys were conductedwith two Smith-Root LR-24 electrofishers, to survey for fish in the reach, and if fish weredetected, to survey using the three-pass depletion method (Seber 1982). Electrofishing occurredbetween the Carmen Diversion Dam and the fyke trap location in the grassy meadowsapproximately 50 m (160 ft) downstream of the Carmen Diversion Dam. In areas where fishwere detected, a block net was placed at the upper and lower portions of sampled reaches toprevent fish from entering or leaving the sampling site.During and following high-magnitude spills, snorkel surveys and baited minnow traps were usedto determine if fish were present in areas that were too deep and complex to electrofish. Theminnow traps were 37 cm (14.6 in) long with a variable circular diameter of 19–22 cm (8–9 in)and 0.64-cm (0.25-in) mesh.2.3.4.3 Assessment of residency below Carmen Diversion DamTo document the number and species of fish residing in the perennial pool and riffle below theCarmen Diversion Dam, electrofishing surveys were conducted periodically in Spring, Summer,and Fall 2004, and in late Winter 2005. To determine if the same fish were being recapturedduring surveys, each fish captured by electrofishing was fin-clipped and returned to its capturelocation. Species, length, age, condition, and other pertinent information were collected for allfish captured. All captured amphibians or other species were also documented.2.4 Entrainment at Carmen Diversion TunnelThe Carmen Diversion tunnel diverts water from the Carmen Diversion Reservoir to the SmithReservoir in a 3,471-m (11,380-ft) concrete-lined tunnel (Figure 2-17). To estimate the numbersand species composition of fish entrained into the Carmen Diversion tunnel, an underwater videocamera was used. Sampling was conducted in April 2004 before hatchery rainbow trout werereleased by ODFW into Carmen Diversion Dam, and in May, October, and November, after thehatchery rainbow trout were released (Table 2-4).Table 2-4. Underwater video camera sampling datesand duration at Carmen Diversion tunnel in 2004.Sampling date(2004)Sampling duration14 April 8 hours (1549–2400)15 April 24 hours16 April 4.5 hours (0000–0438)25 May 2 hours (1600–1806)27 May 5 hours (1614–2400)28 May 9.5 hours (1432–2400)29 May 24 hours30 May 3.5 hours (0000–0328)28 October 12.25 hours (1147–2400)20 January 2006 Stillwater SciencesCopyright © 2006 Eugene Water & Electric Board12

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical ReportSampling date(2004)Sampling duration29 October 24 hours30 October 11 hours (0000–1114)3 November 0.5 hours (1005–1023)Total128 hoursDuring initial monitoring in April and May 2004, a Sea View® (Sea Master 600) underwater,color/black and white, infrared-capable video camera with attached lights and a 65º field of viewwas deployed on the Carmen Diversion tunnel intake trash rack. During later monitoring, aSubseas Video Systems underwater color video camera (model 512HW/29/F/xx with a 79º fieldof view) was used. When mounted on the diversion intake, the camera view was across one ofthe intake trash racks and angled slightly downwards. During the first deployment in April 2004,American Dynamics infrared illuminators were installed to illuminate the field of view fornocturnal observations without affecting fish behavior. The infrared illuminators could noteffectively penetrate water at night, and subsequent analysis of footage was limited to thedaytime.Video footage was analyzed with the FishTick computerized video editing system to select thoseportions of the tape with fish or other objects passing the field of view. All occurrences of fishpassing the field of view were reviewed and documented.2.5 Risk at Project TailracesTo assess the risk of fish entering the draft tubes at the Carmen Powerhouse (Figure 2-18) andTrail Bridge Powerhouse tailraces (Figure 2-3) and suffering injury or mortality, directobservation surveys were conducted and PIT tag antennas were installed and monitored, asdescribed below. In addition, Project operations and associated velocities at the tailraces and inthe turbines were examined, to determine the susceptibility for juvenile or adult fish to move intodraft tubes and be injured or killed.2.5.1 Direct observation surveys in Trail Bridge and Carmen powerhousetailracesDirect observation snorkel and video surveys were initiated in Trail Bridge and Carmenpowerhouse tailraces in Spring 2004 (Table 2-5). The specific objectives of the surveys were to:• assess behavior and distribution of juvenile and adult salmonids in the vicinity of theCarmen and Trail Bridge powerhouse tailraces,• determine the potential risk of injury or mortality of juvenile and adult salmonids into thedraft tubes at the Carmen and Trail Bridge powerhouses, and• characterize the potential for delay and false attraction of upstream migrating salmonids inthe Carmen Powerhouse tailrace.20 January 2006 Stillwater SciencesCopyright © 2006 Eugene Water & Electric Board13

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical ReportTable 2-5. Locations and sampling periods for direct observation surveys at Trail Bridge andCarmen powerhouse tailraces.Duration of turbinePowerhouseLocationSampling date and timeoperation prior tooperationsurveyTrail BridgePowerhousetailraceCarmenPowerhousetailraceNA= Not applicable9 July 2004, 2100 to 0100 turbines on > 1 week21 January 2005, 1930 to 2030 turbines on > 1 week11 May 2004, 1400 to 1450 turbines off NA1 August 2004, 1932 to 2027 turbines on 10 hours1 August 2004, 2330 to 2345 turbines on 14 hours1 August 2004, 2345 to 0020 turbines off NA13 August 2004, 2008 to 2203 turbines on 14 hours9 October 2004, 1808 to 2013 turbines on 10 hoursSurveys occurred during upstream migration of bull trout and Chinook salmon (August throughOctober) and periodically during the year. Field crews of 2 to 4 people conducted snorkelsurveys and documented behavior and distribution of juvenile and adult fish in the tailracesduring a range of Project operations. When the turbines were operating, conditions were not safeto perform snorkel surveys; therefore, underwater video footage was taken with an underwatervideo camera attached to a long pole to observe species use of areas around the turbine discharge.When the turbines were off, snorkel surveys were conducted and video sampling was notnecessary. Surveyors noted the species and location of all fish observed, and documented anysign of injuries on fish. Water visibility was high (>6 m [> 20 ft]), and if dead fish were presenton the substrate in the vicinity of the draft tubes it is likely that they would have been detected.Additionally, during late Summer 2005 adult spring Chinook salmon found dead or injured wereexamined for signs of turbine-related injuries. Field crews of 1 to 2 people surveyed the shorelineof Trail Bridge Reservoir downstream of the Carmen Powerhouse for at least 100 m (328 ft), 3 to5 days/week from 13 July 2005 (when adult Chinook salmon were first released into thereservoir) through October 2005 (completion of the spawning period). All observed adults werecounted, and if they were either immobile or dead, they were inspected for signs of turbine strikeor other injuries. Observations of all fish were recorded, and any observations of injuries werephotographed.2.5.2 PIT tag antennas in Project tailracesA PIT tag antenna was installed in the Carmen Powerhouse tailrace to characterize the potentialfor false attraction. Adult spring Chinook salmon were PIT-tagged prior to being released byODFW into Trail Bridge Reservoir in 2004 and 2005. Adult bull trout were also PIT-taggedopportunistically (when captured during various surveys) in 2004 and 2005. The presence ofPIT-tagged adult bull trout and spring Chinook salmon in the vicinity of the powerhouse wasassessed using data from the PIT tag antenna installed in the Carmen Powerhouse tailrace. Thenumber of PIT tag detections that occurred when the turbine was on or off was compared todetermine if fish were more likely to be present when the turbines were generating and thereforeattracted to the powerhouse discharge. The number of fish tagged and detected influenced therigor of this assessment.20 January 2006 Stillwater SciencesCopyright © 2006 Eugene Water & Electric Board14

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical ReportThe Carmen Powerhouse tailrace antenna was attached to a PVC pipe frame with dimensions 0.6x 0.6 x 0.9 m (2 x 2 x 3 ft). Antenna wire was attached to one end of the frame, making a 0.6 x0.6 m (2 x 2 ft) square. This frame was then weighed down and placed on the bottom of thechannel adjacent to the downstream tailrace wall (Figure 2-18). The antenna loop ends extendedup to data loggers on the tailrace platform. Nylon rope was fastened to the PVC frame andsecured to the railing to help maintain its position off the southern, downstream end of theCarmen Powerhouse tailrace wall and railing. The area of antenna coverage was small relative tothe tailrace area, and it was assumed that only a proportion of the fish in the vicinity of thepowerhouse were detected. The antenna operated continuously from 18 August 2004 throughDecember 2005 (data for this report is analyzed through July 2005). Antennas installed in theTrail Bridge Powerhouse tailrace are described in Section 2.1.4. Details on the methods used forinstalling, monitoring, and analyzing PIT tag data are described in the Fish PopulationDistribution and Abundance technical report (Stillwater Sciences 2005a).2.5.3 Vaki Riverwatcher and video in Carmen Bypass ReachThe abundance and timing of bull trout and spring Chinook salmon migrating into the CarmenBypass Reach was monitored using a Vaki Riverwatcher in conjunction with a time-lapse videocamera in Fall 2004. The Vaki Riverwatcher is a system that counts a fish when it swims througha box; the box is an infrared field that is interrupted when the fish swims through, creating adigital “silhouette” of a fish. Video recordings were taken in conjunction with the VakiRiverwatcher to confirm fish species identification and to evaluate fish behavior (Figure 2-19).The unit was placed in the Carmen Bypass Reach approximately 280 m (920 ft) upstream of thebridge. The unit was placed in the channel thalweg and central to a 17-m (55-ft) wide fullchannel double V weir that was constructed to shunt all fish moving upstream or downstreamthrough the box (Figure 2-20). Details on the methods used for installing, monitoring, andanalyzing Vaki Riverwatcher data are described in the Fish Population Distribution andAbundance technical report (Stillwater Sciences 2005a).The potential risk of delay at the Carmen Powerhouse tailrace was assessed based on the timingof fish movement relative to the timing of Carmen Powerhouse operations. Vaki Riverwatcherdata were analyzed by creating a histogram of upstream detection times for bull trout andChinook salmon, overlayed with operations of the Carmen Powerhouse turbines (on or off). Ifturbine operations delay upstream migration, then rates of upstream migration were expected tobe higher during periods when the turbines were off.20 January 2006 Stillwater SciencesCopyright © 2006 Eugene Water & Electric Board15

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical Report3 RESULTS3.1 Trail Bridge Turbine3.1.1 Entrainment ratesDetailed results of the hydroacoustic analysis are provided in Fixed-Aspect HydroacousticEvaluation of Fish Passage at Trail Bridge Dam (2004-2005) (Exhibit 3). Review of Exhibit 3 iscritical to interpreting the results of the analysis. A general summary of the results is providedhere.The hydroacoustic transducers collected data for approximately one year. Hydroacousticsampling at Trail Bridge Dam was a challenge because the small headwater reservoir providedfew fish to be entrained relative to the number of non-fish targets such as woody debris andentrained air. Without filtering of the hydroacoustic data, over 156,000 detections were recorded.As described in the Fish Population Distribution and Abundance report (Stillwater Sciences2005a), the fish population in Trail Bridge Reservoir during the period of study was comprised ofan approximate maximum of 2,000 bull trout of all life stages, 14,000 hatchery rainbow trout, and46,000 Chinook salmon fry and juveniles. Including hatchery fish stocked from previous years,an approximate estimate of the total fish population susceptible to entrainment in Trail BridgeReservoir is 65,000. Therefore, Battelle assumed that most of the hydroacoustic detections werenot fish, and subsequently analyzed the data using filters to separate debris from fish detections.Even with the use of data filters, detections are biased by detections of debris, and multipledetections of individual fish. Thus, the hydroacoustic estimates of passage represent a relativeindex rather than an absolute estimate because of filtering of data and false detections fromdebris.Detections of the two larger size classes of fish > 200 mm (7.9 in) (most likely hatchery rainbowtrout or bull trout) were particularly susceptible to overestimates for several reasons. First,filtering based on the speed of the detected object is not as effective on large debris as it is onsmall point scatterers of sound; secondly, large fish with strong swimming ability can be detectedmultiple times before actually passing; and finally, assumptions underlying spatial and temporalexpansions are not as appropriate for large targets as they are for small targets. However, as anindex to fish passage, the estimates should accurately indicate temporal and spatial trends,although they likely do not estimate the magnitude of fish passage accurately.For the one-year study, the filtered hydroacoustics surveys recorded over 23,000 detections, ofwhich 58% were < 100 mm (< 3.9 in) long, 33% were >100–200 mm (>3.9–7.9 in), 8% were>200–350 mm (> 7.9–13.8), and 1% were > 350 mm (>13.8 in) (Table 3-1).20 January 2006 Stillwater SciencesCopyright © 2006 Eugene Water & Electric Board16

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical ReportTable 3-1. Summary of hydroacoustic mean hourly detection rates at the Trail Bridge turbinefrom 10 May 2004 to 17 May 2005.Detection length class38–100 mm (1.5–3.9 in)> 100–200 mm (> 3.9–7.9 in)> 200–350 mm (> 7.9–13.8 in)> 350 mm (> 13.8 in)Potential fish equivalentsChinook salmon and nativetrout fryChinook salmon smolts, nativetrout juveniles, and hatcheryreleasedtroutnative trout juveniles andsubadults, and hatcheryreleasedtroutTrout adults, Chinook salmonadultsMean hourly rates(detections/hour) ± 80% CI1.57 ± 0.090.88 ± 0.050.20 ± 0.020.04 ± 0.01Entrainment into the turbine was much higher in November, December, January, and Februarythan in other months for all length classes of targets, and it was much higher for small targets thanfor successively larger length classes (Figure 3.19 of Exhibit 3). Hourly rates were low (< 1detection per hour) for all length classes from May through September (Figure 3.19 of Exhibit 3).Based on fish distribution and life history timing surveys (Stillwater Sciences 2005a), the fishcomponent of peaks in detections of small objects (38–100 mm [1.5–3.9 in]) in May were mostlikely Chinook salmon fry or bull trout fry; peaks in the fall and winter were mostly likely 0+ and1+ smolts. The fish component of peak detections of objects >100–200 mm (>3.9–7.9 in) duringfall and winter were most likely Chinook salmon smolts, juvenile bull trout, or hatchery rainbowtrout. The fish component of detections of objects >200–350 mm (7.9–13.8 in) during most ofthe year were most likely hatchery rainbow trout, and peaks in detections during November andDecember were most likely juvenile and subadult bull trout. Detections of objects > 350 mm(13.8 in) during summer and early fall were most likely hatchery releases of adult Chinooksalmon, and detections during late fall and winter were most likely adult bull trout and hatcheryrainbow trout.Detections at the turbine were higher during the night and morning than in the afternoon andevening. Diel trends were most obvious for the two smallest length classes of targets. Dailychanges in forebay elevation (which likely affect intake velocities, or create a vortex) accountedfor only 21% of the diel variation in the passage of small targets, suggesting that fish behaviorexplained most of the variation.Hydroacoustic sampling is most effective for indexing entrainment when the number of fishpassing is high (>30 fish/hour), and it is less effective when the ratio of fish to non-fish targets islow. The Trail Bridge hydroacoustic study required discriminating between fish and non-fishtargets because entrainment was low relative to dams on the lower Columbia River wheremillions of juvenile salmonids pass each migration season. Empirical methods including videofilming, rotary screw trapping, and the PIT tag analyses, were used to discriminate between fishand non-fish targets.While hydroacoustic data indicated that entrainment through the turbine was higher during thenight than during the day, only daytime video footage was readable. Videotapes of peak periodswere analyzed to confirm that hydroacoustic detections were fish, rather than debris. Over 250hours of tape were reviewed (Table 3-2). All video observations are estimates, due to the20 January 2006 Stillwater SciencesCopyright © 2006 Eugene Water & Electric Board17

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical Reportdifficulty of counting schools of fish. Out of about 167 observed fish, most were observed withinthe vicinity of the intake, but did not appear affected by the intake velocities, or were observedwhen the turbines were off (Table 3-2) and flow passed at the Trail Bridge spillway(approximately 30m [100 ft] away). Several fish were observed to enter the intake, while otherswere observed to actively swim against the current and avoid entering the intake (Table 3-2).Most of the positively identified fish were rainbow trout, although many of the unidentified smallfish observed to be entrained were most likely Chinook salmon smolts, based on their size andtiming of observation. There were 15 observations of entrained debris (mostly algal mats and afew sticks), which coincided with hydroacoustic detections.Table 3-2. Summary of Trail Bridge turbine intake video observations, based onover 250 daylight hours of footageBehaviorEstimated Flow through Average intake Observationsnumber of fish turbines (cfs) velocities 1 of debrisEntrained 35 640–750 1.1–1.3 m/s (3.6–4.3 ft/s) 15Actively avoidingentrainment21 590–1,400 1.0–2.4 m/s (3.3–7.9 ft/s) 0In vicinity of intakewhen turbine off112 0 0 0Total 167 151 average velocity at turbine intakeDiscrepancies between video camera and hydroacoustic results are due in part to the lack ofoverlap between the video camera field of view and the size of the hydroacoustic transducersample view. For example, hydroacoustics often detected “fish” being entrained (after data wasfiltered) that could not be observed in video footage. There were, however, around 40observations of fish entering the intake during periods when there were hydroacoustic detections.Over one-third of the observations were of debris, and the remainder was fish. There were alsoover 10 instances of fish entering the intake without hydroacoustic detections.Fish in the vicinity of the turbine were observed in the video footage to be influenced by the flowof water moving into the intake while the turbine was on, but were either able to actively swimaway from the trash rack, or swim across the trash rack with little effort. In most observations ofentrainment, fish appear to be swimming against the entraining flow. There were instances inwhich smolt-sized Chinook salmon were observed to swim into the trash rack and back out againwhile the turbine was on. There was no observed difference in the size of fish that entered theturbine intake versus those that did not. Intake velocities within the restricted tunnel section ofthe turbine intake during times when fish were observed avoiding the flow into the turbine rangedfrom 1.0 to 2.4 m/s (3.3 to 7.9 ft/s) at the turbine intake (Table 3-2), though velocities at the trashrack (several feet from the restricted tunnel section) were much lower.Intake velocities during times when fish were observed to enter the intake were the same or lowerthan when fish were observed avoiding entering the turbine (Table 3-2). Because thehydroacoustic transducers detected fish when they are well within the turbine intake, it is notlikely that fish swimming in and out of the trash rack were included as hydroacoustic detections.No large (> 200 mm [7.9 in]) fish were observed in the video footage being entrained. Videoclips provide examples of fish avoiding entering the intake and of fish and debris entering theintake (Exhibit 4).20 January 2006 Stillwater SciencesCopyright © 2006 Eugene Water & Electric Board18

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical ReportCaptures at the rotary screw trap positioned below the Trail Bridge Dam, as well as PIT tagdetections at the antennas at the Carmen-Smith Spawning Channel, confirmed that debris (algae)and fish are entrained into the Trail Bridge turbine, and provided some data on species-specificentrainment. Both bull trout and Chinook salmon were detected via PIT tag detections or rotaryscrew trap captures, confirming that they were entrained at either the spillway or turbine (Table 3-3). One adult rainbow trout and one adult cutthroat trout were captured at the rotary screw trap,but these fish could have been resident in the tailrace pool and not entrained from Trail BridgeReservoir. Table 3-3 summarizes PIT tag and rotary screw trap detections downstream of TrailBridge Dam that confirm entrainment.Table 3-3. Summary of bull trout and Chinook salmon detections downstream of Trail BridgeDam in 2004 and 2005. Based on 244 PIT tagged bull trout, 197 Chinook salmon adults, and 78other trout species tagged as of summer 2005.Chinook salmonBull troutDetection AssociatedOthermethod with spillSubadults/0+ 1+ 2+ Adults JuvenilestroutadultsRotary screw trap 1 Yes 0 0 0 0 0 0 0No 42 80 1 0 0 0 4Tailrace antenna 2 Yes NA NA NA 0 0 0 0No NA NA NA 0 0 0 0Carmen-Smith Yes NA NA NA 30 3 6 0Spawning Channelantenna 2 No NA NA NA 0 1 1 0Trail Bridgevelocity barrierYes NA NA NA 0 0 0 0antenna 2 No NA NA NA 0 0 0 0Trail Bridge Yes NA NA NA 1 3 1 0spillway antenna No NA NA NA NA NA NA NANA= Not applicable1 Total detections not extrapolated based on trap efficiency.2 Detections are only based on PIT-tagged fish that were released above Trail Bridge Dam.Although unidentified trout species were observed in the video footage to be entrained, trout wererarely observed at the rotary screw trap, or by PIT tag antennas. It is not known what the flowthrough the rotary screw trap was relative to the flow through the turbine, but the rotary screwtrap efficiency was estimated to be 6% for both live and dead hatchery Chinook salmon smolts inthe spring of 2004, and 2% for live fish and 9% for dead fish in the summer of 2005.3.1.2 Entrainment effectsA literature review (Literature Review of Fish Entrainment Risk at Hydroelectric Facilities) wasthe primary method used to evaluate entrainment effects at Trail Bridge turbine. Detailed resultsof the literature review can be found in Exhibit 1. In summary, there are currently insufficientpublished studies to derive a predictive relationship between turbine mortality and such variablesas fish size and turbine characteristics. As noted by EPRI (1992), the limited number ofobservations and substantial variability between studies precludes establishing such predictiverelationships. However, Kaplan turbines similar to the one at Trail Bridge Dam are generallyregarded to impose a lesser risk of mortality than other turbine types (e.g., Francis type),especially when run at high efficiency (Skalski et al. 2002). Under almost all operating20 January 2006 Stillwater SciencesCopyright © 2006 Eugene Water & Electric Board19

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical Reportconditions the Trail Bridge Kaplan turbine, efficiency is greater than 90%. From fish passageexperiments prior to 1967 for Francis and Kaplan turbines, data summarized by Bell (1981)indicated mortality rates of 1.0–46.1% for Kaplan turbines. Ledgerwood et al. 1990 foundmortality rates of Chinook salmon smolts (83–99 mm [3–4 in]) of 2–3% on the Kaplan units atBonneville Dam, while Steir and Kynard 1986 (as cited in EPRI 1992) found that mortality ratesof Atlantic salmon smolts (190–280 mm [7.5–11.0 in]) were in the range of 11.8–13.7%. Skalskiet al. (2002) studied smolt passage survival at several facilities with Kaplan turbines usingballoon-tagged fish, and estimated mortality rates ranging from 0–14.6%.Chinook salmon fry and smolts (ages 1+ and 2+) passing through the Trail Bridge turbine willemerge either unharmed, injured, or dead (Table 3-4). In general, captures at the rotary screwtrap below Trail Bridge Dam were highest during winter and spring (Figure 3-1), correspondingto peaks in hydroacoustic detections (Figure 3.19 of Exhibit 3). However, captures at the rotaryscrew trap in Trail Bridge tailrace were likely too low to provide good data on outmigrationtiming. During the fall, when hydroacoustics detects were also high, the rotary screw trap wasnot operational. Thus the number of captures (Table 3-4) likely underestimates the truemagnitude of entrainment. The abrasions and cuts observed on the dead and injured fish appearconsistent with the expected effects of a turbine. However, because samples sizes are small, theactual rate of injury or mortality cannot be assessed from these data. In addition, no bull trouthave been captured in the rotary screw trap, so effects of entrainment on bull trout cannot bedirectly assessed. Turbine mortality and injury rates on bull trout passing via the turbine wouldbe expected to be similar to that of Chinook salmon of the same size, since body size affectsentrainment injury and mortality rates more than fish species (Exhibit 1).Based on the literature review of entrainment effects, mortality rates are highly variable,depending on project operations, specific facilities, fish size, and species. Although manyanalogous Kaplan systems result in less than 5% mortality (Skalski et al. 2002), given thelimitations of applying results of studies conducted on other projects to the Trail Bridge turbine,and based on captures at the rotary screw trap, mortality through the Trail Bridge turbine isassumed to be > 10%, and most likely even higher at the Howell-Bunger valve.Table 3-4. Summary of Trail Bridge Powerhouse tailrace rotary screw trap captures from April2004 to July 2005, based on 145 days of trapping.SpeciesLifestageYearTotal(#)Injured(#)Dead Mean FL Minimum FL Maximum FL(#) (mm) (in) (mm) (in) (mm) (in)2004 16 0 0 38 1.5 31 1.2 55 2.2Fry2005 25 0 0 36 1.4 30 1.2 52 2.0Chinook2004 30 10 5 131 5.2 95 3.7 165 6.5salmon Juvenile2005 52 3 1 115 4.5 68 2.7 203 8.0Total 123 13 6Unidentifiedtrout 1 Juvenile 2004 1 0 1 NA NA NA NA NA NACutthroattroutAdult 2004 1 0 0 NA NA 225 8.9 225 8.9Rainbow2004 1 0 0 NA NA 300 4.8 300 11.8Adulttrout2005 1 0 0 NA NA 220 8.7 220 8.71 Fish was too damaged to identify to species, or measure fork length20 January 2006 Stillwater SciencesCopyright © 2006 Eugene Water & Electric Board20

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical Report3.2 Trail Bridge Spillway3.2.1 Spill frequencySeveral data sets were reviewed to evaluate the frequency of spill at Trail Bridge. Details on themethods and results of analyzing the spill frequency record are in the Hydrologic Regimes report(Stillwater Sciences 2005b), and are summarized here. Spill data at Trail Bridge spillway arebased on telemetry data recorded by the Sutron system from April 2003 to June 2005 at TrailBridge Reservoir. In addition, generation records from the Trail Bridge Powerhouse werecombined with the discharge data from the USGS Trail Bridge gage, to synthesize an additionalspill record back to 1 December 1998. On an annual basis, the synthesized extended recordindicated an average of 45 spill days (any day in which spill occurs, however short in duration)per year. Based on the telemetry data, the annual frequency of spill days was 29 days per year,which is 16 days per year less than the extended record.The average number of hours of spill from both the synthesized and Sutron record on days withspill was 16 hours for both the operational and high inflow spills. For the synthesized, extendedperiod of record, the average daily spill was 567 cfs; average daily spill due to Project operationswas 660 cfs, and the average daily spill due to high reservoir inflow was 242 cfs. (Note: althoughthe average daily spill due to high inflow is less than that due to Project operations, total flowdownstream of Trail Bridge Dam is often greater during times of high inflow because turbinedischarge would be at its maximum capacity of 1,780 cfs.) Thus, the average daily discharge inthe McKenzie River downstream of Trail Bridge Dam is approximately 1,820 cfs plus theaverage daily spill due to high reservoir inflows.). Average daily spill magnitudes are highest inMay and June at 735 and 1,050 cfs, respectively (e.g., Figure 3-2); the lowest magnitude averagedaily spills occur in January through March, and August (e.g., Figure 3-3 to 3-5). The highestmaximum daily spill for the December 1998 to June 2005 period of record (1,893 cfs) occurredduring high inflow on 26 November 1999, when discharge at the USGS Trail Bridge gagedownstream peaked at about 4,865 cfs. The highest maximum daily spills occurred from Aprilthough June, exceeding 1,400 cfs in all months in that range.Use of the Howell-Bunger bypass valve during high reservoir inflows and project operations wassummarized by comparing the telemetric record for Trail Bridge Dam spillgate with records forthe bypass valve from March 2003 to June 2005. The bypass valve was not opened during thethree spills due to high reservoir inflows. The bypass valve was opened during all spills due toProject operations. To control the amount of flow fluctuation in the river below Trail Bridgeduring a powerhouse outage, water is first shunted to the bypass valve and then transferred to thespillway. The process is reversed when the turbine is restarted. There were six days in this recordwhen the turbines were shut down and the bypass valve was opened, but the spillgate remainedclosed. The bypass valve is also operated during periods when power generation is ongoing butthe spillgate is closed, generally to regulate flow to the McKenzie River and reduce the number ofspillgate openings caused by high inflowsThe frequency of valve operation was evaluated from January 2000 to June 2005, during whichthe valve was operated on an average of 44 days (any day in which the valve was operated,however short in duration) per year. By month, valve operation remains relatively steady, withvalve operation averaging 3 to 7 days per month. November had the highest frequency ofoperation at about 7 times per month, and the valve was only operated one day during the 5-yearperiod in August. Flow discharge through the valve was analyzed for the available telemetry20 January 2006 Stillwater SciencesCopyright © 2006 Eugene Water & Electric Board21

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical Reportrecord between September 2002 and June 2005; the highest average (on days when the valve wasoperated) and maximum daily discharge occurred in January, with an average of 429 cfs and amaximum daily discharge of 692 cfs. Typical average daily discharge (on days when the valvewas operated) through the valve is 50–60 cfs for most months. The highest instantaneousdischarge through the valve for the period of record was 1,712 cfs on 4 January 2003.3.2.2 Entrainment ratesDetailed results of the hydroacoustic analyses are provided in Fixed-Aspect HydroacousticEvaluation of Fish Passage at Trail Bridge Dam (2004-2005) (Exhibit 3). Review of Exhibit 3 iscritical to interpreting the results of the analysis. A general summary of the results is providedhere.The hydroacoustic transducers collected data for one year of operation at Trail Bridge spillway,evaluating 522 hours of spill (on 42 different days) (Table 3-5). The number of days of spillduring the study was typical, and the average daily spill during was also typical, with theexception of the month of December 2004, which had the highest average daily spill during theperiod of record. The months of December 2004, February 2005, and March 2005 each had amaximum instantaneous spill that was the highest on record for those months. Although each ofthese spills was high in magnitude (>600 cfs), the duration was between 3 and 5 hours, and didnot appear to be associated with increased detections at the spillway.Table 3-5. Summary of hydroacoustic mean hourly detection rates at the Trail Bridge spillway,10 May 2004 to 17 May 2005 (522 hours of spill).Detection length classPotential fish equivalentsMean hourly rates(detections/hour) ±80% CI38–100 mm (1.5–3.9 in) Chinook salmon and native trout fry 25.7 ± 2.0> 100–200 mm (> 3.9–7.9 in)Chinook salmon smolts, native troutjuveniles, and hatchery released trout9.5 ± 0.8> 200–350 mm (> 7.9–13.8 in)Native trout juveniles and subadults, andhatchery released trout3.9 ± 0.5> 350 mm (> 13.8 in) Trout adults, Chinook salmon adults 0.9 ± 0.2Hydroacoustic sampling recorded nearly 21,000 detections at the Trail Bridge spillway, of which64% were < 100 mm (100–200 mm (>3.9–7.9 in), 10% were >200–350 mm (>7.9–13.8), and 2% were > 350 mm (>13.8 in). Passage estimates for the two largersize classes of fish, which would include bull trout subadults and adults, were probablyoverestimated at the spillway for the same reasons as at the Trail Bridge turbine intake (Section3.1.1).December and January have the highest frequency of spills due to high reservoir inflow. Fish thatare expected to migrate downstream during December include bull trout subadults and adults, andChinook salmon smolts. In January, migrating fish would most likely include Chinook salmonsmolts. However, it appears that natural migration timing was affected by the timing of the spills.20 January 2006 Stillwater SciencesCopyright © 2006 Eugene Water & Electric Board22

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical Report3.2.2.1 Spillway passage efficiencySpill-passage efficiency (percentage of detections at the spillway versus total detections at intakeand spillway combined) and fish-passage efficiency are nearly identical because the spillway isthe only non-intake route of passage. Passage estimates were very high at the Trail Bridgespillway relative to the Trail Bridge turbine in all seasons, though some of the difference mayhave resulted from false detections of debris at the spillway. During spill, flotsam usually wasobserved accumulating in the spillway area upstream of the gate, especially on the southeast sideof the spillway. The number of detections by the acoustic beam sampling the southeast half ofthe spillway was 2.2 times higher than the number detected by the beam sampling the northwesthalf. This suggests that debris loading was still a problem, even after the strongest target-speedfilter was applied. Hourly rates of passage through the northwest half of the spillway probablyare more reasonable than those for the southeast half. Recalculating passage based upon twicethe number of detections in the NW beam, the spillway passage estimates would be reduced to62.6% of the two-beam estimate.Due to the difficulties in filtering out debris noise, the absolute magnitude of fish passage overTrail Bridge spillway is unknown, and the hydroacoustic estimates of passage is a relative index.During the one-year of study, spill passage efficiency was 51.5% for targets ≤ 100 mm (≤ 3.9 in),41.5% for targets > 100-200 mm (>3.9–7.9 in), 55% for targets 200-350 mm (> 7.9–13.8), and58.3% for targets > 350 mm (> 13.8 in), even though the Project spilled water just 6% of the time(522 hours).Patterns of passage at the Trail Bridge spillway were highly dependent on the frequency, timing,and duration of spill events rather than a temporal pattern driven by fish behavior or entrainmentvulnerability (Table 3-6). The number of spill hours per day explained 61% of the variation inthe number of detections per day. The mean hourly number of detections, which is independentof the number of hours of spill, was clearly higher during the day than at night for all lengthclasses pooled and for individual length classes. For the two smallest length classes, there alsoappeared to be a brief, minor peak around sunset.Table 3-6. Summary of weekly detections at Trail Bridge spillway during periods of spill, May2004 to May 2005.Week startingTotaldurationof spill(s)(hours)Averagedailyspill 1(cfs)Maximuminstantaneousspill(cfs)Number of detections per sizeclass38– 100– 200–> 350100 200 350mmmm mm mm9 May 2004 6.5 283 1,055 66 31 9 96 June 2004 < 1 19 846 0 0 12 020 June 2004 2 135.5 876 1,100 4,911 1,328 328 4727 June 2004 2 131.5 783 903 5,626 1,738 449 7811 July 2004 3 14 123 390 192 346 309 1405 September200420 270 771 644 379 245 10819 September20049.5 122 310 265 296 326 1624 October2004< 1 15 451 58 30 0 07 November 18 231 1,423 806 390 256 7720 January 2006 Stillwater SciencesCopyright © 2006 Eugene Water & Electric Board23

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical ReportWeek startingTotaldurationof spill(s)(hours)Averagedailyspill 1(cfs)Maximuminstantaneousspill(cfs)Number of detections per sizeclass38– 100– 200–> 350100 200 350mmmm mm mm2004 212 December2004 3 12.5 764 1,440 561 220 93 149 January 2005 28.5 80 396 94 56 15 027 February4.5 106 675 22 35 0 0200527 March 2005 16 123 497 19 0 0 010 April 2005 2 < 1 29 1,649 163 85 15 01 For spills occurring less than one day, average daily spill is averaged for the hours spill occurred. For spillslasting more than one day or less than one day but spanning over two days, average daily spill includes datafrom all days having spill.2 A single spill (annual maintenance outage) spanning more than 11 days began the week of 20 June 2004 andended the week of 27 June 2004.3 Two unique spills occurred during this week.4 Three unique spills occurred during this week.Hourly spill-passage efficiency during simultaneous turbine and spillway operation was 100%,96% of the time, because hourly spillway detections were more frequent than hourly turbinedetections, but when it was less than 100%, it was weakly correlated with the hour of the day(Figure 3.34 of Exhibit 3). It appears that the relationship results from differential diel patterns ofpassage at the spillway and turbine, with highest turbine passage at night and in the morning andhighest spillway passage during the afternoon (Exhibit 3).Spill-passage effectiveness is the ratio of the proportion of fish to the proportion of water spilled,and it ranged from 4.5 to 20.1 among seasons and was 9.6 for the year (Exhibit 3, Figure 3.35). Aspill effectiveness of 9.6 means that the proportion of fish spilled was 9.6 times higher than theproportion of water spilled, whereas a spill effectiveness of 1 would indicate that the proportionsof fish and water spilled were the same. A spill effectiveness of 1 is common for spillways atlarge Columbia River projects, and the Trail Bridge spill effectiveness is much more like that ofsurface passage routes at Columbia River dams, where surface-passage effectiveness ranges fromabout 5 to 20 (Exhibit 3).3.2.2.2 PIT tag detectionsAlthough debris loading was apparently high at the spillway, PIT tag results confirm thatjuvenile, subadult and adult bull trout and adult Chinook salmon did pass via the spillway (Table3-7 and 3-8). Nearly all PIT-tag detections at the spawning channel of adult bull trout andChinook salmon in 2004 and 2005 occurred during, or shortly after, spill events at Trail BridgeDam, indicating that the fish probably used the spillway as a passage route. Hydroacousticresults corroborated the PIT tag results indicating that fish (especially large size classes) weremore likely to pass over the spillway than through the turbine, even though the Project spilled just6% of the time (Exhibit 3). The Trail Bridge spillway antenna was not operating during theperiod when most adult Chinook salmon were detected at the Carmen-Smith Spawning Channelantenna, likely explaining why they were not detected at both locations.20 January 2006 Stillwater SciencesCopyright © 2006 Eugene Water & Electric Board24

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical ReportIn fall 2005, 29 adult Chinook salmon that were PIT tagged and released into Trail BridgeReservoir were detected downstream of Trail Bridge Dam (Table 3-7). Of these, all weresubsequently detected in the Carmen-Smith Spawning Channel, or as far downstream as SouthFork McKenzie River. Most of the Chinook salmon adults detected falling back over the damwere males (23 of 29), and about half (16 of 29) had been detected in a spawning reach prior topassing over the dam. About half (18 of 29) of the fish were from the late September release ofadult hatchery Chinook salmon, and were predominantly the fish that were not detected in aspawning reach prior to passing over the dam.Table 3-7. PIT tag detections of fish passing over Trail Bridge Dam and detected at Carmen-Smith Spawning Channel in relation to spill events. Based on 244 PIT tagged bull trout, 197Chinook salmon adults, and 78 other trout species tagged by summer 2005. In 2005 60 of thePIT tagged adult Chinook salmon were released in July, and 55 were released in September.Originallytransferred overSize at lastcapture (orSpeciesTrail Bridge Dam, gender formonth of release for ChinookDate of detection Date(s) of spillChinook salmon salmon)(PIT tag number) mm inYes (113515561)1st584 22.9 14 July 2004 14 July 2004Yes (113515561)2nd635 25.0 22 June 2005 21 June–1 July 2005No (113728247) 128 5.0 9 June 2005 14–15 April 2005BulltroutNo (113728272) 149 5.9 14 July 2004 14 July 2004No (113728293) 355 13.9 26 October 200523 September–2 November2005Yes (126969443) 549 21.6 5 September 2005 5–19 September 2005No (130117902) 295 11.6 18 July 2005 21 June–1 July 2005No (130117909) 670 26.4 1 October 200523 September–2 November2005ChinooksalmonNo (130150182) 180 7.1 20 September 2005 5–19 September 2005No (130150223) 170 6.7 12 September 2005 5–19 September 2005No (130117910) 350 13.8 16 December 200523 September–2 November2005July (130148867) Male 9 September 2004 9–10 September 2004July (130150198) NA 8 September 2005 5–19 September 2005September23 September–2 NovemberMale 30 September 2005(132145414)2005September23 September–2 NovemberMale 4 October 2005(132145417)2005September23 September–2 NovemberMale 1 October 2005(132145424)2005September23 September–2 NovemberMale 29 September 2005(132145429)2005September23 September–2 NovemberFemale 29 September 2005(132145431)2005September23 September–2 NovemberMale 3 October 2005(132145434)2005September23 September–2 NovemberFemale 30 September 2005(132145446)200520 January 2006 Stillwater SciencesCopyright © 2006 Eugene Water & Electric Board25

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical ReportSpeciesOriginallytransferred overSize at lastcapture (orTrail Bridge Dam, gender formonth of release for ChinookDate of detectionChinook salmon salmon)(PIT tag number) mm inSeptember(132145454)Male 1 October 2005September(132145456)Male 1 October 2005September(132145462)Male 6 October 2005September(132145473)Male 3 October 2005September(132145479)Male 1 October 2005September(132145484)Male 30 September 2005September(132145485)Male 1 October 2005September(132145486)Male 30 September 2005September(132145487)Female 30 September 2005September(132145488)Female 30 September 2005SeptemberFemale 2 October 2005Date(s) of spill23 September–2 November200523 September–2 November200523 September–2 November200523 September–2 November200523 September–2 November200523 September–2 November200523 September–2 November200523 September–2 November200523 September–2 November200523 September–2 November200523 September–2 November2005(132145492)July (132590063) Male 11 September 2005 5–19 September 2005July (132590080) Male 7 September 2005 5–19 September 2005July (132590081) Male 8 September 2005 5–19 September 2005July (132590084) Male 24 September 200523 September–2 November2005July (132590086) Male 5 September 2005 5–19 September 2005July (132590088) Male 9 September 2005 5–19 September 2005July (132590107) Male 10 September 2005 5–19 September 2005July (132590111) Male 12 September 2005 5–19 September 2005July (132590120) Male 23 September 200523 September–2 November2005July (132590122) Male 11 September 2005 5–19 September 2005NA=Not available20 January 2006 Stillwater SciencesCopyright © 2006 Eugene Water & Electric Board26

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical ReportTable 3-8. PIT tag detections of fish detected at Trail Bridge spillway. Antenna wasoperational from 20 April to 20 July 2005, and from 10 September to 1 November 2005. Basedon 244 PIT tagged bull trout, 197 Chinook salmon adults, and 78 other trout species tagged bysummer 2005.SpeciesOriginallytransferred overTrail Bridge Dam(PIT tag number)Size attaggingmminDate ofdetectionDateAssociated spillInstantaneousmaximum (cfs)No (130148981) 155 6.1 29 June 2005 21 June–1 July 2005 693No (130150165) 195 7.724 October2005Bull troutNo (130150168) 290 11.420 October2005No (130149000) 293 11.521 September2005No (130150167) 202 8.021 September2005No (130150240) 187 7.423 September2005ChinookYes (132145485) 130 SeptemberAdultsalmon20051 Subsequently detected at Carmen-Smith Spawning Channel.23 September–2November 20056643.2.3 Entrainment effectsA literature review (Information on Entrainment at Spillways) was the primary method used toevaluate entrainment effects at Trail Bridge spillway. Detailed results of the literature review canbe found in Exhibit 2. In summary, broad confidence bands associated with point estimates ofspillway passage survival in the scientific literature make assigning a specific risk to the TrailBridge spillway problematic. However, the Trail Bridge spillway likely presents a less severerisk of injury or mortality than most spillways discussed in the scientific literature because:• The dam has only one spillway.• The spillway has a smooth surface.• The spillway chute is relatively short compared with those at larger dams.• No boulders or other objects are in the chute or stilling basin, which exist at other facilitiesto dissipate energy.• Flows in the spillway are rarely less than 50 cfs, so shallow water depths that can increaseabrasion are uncommon. At 50 cfs water depth in the spillway is approximately 2.54 cm (1in). During an average spill (~550 cfs) water depth in the spillway is approximately 22.8cm (9 in).• Flows in the spillway are not typically high (> 1,000 cfs), thus reducing risk from sheerforces in the ski-jump bucket.• Water velocities into the tail-water plunge pool are effectively reduced by the ski-jumpbucket dissipater.Rotary screw trap captures during spill events were too limited to determine the effects ofentrainment at the spillway. The effects of entering the plunge pool below the Trail Bridgespillway on fish were not assessed in this study. The plunge pool appears deep, and devoid of20 January 2006 Stillwater SciencesCopyright © 2006 Eugene Water & Electric Board27

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical Reportand 3-8), over 28 m (85 ft) above the intake. During reservoir trapping efforts, rainbow trout,whitefish, and cutthroat trout were rarely captured in baited frame traps set in deep water, andwere typically captured in baited frame traps or Oneida traps set in shallow water along thereservoir margins. Frame traps were deployed in depths ranging from 3 to 53 m (10 to 175 ft).No fish were captured in water deeper than 13 m (42 ft), which corresponds with the results ofsonar surveys. In both the sonar and trapping efforts, the highest fish densities were observed inthe upstream portion of Smith Reservoir, nearly 1.6 km (1 mile) from the intake. Detailed resultsof the sonar and reservoir trapping surveys can be found in the Fish Population Distribution andAbundance technical report (Stillwater Sciences 2005a).The species composition in Smith Reservoir was assessed to determine the species thatpotentially could be entrained at Smith intake or the Smith spillway. Brook trout comprised 21%of the fish captured in Smith Reservoir; 53% were hatchery rainbow trout, 16% were cutthroattrout, and 10% were mountain whitefish (Prosopium williamsoni). No bull trout were observedin the reservoir or in the Smith River upstream of Smith Reservoir. Detailed results of reservoirtrapping are provided in the Fish Population Distribution and Abundance technical report(Stillwater Sciences 2005a). Based on literature review, field surveys of fish distribution, and thedocumented species composition in Smith Reservoir, the risk of entrainment for resident trout,and in particular cutthroat trout, is low at the Smith intake.The rate of injury or mortality of any fish that are entrained at the Smith intake was not directlyassessed, and is not known. However, based on the literature review provided in Exhibit 1, if fishwere entrained at the Smith intake, injury and mortality rates are assumed to be > 10%.3.5 Smith SpillwayAs described in the Hydrologic Regimes technical report (Stillwater Sciences 2005b), spill datafrom Smith spillway is based on telemetry data from March 2003 to June 2005, which is the onlyreliable spill history record for the Smith Dam. Details on the methods and results of analyzingthe spill frequency record are in the Hydrologic Regimes report (Stillwater Sciences 2005b), andare summarized here. Based on the telemetry data record, spill occurred on 11 days during a totalof 7 spill events at Smith Dam over an 833-day record (excluding the 9 spills for the purpose ofrelicensing studies, and one extended spill event during major work in the Carmen Powerhouse infall 2003), which is the equivalent to about 5 days when spill occurs per year. There were nospills due to large flood events over the 2-year period of record. The average spill duration whenexcluding the extended fall 2003 maintenance spill was 17 hours. The range of spill duration(excluding the maintenance period) was 57 minutes to about 71 hours, but except for the longestspill, all spills were less than 24 hours. The average daily spill was about 154 cfs and the range ofaverage daily spills was 20 to 424 cfs. The average peak spill discharge was 514 cfs, and thehighest peak spill discharge was 784 cfs, which occurred on 25 February 2004 due to a lineoutage.No direct data on entrainment at the Smith spillway were collected. A literature review(Information on Entrainment at Spillways) was the primary method used to evaluate entrainmenteffects at Smith spillway. Detailed results of the literature review can be found in Exhibit 2. Insummary, the spillway is a “flip bucket”, leading to a 46 m (150 ft) freefall to a bedrock pool,making the likelihood of injury and mortality of any fish traversing the spillway high. However,because of the species composition and distribution in the reservoir (described above in section20 January 2006 Stillwater SciencesCopyright © 2006 Eugene Water & Electric Board29

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical Report3.3), and because of the infrequency of spills at the spillway, few native fish are expected to beentrained at the Smith spillway.3.6 Carmen Diversion SpillwayAs described in the Hydrologic Regimes technical report (Stillwater Sciences 2005b), the CarmenDiversion Dam spill records from telemetry data extend from March 2003 to June 2005.Montgomery Watson Harza's (MWH's) Operations Model for the "average daily spill" scenario(MWH 2004) was used to extend the Carmen Diversion Dam spill record to 1961. Based on thismodel combined with the telemetry data, for the period of record from 1961 to 2005, the CarmenDiversion Dam spills on average about 76 days annually. Typically, spill events occur about 4times per year (a spill event is defined by consecutive days with spill) and the average spillduration is 20 days. Spill events occur in a similar frequency from November through May, asabout one spill event occurs approximately every other year during these months (for a spill eventthat spans multiple months, the event is categorized by its starting month). Spills beginning inMarch through May have a longer average duration (24–33 days) but are smaller in magnitudethan spills occurring from November through February. Spills occurring in winter months ofNovember through February have shorter durations (13–16 days) than the springtime spills, butthe winter spills are of higher magnitude, on an average and maximum daily basis. For monthswith spill, the average daily spill calculated from the MWH operations model (2004) ranged from62 to 325 cfs with an annual average of 218 cfs. The maximum daily spill as predicted by theoperations model was 2,615 cfs for the December 1964 flood event.In total, over 625 fish were captured in two seasons of sampling below the Carmen DiversionDam (Table 3-9). The fyke traps were able to remain in place during most spills, though wereonly sampling a portion of the channel during spills greater than 100 cfs. Based on the samplingeffort with the most fish captures, 52% were brook trout, 0.5% were rainbow trout, and 47% weresculpins (Cottidae species) (capture data were not combined between efforts to avoid repeatedlycounting the same individuals). Of the seven rainbow trout that were captured during allsampling efforts combined, five were hatchery fish (distinguishable by adipose fin-clip) and twowere naturalized rainbow trout from previous hatchery releases; no cutthroat trout were captured.Surveydate28 April200429 April200429 April2004Table 3-9. Fish captured directly downstream of Carmen Diversion Dam during 2004and 2005 spill events.AverageMaximumNumber of fish capturedSpillmagnitude Samplingspilldatesof spill technique Rainbow Brook(cfs)(cfs)trout trout27–28April200428–29April200427–29April2004Sculpins52 24 Fyke net 0 0 052 20 Fyke net 0 0 052 22 Electrofishing 0 56 4817 May2004No spill 0 0 Electrofishing 0 34 1229 May 27–29 167 90 Fyke net 0 0 020 January 2006 Stillwater SciencesCopyright © 2006 Eugene Water & Electric Board30

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical ReportSurveydateSpilldates2004 May200429–3131 MayMay2004200431May–1010 JuneJune12 June200424August200422October20046 March200511 May200511 May200520041–12June2004Maximumspill(cfs)Averagemagnitudeof spill(cfs)SamplingtechniqueRainbowtroutNumber of fish capturedBrooktroutSculpins150 105 Fyke net 0 0 074 37 Fyke net 0 0 0167 48 Electrofishing 1 99 91No spill 0 0 Electrofishing 0 62 28No spill 0 0 Electrofishing 0 56 30No spill 0 0 Electrofishing 1 47 a 411–11May c20051–11May c200513 May c200514 May c200515 May c2005261 175 Electrofishing 5 13 b 1261 175 Minnow traps 0 0 013 May200551 40 Fyke net 0 0 014 May200511 10 Fyke net 0 0 015 May200513 10 Fyke net 0 0 0Total 7 367 251a Nineteen of these were recaptures.b Two of these were recaptures.c May 2005 spills were forced spills associated with instream flow investigations.Approximately 1 cfs occurs below the Carmen Diversion Dam, resulting in perennial flow forabout 50 m (164 ft) of the upper Carmen Bypass Reach before it goes into the aquifer. Duringsurveys in June, August, and October 2004, brook trout were captured in this wetted area belowCarmen Diversion Dam, even though no spill was occurring at the dam. Captured fish were finclipped,and were subsequently recaptured in winter and spring of 2005, indicating a residentbrook trout population below Carmen Diversion Dam. Based on these recaptures, the number offish observed during each sampling effort cannot be clearly linked to a particular spill event.The species composition in Carmen Diversion Reservoir was assessed to determine the speciesthat potentially could be entrained into Carmen Diversion tunnel or spillway. Based on reservoirtrapping, brook trout comprised 91% of the fish captured in Carmen Diversion Reservoir, 6%20 January 2006 Stillwater SciencesCopyright © 2006 Eugene Water & Electric Board31

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical Reportwere hatchery rainbow trout, and 3% were cutthroat trout. Details of reservoir trapping areprovided in the Fish Population Distribution and Abundance technical report (Stillwater Sciences2005a).Overall, most fish entrained at Carmen Diversion Dam are brook trout (many of which appear tobe resident below the dam) or hatchery rainbow trout. Cutthroat trout were rarely observed insampling in Carmen Diversion Reservoir during spring, summer, and winter direct observationdives and reservoir trapping (Stillwater Sciences 2005a). No cutthroat trout were observedfollowing spill events in fyke trapping, direct observation dives, or electrofishing surveys (Table3-9).3.7 Carmen Diversion Tunnel IntakeBased on video analysis, daytime entrainment rates at the Carmen Diversion tunnel intake arelow. However, because infrared lights proved ineffective for nocturnal observations, and thevideo camera had only partial coverage of the intake, detections were based on a partial viewduring the daytime, making absolute entrainment estimates unreliable.Observations of many fish being entrained following hatchery releases were more effective withthe naked eye than with the underwater camera, though the camera did detect some entrainment(see video clips in Exhibit 4). Based on observations, no rates of entrainment of hatcheryrainbow trout could be estimated. Entrainment of fish into the Carmen Diversion tunnel occurs,but based on the dominance of brook trout and hatchery rainbow trout, the low abundance ofcutthroat trout in Carmen Diversion Reservoir, and the absence of cutthroat trout below CarmenDiversion Dam (described in Section 3.5); the risk of native cutthroat trout being entrained thereis low.3.8 Project Tailraces3.8.1 Trail Bridge Powerhouse tailraceUpstream migrating fish can be injured or delayed at draft tubes when they attempt to enter thedraft tubes because of a false attraction to the discharge, or to use the draft tubes as “cover”.Injury and delay are observed typically under the following circumstances (NMFS 1993):• Turbine discharge has better water quality than mainstem river,• Turbine discharge is a large proportion of total flow,• Turbine discharge is rapidly changing, or• Fish are imprinted on water from turbine discharge.The most likely scenario that would put upstream migrating fish at risk is that there is no otherroute past Trail Bridge dam other than the flow from the turbine, so fish may be attracted to thedischarge there. Although a velocity barrier downstream of Trail Bridge Dam is designed toblock upstream fish movement and force fish moving upstream into the spawning channel, thebarrier is not completely effective at blocking all upstream migrants, as evidenced by PIT tagdetections of one bull trout at the spawning channel antenna, and subsequently at the tailraceantenna.20 January 2006 Stillwater SciencesCopyright © 2006 Eugene Water & Electric Board32

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical ReportAdult Chinook salmon were also observed in the Trail Bridge tailrace. However, based on PITtag detections, some adult Chinook salmon placed in Trail Bridge Reservoir “fall-back” over thespillway to the tailrace. In fall 2005 Chinook salmon that were PIT tagged and released into TrailBridge Reservoir were detected downstream of Trail Bridge Dam (see Section 3.2.2.2). All weresubsequently detected in the Carmen-Smith Spawning Channel, or as far downstream as SouthFork McKenzie River, indicating that although Trail Bridge Dam is a barrier to upstream passage,Chinook salmon that migrate to the tailrace are not prevented from migrating downstream tolocate spawning habitat.The velocity barrier, while not a complete barrier, clearly reduces access to the tailrace if thenumbers of spawning fish in the Carmen-Smith Spawning Channel are compared with thenumbers of fish observed above the barrier. During snorkel surveys in the Trail Bridge tailraceJuly 2004, three Chinook salmon and one juvenile were observed, as well as several otherspecies. None of the observed fish were injured. During snorkel surveys in the tailrace inJanuary 2005, only rainbow trout were identified, with no signs of injury. More extensivesurveys in the Trail Bridge Powerhouse tailrace were not possible because of safety concerns. Itis also possible that fish are accessing the tailrace after moving across Trail Bridge Dam via thespillway or powerhouse, rather than up the velocity barrier (see Section 3.2.2.2).For turbine strike to occur, fish would have to swim approximately 18 m (60 feet) into the drafttube (Figure 3–9) to reach the turbine at Trail Bridge Powerhouse. The average water velocity inthe draft tubes is 1.2–4.6 m/s (3.9–15.1 ft/s) while the turbine is operating (Table 3-10). Typicalcritical swimming speeds (top speed that a fish can maintain for several minutes) for an adultChinook salmon are 1.04–3.29 m/s (3.4–10.8 ft/s) (Bjornn and Reiser 1991). Therefore, an adultChinook salmon could under some circumstances overcome the turbine velocities and gain accessto the turbine blades, or could swim up draft tubes when the turbine is not operating. The turbineat Trail Bridge powerhouse typically operates more than 90% of the time. The turbine istypically off only for maintenance, for periods of one or more days (see Section 3.2.1). Criticalswimming speeds (speeds maintainable for several minutes) for adult bull trout (32–42 cm [13–17 in]) in water temperatures similar to the McKenzie River are 0.74 m/s (2.4 ft/s) (Mesa et al.2004), indicating that bull trout are unlikely to gain access to the draft tubes during turbineoperation. The risk of adult bull trout or Chinook salmon entering the Trail Bridge Powerhousedraft tubes and suffering injury or mortality is not known, but is decreased by the presence of thevelocity barrier to prevent upstream migration, and infrequent off-line turbine periods.Table 3-10. Typical average velocities in draft tubes at the Trail BridgePowerhouse tailrace when power is being generated. (See Figure 3-9 for velocitylocations.)VelocityRunner exit Pier nose Turbine Exitm/s ft/s m/s ft/s m/s ft/sMinimum 2.4 8.0 1.4 4.6 0.6 2.1Maximum 8.9 29.2 5.1 16.7 2.3 7.6Mean 4.6 15.1 2.6 8.6 1.2 3.920 January 2006 Stillwater SciencesCopyright © 2006 Eugene Water & Electric Board33

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical Report3.8.2 Carmen Powerhouse tailraceCarmen Powerhouse has no tailrace velocity barrier, and fish have access to the draft tubes andturbines. Based on direct observation surveys and PIT tag detections, juvenile and adult trout andsalmon are distributed within the vicinity of the powerhouse during most of the year. Upstreammigrating fish can be injured or delayed at draft tubes when they attempt to enter the draft tubesbecause of a false attraction to the discharge, or to use the draft tubes as “cover”. Injury anddelay are observed typically under the following circumstances (NMFS 1993):• Turbine discharge has better water quality than mainstem river,• Turbine discharge is a large proportion of total flow,• Turbine discharge is rapidly changing, or• Fish are imprinted on water from turbine discharge.Of these potential circumstances, the only one that applies to the Carmen Power Powerhouse isthat when it is operating the discharge is a large proportion of the total flow. The water quality inTrail Bridge Reservoir, and in the Carmen Bypass Reach is very high (Stillwater Sciences2005d), turbine discharge is not rapidly changing, and fish are most likely to be imprinted onwater from the Carmen Bypass Reach or other tributaries to Trail Bridge Reservoir rather thanwater from Smith Reservoir and the Carmen Powerhouse. To reach the powerhouse turbines,adult upstream migrating fish would have to swim approximately 20 m (65 ft) into the draft tubes(Figure 3-10). Typical average velocity in the draft tubes is 1.1–4.5 m/s (3.6–14.6 ft/s) whileturbines are operating (Table 3-11). Based on critical swimming speeds, an adult Chinooksalmon could possibly overcome the velocities of the turbine to gain access to the draft tubesunder some circumstances, or could swim up draft tubes when the turbine is off-line. Based oncritical swimming speeds for adult bull trout in water temperatures similar to the McKenzieRiver, bull trout are unlikely to gain access to the draft tubes during turbine operation. Althoughthe Carmen Powerhouse is generating (at least one turbine on) more than 80% of the time,turbines are typically off from midnight until around 0600 hours each day.Table 3-11. Typical velocities in draft tubes at Carmen Powerhouse tailracewhen power is being generated. (See Figure 3-10 for velocity locations.)VelocityRunner exit Pier nose Exitm/s ft/s m/s ft/s m/s ft/sMinimum 2.9 9.7 1.5 5.0 0.7 2.4Maximum 7.7 25.3 3.9 13.0 1.9 6.2Mean 4.5 14.6 2.3 7.5 1.1 3.6During six snorkel surveys on 4 days in the Carmen Powerhouse tailrace, 238 fish were observed(Figures 3-11 and 3-12). Fish were observed in the vicinity of the powerhouse while the turbineswere operating, as well as when they were off (Figures 3-11, Exhibit 4). However, the draft tubesoutlets are 1.2–4.9 m (4–16 ft) underwater (depending on reservoir water level), and 3 m (10 ft)under the generator observation deck, so no direct observations were possible within the drafttubes (Figure 3-10). None of the fish observed in the tailrace were dead, or had apparent injuries,scars, bruises, or abrasions.A total of 30 surveys for injured or dead fish were conducted in the Carmen Powerhouse tailracebetween 22 July and 2 November 2005. Three dead adult Chinook salmon were observed, north(upstream) of the Carmen Powerhouse, near the Trail Bridge Reservoir Bridge. There were no20 January 2006 Stillwater SciencesCopyright © 2006 Eugene Water & Electric Board34

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical Reportsigns of injuries on two of the fish, and the third had apparently been consumed (most likelyotter). One rainbow trout adult was also observed near the bridge, with no visible injuries. Thecurrent runs south from the Carmen Bypass Reach past the powerhouse, so any fish killed by theturbine would be expected to float downstream (south) of the powerhouse. No dead or injuredfish were found south of the powerhouse. During snorkel surveys, and examinations of adultChinook salmon, there was no evidence of fish entering the draft tubes and being injured orkilled.Delay at Carmen PowerhouseAdult hatchery Chinook salmon released into Trail Bridge Reservoir, or adult bull trout, could bedelayed at the discharge from the Carmen Powerhouse prior to spawning. Six direct observationsnorkel and video surveys were conducted on four occasions at the Carmen Powerhouse tailrace(Figures 3-11 and 3-12) in spring, summer, and fall 2004. Four surveys were conducted while thepowerhouse was operating, and two were conducted while the turbines were off-line. Mostobservations were of hatchery rainbow trout, although adult Chinook salmon, and juvenile,subadult, and adult bull trout were also observed.Greater numbers of fish were observed during daytime snorkel surveys (when turbines were on)than during nighttime surveys (turbines are off only at night). In contrast, slightly highernumbers of fish were observed when turbines were off than when they were operating. However,because of turbulence from the turbine discharge, the probability of observation was higher whenthe turbines were off (see video clips in Exhibit 4).Fish were found widely distributed in the vicinity of the powerhouse when turbines were notoperating, and shifted away from the turbine discharge when the powerhouse was operating. Dueto the bubbles in the extremely turbulent water closest to the draft tube outlets, divers were unableto distinguish fish in that area. The snorkel dive field effort in the vicinity of the CarmenPowerhouse was complemented with the PIT tag work described below.As of summer 2005, the Carmen Powerhouse PIT tag antenna detected 27 individual PIT-taggedbull trout, one cutthroat trout, and one adult Chinook salmon. Equal numbers of bull trout adults,subadults, and juveniles were detected. Twenty-seven percent of all detections occurred when theturbines were off, and 73% occurred when the turbines were on, which corresponds roughly withthe average time that the turbines are on versus off, indicating that the PIT tag data show nopreference for fish presence when the turbine is on or off.To further examine potential for delay, Vaki Riverwatcher data were examined to determine if apattern to the upstream migration of adult bull trout or spring Chinook salmon during thespawning season could be observed, that could be related to project operations at the CarmenPowerhouse. Adult bull trout migrated upstream in the Carmen Bypass Reach during all hours,with the exception of the early morning (0200–0600), when no upstream migrants were observed.Movement patterns of adult bull trout had no relationship to powerhouse operations (Figure 3-13). Adult spring Chinook salmon migrated upstream in the Carmen Bypass Reach during allhours, although upstream movement peaked around midnight, and was lowest around noon(Figure 3-14). Movement patterns for adult spring Chinook salmon also had no relationship topowerhouse operations. No pattern of fish upstream migration being delayed by discharge at theCarmen Powerhouse tailrace was observed.20 January 2006 Stillwater SciencesCopyright © 2006 Eugene Water & Electric Board35

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical Report4 LITERATURE CITEDBaldwin, C. M., D. A. Beauchamp, and J. J. Van Tassell. 2000. Bioenergetic assessment oftemporal food supply and consumption demand by salmonids in the Strawberry Reservoir foodweb. Transactions of the American Fisheries Society 129: 429-450.Bell, M. C. 1981. Updated compendium on the success of passage of small fish through turbines.Contract No. DACW-68-76-C-0254. U. S. Army Corps of Engineers, North Pacific Division.Bjornn, T. C., and D. W. Reiser. 1991. Habitat requirements of salmonids in streams. Pages 83-138 in W. R. Meehan, editor. Influences of forest and rangeland management on salmonid fishesand their habitats. Special Publication No. 19. American Fisheries Society, Bethesda, Maryland.EPRI (Electric Power Research Institute). 1992. Fish entrainment and turbine mortality reviewand guidelines. Final Report. Research Project 2694-01; EPRI TR-101231. Palo Alto, California.EWEB (Eugene Water & Electric Board). 2003. Initial consultation package for relicensing theCarmen-Smith Hydroelectric Project (FERC No. 2242). Final report. Prepared by StillwaterSciences, Arcata, California for EWEB, Eugene, Oregon.Federal Power Commission. 1959. Order issuing license (major). Submitted by City of Eugene,Oregon, by and through its Eugene Water & Electric Board, Project No. 2242.FERC (Federal Energy Regulatory Commission). 2003. Order approving conservation measuresand requiring study plans and reports with respect to threatened and endangered species (issuedAugust 1, 2003). Eugene Water & Electric Board, Project No. 2242-051. 104 FERC 62,080.Goetz, F. 1989. Biology of the bull trout, Salvelinus confluentus, a literature review. USDAForest Service, Willamette National Forest, Eugene, Oregon.Knutzen, J. 1997. Evaluation of fish entrainment potential from the Chester Morse Lake/MasonryPool system. Prepared by Foster Wheeler Environmental Corporation, Bellevue, Washington forSeattle City Light, Seattle, Washington.Ledgerwood, R. D., E. M. Dawley, L. G. Gilbreth, P. J. Bently, B. P. Sanford, and M. H.Schiewe. 1990. Relative survival of subyearling chinook salmon which have passed Brown Damvia the spillway or the second powerhouse turbines or bypass system in 1989, with comparisonsto 1987 and 1988. Contract E85890024/E86890097. National Marine Fisheries Service and U. S.Army Corps of Engineers.Mesa, M. G., L. K. Weiland, G. B. Zydlewski. 2004. Critical swimming speeds of wild bull trout.Northwest Science 78(1): 59-65.MWH (MWH Americas, Inc.). 2004. Carmen-Smith Hydroelectric Project potential generationimprovements study. Preliminary report. Prepared for Eugene Water & Electric Board, Eugene,Oregon by MWH Americas, Inc., Bellevue, Washington.20 January 2006 Stillwater SciencesCopyright © 2006 Eugene Water & Electric Board36

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical ReportNMFS (National Marine Fisheries Service). 1993. The use of barriers to prevent adult salmondelay and injury at hydroelectric powerhouses and wasteways. Working Paper. NMFS,Environmental & Technical Services Division, Portland, Oregon.NMFS (National Marine Fisheries Service). 1999. Endangered and threatened species; threatenedstatus for three Chinook salmon Evolutionarily Significant Units (ESUs) in Washington andOregon, and endangered status for one Chinook salmon ESU in Washington. Federal Register 64:14308-14328.NMFS (National Marine Fisheries Service). 2005a. Endangered and threatened species; finallisting determinations for 16 ESUs of West Coast salmon, and final 4(d) protective regulations forthreatened salmonid ESUs. Federal Register 70: 37160-37204.NMFS (National Marine Fisheries Service). 2005b. Endangered and threatened species;designation of critical habitat for 12 Evolutionarily Significant Units of west coast salmon andsteelhead in Washington, Oregon, and Idaho. Federal Register 70: 52630-52858.NOAA Fisheries. 2004. Biological opinion and Magnuson-Stevens Fishery Conservation andManagement Act consultation: Operation of the Cowlitz River Hydroelectric Project (FERC No.2016) through 2038, Cowlitz River, HUC 17080005, Lewis County, Washington. EndangeredSpecies Act Section 7(a)(2) consultation. NOAA Fisheries, Northwest Region, HydropowerDivision, Seattle, Washington.Ploskey, G. R., G. Weeks, S. Scherck, C. Shilt, P. Johnson, and J. M. Nestler. 1995. Richard B.Russell Phase II Completion Report: Impacts of two-unit pumpback operation. Technical reportprepared by the U.S. Army Engineer Waterways Experiment Station for the U. S. Army EngineerDistrict, Savannah, Georgia.Rowe, D. K., and B. L. Chisnall. 1995. Effects of oxygen, temperature and light gradients on thevertical distribution of rainbow trout, Oncorhynchus mykiss, in two North Island, New Zealand,lakes differing in trophic status. New Zealand Journal of Marine and Freshwater Research 29:421-434.Seber, G. A. F. 1982. The estimation of animal abundance and related parameters. Secondedition. Macmillan, New York.Skalski J. R., D. Mathur, and P. G. Heisey. 2002. Effects of turbine operating efficiency on smoltpassage survival. North American Journal of Fisheries Management 22: 1193–1200.Steir, D. J. and B. Kynard. 1986. Use of radio telemetry to determine the mortality of Atlanticsalmon smolts passed through a 17-MW Kaplan turbine at a low-head hydroelectric dam.Transactions of the American Fisheries Society 115: 771-775.Stillwater Sciences. 2004. Fish entrainment. Final study plan for the Carmen-SmithHydroelectric Project relicensing (FERC No. 2242). Prepared by Stillwater Sciences, Arcata,California for Eugene Water & Electric Board, Eugene, Oregon.Stillwater Sciences. 2005a. Fish population distribution and abundance in the Carmen-SmithHydroelectric Project area, upper McKenzie River basin, Oregon. Agency draft report. Preparedby Stillwater Sciences, Arcata, California for Eugene Water & Electric Board, Eugene, Oregon.20 January 2006 Stillwater SciencesCopyright © 2006 Eugene Water & Electric Board37

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical ReportStillwater Sciences. 2005b. Hydrologic Regimes in the Carmen-Smith Hydroelectric ProjectArea, Upper McKenzie River Basin, Oregon. Agency draft report. Prepared by StillwaterSciences, Arcata, California for Eugene Water & Electric Board, Eugene, Oregon.Stillwater Sciences. 2005c. Protection, Mitigation, and Enhancement Opportunities in theCarmen-Smith Hydroelectric Project Area, Upper McKenzie River Basin, Oregon. Agency draftreport. Prepared by Stillwater Sciences, Arcata, California for Eugene Water & Electric Board,Eugene, Oregon.Stillwater Sciences. 2005d, in preparation. Water quality in the Carmen-Smith HydroelectricProject area, upper McKenzie River basin, Oregon. Agency draft report. Prepared by StillwaterSciences, Arcata, California for Eugene Water & Electric Board, Eugene, Oregon.USFWS (U. S. Fish and Wildlife Service). 1998. Endangered and threatened wildlife and plants;determination of threatened status for the Klamath River and Columbia River distinct populationsegments of bull trout. Federal Register 63: 31647-31674.USFWS (U. S. Fish and Wildlife Service). 2003. Biological/conference opinion on the effects ofEWEB's Carmen-Smith Part 12 submittal to FERC for Trail Bridge spillway expansion, andinterim operation of the Carmen-Smith Hydroelectric Project in the McKenzie Subbasin, Oregonon bull trout, bald eagle, and northern spotted owl. Endangered Species Act - Section 7 (a)(2)Consultation; USFWS Log No. 1-7-03-F-455. Prepared for Federal Energy RegulatoryCommission by USFWS, Oregon Fish and Wildlife Office.USFWS (U. S. Fish and Wildlife Service). 2004. Endangered and threatened wildlife and plants;designation of critical habitat for the Klamath River and Columbia River populations of bulltrout; final rule. Federal Register 69: 59996-60075.Warner, E. J., and T. P. Quinn. 1995. Horizontal and vertical movements of telemetered rainbowtrout (Oncorhynchus mykiss) in Lake Washington. Canadian Journal of Fisheries and AquaticSciences 73: 146-153.Wyman, K. H., Jr. 1975. Two unfished salmonid populations in Lake Chester Morse. Master'sthesis. University of Washington, Seattle.20 January 2006 Stillwater SciencesCopyright © 2006 Eugene Water & Electric Board38

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical ReportFiguresCopyright © 2006 Eugene Water & Electric Board - the following Figures for the Fish Entrainment Technical Report

Figure 1-1. Study Area.

HydrologicRegimesRIVER CHANNEL DYNAMICSSedimentBudgetLarge WoodyDebrisDynamicsAQUATIC HABITAT CONDITIONSWater QualityFluvial GeomorphicProcesses andChannel MorphologyAquatic Habitatsand Instream FlowsAquatic HabitatConnectivityFISHERIESBOTANY AND WILDLIFESOCIAL SCIENCESFish Distribution andAbundanceVegetation and WetlandMapping andCharacterizationHistorical andArchaeological ResourcesEntrainmentBotanical Field SurveysExisting Recreational UseFlow Fluctuations andStrandingWildlifeDistributionRecreation SuitabilityPopulation Dynamics of BullTrout and Spring ChinookSalmonWildlife AnalysesWhitewater BoatingFeasibilityFish Passage FeasibilityAesthetic ResourcesAquatic Protection,Mitigation, andEnhancement OpportunitiesLicense ApplicationLand Use and ManagementFigure 1-2. Relationship of the Fish Entrainment study to other Carmen-Smith Hydroelectric Project relicensing studies.

Figure 2-1. Rotary screw trap in Trail Bridge tailrace.Figure 2-2. Trail Bridge tailrace helical antenna.

Figure 2-3. Trail Bridge tailrace, with the square-shaped antenna represented in red.Figure 2-4. Carmen-Smith Spawning Channel antenna.

Figure 2-5. Trail Bridge Velocity Barrier antennas.Figure 2-6. Smith intake.

Figure 2-7. Trail Bridge spillway (from the reservoir facing downstream).

This Figure is designated as Critical Infrastructure Information(CEII) FERC Only

Figure 2-9. Trail Bridge spillway antenna, facing up the spillway (upper image) with theantenna highlighted in red, and facing perpendicular to the spillway (lowerimage).

Figure 2-10. Smith spillway.

Figure 2-11. Smith spillway, facing downstream.

This Figure is designated as Critical Infrastructure Information(CEII) FERC Only

Figure 2-13. Smith spillway scour hole, two-foot contours.

Figure 2-14. Carmen Diversion spillway.Figure 2-15. Fyke trap in 2004, shown at 80 cfs.

Figure 2-16. Fyke trap in 2005, shown at 1 cfs.Figure 2-17. Carmen Diversion tunnel intake.

Figure 2-18. Carmen Powerhouse tailrace, with antenna represented in red.Figure 2-19. Underwater view of lower Carmen Bypass Reach Vaki Riverwatcher and weir.Highlighted box shows the passage of an adult Chinook salmon.

Figure 2-20. Lower Carmen Bypass Reach Vaki Riverwatcher and weir.

3530FryJuvenileNumber of fish252015Trap not operating or live boxwas malfunctioning between 7September and 21 January 2004.1050Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov DecMonthFigure 3-1. Trail Bridge tailrace rotary screw trap captures of Chinook salmon fry and juveniles. Data was averaged by month from 12 April–7 August2004 and 26 January–10 June 2005. Captures rates were too low to allow estimates of total numbers of downstream migrants.

Figure 3-2. Trail Bridge spillway at a high-magnitude spill (

Figure 3-4. Trail Bridge spillway at low-magnitude spill (

Figure 3-6. Trail Bridge spillway pool with no spill.

Figure 3-7. Smith Reservoir sonar survey before hatchery rainbow trout release.

Figure 3-8. Smith Reservoir sonar survey after hatchery rainbow trout release.

This Figure is designated as Critical Infrastructure Information(CEII) FERC Only

This Figure is designated as Critical Infrastructure Information(CEII) FERC Only

Nighttime observations withgenerationNighttime observations withno generationFigure 3-11. Nighttime direct observation snorkel and video surveys at Carmen Powerhouse tailrace. Data from 13 August and 9 October 2004.

Daytime observations with generationFigure 3-12. Daytime direct observation snorkel surveys at Carmen Powerhouse tailrace. Data from the 13 August and 9 October 2004 whileturbines were generating.

Vaki Riverwatcher detections (#)0 2 4 6 8 10 12CarmenPowerhouseTypically OffOff0000 0500 5 1000 1500 20000000 0500100015002000HourTime (hours)Figure 3-13. Bull trout movement in Carmen Bypass Reach, 8 September 2004 to 29 October 2004.

Vaki Riverwatcher detections (#)0 5 10 15 20 25 30CarmenPowerhouseTypically OffOff0000 0000 0500 5 100015002000HourTime (hours)Figure 3-14. Adult Chinook salmon movement in Carmen Bypass Reach, 23 August 2004 to 31 October 2004.

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical ReportExhibitsCopyright © 2006 Eugene Water & Electric Board - the following Exhibits for the Fish Entrainment Technical Report

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical ReportExhibit 1Literature review of fish entrainment riskat hydroelectric facilitiesCopyright © 2006 Eugene Water & Electric Board - the following Exhibit 1 for the Fish Entrainment Technical Report:Exhibit 1Literature review of fish entrainment riskat hydroelectric facilities

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical ReportTable of Contents1 INTRODUCTION AND PURPOSE .......................................................................................12 SUMMARY OF CARMEN-SMITH HYDROELECTRIC PROJECT FACILITIESRELEVANT TO ENTRAINMENT..................................................................................E1-22.1 Carmen Diversion Reservoir, Spillway, and Diversion Tunnel................................. E1-42.2 Smith Reservoir, Power Tunnel, Spillway, and Carmen Powerhouse ....................... E1-42.3 Trail Bridge Reservoir and Powerhouse .................................................................... E1-43 FISH ANALYSIS SPECIES ..............................................................................................E1-54 INJURY TYPES .................................................................................................................E1-65 SOURCES OF INFORMATION ......................................................................................E1-66 ENTRAINMENT RISK FACTORS .................................................................................E1-76.1 Biological Factors ...................................................................................................... E1-76.1.1 Fish size............................................................................................................. E1-76.1.2 Species composition.......................................................................................... E1-86.1.3 Seasonal timing ............................................................................................... E1-126.2 Physical Factors ....................................................................................................... E1-126.2.1 Entrainment through turbines.......................................................................... E1-136.2.2 Entrainment at spillways ................................................................................. E1-176.2.3 Entrainment at tailraces................................................................................... E1-196.3 Extrapolation of Entrainment Data to Unstudied Projects....................................... E1-197 CONCLUSIONS...............................................................................................................E1-218 LITERATURE CITED ....................................................................................................E1-22January 2005Copyright © 2006 Eugene Water & Electric BoardE1-iStillwater Sciences

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical ReportTables:Table E1-1. Physical features of the Carmen-Smith Project facilities. .....................................E1-3Table E1-2. Fish species having risk of entrainment at the Carmen-Smith Hydroelectric Projectunder current conditions. ......................................................................................E1-5Table E1-3. Sustained and burst swimming speeds of fish reported in FishBase. ....................E1-8Table E1-4. Mean approach velocities and median water depths for power diversion intakestructures.............................................................................................................E1-10Table E1-5. Mortality rates and characteristics for Francis and Kaplan type turbine studies .E1-14Table E1-6. Mortality rates and characteristics for studies of various spillway types. ...........E1-18Table E1-7. Physical characteristics of reservoirs for comparative purposes. ........................E1-20Figures:Figure 1-1.Carmen-Smith Hydroelectric Project Area (in Figures section of Fish Entrainmentreport).Figure E1-2. Estimated velocity within the Carmen Diversion tunnel and at the intake entrancefor normal pool level.Figure E1-3. Estimated velocity within the Smith power tunnel and at the intake entrance forminimum and maximum pool levels.Figure E1-4. Estimated velocity within the Trail Bridge power tunnel and at the intake entrancefor minimum and maximum pool levels.Figure E1-5. Estimated spill velocity at Trail Bridge spillway.January 2005Copyright © 2006 Eugene Water & Electric BoardE1-iiStillwater Sciences

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical Report1 INTRODUCTION AND PURPOSEFor certain fish populations residing in the vicinity of hydroelectric projects, a major source ofdirect and indirect mortality is the physical damage or stress individuals incur as they attemptpassage through hydropower facilities (OTA 1995, NRC 1996, Cada et al. 1997, all cited inCoutant and Whitney 2000). Migratory fish species, such as salmon, bull trout, and Pacificlamprey, are especially affected because they may need to migrate downstream to successfullycomplete their life cycle. The phenomenon of fish being drawn into physical features ofhydropower facilities is termed “entrainment,” and has become a key issue to be resolved innearly all relicensing proceedings under federal law. This report is intended to meet theobligations of Task 7.1.1 (literature review) of the Carmen-Smith Fish Entrainment study plan(Stillwater Sciences 2004). As defined in the study plan, “entrainment” is considered themovement of fish from a reservoir through various water conveyances at each dam todownstream exit locations. This study also addresses the potential for delay or injury associatedwith Carmen-Smith Hydroelectric Project (Project) tailraces.The following key question from the Fish Entrainment study plan (Section 4) is addressed by thisliterature review:• Can fish injury and mortality rates from studies at facilities similar to the Trail Bridge andSmith developments be used in lieu of conducting site-specific entrainment andturbine/spill mortality studies at the Carmen-Smith Project?This literature review has been conducted to provide context for evaluation of the relative risksfrom possible entrainment of juvenile and adult fish associated with Project facilities located onthe upper McKenzie and Smith rivers in Oregon (Figure 1-1). Summaries of studies onentrainment at hydropower project facilities were reviewed to assess general patterns ofentrainment for the analysis fish species noted above. In the majority of studies examined, injuryand/or mortality rates for entrained fish are reported for various hydropower features rather thanactual entrainment numbers or rates.At present, fish residing in Project reservoirs and Project-affected stream reaches include: (1)native bull, cutthroat, and rainbow trout, (2) hatchery-origin spring Chinook salmon, cutthroattrout, and rainbow trout, and (3) naturalized brook trout. Pacific lamprey are generally thought tobe native to the McKenzie River downstream of the Project; however, they are not currentlyfound upstream of the Project and cannot migrate upstream of the lowermost dam. Within therange of migratory salmonids, many existing bypass structures at hydropower facilities weredesigned without a complete understanding of the behavioral cues and tendencies of outmigratingsmolts. Not surprisingly, these structures vary in their overall effectiveness as a function ofdesign constraints, including flow and approach characteristics (Coutant and Whitney 2000).There are no passage facilities at the Project, although adult hatchery-origin spring Chinooksalmon are released in Trail Bridge Reservoir. None of the various Project intake facilities havescreening facilities that would exclude fish from being drawn into the two power generationturbine arrays associated with the Project. Ongoing studies are evaluating entrainment fordownstream-migrating fish at Project dams, and the risks imposed on any upstream-migratingadult fish that may move into the vicinity, or actually enter, tailraces and turbines at Carmen andTrail Bridge powerhouses.January 2005Copyright © 2006 Eugene Water & Electric BoardE1-1Stillwater Sciences

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical Report2 SUMMARY OF CARMEN-SMITH HYDROELECTRIC PROJECTFACILITIES RELEVANT TO ENTRAINMENTThe Project has three impoundments and associated dams: Carmen and Trail Bridge reservoirs onthe mainstem McKenzie River, and Smith Reservoir on the Smith River (Figure E1-1). Importantphysical characteristics of Project facilities are summarized (Table E1-1). The Carmen-SmithHydroelectric Project has three reservoirs of varying sizes and depths, two intakes associated withpower generation facilities, and one intake associated with a diversion tunnel. The sizes anddepths of the reservoirs associated with the Project are quite variable (Table E1-1). CarmenDiversion Reservoir is shallow and relatively small in size. Smith Reservoir is the deepest andhas the largest area of the three reservoirs, with few shallow, shoreline habitats. The Trail Bridgedevelopment is operated as a re-regulating facility, and has the potential to entrain outmigratingjuvenile and adult fish, and to attract upstream-migrating adults and rearing juveniles into theturbine housing at the tailrace.January 2005Copyright © 2006 Eugene Water & Electric BoardE1-2Stillwater Sciences

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical ReportTable E1-1. Physical features of the Carmen-Smith Project facilities.FacilityReservoirsizeachaPowerhouseturbine type &generationMaximumflow capacityof intakeReservoirdepthIntakedepth 1MaximumintakevelocityDamheight(cfs) m ft m ft m/s ft/s m ftSpillwaytypeCarmenDiversion Damand tunnelSmith Dam,Smith powertunnel, andCarmenPowerhouseTrail BridgeDam andPowerhouse30.6 12.4 N/A 1,450170.0 68.873.4 29.7Francis type:two 55-MWunits = 110MW totalKaplan type:one 10.5-MWunit3(avg)2,700 1 63(max)21(avg)2,00023(max)7(avg)9(avg)208(max)70(avg)75(max)24(avg)0 0 5.5 18.1 7.6 2533.8 110 4.1 13.3 71.6 23518 60 7.5 24.5 27 901 Refers to the relative depth at the top of the intake to mean pool elevation.2 Actual capacity of Smith power tunnel is 2, 850 cfs; however, capacity is limited by the 2,700 cfs capacity of Carmen Powerhouse.Weir andfuse plugGatedOgee crestGatedOgee crestJanuary 2005Copyright © 2006 Eugene Water & Electric BoardE1-3Stillwater Sciences

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical Report2.1 Carmen Diversion Reservoir, Spillway, and Diversion TunnelFish residing in Carmen Diversion Reservoir are potentially vulnerable to entrainment either atthe Carmen Diversion tunnel or over the Carmen Diversion spillway. Because there is no fishscreen, fish that are entrained at the Carmen Diversion tunnel must first pass through a trash rackat the tunnel entrance prior to traveling through the 3,449 m (11,381 ft)-long Diversion Tunnelwhich enters the Smith Reservoir approximately 18 m (60 ft) below average water surface. Theflow area at the intake is approximately 30 m 2 (320 ft 2 ) at the trash rack entrance, which tapersinto the roughly 7 m 2 (80 ft 2 ) Diversion Tunnel. Fish that are entrained at the Carmen Diversionspillway exit into the upper Carmen Bypass Reach of the McKenzie River (Figure E1-1). Thespillway is a 19 m (63 ft)-long uncontrolled structure comprised of an overflow weir with two 2.6m (8.5 ft)-long sluice gates that are controlled with concrete stoplogs.2.2 Smith Reservoir, Power Tunnel, Spillway, and Carmen PowerhouseFish from Smith Reservoir are vulnerable to entrainment at the intake to the Smith Power Tunneland Carmen Powerhouse, or during relatively infrequent spills at the Smith spillway. Theunscreened turbine intake via the Smith Power Tunnel is located approximately 34 m (110 ft)beneath the average water surface of Smith Reservoir. The Smith intake is 10 m (34 ft) wide atthe entrance. The water depth above the intake entrance is approximately 11 m (35 ft) atminimum and 36 m (118 ft) at maximum pool level, with associated flow areas of 1,190 ft 2 and4,010 ft 2 , respectively. The Smith Power Tunnel has a diameter of 4.5 m (14.8 ft), with an area ofapproximately 14 m 2 (150 ft 2 ). Any fish that are entrained at the intake to the Smith PowerTunnel would then enter a surge chamber prior to entering the Carmen penstock, which splitsprior to reaching the Carmen Powerhouse (Figure E1-1). Fish entrained into the CarmenPowerhouse would pass through one of two 55-MW Francis turbines before they exit into theMcKenzie River arm of Trail Bridge Reservoir. There is no barrier at the Carmen Powerhousetailrace to prevent fish from moving into the draft tubes. Operations modeling conducted byMWH (2003) indicates that spill over Smith Dam is rare; however, due to the spillwayconformation and relatively high head, this should not be considered a safe passage route for fishduring spill events. Fish that are entrained at the Smith spillway via a gated Ogee crest wouldexit into the Smith Bypass Reach (Figure E1-1).2.3 Trail Bridge Reservoir and PowerhouseFrom Trail Bridge Reservoir to the McKenzie River downstream of Trail Bridge Dam, fishentrainment occurs primarily through the intake to Trail Bridge Powerhouse, but may also occurduring occasional periods of spill at Trail Bridge Dam. The top of the penstock intake for TrailBridge Powerhouse is located approximately 18 m (60 ft) beneath the average water surface ofTrail Bridge Reservoir. Though the penstock intake is unscreened, a trash rack over the entranceprevents large debris from entering. The flow area at the trash rack entrance is estimated to be 58m 2 (620 ft 2 ) at the minimum pool level and 145 m 2 (1,560 ft 2 ) at the maximum pool level, andapproximately 10 m 2 (110 ft 2 ) within the penstock. Fish entrained at the intake may be injured orkilled as they pass through the 10.5-MW Kaplan turbine or through the Howell-Bunger bypassvalve during turbine maintenance or emergency shut-downs. Fish are also susceptible to injuriesduring spill at the Trail Bridge Dam. Spill occurs over the Trail Bridge Dam when the turbinesare not operating (e.g., during maintenance or emergency shutdowns), or during high winterflows that exceed the capacity of the diversion. Downstream from the Trail Bridge PowerhouseJanuary 2005Copyright © 2006 Eugene Water & Electric BoardE1-4Stillwater Sciences

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical Reporttailrace is a velocity barrier that was constructed to exclude adult fish from moving upstream tonear the outfall. The velocity barrier is not completely effective. Studies associated with thisrelicensing process are providing information on options for improving it.3 FISH ANALYSIS SPECIESBull trout, spring Chinook salmon, Pacific lamprey, non-native brook trout, and rainbow andcutthroat trout (both hatchery and native stocks) are the primary analysis species for this study.Bull trout may be particularly vulnerable to entrainment because they often inhabit the deeperportions of lakes and are a highly migratory, fluvial species (Wyman 1975 and R2 ResourceConsultants 1995, both as cited in Knutzen 1997), though their vertical distribution may bestrongly temperature dependent (Goetz 1989). At this time, adult Pacific lamprey cannot migrateupstream beyond Trail Bridge Dam; however, if adult passage facilities were in place, they wouldalso be vulnerable to entrainment both as adults and young moving downstream.The various species at risk and specific Project facilities associated with their possibleentrainment are summarized (Table E1-2). Although information from the Fish PopulationDistribution and Abundance study will be used to characterize fish populations in Projectreservoirs (a key consideration in judging the potential entrainment risk of fish duringdownstream migration), only preliminary study results are currently available, which presentlylimit certainties on the relative risk of entrainment.Table E1-2. Fish species having risk of entrainment at the Carmen-Smith Hydroelectric Projectunder current conditions.Carmen-SmithProject facilityMigratory speciesChinookBull troutsalmonCarmen DiversionDam and Diversion NA NAtunnel 1CutthroattroutJuvenileand adultResident speciesBrooktroutJuvenileand adultRainbowtroutJuvenileand adultSmith Dam andCarmenPowerhouseNANAJuvenileand adultJuvenileand adultJuvenileand adultTrail Bridge Damand PowerhouseJuvenileand adultJuvenileJuvenileand adultJuvenileand adultJuvenileand adult1Injury is unlikely to individual fish because entrainment results in fish being moved from CarmenDiversion reservoir through a low-gradient Diversion Tunnel into Smith Reservoir. Population-leveleffects from removal of individuals may result, but since population is artificially supplemented,population effects are inconsequential.January 2005Copyright © 2006 Eugene Water & Electric BoardE1-5Stillwater Sciences

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical Report4 INJURY TYPESEicher Associates (1987) provides a synopsis of the typical injury types and mechanisms that fishsuffer when passing through turbines. Descaling, lacerations, torn gill rakers, and blunt forceinjuries are all common signs of lethal and sublethal injuries suffered by fish passing throughturbines. Sources of injuries include those from mechanical injury caused by contact with hardsurfaces, pressure-induced injuries incurred within the turbine chamber, and those induced byshear stress from differential water velocities. Shear occurs when two bodies of water, travelingat opposing and different velocities, suddenly merge. Fish passing from one body of water toanother can suffer shear-stress-related injury. At present, a rate of injury to a particular sourcecan not be assigned. Additionally, most of the studies evaluating mortality included injured butnot yet dead fish in their counts of mortalities.Aside from obvious death or injury to individual fish, some evidence indicates that passagethrough hydropower facilities results in cumulative stress that further diminishes the likelihood ofsurvival of individual fish. This is a particularly difficult phenomenon to quantify in terms ofoverall effect at the population level. For outmigrating juvenile salmon and trout in particular,this cumulative stress may reduce overall fitness to adapt to the osmotic challenges andphysiological adjustments necessary to survive entry into marine waters (NRC 1996, Budy et al.2002).5 SOURCES OF INFORMATIONOur approach to this review was to first examine some of the broader assessments thatincluded information on a wide range of projects in order to evaluate the utility of suchassessments for comparison of entrainment risks at the Carmen-Smith HydroelectricProject. No projects were found that closely match the physical and biological conditionsfound at the Carmen-Smith Hydroelectric Project, and that could serve as a basis toestimate likely entrainment rates and associated rates of injury or mortality for analysisspecies. The closest example to this approach is the evaluation reported by Knutzen(1997), which attempted a similar extrapolation of entrainment risk to the Chester MorseProject on the Cedar River in Washington (see discussion below).The issue of fish entrainment at hydropower facilities has received considerable attentionover the last few decades; however, much of the information is only available indocuments prepared for hydropower clients and are not generally published in scientificjournals. A number of useful compendium articles have been written in the past decade,including a study commissioned in 1992 by the Electric Power Research Institute (EPRI),which reviewed and summarized existing sources of information and developed a set ofrecommendations and guidelines for others interested in assessing entrainment riskthrough field studies (EPRI 1992). This report evaluated various methods fordetermining entrainment risk and turbine mortality, relying mostly on studies completedat project sites in Wisconsin and Michigan. It summarized recent studies focused onthese two topics, and recommended approaches to the design of studies and interpretationof the significance of entrainment on resident and migratory fish populations.January 2005Copyright © 2006 Eugene Water & Electric BoardE1-6Stillwater Sciences

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical ReportIn 1995, the Federal Energy Regulatory Commission (FERC) conducted an assessment offish entrainment that reviewed 45 hydropower projects, primarily in the Midwest andeastern United States (FERC 1995). Recognizing the high cost burden of project-specificentrainment studies, the FERC report analyzed relevant data from these facilities, to finduseful correlations that might allow extrapolation of results to projects not yet studied. Italso provided guidance on how to conduct entrainment studies.Little information is available on bull trout entrainment risk at hydropower facilities, reflectingthe short history of management concern for this species. Much more information exists forChinook salmon entrainment risk, with most of the information associated with studies of theColumbia and Snake River dams. There are some useful and current papers that discuss theconsequences of dams to Pacific lamprey (Section 6.1.2.4), a species that until recently has beenpoorly represented in the published literature.This review does not include a review of guidelines for fish passage, nor discuss relativemerits of conventional or experimental fish bypass or intake screening devices. Readersinterested in these issues should refer to several recent reviews including OTA (Office ofTechnology Assessment) (1995), Taft et al. (2000), and Reiser and Oliver (2002).6 ENTRAINMENT RISK FACTORSIn a review of entrainment and passage issues at hydropower facilities, FERC (1995) noted somecommon trends and correlations in a number of biological and physical site conditionsinfluencing entrainment and injury/mortality rates. These biological and physical factors aredescribed below.6.1 Biological Factors6.1.1 Fish sizeA number of studies have examined the relationship of fish size and turbine entrainment. Bodysize, especially length, influences the likelihood of a fish becoming entrained at a turbine, andalso relates injury and mortality rates for entrained fish. Smaller fish are generally lesssusceptible to injury and mortality because they are less likely to encounter hard surfaces andprotrusions that might injure larger fish. In addition, smaller fish entrained at intake structuresare often passively swept through narrow passages that might injure stronger-swimming largerfish.In twelve hydroelectric projects examined by CH2MHill (2003), more than 75% of entrained fishat eight of the projects and more than 90% of entrained fish at three of the projects were < 10 cm(4 in) long. In controlled studies where salmon of a known size were released into turbine intakesand recovered, the interpretation of the results between different facilities is obscured in part bydifferences in turbine unit size, among other factors. Eicher Associates (1987) stated that theissue of fish size and risk could be studied most effectively with controlled releases of severalsizes of fish at one project facility. In nearly all studies for which size data are available, greaterthan 90% of those entrained were smaller than 20 cm (8 in) in length (EPRI 1992). In most of thestudies examined by EPRI (1992), disproportionate numbers of fish smaller than 10 cm (4 in) inJanuary 2005Copyright © 2006 Eugene Water & Electric BoardE1-7Stillwater Sciences

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical Reportlength were entrained in hydropower project intakes. Preliminary fish size data for the Carmen-Smith Hydroelectric Project reservoirs indicate that the majority of salmonids are less than 20 cm(8 in) in length, although subadult and adult bull trout greater than 20 cm (8 in) are found in TrailBridge Reservoir.At many of the projects examined by EPRI (1992), bars placed in front of turbine intakes on trashracks spaced 3–8 cm (1–3 in) apart were found to preclude larger (presumably adult) fish frompassing through the openings. However, bar spacing at trash racks at the Project intakes aregreater than 8 cm (3 in).Risk of entrainment also depends upon the approach velocities and swimming abilities of fishcoming close to the intake. Estimated approach velocities vary with discharges at Carmen-Smithintake structures (Figures E1-2a–E1-2c). Fish size determines swimming ability for each species,therefore it affects the ability of a fish to avoid entrainment. A general “rule-of-thumb” is that afish is able to maintain a cruising speed equal to about four fish-lengths per second for longperiods, and speeds of about ten fish-lengths per second for short bursts (Clay 1961 andAlexander 1967, both as cited in DTA 2004). For example, a 7.6 cm (3.0 in)-long trout would becapable of a cruising speed of about 0.3 m/s (1.0 ft/s) and a burst speed of about 0.6 m/s (2.5 ft/s),while a 15-cm (6.0-in) trout could maintain a cruising speed of 0.5 m/s (2.0 ft/s) and a burst speedof 0.1 m/s (5 ft/s). Available swimming speeds are reported for the analysis species consideredhere, or their close relatives, as reported in FishBase (Froese and Pauly 2004) (Table E1-3).These date support this general “rule-of-thumb.”Table E1-3. Sustained and burst swimming speeds of fish reported in FishBase.SpeciesNumber of fishexaminedSwim mode(mm)Size range(in)Mean fishlength/secondRainbow troutBrown trout(anadromous)32 Sustained 100–640 3.9–25.2 4.96 Burst 40–280 1.5–11.0 13.41 Sustained 340 13.4 2.72 Burst 240–380 9.4–15.0 9.2Sockeye salmon 10 Sustained 60–630 2.4–24.8 2.96.1.2 Species compositionEPRI (1992) noted that comparisons of the species compositions from samples of entrained fishto the population found in the upstream reservoir is difficult due to sampling bias usuallyassociated with determining relative population levels in reservoirs. They note that among theirmost significant findings is the lack of consistent differences in mortality between speciesentrained at different projects.January 2005Copyright © 2006 Eugene Water & Electric BoardE1-8Stillwater Sciences

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical ReportIn the case of anadromous species such as Chinook salmon, in which all juveniles of a cohortmigrate downstream, one can assume that all will pass through hydroproject facilities. Some maybecome resident in reservoirs, but these individual fish contribute little to the anadromouspopulation. For species such as resident trout and bull trout, the numbers of individuals within agiven population that may be adfluvial are not yet available, and so ”rates” are hard to determine.Juvenile salmonids, outmigrating in mass during short periods of the year, should havesubstantially higher rates of entrainment per unit time for that period. Knutzen (1997) compiledentrainment data from four reservoirs and expressed rates as fish/10 6 ft 3 of discharge, as well asannual estimates. Two of these reservoirs had large populations of kokanee salmon, whichskewed the estimated rate of entrainment. Not including kokanee, entrainment rates were0.0021–0.2701 fish/10 6 ft 3 of discharge or approximately 700–31,000 fish entrained on an annualbasis. Additionally, when taking into consideration all sources of information compiled in theEPRI (1992) study, average mortality rates for salmonids entrained at hydropower turbines seemto be slightly less than for most non-salmonid species for which information is available,although the “rate” was not specified as being per unit of discharge or per unit of time, or both.6.1.2.1 Chinook salmonTo fulfill life history requirements, both adult and juvenile anadromous and adfluvial populationsof fish such as Chinook salmon migrate upstream and downstream. This requires them to attemptto pass through hydroproject facilities including turbine intakes or over spillways. On largerhydropower facilities such as those found on the Columbia and Snake rivers, bypass facilitiesattempt to safely divert migrating juveniles away from turbine intakes, thus increasing survivalrates.Survival of juvenile salmon passing through hydropower dams has been extensively studied at alarge number of Columbia and Snake river dams. Estimates of annual survival over the entiresystem for Chinook salmon and steelhead juveniles and smolts ranged from 31% to 59% in the1990s (Williams et al. 2001). At the Rocky Reach Dam, Mathur et al. (1996) estimated a 93%survival rate over a 48-hour observational period for Chinook salmon passing through a turbine,which was 5–24% higher than survival rates reported from other studies at large dams on theColumbia (Schoeneman et al. 1961, Bell 1981, Eicher Associates 1987, NPPC 1987, and Reimanet al. 1991; all as cited in Mathur et al. 1996). These findings were attributed to samplingmethodologies and discounted differences associated with fish sizes used in these experiments.turbine survival estimates at individual Snake River dams has ranged from 81% to 98%, but wasconsistently higher when passage was via spill (Muir et al. 2001).Salmon smolts migrating downstream have evolved to respond to cues associated with flowingwater and related microhabitats of stream environments. When confronted with passage barriersat dams, salmonids are strongly oriented to swim near the surface and follow flow pathways.This behavior allows some measure of control in guiding smolts away from turbine intakes andtowards spill pathways or diversion bypass structures, if velocity gradients and intake depthsallow. Coutant and Whitney (2000) concluded that fish are behaviorally reluctant to swim intodeep water at the dam forebay. Entering into turbine intakes deep below the surface is thus verylikely a passage of last resort rather than a preference of migrating fish.Preliminary data from rotary screw trap captures in the Trail Bridge Powerhouse tailrace indicatethat spring Chinook salmon fry and smolts (naturally produced from hatchery-released adults) areJanuary 2005Copyright © 2006 Eugene Water & Electric BoardE1-9Stillwater Sciences

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical Reportentrained at the Trail Bridge Powerhouse turbine, some of which are killed or injured, and someof which survive.6.1.2.2 Bull troutBull trout are found in deeper and cooler waters than many other fish species, especially withinthermally stratified reservoirs. Adult bull trout are at some risk of becoming entrained if: (1) theapproach to the intake portal has no trash rack; and (2) the approach velocities at the intake portalexceed the burst swimming capabilities of the adult fish, which is generally unlikely. Very littlepublished information was found on entrainment of bull trout, either adults or juveniles, with onenotable exception (Knutzen 1997). Recent radio telemetry studies of adult bull trout in the BoiseRiver system (Idaho) above Arrowrock Reservoir have confirmed entrainment of bull trout (M.Dare, Boise State University, pers. comm. 2004). Similarly, radio telemetry studies of bull trouton the Lewis River, Washington in the Yale and Merwin project areas have also given strongevidence of entrainment of bull trout from upstream areas to areas downstream of the dams (F.Schrier, PacifiCorp, pers. comm., 2004).Preliminary data from PIT-tagged bull trout have documented entrainment of bull trout from TrailBridge Reservoir to downstream areas, though the route of passage (spillway or turbine) is notknown. Thus far, both of the entrained bull trout detected have survived though overallentrainment effects have not been assessed.6.1.2.3 Resident troutBased on a comparison of the Smith intake with the intake depths for other dam facilities (TableE1-4), it seems unlikely that the Smith intake poses much of a risk in terms of entrainment forresident fish. Due to their preferences for temperature, DO, food, and cover, rainbow andcutthroat trout are rarely found near the bottom of deep reservoirs (DTA 2004). Adult rainbowand cutthroat trout are usually in the top one-third of the water column and are rarely found belowthe thermocline even when conditions in the hypolimnion are optimal (Warner and Quinn 1995,Rowe and Chisnall 1995, Baldwin et al. 2000, all as cited in DTA 2004). Young trout prefer theshallow portions of the reservoirs near the shore where cover is abundant (Raleigh et al. 1984, ascited in DTA 2004). Similarly, because of their preference for fluvial or shallow water rearinghabitats, trout fry and juveniles are not expected to be found in the vicinity of deepwater intakes(DTA 2004).Table E1-4. Mean approach velocities and median water depths for power diversion intakestructures (adapted from DTA 2004).Mean approach velocity at intakeMedian depth at top of intakestructureLowest Highest Least Greatestm/s ft/s m/s ft/s m ft m ftStorage reservoirSmith -- -- -- -- 32.4 106.2 1 35.7 117.2 1Loon Lake 0.06 0.20 0.20 0.64 10.9 35.8 21.9 71.1Ice House 0.06 0.19 0.17 0.57 20.5 67.3 32.3 105.9Union Valley 0.08 0.26 0.21 0.70 48.3 158.5 65.3 214.2January 2005Copyright © 2006 Eugene Water & Electric BoardE1-10Stillwater Sciences

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical ReportMean approach velocity at intakeMedian depth at top of intakestructureLowest Highest Least Greatestm/s ft/s m/s ft/s m ft m ftReregulating reservoirJunction 0.07 0.22 0.19 0.61 12.1 39.6 12.5 41.1Camino 0.08 0.25 0.18 0.59 10.1 33.1 10.3 33.8Brush Creek N/A N/A N/A N/A 13.9 45.5 15.1 49.6Slab Creek 0.06 0.19 0.25 0.81 41.5 136.2 42.1 138.21Values given are for mean depth at bottom of intake structure.Young trout prefer the shallow portions of the reservoirs near shore where cover is abundant.Similarly, because of their preference for fluvial or shallow water rearing habitats, trout fry andjuveniles are not expected to be found in the vicinity of deepwater intakes (DTA 2004). Giventhat no trout spawning habitat occurs in the vicinity of Smith or Trail Bridge reservoir intakes, itseems unlikely that newly emergent fry or young-of-the-year trout would be entrained intoProject powerhouses. Thus far, one adult coastal cutthroat trout has been captured at the rotaryscrew trap in the Trail Bridge Powerhouse tailrace. No other trout have been captured at thislocation.6.1.2.4 Pacific lampreyAlthough Pacific lamprey do not currently reside upstream of Trail Bridge Reservoir, a discussionis included here to inform any future discussions regarding their movement and distributionthroughout Project waters. As adults, Pacific lamprey are parasitic on other fish in the ocean.They migrate from the ocean into rivers to spawn, and their larvae develop in the gravel and mudsubstrates for several years before beginning their downstream migration as ammocoetes. Mostof the extant information on lamprey passage past dams comes from investigations of severalmainstem facilities on the Columbia River (Moser et al. 2002), or compiled from life historystudies and FERC relicensing investigations (Kostow 2002).Hydropower dam facilities pose a significant risk during the period of downstream migration ofsubadults, which occurs from early April through mid-August in the Columbia Basin. Asoutmigrating subadults, lamprey are weak swimmers. They lack a swim bladder to controlbuoyancy, and have no paired pectoral fins to increase propulsion and thus swimming ability,thus they rely on their tail to move their body to propel themselves forward. In recent studiesconducted at the John Day Dam on the Columbia River, Moursund et al. (2000) demonstratedthat a large proportion (70–97%) of out-migrating subadult Pacific lamprey became impinged onbypass screens near turbine intakes. They concluded that weak swimming ability in conjunctionwith the tendency to swim lower in the water column than salmonids because of their somewhatnegative buoyancy predisposed these lamprey to greater entrainment risk. Bypass screens on theJohn Day Dam designed to deflect juvenile salmon do not appear to be very effective inpreventing entrainment of lamprey. However, subadult lamprey appear to be relatively immuneto the ill effects of turbine passage, as a consequence of their smaller, less buoyant bodies, andtheir lack of actively swimming against the currents encountered in the turbine (Moursund et al.2000).January 2005Copyright © 2006 Eugene Water & Electric BoardE1-11Stillwater Sciences

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical Report6.1.3 Seasonal timingWith few exceptions, fish are generally less active when water temperatures are low. Duringwinter and early spring, if foothill or mountain reservoirs are drawn down to their lowest levels ofthe year, water temperatures are generally cold, and the potential for entrainment should belimited (DTA 2004). Typical water elevations during winter operations average 2.1 and 1.8 m(7.0 and 5.8 ft) lower than during summer operations in Smith and Trail Bridge reservoirs,respectively. Several studies support the notion that peak risk of entrainment likely occurs inspring and summer months (FERC 1995, CH2MHill 2003), but this is driven largely by thespecies composition and life history characteristics of the species residing in the reservoirs. Forsalmonid and lamprey species with a strong seasonal pattern of adult and juvenile migration,predictions of times when entrainment risk is highest is a relatively straightforward matter. Bulltrout are likely an exception to many of these findings, in that they are most active at coldertemperatures and their movements upstream to spawn and back into reservoirs is only nowbecoming well understood.Juvenile Chinook salmon are generally thought to migrate downstream in the spring when streamflows are high due to snowmelt events. These high flow conditions have correspondingly highlevels of suspended sediment and drifting debris, reducing water clarity. These factors interferewith studies directed towards understanding the behaviors of migrating juvenile salmon undernatural conditions. The behavior of juveniles to seek out refuge habitats is an important and oftenoverlooked factor in evaluating risk of injury or delay of downstream migrants since salmonoutmigrants employ various behaviors and “strategies” to avoid predation and respond to otherenvironmental cues that imply a risk of injury (Bakshtansky et al. 1993).EPRI (1992) examined a number of studies at hydropower facilities and compiled information onthe timing of peak entrainment rates. Timing of entrainment depends on factors related tospecies- and life-history-specific behaviors, environmental conditions including temperature andhydrology, and project configuration. With few exceptions, peaks in the reported entrainmentrates occurred between April and July, with consistently low rates detected in the fall and wintermonths, from October through March.The characteristics of juvenile Chinook salmon migratory behavior in the McKenzie River systemare somewhat more complex than one might expect, primarily as a result of its volcanic geologyand topography, and the underlying groundwater-source hydrology. With headwaters of the basinin both the high Cascades and western Cascades geological provinces, most flow contributions inthe winter come from portions of the basin in the western Cascades, while during the summer’slow flow periods, most water comes from the portion of the basin lying in the high Cascadesgeology (Grant 2002). At Leaburg Dam on the McKenzie River downstream of the Carmen-Smith Hydroelectric Project, for example, newly emerged Chinook fry migrate in the spring (aswould be expected), but the pattern for fingerling/smolts is less defined. Usually a small peak(relative to fry numbers) in migration of this age group occurs in October or November(seemingly dependent on increased flows), with a protracted migration of 1+ age class inJanuary–April. These outmigration patterns are currently being evaluated in light of the Project’smore complex hydrology.6.2 Physical FactorsMany physical factors are thought to interact at any given project to affect entrainment risk(FERC 1995; Normandeau Associates, Inc. 2002). Although several studies cited in this reviewattempted to evaluate correlations and causal relationships between physical features of projectsJanuary 2005Copyright © 2006 Eugene Water & Electric BoardE1-12Stillwater Sciences

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical Reportand entrainment risk, the results were inconsistent and sometimes contradictory. PacifiCorpcommissioned a literature-based study of fish entrainment and turbine mortality for its fourprojects (reservoirs and powerhouse intakes) on the Klamath River, California, which weredescribed as being conducted in lieu of expensive and protracted site-specific studies withuncertain results (CH2MHill 2003). The authors evaluated published studies of fish entrainmentrates and species composition at 26 hydropower projects from around the country that werenominally comparable in physical characteristics to those on the Klamath River. Their evaluationsuggested a strong positive correlation between reservoir size and median annual entrainmentnumbers; however, the 1995 review by FERC suggests little or no statistical correlation betweenreservoir size and entrainment rate (FERC 1995). The correlation suggested in the CH2MHillreview makes some intuitive sense when considering that larger reservoirs might likely supportlarger standing crops and likely greater species diversity than smaller reservoirs. With oneexception, all studies of entrainment examined in the CH2MHill review are from low-headfacilities in Michigan and Wisconsin, which naturally have a greater diversity of fish fauna than isthe case at the Carmen-Smith Hydroelectric Project. CH2MHill concluded that entrainment riskappears to be higher at lower head projects, where shallow and presumably warmer reservoirsmight support a larger standing crop of sunfish and minnows, for example (CH2MHill 2003).Physical features of hydropower facilities interact with biological attributes to influenceentrainment risk. These factors include reservoir size, height of the dam, the configuration of thedam forebay, the depth of the intake, and the volume of water passing into the intake and throughthe powerhouse. Habitat utilization by fish during key life history stages and their associatedbehaviors account for much of the relative risk of entrainment at any given project.6.2.1 Entrainment through turbines6.2.1.1 Turbine design typeSeveral studies evaluating turbine passage mortality report mortality rates without discussion ofphysical attributes associated with them. Coutant and Whitney (2000) stated that turbine passagemortality is typically on the order of 5–15%; however, they do not indicate factors associatedwith these rates such as turbine design type or efficiency. Studies on entrainment rates in relationto turbine design type tend to focus on comparisons of injury and mortality rates for entrained fishrather than entrainment risk, and opinions differ about the interpretation of data comparingmortality rates between the two major turbine types, Francis and Kaplan. The Carmen-SmithProject has two Francis turbines at the Carmen Powerhouse, while Trail Bridge Powerhouse hasone Kaplan turbine.Kaplan turbines are generally regarded to impose a lesser mortality risk, especially when run athigh efficiency. Data from fish passage experiments prior to 1967 for Francis and Kaplanturbines were summarized by Bell (1981) and indicated mortality rates of 1.0–46.1% for Kaplanturbines. Ledgerwood et al. 1990 found mortality rates of Chinook salmon smolts (83.4–99.4 mm[3.3–3.9 in]) ranged from 2–3% at Bonneville Dam, while Steir and Kynard (1986) found thatmortality rates of Atlantic salmon smolts (190–280 mm [7.5–11.0 in]) ranged from 11.8–13.7%.EPRI (1992) noted that mortality rates are generally thought to be about 11% at typical Kaplanturbines on Columbia River facilities, citing two older studies (Schoeneman et al. 1961, Olsonand Kaczynski 1980, both as cited in EPRI 1992). Skalski et al. (2002) studied smolt passagesurvival at several facilities with Kaplan turbines using balloon-tagged fish, and estimatedJanuary 2005Copyright © 2006 Eugene Water & Electric BoardE1-13Stillwater Sciences

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical Reportmortality rates ranging from 0–14.6%. Mortality rates for studies summarized by Bell (1981),EPRI (1992), and Skalski et al. (2002) are provided (Table E1-5).Facility nameTable E1-5. Mortality rates and characteristics for Francis and Kaplan type turbine studies(adapted from Bell 1981, EPRI 1992, and Skalski et al. 2002).FishspeciesFish size(mm)Turbinediameter(in)Head(ft)RPMElevationof runnerto tailwater(ft)Turbineoperation(%)Mortalityrate (%)Francis turbinesCarmenPowerhouseNA NA 120 359 240 7–21 NA NAGold Bay 1 NA NA NA 20 NA NA NA 4.43Stayton 1 NA NA NA 16 NA 5 NA 10.3Leaburg 1 NA NA 90 89 NA NA NA 4.8Cushman CohoNo.2 1salmonNA 83 450 NA 1–12 NA 39.5Cushman CohoNo.2 1salmonNA 83 450 NA 6–8 NA 47.5Rainbowtrout,Shasta 1 Steelhead, NA 183 410 NA 2–3 NA 29.0–40.2ChinooksalmonShasta 1Rainbowtrout,Steelhead, NA 183 432 NA 2 NA 18.0–37.2ChinooksalmonCohoBaker Dam 1 salmon,SockeyeNA 65 250 NA 5–8 NA 28.3–33.6salmonLower Elwha 1 NA NA 59 104 NA 14 NA 0.0GlinesCanyon 1 NA NA 92 194 NA 7 NA 33.0Seton Creek 1 NA NA 144 142 NA 7–16 NA 9.2Petledge 1 NA NA 85 340 NA 2.0 NA 32.7Ruskin 1 NA NA 149 124–130 NA 13–-2 NA 10.5CrownZellerbach 1 NA NA NA 41 NA 24 NA 24.1–99.8Publisher’sPaper Co. 1 NA NA NA 43 NA 23 NA 13.2Alcona 2 Rainbowtrout103–147 100 43 90 NA 60–75 0.0FiveRainbowChannels 2 trout69–137 55 36 150 NA 81–90 4.2Rogers 2 Rainbowtrout57–158 60 39 150 NA 82–100 10.1Alcona 2 Rainbowtrout223–345 100 43 90 NA 60–75 10.6FiveRainbowChannels 2 trout275–360 55.0 36 150 NA 81–90 22.2January 2005Copyright © 2006 Eugene Water & Electric BoardE1-14Stillwater Sciences

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical ReportFacility nameFishspeciesFish size(mm)Turbinediameter(in)Head(ft)RPMElevationof runnerto tailwater(ft)Turbineoperation(%)Mortalityrate (%)Hardy 2 Rainbowtrout81–135 84 100 164 NA NA 28.6Hardy 2 Rainbowtrout280–410 84 100 164 NA NA 31.4Rogers 2 Rainbowtrout228–401 60 39 150 NA 82–100 38.8Kaplan turbinesTrail BridgePowerhouseNA NA 120 67 212 2–14 NA NASullivan Plant 1 NA NA NA 42 NA 19 NA 13.3Tusket Falls 1 NA NA 72 20 NA -9–9 NA 19.0TobiqueNarrows 1 NA NA 104 75 NA -17 NA 18.3Gold Hill 1 NA NA 82 20 NA 7 NA 46.1Waterville 1 NA NA 121 56 NA 0.1 NA 8.5Model turbine,UBC 1 NA NA 10 50 NA 0–15 NA 24.2McNary 1 NA NA 280 80 NA -25–-30 NA 7.8Big Cliff 1 NA NA 148 90 NA -5 NA 13.5Big Cliff 1 NA NA 148 90 NA variable NA 11.8Big Cliff 1 NA NA 148 90 NA variable NA 8.6Bonneville 1 NA NA 280 60 NA -5–-40 NA 7.5Bonneville 1 NA NA NA NA NA NA NA 2.2Bonneville 1 NA NA NA NA NA NA NA 1.0Bonneville 2 nd ChinookPowerhouse 2 salmon83.4–99.4 330 60 69 NA 100 2.5Hadley Falls 2 Atlantic 190.0–salmon 280.0172 51 128 NA 76–80 12.8Chalk Hill 3 Rainbowtrout220.0 4 135 29 100 NA 1.000 5 10.8Townsend RainbowDam 3trout140 4 113 16 152 NA 0.516 5 3.8Townsend RainbowDam 3trout343 4 113 16 152 NA 0.516 5 14.6Wilder 3 AtlanticSalmon191 4 108 51 113 NA 1.000 5 3.9Rocky Reach Chinook(Unit 3) 3 salmon145 4 280 92 90 NA 1.000 5 5.7Rocky Reach Chinook(Unit 8) 3 salmon130 4 311 87 86 NA 1.000 5 3.1Wanapum Coho(3.0 mi) 3 154 4 0.940–285 74 86 NAsalmon1.000 5 5.2–11.5Wanapum Coho(9.1 mi) 3 154 4 0.940–285 74 86 NAsalmon1.000 5 0.0–5.1LowerChinookGranite 3 salmon148 4 312 98 90 NA 1.000 5 5.4Rocky Reach Chinook(Unit 5, 3 m) 3184 4 0.995–280 92 90 NAsalmon1.000 5 1.3–2.7Rocky ReachChinook(Unit 5, 9.1184 4 0.997–280 92 90 NAm) 3 salmon1.000 5 2.3–7.2January 2005Copyright © 2006 Eugene Water & Electric BoardE1-15Stillwater Sciences

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical ReportFacility nameFishspeciesFish size(mm)Turbinediameter(in)Head(ft)RPMElevationof runnerto tailwater(ft)Turbineoperation(%)Mortalityrate (%)Bonneville Chinook(Unit 5, tip) 3155 4 0.993–280 57 75 NAsalmon1.000 5 3.7–9.1Bonneville Chinook(Unit 5, mid) 3155 4 0.993–280 57 75 NAsalmon1.000 5 1.4–4.1Bonneville Chinook(Unit 5, hub) 3155 4 0.993–280 57 75 NAsalmon1.000 5 0.0–3.2Lower GraniteChinook(Unit 4, mid,Intake A) 3 salmon150 4 312 98 90 NA NA 5 2.8–5.4Lower GraniteChinook(Unit 4, mid,Intake B) 3 salmon150 4 312 98 90 NA NA 5 2.5Lower GraniteChinook(Unit 4, mid,Intake C) 3 salmon150 4 312 98 90 NA NA 5 2.5Rock IslandChinook(Unit 5,PH#1) 3salmon179 4 226 45 100 NA NA 5 2.1–4.31 As cited in Bell (1981)As cited in EPRI (1992)As cited in Skalski et al. (2002)4Mean total length5Relative turbine efficiency. Relative turbine efficiency standardized to percent of maximum peak efficiency within a turbine unit.In a comprehensive review, Eicher Associates (1987) found few good cause-effect relationshipsbetween turbine design and operation that would allow prediction of fish injury or mortality. Theone exception points to a clear linkage between mortality of fish and the peripheral runner speedof Francis turbines. Other features of turbine dynamics undoubtedly influence injury andmortality rates, but because actually observing fish as they move through a given turbine isimpossible, convincing evidence is elusive. Most of the turbine mortality studies agree that atsimilar conditions of head pressure, runner elevations above tailrace, and speed of turbine blades,there is essentially no difference in total mortality levels between Kaplan and Francis units. Anyapparent higher mortality associated with Francis turbines seems to be a function of theirplacement rather than their inherent design (Eicher Associates 1987).Designing studies to test assumptions about turbine mortalities is problematic, and controlling forthe myriad of factors that influence study results is a vexing problem. In one example, juvenileChinook salmon (127–217 mm [5.0–8.5 in]) and steelhead smolts (188–287 mm [7.4–11.3 in)were released into the new, more efficient, fixed-blade replacement turbine unit at PortlandGeneral Electric’s T.W. Sullivan Station facility on the Willamette River, Oregon (NormandeauAssociates, Inc. and Skalski 1997). The fixed-blade turbine (type not specified) was installed toreplace an old adjustable Kaplan turbine. The intent was to establish a baseline of injury andmortality rates, which could be used to judge the overall impact of making future turbine designchanges and replacements at this and other facilities. Point estimates of survival probabilitieswere virtually identical for each species at 82% for Chinook salmon and 85% for steelhead (at a90% confidence interval). Injury rates paralleled those of survival, with 11% of Chinook salmonand 20% of steelhead smolts exhibiting injury of some sort. Most of these injuries proved fatalafter 48 hours. Outside of larger Columbia River hydropower facilities, few studies haveJanuary 2005Copyright © 2006 Eugene Water & Electric BoardE1-16Stillwater Sciences

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical Reportattempted to estimate turbine survival of juvenile salmonids in a comprehensive way. Thesestudies are conducted at large facilities, are tailored to the specific facility configuration, and donot provide many useful generalizations to extend to other, smaller facilities such as those of theCarmen-Smith Hydroelectric Project.6.2.1.2 Turbine efficiencyEstimates of turbine efficiency and mortality rates for entrained fish are abundant in the literature,but lack of standard assessment techniques preclude interpretation and confidence in makinggeneralizations. Mortalities of juvenile salmonids were estimated to be about 10% at mostinstallations when operated at peak efficiency, but might be > 50% at some units with high headpressures and smaller blade clearances (Collins and Ruggles 1982, as cited in EPRI 1992).Eicher Associates (1987) noted that almost all of the studies in this field agree that the higher theturbine efficiency, the lower the overall fish mortality, especially through Francis turbines. Thisphenomenon may be related to correspondingly reduced cavitation within the turbine chamber asa function of greater efficiency balancing head and turbine speed. The related factors of runnerspeed at the turbine shaft and margin on mortality rates seem to be a major concern in the case ofFrancis units, but of no demonstrated importance in Kaplan-type turbines. Fish enter the turbinehousing at the periphery of Francis turbines, and are thus exposed to the runner blade, while inKaplan turbines, downstream migrant fish move through the upper level of the intakepassageway, and are suspected of moving down along the runner hub, thus avoiding contact withthe runner periphery (Eicher Associates 1987). The results of experiments reported by Skalski etal. (2002) corroborated Eicher Associates (1987), finding that maximum passage survival for fishentering Kaplan turbines is higher when operating conditions are within 1% of peak efficiency,though meta-analysis found no overall relationship between survival and efficiency.6.2.2 Entrainment at spillwaysOnly a few studies have looked directly at survival of fish when passed over dams via spillways(EPRI 1992). Coutant and Whitney (2000) evaluated the literature on experiments to comparemortality of juvenile salmon at mainstem Columbia and Snake river dams via bypass facilities,spillways, and through turbines. Survival of migrating juvenile salmon was consistently highestwhen passing over spillways.Physical constraints imposed by the turbulence associated with spill volumes make placement ofcapture nets difficult during studies at spillways. In one study conducted at the Leaburg Dam onthe McKenzie River downstream of the Carmen-Smith Hydroelectric Project, EA Engineering(1990) evaluated passage survival via a spillway that included an array of concrete energydissipaters fully spanning the flow pathway. Placement of and mortality associated withsampling nets under turbulent flows associated with the maximum flow release confoundedinterpretation of the resulting data. EPRI (1992) concluded that current information isinsufficient to allow development of useful predictive mortality models for individual speciesentrained or spilled at hydropower facilities.Passing fish at spillways is recognized as being more benign than passing them through turbines.Spill studies on the Columbia River have indicated juvenile salmon mortalities of 0–4% (FPC1997) but typically more on the order of 0–2% for standard spill bay configurations, while turbinepassage mortality is 5–15% (Coutant and Whitney 2000). For a given spill event, the percentageJanuary 2005Copyright © 2006 Eugene Water & Electric BoardE1-17Stillwater Sciences

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical Reportof all fish passed in spill relative to the proportion of river flow that is spilled is non-linear andhighly variable (Coutant and Whitney 2000).Bell and DeLacy (1972) summarized early experiments (Table E1-6) designed to evaluate injuryrates of juvenile fish from high velocity water, sudden changes in pressure, shear forces, andimpact to solid objects, all of which might be encountered at spillways. Most of theseexperiments were conducted at large dams in the Pacific Northwest. spillways with roughsurfaces or protruding structures (i.e., energy dissipaters) reduced overall survival of juveniles.Fish falling from a plume of water to a pool and traveling at 15 m/s (50 ft/s) generally survivedwithout injury; however, when the velocity of the plume was increased to 18 m/s (60 ft/s),mortality rates (not including injury) increased to 20%. Successive trials with increasingvelocities resulted in greater mortality, and was thought to be 100% at velocities of 24 m/s (80ft/s) or greater. Velocity in the Trail Bridge spillway is less than 15 m/s (50 ft/s) when flows arebelow approximately 825 cfs (Figure E1-6).FacilityTrailBridgeDamTable E1-6. Mortality rates and characteristics for studies of various spillway types(adapted from Bell and DeLacy 1972).Smith DamCarmenDiversionDamMcNaryand BigCliffBonneville,McNary,and ElwhaElwha andGlinesBakerBakerCapilanoRiverSpillwaytypeHead(ft)Ski jumpto pool 1 60Estimatedmaximumvelocity(ft/s)See FigureE1-2Discharge(cfs)See FigureE1-2FishspeciesFish sizeMortality(%)NA NA NAFreefall topool 1 NA NA NA NA NA NAOgeespillwaywithoutNA NA NA NA NA NAbucket 1Ogee withbucketOgee withbucketand chuteChute andfreefallFreefall tochuteFreefall tochute85–90 83 1,80085 > 40–83 NA100 and80> 40–terminalNA240 > 80 300–500250 > 80 1,850Ski jump 240 Terminal 900ChinooksalmonChinooksalmonChinookand cohosalmonCohosalmonSockeyeand cohosalmonCohosalmonandsteelheadCohosalmonFlume andAlder Dam26 29–49 5–15freefall1Naming convention from Bell and DeLacy (1972) used for comparative purposes50–150mm(2–6 in)2Fingerling 0.5–45.8Fingerlingandyearling6–37Yearling 17–32NA 54–64Smolt 50NA 0–3January 2005Copyright © 2006 Eugene Water & Electric BoardE1-18Stillwater Sciences

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical Report6.2.3 Entrainment at tailracesDelay and mortality or injury of adult and subadult fish at hydropower turbine outfalls (i.e.,tailraces) can be an important issue at some projects, though discussion of this factor was limitedin the scientific literature. Concern for entrainment of adults at the City of Seattle’s ChesterMorse Powerhouse outfall on the Cedar River in Washington prompted the 2003 construction ofan effective tailrace barrier to prevent adult fish from entering into the turbine during projectshutdowns (L. Ablow, Seattle City of Light, pers. comm., 2004,).6.3 Extrapolation of Entrainment Data to Unstudied ProjectsMaking inferences from published accounts of entrainment risk, rates, and remedies athydropower facilities, to Carmen-Smith Hydroelectric Project facilities is problematic. Projectsselected for comparison should have similar physical features as well as biological communitycharacteristics. The efforts described by Knutzen (1997, see below) demonstrate the difficulty inmaking comparisons in a reliable manner. The relative and synergistic role played by dominantphysical features in the entrainment-risk equation is not well supported by the literature, ascorroborated by FERC’s (1995) review and analysis of published studies from dozens ofhydropower projects. Every project has its unique combination of determining physical andbiological factors that interact in myriad ways to affect entrainment risk rates, magnitude, andtiming. Reservoir depth; flow characteristics and capacities of intakes; intake depth and approachvelocities; and turbine type, efficiency, flow capacity, and head are among the project-specificconditions that control entrainment characteristics. Risk and relative rates of fish entrainmentalso largely depend upon fish community composition and population characteristics of theanalysis species.Studies in the 1950s to evaluate entrainment rates at EWEB’s Leaburg and Waltervillehydropower facilities illustrate the difficulty in defining a reliable turbine entrainment mortalityrate. Mortalities from studies initiated in 1956 and extending through 1958 were determinedusing a variety of techniques, all of which presented problems in execution. Known numbers ofhatchery rainbow juveniles were placed in the turbine forbay and recovered at the outlet. Acontrol group was also established. Early tests made at the Leaburg Powerhouse indicatedmortalities of 31–43%, while later studies suggested mortality rates of 4.8% (+/- 1.2%, at a 95%confidence interval), and similar studies conducted at the Walterville facility showed a lower rateof 2.54% (+/- 1.9%, at a 95% confidence interval). These tests were performed using differentoperation loads, which compounds the problem of interpretation and extrapolation (EWEB 1959).Others have attempted to make inferences about entrainment rates for their project frominformation gathered at other hydropower facilities. Seattle City Light commissioned anevaluation of inferential entrainment risk at their Chester Morse Lake/Masonry Pool reservoirsystem in the Cedar River Watershed (Knutzen 1997) where the fish analyis species includedrainbow trout, pygmy whitefish, and bull trout. Only four studies at existing reservoirs werefound to provide data suitable in developing estimates of entrainment risk that could beextrapolated to the Chester Morse system (Table E1-7).January 2005Copyright © 2006 Eugene Water & Electric BoardE1-19Stillwater Sciences

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical ReportReservoirTable E1-7. Physical characteristics of reservoirs for comparative purposes (adaptedfrom Knutzen 1997).Smith Reservoir 170 69Trail BridgeReservoirArea Depth Intake depthac ha m ft m ft63 208(max) (max)21 70(avg) (avg)73 30CarmenDiversionReservoir31 13Chester MorseLake 3 1,680 680Masonry Pool 3 160 65Lemolo Lake 4 420 170Twin Lakes 5 1,833 742Banks Lake 6 27,200 11,007Libby Reservoir 6 46,500 18,81723(max)7(avg)75(max)24(avg)Mean flow(cfs)Turnover rate(days)34 110 2,850 2 218 60 2,000 2 1-23(avg) 1 9(avg) 1 0 0 1,450 2 > 138(max)19(max)9–30(max)15(avg)13(avg)107(max)38(avg)125(max)62(max)28–100(max)50(avg)44(avg)350(max)126(avg)6–18 20–60 300 > 1005–7 16–22 300 1014–22 47–72 436 2715 50 230 2106–1211–171 Value based on relationship between volume and area at normal high water2 Design capacity3 Cedar River, Washington4 Umpqua River, Oregon5 High elevation lakes, Colorado6 Columbia River, Eastern Washington7 Kootenai River, Montana20–4135–565,000 90–18015–58 50–190 11,000 269Only Libby Reservoir (with low bull trout population estimates), and Chester MorseLake/Masonry Pool contain bull trout populations of sufficient size to make judgments aboutentrainment. Twin Lakes Reservoir contains no bull trout, but does support another char, laketrout, which has similar habitat use preferences. In Libby Reservoir, the annual entrainment rateof 69 bull trout represents 0.04% of the total annual fish entrainment rate, while at Twin LakesReservoir, the annual rate of 4,710 lake trout represents approximately 3% of the total annual fishentrainment rate. According to Knudsen (1997), estimates of annual entrainment for bull troutderived from Libby Reservoir were judged to be too low, while those from lake trout estimatesfor Twin Lakes were judged to be too high to provide a useful comparison. Banks LakeReservoir has a high entrainment rate for all species of fish. Although no mention is made of bulltrout being present in Banks Lake, Knutzen (1997) reports an annual entrainment rate of 18 bulltrout/year based on data from Stober et al. (1977), an inconsistency that is not obviouslyexplained. Similar to Libby Reservoir, the entrainment rate from Banks Lake was too small of aJanuary 2005Copyright © 2006 Eugene Water & Electric BoardE1-20Stillwater Sciences

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical Reportnumber to be useful of making comparisons with Chester Morse Lake project. Based on thesecomparisons with other reservoirs, Knutzen (1997) concluded an annual estimate for ChesterMorse Lake complex at 200 bull trout/year, with a range from < 10 to several hundred in anestimated bull trout population ranging from 804 (Wyman 1975, as cited in Knutzen 1997) to3,100 (R2 Resource Consultants 1995, as cited in Knutzen 1997).7 CONCLUSIONSAs an alternative to conducting site-specific evaluations, making confident inferences from otherstudies about the rate of entrainment-related mortality or injury is not broadly supported by theliterature. As noted in the EPRI (1992) study, the limited number of observations and substantialvariability between studies precludes establishing a predictive relationship between turbinemortality and variables such as fish size, or turbine head and peripheral runner speed which areassociated with the turbine structure itself. In particular, the authors caution that variabilitybetween different studies designed to examine relationships between fish size, species, andmortality or injury rates makes forming simple conclusions difficult and risky (EPRI 1992).There was generally little or no agreement on the relative contribution to entrainment “risk” ofphysical attributes associated with hydropower facilities, including: the type of turbine; theefficiency of turbines as operated; the capacity in terms of flow volume; the size, depth, andapproach velocities at the intake; or the dimensions and turnover rate of the reservoir (FERC1995, EPRI 1992). The significance of a given feature at one facility may be less at another, andthere is no statistically valid way to assign a quantitative entrainment risk for a given condition.In the evaluation of studies at 46 hydropower facilities, variability in entrainment results betweenprojects allowed little statistical basis for extrapolation of study results to untested facilities(FERC 1995). The one specific example most relevant to the objectives of this review was donefor the Chester Morse Reservoir complex on the Cedar River, Washington; that study found verylittle basis for making reliable estimates of entrainment rates from other studies (Knutzen 1997).These estimates of entrainment rates spanned two orders of magnitude.No references were found that discussed the issue of adult fish attraction and injury athydropower turbine tailraces. Most discussion of adult fish encountering dams related todelay of upstream migration or difficulty in ascending various fish ladders. Specificdiscussions of injury or mortality of either juvenile or adult fish passing over dams viaspillways was restricted to comparative experiments done on Columbia or Snake riverdams. Generally, survival of fish passing these hydropower dams via spill wassignificantly higher than all other passage routes.January 2005Copyright © 2006 Eugene Water & Electric BoardE1-21Stillwater Sciences

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical Report8 LITERATURE CITEDAlexander, R. M. 1967. Functional design in fishes. Hutchinson and Co., London, England.Bakshtanskiy, E. L., V. D. Nesterov, and A. Haro. 1993. Some aspects of juvenile anadromoussalmonid behavior and behavioral studies, and their application to development of fish passagesystems. Pages 205-209 in K. Bates, editor. Fish passage policy and technology—proceedings ofa symposium. American Fisheries Society, Bioengineering Section, Bozeman, Montana.Baldwin, C. M., D. A. Beauchamp, and J. J. Van Tassell. 2000. Bioenergetic assessment oftemporal food supply and consumption demand by salmonids in the Strawberry Reservoir foodweb. Transactions of the American Fisheries Society 129: 429-450.Bell, M. C. 1981. Updated compendium on the success of passage of small fish throughturbines. Contract No. DACW-68-76-C-0254. U. S. Army Corps of Engineers, North PacificDivision, Portland, Oregon.Bell, M.C. and A.C. DeLacy. 1972. A compendium on the survival of fish passing throughspillways and conduits. Prepared for the Fisheries Engineering Research Program, US Corp ofEngineers, Portland, Oregon.Budy, P., G. P. Thiede, N. Bouwes, C. E. Petrosky, and H. Schaller. 2002. Evidence linkingdelayed mortality of Snake River salmon to their earlier hydrosystem experience. NorthAmerican Journal of Fisheries Management 22: 35-51.Cada, G.F., C. C. Coutant, and R. R. Whitney. 1997. Development of biological criteria for thedesign of advanced hydropower turbines. Report DOE/ID-10578. U. S. Department of Energy,Idaho Operations Office, Idaho Falls.CH2MHill. 2003. Literature based characterization of resident fish entrainment and turbineinducedmortality – Klamath Hydroelectric Project (FERC No. 2082). Draft TechnicalMemorandum prepared for PacifiCorp, Portland, Oregon.Clay, C. H. 1961. Design of fishways and other fish facilities. Canada Department of Fisheries,Ottawa.Collins, N.H. and C.P. Ruggles. 1982. Fish mortality in Francis turbines. Prepared by MontreEngineering for the Canadian Electrical Association. Research Report 261.Coutant, C. C., and R. R. Whitney. 2000. Fish behavior in relation to passage throughhydropower turbines: a review. Transactions of the American Fisheries Society 129: 351-380.DTA (Devine Tarbell & Associates, Inc.). 2004. Technical report on deepwater intakeentrainment. Upper American River Project (FERC No. 2101). Report No. 012904. Prepared forSacramento Municipal Utility District, Sacramento, California.January 2005Copyright © 2006 Eugene Water & Electric BoardE1-22Stillwater Sciences

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical ReportEA Engineering (EA Engineering, Science, and Technology). 1990. Fish passage studies atLeaburg Dam, McKenzie River, Oregon. Prepared by EA Engineering for Eugene Water andElectric Board (EWEB), Eugene, Oregon.Eicher Associates. 1987. Turbine-related fish mortality: review and evaluation of studies. FinalReport, EPRI AP-5480. Prepared for Electric Power Research Institute, Palo Alto, California.EWEB (Eugene Water & Electric Board). 1959. Leaburg and Walterville turbine studies,McKenzie River. EWEB, Eugene, Oregon.EPRI (Electric Power Research Institute). 1992. Fish entrainment and turbine mortality reviewand guidelines. Final Report prepared by Stone & Webster. Research Project 2694-01, EPRI TR-101231. Palo Alto, California.FERC (Federal Energy Regulatory Commission). 1995. Preliminary assessment of fishentrainment at hydropower Projects. Volume 1: a report on studies and protective measures.Paper No. DPR-10. Prepared by Stone & Webster Environmental Technology and Services forFERC, Office of Hydropower Licensing, Washington, D. C.FPC (Fish Passage Center). 1994. Fish Passage Center annual report for 1993. BonnevillePower Administration, Report DOE/BP-38906-3, Portland, Oregon.Froese, R., and D. Pauly, editor. 2004. FishBase. http://www.fishbase.org/home.htm.Goetz, F. 1989. Biology of the bull trout, Salvelinus confluentus, a literature review. USDAForest Service, Willamette National Forest, Eugene, Oregon.Grant, G. 2002. Geology as destiny: cold waters run deep in western Oregon. Science Findings49: 1-5. USDA Forest Service, Pacific Northwest Research Station, Portland, Oregon.Knutzen, J. 1997. Evaluation of fish entrainment potential from the Chester MorseLake/Masonry Pool System. Report prepared by Foster Wheeler Environmental Corporation forSeattle City Light, Environmental and Safety Division, Seattle, Washington.Kostow, K. 2002. Oregon Lampreys: Natural history status and problem analysis. OregonDepartment of Fish and Wildlife, Corvallis, Oregon.Ledgerwood, R. D., E. M. Dawley, L. G. Gilbreth, P. J. Bently, B. P. Sanford, and M. H.Schiewe. 1990. Relative survival of subyearling chinook salmon which have passed Brown Damvia the spillway or the second powerhouse turbines or bypass system in 1989, with comparisonsto 1987 and 1988. Contract E85890024/E86890097. National Marine Fisheries Service and U. S.Army Corps of Engineers.Mathur, D., P. G. Heinsey, E. T. Euston, J. R. Skalski, and S. Hays. 1996. turbine passagesurvival estimation for Chinook salmon smolts (Oncorhunchus tshawytscha) at a large dam onthe Columbia River. Canadian Journal of Fisheries and Aquatic Sciences 53:542-549.Moursund, R. A., D. D. Dauble, and M. D. Bleich. 2000. Effects of John Day Dam bypassscreens and project operations on the behavior and survival of juvenile Pacific lampreyJanuary 2005Copyright © 2006 Eugene Water & Electric BoardE1-23Stillwater Sciences

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical Report(Lampetra tridentata). Final report. Prepared by Pacific Northwest National Laboratory,Richland, Washington for U. S. Army Corps of Engineers, Portland District, Portland, Oregon.Moser, M. L., P. A. Ocker, L. C. Stuehrenberg, and T. C. Bjornn. 2002. Passage efficiency ofadult Pacific lampreys at hydropower dams on the lower Columbia River, USA. Transactions ofthe American Fisheries Society 131: 956-965.Muir, W. D., S. G. Smith, J. G. Williams, and B. P. Sandford. 2001. Survival of juvenilesalmonids passing through bypass systems, turbines, and spillways with and without flowdeflectors at Snake River dams. North American Journal of Fisheries Management 21: 135-146.MWH (MWH Americas, Inc.). 2003. Carmen-Smith Hydroelectric Project potential generationimprovements study. Draft preliminary report. Prepared for Eugene Water & Electric Board,Eugene, Oregon by MWH, Bellevue, Washington.NPPC (Northwest Power Planning Council). 1987. Columbia River basin fish and wildlifeprogram. NPPC, Portland, Oregon.NRC (National Research Council). 1996. Upstream: salmon and society in the PacificNorthwest. National Academy of Sciences, Washington, D. C.Normandeau Associates, Inc. and J. R. Skalski. 1997. Survival estimation of juvenile salmonidsin passage through a new turbine at T. W. Sullivan station, Willamette River, Oregon. Preparedfor Portland General Electric Company, Portland, Oregon.Normandeau Associates, Inc. 2002. Fish entrainment assessment. Tapoco Hydroelectric Project,FERC No. 2169. Fish and Aquatic Study 5. Draft report. Prepared for APGI, Tapoco Division,Alcoa, Tennessee.Olson, F. W., and V. N. Kaczynski. 1980. Survival of downstream migrant coho salmon andsteelhead through bulb turbines. Prepared by CH2M Hill for Public Utility District No. 1 ofChelan County, Wenatchee, Washington.OTA (Office of Technology Assessment). 1995. Fish passage technologies: protection athydropower facilities. US Government Printing Office, Report OTA-ENV-641, Washington.D.C.R2 Resource Consultants. 1995. Upper Cedar River watershed fisheries study. Preliminary draftreport. Prepared by R2 Resource Consultants, Redmond, Washington for Seattle WaterDepartment, Seattle, Washington.Raleigh, R. F., T. Hickman, R. C. Solomon, and P. C. Nelson. 1984. Habitat suitabilityinformation: rainbow trout. FWS/OBS-82/10.60. U. S. Fish and Wildlife Service, Fort Collins,Colorado.Reiser, D. W., and K. T. Oliver. 2002. Review of Projects employing conventional fish screens -existing information analysis. Prepared by R2 Resource Consultants, Inc., Redmond, Washingtonfor Portland General Electric Company, Portland, Oregon.January 2005Copyright © 2006 Eugene Water & Electric BoardE1-24Stillwater Sciences

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical ReportRieman, B. E., R. C. Beamesderfer, S. Vigg, and T. P. Poe. 1991. Estimated loss of juvenilesalmonids to predation by northern squawfish, walleyes, and smallmouth bass in John DayReservoir, Columbia River. Transactions of the American Fisheries Society 120: 448-458.Rowe, D. K., and B. L. Chisnall. 1995. Effects of oxygen, temperature and light gradients on thevertical distribution of rainbow trout, Oncorhynchus mykiss, in two North Island, New Zealand,lakes differing in trophic status. New Zealand Journal of Marine and Freshwater Research 29:421-434.Schoeneman, D.E., R. Presseley, and C.O. Junge, Jr. 1961. Mortality of downstream migrantsalmon at McNary Dam. Transaction of the American Fisheries Society 90(1):58-72.Skalski J. R., D. Mathur, and P. G. Heisey. 2002. Effects of turbine operating efficiency on smoltpassage survival. North American Journal of Fisheries Management 22: 1193–1200.Steir, D. J. and B. Kynard. 1986. Use of radio telemetry to determine the mortality of Atlanticsalmon smolts passed through a 17-MW Kaplan turbine at a low-head hydroelectric dam.Transactions of the American Fisheries Society 115: 771-775.Stillwater Sciences. 2004. Fish entrainment. Final study plan for the Carmen-SmithHydroelectric Project relicensing (FERC No. 2242). Prepared by Stillwater Sciences, Arcata,California for Eugene Water & Electric Board, Eugene, Oregon.Stober, Q. J., R. W. Tyler, J. A. Knutzen, D. Gaudet, C. E. Petrosky, and R. E. Nakatani. 1977.Operational effects of irrigation and pumped storage on the ecology of Banks Lake, Washington.Fourth Annual Progress Report, Contract No. 14-06-100-7794. Prepared for U. S. Bureau ofReclamation.Taft, N., K. Bates, T. Brush, J. Harn, A. Sonlosky, M. Whitman and E. Zapel. 2000. Guidelinesfor evaluating fish passge technologies. Report of the American Fisheries Society,Bioengineering Section, Bethesda, Maryland.Warner, E. J., and T. P. Quinn. 1995. Horizontal and vertical movements of telemetered rainbowtrout (Oncorhynchus mykiss) in Lake Washington. Canadian Journal of Fisheries and AquaticSciences 73: 146-153.Williams, J.G., S.G. Smith and W.D. Muir. 2001. Survival estimates for downstream migrantyearling juvenile salmonids through the Snake and Columbia rivers hydropower system, 1966-1980 and 1993-1999. North American Journal of Fisheries Management 21(2): 310-317.Whitney, R.R., L. D. Calvin, M.W. Erho, Jr., and C.C. Coutant. 1997. Downstream passage forsalmon at hydroelectric projects in the Columbia River basin: development, installation,evaluation. Northwest Power Planning Council, NPPC Report 97-15, Portland, Oregon.Wyman, K. H., Jr. 1975. Two unfished salmonid populations in Lake Chester Morse. Master'sthesis. University of Washington, Seattle.January 2005Copyright © 2006 Eugene Water & Electric BoardE1-25Stillwater Sciences

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical Report1816At the entranceWithin the tunnelEstimated average velocity (ft/s)141210864200 200 400 600 800 1000 1200 1400Discharge (cfs)Figure E1-2. Estimated velocity within the Carmen Diversion tunnel and at the intakeentrance for normal pool level.1412At the entrance, minimum pool levelAt the entrance, maximum pool levelWithin the tunnelEstimated average velocity (ft/s)10864200 200 400 600 800 1000 1200 1400 1600 1800 2000Discharge (cfs)Figure E1-3. Estimated velocity within the Smith Power tunnel and at theintake entrance for minimum and maximum pool levels.January 2005Copyright © 2006 Eugene Water & Electric BoardE1-26Stillwater Sciences

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical Report26Estimated average velocity (ft/s)242220181614121086At the entrance, minimum pool levelAt the entrance, maximum pool levelWithin the tunnel4200 500 1000 1500 2000 2500Discharge (cfs)Figure E1-4. Estimated velocity within the Trail Bridge Power tunnel and atthe intake entrance for minimum and maximum pool levels.10090VelocityDepth87Estimated velocity (ft/s)8070605040302010654321Estimated depth (ft)000 500 1000 1500 2000 2500 3000Discharge (cfs)Figure E1-5. Estimated spill velocity at Trail Bridge spillway.January 2005Copyright © 2006 Eugene Water & Electric BoardE1-27Stillwater Sciences

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical ReportExhibit 2Information on entrainment at spillwaysCopyright © 2006 Eugene Water & Electric Board - the following Exhibit 2 for the Fish Entrainment Technical Report:Exhibit 2Information on entrainment at spillways

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical ReportTable of Contents1 SPILLWAY AT TRAIL BRIDGE DAM .........................................................................E2-11.1 Trail Bridge Dam Main Spillway Configuration ....................................................... E2-11.2 Spill Records.............................................................................................................. E2-11.3 Evidence of Fish Passage via the Trail Bridge Spillway ........................................... E2-22 INFORMATION FROM THE SCIENTIFIC LITERATURE ON FISH INJURY ANDMORTALITY AT SPILLWAYS ......................................................................................E2-22.1 Sources of Information............................................................................................... E2-22.2 Mechanisms of Injury ................................................................................................ E2-22.3 Injury and Mortality Rates ......................................................................................... E2-32.4 Application of Information from the Scientific Literature to the Trail Bridge Spillway. ..................................................................................................................................... E2-53 LITERATURE CITED ......................................................................................................E2-6TableTable E2-1. Mortality rates and characteristics for studies of various spillway types .......... …..E2-4FigureFigure E2-1. Trail Bridge spillway construction drawing.March 2005Copyright © 2006 Eugene Water & Electric BoardE2-iStillwater Sciences

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical Report1 SPILLWAY AT TRAIL BRIDGE DAM1.1 Trail Bridge Dam Main Spillway ConfigurationTrail Bridge Dam has one concrete main spillway, located on the left abutment of Trail BridgeDam, with a spillway crest elevation of 628 m (2,060.5 ft) (Figure E2-1). The spillway is 9 m (30ft) wide and has a radial gate to allow controlled flow releases. The flip bucket type spillwaynarrows to a steep (34%), 6 m (20 ft)-wide chute section, which then flattens to a 0% slopesegment, before inclining into a 10% slope along the “flip”. The horizontal length of thespillway, from radial gate opening to flip bucket deflector, is approximately 61 m (200 ft). Thedeflector is at an elevation of 612 m (2,008.0 ft).Water surface elevation downstream of the Trial Bridge Dam ranges between approximately 611m (2,005 ft) and 612 m (2,008 ft). The spillway operates under typical reservoir water surfaceelevations between 633 m (2,078 ft) and 637 m (2,090 ft), and thus, the total head of the spillwayoperation is between 21 m (70 ft) and 26 m (85 ft). However, because the flow release iscontrolled with the radial gate, water velocity and depth in the spillway channel are controlled bydischarge, rather than head.The spillway has a smooth concrete surface, and is not equipped with aerators or energydissipaters (e.g., concrete blocks or boulders). Although the spillway has a design capacity of19,000 cfs, releases are typically less than 1,200 cfs. Hydraulic conditions under a range oftypical flows and operation scenarios are documented in Stillwater Sciences (2005). A hydraulicjump forms in the flip bucket which can be seen in the lower portions of the photos.Potential injuries to fish passing through the Trail Bridge spillway include: (1) friction andabrasion from spillway surfaces in the chute section, and (2) shear forces due to velocitydifferences in the flip bucket from the hydraulic jump. Once they pass through the flip bucket,potential injury to fish is expected to be minimal because water velocity decreases following thehydraulic jump, and because fish entering the tailrace are within a water column, rather than infree-fall. At low flows, the potential for abrasion injury is expected to be greatest within thechute section; at higher flows, the injury potential will be greater within the hydraulic jump in theflip bucket.As required by FERC, an emergency spillway was constructed in 2003 to pass floods expectedduring a probable maximum flood (PMF). This allowed for the spill capacity at Trail BridgeDam to increase from the 19,000 cfs design capacity of the main spillway to an overall capacityof 28,300 cfs. The emergency spillway was constructed on the left side of Trail Bridge Dam, bylowering a section of the Saddle Dike to elevation 638 m (2092.5ft). The emergency spillway isarmored with articulated concrete blocks. It is expected to pass water during events greater thanthe 1,000-year flood.1.2 Spill RecordsBased on Sutron gage data for Trail Bridge Reservoir, 25 spills were recorded for Water Year2004. The spills’ median duration was 7 hours, but ranged from 0.5 hours to several days. Mostspills (60%) occurred during April, May, and June. No spills occurred during the months ofFebruary, March, or August. Spills typically convey all of the flow in the McKenzie River at theMarch 2005Copyright © 2006 Eugene Water & Electric BoardE2-1Stillwater Sciences

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical Reporttime of the spill. Less frequently, flow at Trail Bridge Dam is divided between the spillway andthe turbine and/or the Howell-Bunger bypass valve. As a component of the Hydrologic Regimesstudy, the frequency, magnitude, duration, and timing of spill events from Project reservoirs willbe further analyzed and described; this information will be key to fully assessing the risk of injuryand mortality of fish passing via the spillway.1.3 Evidence of Fish Passage via the Trail Bridge SpillwayHydroacoustic data was collected with transducers located at the Trail Bridge turbine andspillway. Preliminary analysis indicates that when both the spillway and turbine are conveyingflow, most fish pass via the spillway. In 2004, a PIT-tagged bull trout adult (634 mm/ 25 in), abull trout juvenile (149 mm/ 6 in), and an adult Chinook salmon were detected at an antennaeupstream of Trail Bridge Reservoir, and were later detected downstream of Trail BridgeReservoir. The two bull trout were detected downstream of Trail Bridge Reservoir on 14 July2004, and the Chinook salmon on 9 September 2004. Both dates correspond to spills at TrailBridge Reservoir, indicating that adult fish use the spillway, possibly preferentially over theturbine. All Chinook salmon smolts captured during spills were un-injured, although few (< 10)fish have been captured during spills, due to the low capture efficiency at the trap.2 INFORMATION FROM THE SCIENTIFIC LITERATURE ON FISHINJURY AND MORTALITY AT SPILLWAYS2.1 Sources of InformationThe purpose of this summary is to document what other researchers have found when observingspillway mortality at hydropower facilities, and apply this body of research to assessing injuryand mortality risk to fish at the Trail Bridge spillway. Among the sources of information, threereview papers are particularly relevant:• Bell and Delacy (1972) comprehensively reviewed all information current at that time, forthe Army Corp of Engineers (ACOE).• Ruggles and Murray (1983) reviewed information for the Department of Fisheries andOceans of Nova Scotia, Canada.• R2 Resource Consultants (1998) reviewed information for the ACOE, primarily to aid inmitigation planning at various Columbia and Snake River dams.The review by R2 Resource Consultants (1998) was weighted more heavily for our discussionbecause it provides a succinct review of the former two sources, and is the most current of thethree.2.2 Mechanisms of InjuryThree types of fish injury have been identified, in association with spillway passage:• Immediate mechanical injury. This injury is from abrasion, strike, and related mechanisms asfish pass over spillways and through stilling basins. This type of injury is the bestunderstood, and most thoroughly studied of injury types.March 2005Copyright © 2006 Eugene Water & Electric BoardE2-2Stillwater Sciences

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical Report• Short-term delayed injury. This injury usually occurs within the first few minutes of fishentering the stilling basin. Little quantitative information on this type of injury is available(R2 Resource Consultants 1998).• Longer-term injury. This injury may involve changes in behavior from disorientation andphysical stress. Examples of behavior change include decreased predator avoidance and orswimming into obstructions; physical stress could be exemplified by disease or reducedfitness from physical injuries sustained during passage. These injuries are most commonlyassociated with facilities using gas abatement devices.In spillway discharges on larger dams, particularly those on the Snake and Columbia Riverswhere multiple dams are aligned within a relatively short distance, one issue is gassupersaturation and its resulting gas bubble disease that afflicts juvenile fish entrained within thespillway discharges. This situation is unlikely to occur at Trail Bridge Dam because: (1) the damis not located within a series of large dams, (2) the volume of water discharged is limited, and (3)spill events are infrequent and, on average, of short duration. However, this issue has not beensystematically evaluated at Trail Bridge Dam to date. Attempts to address gas supersaturation onthe Columbia and Snake River dams have at times increased the relative risk to fish from strikeand shear injuries (R2 Resource Consultants 1998; Mike Langley, ACOE, pers.comm., 2004).2.3 Injury and Mortality RatesIn evaluating the risk of fish injury or mortality as they exit project reservoirs via spillways, muchwork has been in conjunction with overall efforts to increase survival of anadromous salmonidson hydropower projects on the Columbia and Snake Rivers. In general, passing fish overspillways is viewed as a more desirable alternative than moving fish downstream throughpowerhouse turbines or bypass facilities, where injury and mortality rates can be considerable.However, spillway passage, especially on hydropower facilities with high dams and/or largevolumes of spillway discharge, can pose its own risks to migrating fish through direct and indirectmechanisms of injury.Passing fish over dams via the spillway is generally regarded to have a number of importantbenefits, including reduced mortality; reduced migrational delays (faster movement throughforebays, tailraces, and reservoirs); and reduced exposure to predation risk, high watertemperatures, and diseases (Whitney et al. 1997). Previous studies have found that passagesurvival for juvenile salmonids at Columbia River and Snake River dams is generally highest forspillways, followed by bypass systems, and then turbines (Whitney et al. 1997; Ferguson 2004).Applying fish mortality and injury rates from one facility to another facility is challenging. Noconsistent method that allows reliable extrapolation of injury and mortality results, from onefacility to another, has been found (R2 Resource Consultants 1998). However, the relativemagnitude of expected impacts from other studies can be compared to those of Trail Bridgespillway. The following table (copied from the Entrainment Literature Review, Exhibit 1)compares spillway characteristics and associated mortality rates from studies at various facilities.March 2005Copyright © 2006 Eugene Water & Electric BoardE2-3Stillwater Sciences

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical ReportTable E2-1. Mortality rates and characteristics for studies of various spillway types(adapted from Bell and DeLacy 1972).FacilityTrailBridgeDamSmith DamCarmenDiversionDamMcNaryand BigCliffBonneville,McNary,and ElwhaElwha andGlinesBakerBakerCapilanoRiverSpillwaytypeFlipbucket 1 topoolFlipbucket 1freefall topoolFreefallover weirto spillwaywithoutbucketOgee withbucketOgee withbucket andchuteChute andfreefallFreefall tochuteFreefall tochuteHead(ft)Estimatedmaximumvelocity(ft/s)Discharge(cfs)FishspeciesFish sizeMortality(%)80 NA NA NA NA NANA NA NA NA NA NANA NA NA NA NA NA85–90 83 1,80085 > 40–83 NA100 and80> 40–terminalNA240 > 80 300–500250 > 80 1,850Flipbucket 1 240 Terminal 900Flume andAlder Dam26 29–49 5–15freefall1Flip bucket also known as ski jumpChinooksalmonChinooksalmonChinookand cohosalmonCohosalmonSockeyeand cohosalmonCohosalmon andsteelheadCohosalmon50–150 mm(2–6 in)Fingerling 0.5–45.8Fingerlingand yearling26–37Yearling 17–32NA 54–64Smolt 50NA 0–3Upon comparing the information from many facilities (Table 1), Bell and DeLacy (1972) came tothe following conclusions:• Injuries to fish included abrasions, eye damage, internal organ damage, embolisms, andhemorrhaging typically associated with physical scraping on hard surfaces and exposure toshear zones.• The physical factors of spillway passage that might cause injury to fish include the volumeof discharge relative to physical dimensions of the spillway itself, the spillway type,pressure changes, direct impact on hard surfaces, abrasion, high water velocities, and shearforces associated with pressure differentials.• Survival rates of fish were generally high, with 98 to 100% survival for fish falling intopools from free fall velocities less than 15 m/s (50 fps), and with ~ 80% survival for fishentering pools at 18 m/s (60 fps). However, survival decreased to zero for entry velocitiesgreater than 24 m/s (80 fps).March 2005Copyright © 2006 Eugene Water & Electric BoardE2-4Stillwater Sciences

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical Report• Survival rates are high (98–100%) for fish entering plunge pools such as the Trail Bridgetailrace within a column of water (as opposed to free falls where fish are not suspended in awater column).• Survival rates of fish passing through a hydraulic jump or stilling pool such as that found atTrail Bridge were found to be approximately 93 to 98%, although if fish experience adirect hit on a hard object (not found at Trail Bridge), the survival rate will obviouslydecrease.• Only a few laboratory-based studies have attempted to describe cause-and-effectrelationships between physical conditions within the spillway and stilling pool, and injuryor mortality rates. Extrapolation of generalized laboratory-derived injury rates tohydropower facilities is dubious and not recommended.• Survival rates in spillway and stilling basins can be increased by minimizing turbulenceand the amount of energy dissipation per unit area.The most important factors affecting survival of fish passing through spillways are probablywater velocities in the chute section of the spillway, and the way in which falling water energy isdissipated as it enters the stilling pool. Fish mortality in spillways and stilling basins is related tothe form and intensity of energy dissipation associated with the spillway configuration. Forspillways such as the flip bucket configuration found at Trail Bridge Dam, injury and mortalityare likely related to the concentration of flow and the depth of the tail-water plunge pool. Theserelationships have not been quantified to the degree that allows precise estimates to be made atTrail Bridge spillway. However, fish survival rates at spillways with a flip bucket configurationare high, particularly at facilities such as Trail Bridge spillway, where the risk of a fish strikingagainst hard objects is low, and where stilling basins are deep.2.4 Application of Information from the Scientific Literature to the TrailBridge SpillwayThe Trail Bridge spillway presents a less severe risk of injury or mortality than most spillwaysdiscussed in the scientific literature. Based on comparing Trail Bridge to relatively low riskspillways, mortality rates of less than 3% are expected for the following reasons:• The dam has only one spillway.• The spillway has a smooth surface.• The spillway chute is relatively short (< 76 m/250 ft), with a low gradient (< 35%)compared to those at larger dams.• No boulders or other energy dissipation objects are in the chute or stilling basin, as oftenexist at other facilities to dissipate energy.• Flows in the spillway are rarely less than 50 cfs, so shallow water depths that can increaseabrasion are uncommon.• Flows in the spillway are not typically high (> 1,000 cfs), thus risk from sheer forces in theflip bucket is reduced.• The water column from the flip bucket to the tailrace pool is continuous, which limits freefall.• Water velocities into the tail-water plunge pool are effectively reduced by the flip bucketdissipater.• The tail-water plunge pool is deep, and fish do not encounter rocks or concrete upon entry.March 2005Copyright © 2006 Eugene Water & Electric BoardE2-5Stillwater Sciences

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical Report3 LITERATURE CITEDBell, M.C. and A.C. DeLacy. 1972. A compendium on the survival of fish passing throughspillways and conduits. Prepared for the Fisheries Engineering Research Program, US Corp ofEngineers, Portland, Oregon.Ferguson, J. W., G. M. Matthews, R. L. McComas, R. F. Absolon, D. A. Brege, M. H. Gessel,and L. G. Gilbreath. 2004. Passage of adult and juvenile salmon through federal Columbia Riverpower system dams. NOAA Technical Memorandum. NOAA Fisheries, Fish Ecology Division,Fish Ecology Division, Northwest Fisheries Science Center.Ruggles, C. P., and D. G. Murray. 1983. A review of fish response to spillways. CanadianTechnical Report of Fisheries and Aquatic Sciences No. 1172.R2 Resource Consultants. 1998. Annotated bibliography of literature regarding mechanicalinjury with emphasis on effects from spillways and stilling basins. Contract DACW57-96-D-0007mon at hydroelectric projects in the Columbia River basin: development, installation,evaluation. Northwest Power Planning Council, NPPC Report 97-15, Portland, Oregon.Stillwater Sciences. 2005. Fish Entrainment in the Carmen-Smith Hydroelectric Project Area,Upper McKenzie River Basin, Oregon. Draft Report. Prepared by Stillwater Sciences, Arcata,California for Eugene Water & Electric Board, Eugene, Oregon.Whitney, R.R., L. D. Calvin, M.W. Erho, Jr., and C.C. Coutant. 1997. Downstream passage forsalmon at hydroelectric projects in the Columbia River basin: development, installation,evaluation. Northwest Power Planning Council, NPPC Report 97-15, Portland, Oregon.March 2005Copyright © 2006 Eugene Water & Electric BoardE2-6Stillwater Sciences

This Figure is designated as Critical Infrastructure Information(CEII) FERC Only

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical ReportExhibit 3Hydroacoustic evaluation of fish passage throughTrail Bridge Dam (2004–2005)Ploskey and Weiland 2005Copyright © 2006 Eugene Water & Electric Board - the following Exhibit 3 for the Fish Entrainment Technical Report:Exhibit 3Hydroacoustic evaluation of fish passage throughTrail Bridge Dam (2004–2005)Ploskey and Weiland 2005

PNWD-3596Hydroacoustic Evaluation of Fish PassageThrough Trail Bridge Dam (2004-2005)G. R. PloskeyM. A. WeilandJanuary 2006Prepared for Stillwater Sciences, Inc. and theEugene Water and Electric Board

LEGAL NOTICEThis report was prepared by Battelle Memorial Institute (Battelle) as an accountof sponsored research activities. Neither Client nor Battelle nor any personaction on behalf of either:MAKES ANY WARRANTY OR REPRESENTATION, EXPRESS ORIMPLIED, with respect to the accuracy, completeness, or usefulness of theinformation contained in this report, or that the use of any information,apparatus, process, or composition disclosed in this report may not infringeprivately owned rights; orAssumes any liabilities with respect to the use of, or for damages resulting fromthe use of, any information, apparatus, process, or composition disclosed in thisreport.Reference herein to any specific commercial product, process, or service bytrade name, trademark, manufacture or otherwise, does not necessarily constituteor imply its endorsement, recommendation, or favoring by Battelle. The viewsand opinions of authors expressed herein do not necessarily state or reflect thoseof Battelle.This document was printed on recycled paper.(9/2003)

PNWD-3596Hydroacoustic Evaluation of Fish PassageThrough Trail Bridge Dam (2004-2005)G. R. PloskeyM. A. WeilandJanuary 2006Prepared for Stillwater Sciences, Inc. and theEugene Water and Electric BoardBattelle – Pacific Northwest DivisionRichland, Washington 99352

Executive SummaryBackground and General MethodsFrom May 11, 2004 until May 17, 2005, Battelle – Pacific Northwest Division and StillwaterSciences conducted a hydroacoustic study of fish entrainment at Trail Bridge Dam on the McKenzieRiver, Oregon. The purpose of the study was to estimate entrainment rates and describe seasonal, diel,and route-specific trends in passage for the turbine and spillway. The Eugene Water and Electric Boardneeds the data for the relicensing process. Hydroacoustic sampling uses high-frequency sound to detectobjects with densities different than that of water, and therefore cannot discriminate between species offish, although split-beam transducers do provide an indication of target size. Two 12-degree split-beamtransducers were installed inside the turbine intake entrance just downstream of the trash racks, and twoother 12-degree split beams were installed just upstream of the tainter gate at the spillway. There werethree modes of temporal sampling depending upon which routes were passing water: 1) continuoussequential sampling of all four transducers for simultaneous spill and turbine operations, 2) continuoussequential sampling of two spillway transducers for spill-only operations, and 3) sequential sampling oftwo turbine intake transducers for turbine-only operations. During simultaneous turbine and spilloperations, four transducers were sampled repeatedly and sequentially for 1-minute each, so that 15one-minute samples were obtained from each transducer. This provided one-quarter-time sampling foreach half of the spillway and for the top and bottom halves of the turbine. During spill-only operations,the two spillway transducers were multiplexed sequentially and continuously to provide 30 1-minutesamples per hour from each half of the spillway. During turbine-only operations, intake transducerssampling the top and bottom halves of the intake opening were operated repeatedly and sequentially for40 randomly selected minutes per hour. This provided 20 1-minute samples per hour for each half of theopening (i.e., one-third-time sampling).Consecutive echoes from targets passing through hydroacoustic beams form echo traces, and six ormore echoes were required to classify a trace as a potential fish. Detectability of targets with at least sixechoes was modeled for each season to calculate effective-beam angle as a function of range from eachtransducer. Counts of acceptable detections passing transducer-specific filtering criteria were expandedby multiplying by the ratio of spillway width or turbine intake diameter to the diameter of the acousticbeam at the range a target was detected. Next, spatially expanded counts of detections from the spillwayand turbine intake were temporally expanded to the whole hour by multiplying counts by 60 divided bythe number of minutes sampled each hour. Sample variances also were temporally expanded to the wholehour. Sequential sampling of 2 to 4 transducers allowed a maximum pulse repetition rate of 30 pulses persecond to ensure adequate detectability, and detectability was verified by examining echo-count statisticsand frequency distributions of target strengths.Mean target strengths of echo traces, which are correlated to fish lengths, were used to categorizedetected targets into four fish-equivalent length classes: 1) 38-100 mm, 2) >100-200 mm, >200-350 mm,and >350 mm. The probability that a target is a fish also is much higher for targets moving slower thanthe median speed of the smallest targets, which move at about the speed of the water. Consequently,target speed and direction were important filters, as were the number of echoes per trace, which typicallyiii

is inversely correlated with target speed. Non-fish targets cannot move slower or faster than the velocityof flow, so speed and number of echoes per trace were good discriminating variables.FeasibilityDuring the first week of study, we assessed the feasibility of sampling the turbine and spillwayenvironments with hydroacoustic methods. The major conclusions were as follows:1. Noise resulting from echoes from structure, volume reverberation, and episodic events such asvortexes was infrequent and should not affect target detection or tracking adversely in most rangestrata.2. Detectability of small targets was high enough over the entire tracking range to provide reliablefactors for spatially expanding counts of detected targets based on model estimates of effective beamangle at the range each target was detected.3. The autotracker performed exceptionally well and provided counts that were highly correlated withmanual tracker counts, which is typical for relatively noise-free echograms.An underwater video camera also was deployed on intake trash racks to record the approach andpassage of fish at a small area of the turbine intake. Given the results of the pilot study, the EWEB andStillwater Sciences decided to proceed with a one-year evaluation of fish entrainment using hydroacousticsampling techniques. Pilot study data collected in May 2004 did not indicate that high proportions ofnon-fish targets might be detected at the turbine intake or spillway.One-Year StudyMajor findings of the one-year study were as follows:The target strength of echo-traces (in dB) varied much more among associated length classes than itdid among seasons, so detectability was modeled by length class rather than by time of year. At the samerange of detection, smaller targets produced narrower effective-beam angles and larger spatial expansionsthan larger targets.Hydroacoustic sampling at Trail Bridge Dam was a challenge because the small reservoir providedfew fish to be entrained relative to the number of non-fish targets composed of echoes from debris andentrained air. For an index to fish passage to be of value for describing seasonal, diel, vertical, and routespecifictrends, it must contain more fish than non-fish targets, so we had to eliminate most non-fishtargets from samples. Larger targets usually moved slower than small targets through acoustic beams,and differences in speed provided a valuable tool for discriminating between fish and non-fish targets.Filtering based upon target speed had a significant impact on target-detection estimates for the turbine andspill bay, so we processed data for each length class of target with five different sets of filters to explorethe sensitivity of passage estimates to filtering. The four filtering methods were as follows:1. No speed filtering2. Removal of traces moving within ±15% of the median speed of small targets (

4. Removal of traces moving >75% of the median speed of small targets5. Removal of traces moving >50% of the median speed of small targetsWe plotted target-passage estimates by passage route, length class, and filter to illustrate filter effects(see Results Figures 3.16 and 3.17). The number of detections remaining after filtering on target speed atthe turbine entrance was most sensitive to the initial filter (±15% of median speed) than it was tosuccessively stronger filters. For the spillway, the initial filter (±15% of median speed) and the final filterhad the most impact on the number of detections remaining. Filtering reduced passage estimates forsmall fish more than it did for large fish. Other than Figures 3.16 and 3.17, all figures and tables in thisreport were based on data remaining after the application of Filter 5.We used Filter 5 for several reasons. First, we plotted the frequency of target speeds for two groupsof targets – small targets -50 dB. Plots revealed that below about 50% of themedian speed of small targets, the large-target group had a relatively high frequency of slow-movingtargets that was noticeably absent from the small-target group. In addition, the frequency of targetsmoving faster than the median speed of small targets was similar for both small- and large-target groups.Second, underwater video revealed that 100% of fish swept into the turbine intake were oriented upstreamand swimming against the flow and therefore were moving slower than the water surrounding them.Third, passage estimates based on Filter 5 were the most reasonable relative to the size of the fisheryresource, as determined from available data.Even with strong filtering on target speed, errors in speed estimates make it likely that not all non-fishtargets were eliminated by Filter 5, and it is also likely that Filter 5 eliminated small, weak swimming fish(38-50 mm long) and any fish that were not actively swimming when they were detected. Errors in speedestimates may result from corrupt phase data from echoes off of large non-point scatterers of sound suchas clumped debris or large sticks, or targets very near structure.For the one-year study (about 8,381 hours of >3.2 MW operation), the filtered hydroacoustic estimateof passage through the turbine was 23,978, of which 58% were 100-200 mm,8% were >200-350 mm, and 1% were > 350 mm. Passage during 522 hours of spill was 20,898, of which64% were 100-200 mm, 10% were >200-350 mm, and 2% were >350 mm. Asummary of passage estimates is presented in Table S.1, and mean and median hourly rates of passage areshown in Table S.2. Fifty percent of all hours sampled (i.e., median rates) had zero passage per hourpassing through the turbine, regardless of length class, and the same was true for the spillway for targets>100 mm. These medians indicate that means were biased high by a few large hourly estimates.Passage estimates for the two larger size classes of targets in this study likely were overestimated byan order of magnitude for several reasons. First, speed filtering is not as effective on large debris as it ison small point scatterers of sound. Second, large fish with strong swimming ability can be detectedmultiple times before actually passing, while fish

Table S.1. Project Spill Passage Efficiency (or fish-passage efficiency), Turbine Intake Detections,Spill Passage Detections, and Total Detections During a 1-yr Hydroacoustic Study Basedon Filtering Targets Moving >50% of the Median Speed of Small Targets(350 57 5.6 359 70.6 1 480 139 2 839Total 47 2.9 23,978 1168.8 20,898 1562 44,876Table S.2. The Mean and Median (in parentheses) Hourly Rates of Passage Through the Turbine andSpillwayLength ClassTurbine Mean±80% CI (Median)Spillway Mean ±80% CI(Median)38–100 mm 1.57 ± 0.09/h (0/h) 25.72 ± 2.04/h (12.2 ± 2.0/h)>100–200 mm 0.88 ± 0.05/h (0/h) 9.45 ± 0.80/h (0/h)>200–350 mm 0.20 ± 0.02/h (0/h) 3.94 ± 0.47/h (0/h)>350 mm 0.04 ± 0.01/h (0/h) 0.92 ± 0.18/h (0/h)(a) CI = Confidence limit.9-12%, which was the contribution of those length classes to the total number of detections. Revisedestimates would be 40,614 (total), 22,040 (turbine), and 18,574 (spillway).Passage estimates were very high at the spillway relative to the turbine in all seasons, and some of thedifference may have resulted from false detections of debris at the spillway. During spill, flotsam usuallywas observed accumulating in the spillway area upstream of the tainter gate, especially on the southeastside. The number of detections by the acoustic beam sampling the southeast half of the spillway was2.2 times higher than the number detected by the beam sampling the northwest half, and this suggests thatdebris loading was still a problem, even after the strongest target-speed filter was applied. Large debrislike that accumulating on the southeast side of the spillway is difficult to filter based on target speedbecause phase information often is corrupt when targets are not small point scatterers of sound. Hourlyrates of passage through the northwest half of the spillway probably are more reasonable than those forthe southeast half. Recalculating passage based upon twice the number of detections in the NW beam, thespillway passage estimates would be reduced to 62.6% of the two-beam estimate. The effect of asampling-location adjustment would reduce estimates in Table S.1 to 37,000 per year (total), 23,979(turbine), and 13,076 (spillway).The hydroacoustic estimates of passage in this report represent a relative index rather than an absoluteestimate because of very intensive filtering to eliminate targets moving >50% of the speed of flow, asindexed by the median speed of the smallest targets. As an index to fish passage, the estimates shouldaccurately indicate temporal and spatial trends, although they may not accurately estimate the magnitudevi

of fish passage. Clearly, we did not eliminate all false targets during processing. If the number of fishavailable for passage was 47,000, as suggested by densities of fish at The Dalles Dam, then our passageestimate of 45,000 would indicate that most of the fish left the reservoir over a one-year period and thatseems very unlikely. If the population was about 65,000, as suggested by conventional sampling methodsat Trail Bridge Dam and by average densities per m 2 in Bonneville Dam forebay areas, then 47,000detections would represent 72 percent of the population, which also would make our passage estimatesseem high.The true magnitude of fish passage through Trail Bridge Dam is unknown, even though we cancalculate that the large-fish and spillway-location adjustments, as described in the previous twoparagraphs, would reduce the annual passage estimates to 33,421 (total), 22,040 (turbine), and 11,381(spillway). We simply cannot determine how many small, weak-swimming fish or larger non-swimmingfish might have been eliminated by speed filtering or how much large debris was not eliminated becauseof inaccurate speed estimates from non-point or multipoint scatterers of sound. Only simultaneoussampling with hydroacoustics and netting could conclusively resolve uncertainty about filter effects, andwe do not recommend such an expensive study. Only about 5% of the echo traces detected inside theturbine intake had fewer than 30 echoes, and a strong inflection at 5% and 30 echoes suggested that thespeed filter was very effective at eliminating non-fish echoes from turbine data. In contrast, 30% ofspillway detections had fewer than 30 echoes, which suggest that the speed filter was less effective at thespillway than it was at the turbine. We recommend that a DIDSON acoustic camera be deployed for afew days at the turbine and spillway to help resolve uncertainties about fish and debris. Images withinabout 18 m of the device are clear enough that undulating movements of fish and swimming direction canbe discerned, and this would allow real-time discrimination between fish and non-fish targets. Given thewide field of view (30 degrees horizontal and 12 degrees vertical), the DIDSON could image most of thespillway gate or turbine intake of Trail Bridge Dam. We also recommend conducting several mobilehydroacoustic surveys using split-beam transducers or a DIDSON to estimate the density of fish in thereservoir. This would provide a check on the estimated size of the fishery resource.Seasonally, entrainment into the turbine was much higher in November, December, January, andFebruary than in other months for the three length classes of targets, and much higher for small targetsthan for successively larger length classes (Figure S.1). Hourly rates were low (

Mean Number / Hour5432138-100 mm>100-200 mm>200-350 mm>350 mm05 6 7 8 9 10 11 12 1 2 3 4 5Month (2004-2005)Figure S.1.Plot of Mean Hourly Rates of Entrainment at the Trail Bridge Dam Turbine. Vertical barsare 80% confidence intervals.The number of spill hours per day explained 61% of the variation in the number of fish passing per day,and the number of spill hours per year by hour of the day explained 54% of the variation in the dielpassage of fish.The diel pattern of passage through the turbine was higher at night and during the morning than it wasin the afternoon and evening, and higher nighttime passage is consistent with what has been observed atBonneville Dam turbines (Figure S.2). Diel trends were most obvious for the two smallest length classesof targets. Diel changes in forebay elevation explained only 21% of the diel variation in the passage ofsmall targets, leaving 79% to be explained by something else like fish behavior. Higher nighttimepassage seems to be common for deep passage routes.4.0TurbineMean Number / Hour3.53.02.52.01.50 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24Hour of the DayFigure S.2.Estimated Mean Hourly Rate of Detections of all Length Classes of Targets by Hour of theDay for the Trail Bridge Turbine Intake Based on Sampling from May 11, 2004 ThroughMay 17, 2005. The line is a 2-hour moving average.viii

Diel variation in the passage of fish through the Trail Bridge Spillway, with higher passage during theday than at night (Figure S.3), was consistent with diel patterns of passage for surface bypass routes suchas the Bonneville Second Powerhouse sluiceway, which has a depth similar to that of the Trail BridgeDam spillway.76Percent of Detections5432100 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23HourFigure S.3.Hydroacoustic Estimates of the Mean Hourly Rate of All Filtered Detections at theSpillway from May 11, 2004 Through May 17, 2005 Versus Hour of Day. The fittedline is a 2-hour moving average.Vertical distributions of detections inside the turbine at Trail Bridge Dam (Figure S.4) were similar tothose often reported for turbines on the lower Columbia River. Given the depth of most turbine intakesand relative shallow vertical distributions of fish at most locations, it is not surprising that passage wouldbe skewed upward.2,0342,0322,030WinterAutumnSpringSummerElevation (ft)2,0282,0262,0242,0222,0202,0180 5 10 15 20 25 30 35 40 45%50.040.030.020.010.00.0Percent of DetectionsSpring Summer Autumn WinterSeasonFigure S.4.Percent Vertical Distribution of all Sizes of Fish Detected Passing Inside the TurbineIntake. The heavy line at 2,026 ft elevation is the center line of the 15-ft-diameter penstockopening downstream of trash racks.ix

Spill passage efficiency at Trail Bridge Dam depended upon the number of hours of turbineoperations versus spill operations and the relative rate of passage through each route. Spill and fishpassage efficiency are identical for Trail Bridge Dam because the spillway is the only non-turbine route ofpassage. For the entire one-year study, spill passage efficiency was 51.5% for targets ≤100 mm, 41.5%for targets >100-200 mm, 55% for targets 200-350 mm, and 58.3% for targets >350 mm, even though theProject spilled water just 6% of the time (522 hours). Reducing spillway estimates by the samplinglocationadjustment described in 4.1.3 above, spill passage efficiency was 35.3% for the year.During simultaneous spill and turbine operations, spill passage efficiencies

AcknowledgmentsMany people made valuable contributions to this study and deserve acknowledgment. Liz Gilliamand Trevor Lucas downloaded data from the data acquisition computer to a FireWire drive, backed updata on DVD disks, and monitored the acoustic system to ensure that the system was operating andcollecting data. Kevin Wiles, the Generation Team Leader with EWEB and his staff, made manyvaluable suggestions for installation and provided logistical support and electrical power to the equipmenttrailer. Catrin van Donkelaar with EWEB and Ethan Bell and Steven Kramer with Stillwater Sciences,Inc. provided valuable assistance with deployment logistics. Ethan Bell also provided contract oversightfor Stillwater Sciences. Jennifer Aspittle with Stillwater Sciences sent us hourly estimates of forebayelevation and MW of power generated as these data became available from the EWEB. Gary Johnson ofBattelle reviewed this report.xi

Abbreviations and AcronymscfsdBEBAEWEBfthrmminMWPASµPasSAScubic feet per seconddecibel referenced to 1 µPa at 1 meffective beam angleEugene Water and Electric BoardfeethourmeterminmegawattsPrecision Acoustic Systemsmicro PascalsecondStatistical Analysis Systemxiii

ContentsExecutive Summary .....................................................................................................................................iiiAcknowledgments........................................................................................................................................ xiAbbreviations and Acronyms ....................................................................................................................xiii1.0 Introduction........................................................................................................................................ 1.11.1 Background............................................................................................................................... 1.11.2 Goals......................................................................................................................................... 1.11.3 Objectives................................................................................................................................. 1.12.0 Methods.............................................................................................................................................. 2.12.1 Approach .................................................................................................................................. 2.12.2 Equipment and Calibrations ..................................................................................................... 2.12.3 Deployments............................................................................................................................. 2.32.4 Spatial Expansions.................................................................................................................... 2.42.5 Detectability Modeling............................................................................................................. 2.62.6 Sampling Schemes and Temporal Expansions......................................................................... 2.92.7 Autotracker Calibration .......................................................................................................... 2.102.8 Processing Echograms Manually............................................................................................ 2.142.9 Filtering to Eliminate Poor Echo Traces ................................................................................ 2.212.10 Filtering to Eliminate Non-Fish Echo Traces......................................................................... 2.232.11 Dam Operations Data .............................................................................................................2.282.12 Missing Data........................................................................................................................... 2.282.13 Fish Passage Metrics .............................................................................................................. 2.293.0 Results................................................................................................................................................ 3.13.1 Noise Frequency....................................................................................................................... 3.13.2 Detectability ............................................................................................................................. 3.23.3 Direction of Travel ................................................................................................................... 3.83.4 Dam Operations........................................................................................................................ 3.83.5 Effects of Speed Filters........................................................................................................... 3.113.6 Trends in Passage After Filtering ........................................................................................... 3.123.6.1 Turbine Intake Passage ...................................................................................................... 3.123.6.2 Spillway Passage................................................................................................................3.183.6.3 Spill Passage Efficiency..................................................................................................... 3.213.6.4 Spill Passage Effectiveness ................................................................................................ 3.22xv

3.6.5 Appendixes......................................................................................................................... 3.234.0 Discussion .......................................................................................................................................... 4.14.1 Passage Estimates..................................................................................................................... 4.14.1.1 Effect of Filters on the Magnitude of Passage ..................................................................... 4.14.1.2 Effects of Expansion on Passage Estimates for Fish >200 mm ........................................... 4.24.1.3 Effect of Location and Debris on Spillway Passage Estimates............................................ 4.34.1.4 Addressing Uncertainties in Passage Estimates ................................................................... 4.34.2 Season Trends........................................................................................................................... 4.44.3 Diel Trends ............................................................................................................................... 4.54.4 Vertical Distribution in the Turbine Intake .............................................................................. 4.54.5 Spill Passage Efficiency ........................................................................................................... 4.54.6 Spill Passage Effectiveness ...................................................................................................... 4.85.0 References.......................................................................................................................................... 5.1Appendix A – Passage Estimates Based on Filtering of Targets Moving >50 of the MedianSpeed of the Smallest Detected Targets............................................................................ A.1Appendix B – Mean Hourly Rates of Passage Based on Filtering of Targets Moving >50%of the Median Speed of the Smallest Targets.....................................................................B.1Appendix C – Median Hourly Rates of Passage Based on Filtering of Targets Moving>50% of the Median Speed of the Smallest Targets ..........................................................C.1xvi

FiguresS.1 Plot of Mean Hourly Rates of Entrainment at the Trail Bridge Dam Turbine .................................viiiS.2 Estimated Mean Hourly Rate of Detections of all Length Classes of Targets by Hour ofthe Day for the Trail Bridge Turbine Intake Based on Sampling from May 11, 2004Through May 17, 2005.....................................................................................................................viiiS.3 Hydroacoustic Estimates of the Mean Hourly Rate of all Filtered Detections at theSpillway from May 11, 2004 Through May 17, 2005 Versus Hour of Day....................................... ixS.4 Percent Vertical Distribution of All Sizes of Fish Detected Passing Inside theTurbine Intake .................................................................................................................................... ix1.1 Diagram of Trail Bridge Dam waterworks Showing the Turbine Intake Upstream in TrailBridge Reservoir, the Spillway Gate, and the Turbine..................................................................... 1.21.2 Photograph of the Single-Bay Spillway at the Southeast End of Trail Bridge Dam ........................ 1.31.3 Photograph of the Single-Turbine Powerhouse just Below Trail Bridge Dam ................................ 1.32.1 Spillway Transducer Mounts Showing 3-inch-Diameter Aluminum Pipe Extending down intothe Water from the Upstream Side of the Roadway Above the Tainter Gate at the Spillway.......... 2.32.2 Cross-Section and Front View of the Spill Bay at Trail Bridge Dam Showing the AimingAngles of Two 12-Degree Split-Beam Transducers Deployed on 3-inch-Diameter AluminumPipe Mounts...................................................................................................................................... 2.32.3 Plan View and Cross-Section View of the Turbine Intake at Trail Bridge Dam Showing theDeployment of Two 12-Degree Split-Beam Transducers ................................................................ 2.42.4 Diagram Illustrating Spatial Expansions of a Detection at the Turbine Intake Based on theRatio of the Length of a Chord Across the Circular Penstock Entrance to the Acoustic BeamDiameter at the Range of Detection ................................................................................................. 2.52.5 Illustration of Trajectories of Targets Passing Through the Up- and Down-LookingHydroacoustic Beams Inside the Turbine Intake at Trail Bridge Dam ............................................ 2.62.6 Plots of Plunge as a Function of Range from Transducers, Where Plunge is the Angle Offof a Line Perpendicular to the Main Axis of the Acoustic Beam..................................................... 2.82.7 Plots of Target Speed as a Function of Range from Transducers..................................................... 2.82.8 Plots of the Acoustic Beam Pattern for Transducer 457 Deployed Down-Looking Inside theTrail Bridge Dam Turbine Intake ..................................................................................................... 2.92.9 Correlations of Manual Tracker Counts with Autotracker Counts for Transducer Deploymentsat Trail Bridge Dam........................................................................................................................ 2.132.10 Image of an Echogram from the Up-Looking In-Turbine Transducer at Trail Bridge Dam.......... 2.152.11 Echogram from the Down-Looking In-Turbine Transducer at Trail Bridge Dam ......................... 2.152.12 Echogram from the Down-Looking Spillway Transducer Sampling the Southeast Half of theSpillway at Trail Bridge Dam......................................................................................................... 2.162.13 Echogram from the Northwest Down-Looking Spillway Transducer at Trail Bridge Dam........... 2.16xvii

2.14 Echogram from the Down-Looking Transducer Sampling the Southeast Half of the Spillwayat Trail Bridge Dam........................................................................................................................ 2.172.15 Echogram from the Down-Looking Transducer Sampling the Northwest Half of the Spillwayat Trail Bridge Dam........................................................................................................................ 2.172.16 Echogram from the Down-Looking Transducer Sampling the Turbine at Trail Bridge Dam........ 2.182.17 Echogram from the Down-Looking Transducer Sampling the Turbine at Trail Bridge Dam........ 2.182.18 Echogram from the Down-Looking Transducer Sampling the Turbine at Trail Bridge DamShowing a Tracked Echo Trace with Echoes Highlighted in White and Trace StatisticsDisplayed in the Track ID Box....................................................................................................... 2.192.19 Echogram From the Up-Looking Transducer Sampling the Turbine at Trail Bridge DamShowing Two Tracked Echo Traces with Echoes Highlighted in White ....................................... 2.192.20 Echogram from the Down-Looking Transducer Sampling the Southeast Half of the Spillwayat Trail Bridge Dam Showing Nine Tracked Echo Traces with Individual Echoes Highlightedin White .......................................................................................................................................... 2.202.21 Echogram from the Down-Looking Transducer Sampling the Southeast Half of the Spillway atTrail Bridge Dam Showing Echoes from Entrained Air Associated with a Vortex ....................... 2.202.22 Same Echogram as Figure 2.21 After Noise Processing, Tracking, and Filtering ......................... 2.212.23 Arbitrarily Assigned Probabilities That a Target Was a Fish as a Function of Relative Speed ..... 2.242.24 Proportion of Detections of Targets < -50 dB and ≥ -50 dB as a Function of Speed ofMovement Through Acoustic Beams............................................................................................. 2.252.25 Regression Plots of the Speed of Small Targets as a Function of Megawatts of PowerGenerated for Each of Three 1-m Range Strata from the Down-Looking HydroacousticBeam Inside the Trail Bridge Turbine Intake................................................................................. 2.272.26 Regression Plots of the Speed of Small Targets as a Function of Megawatts of PowerGenerated for Each of three 1-m Range Strata from the Up-Looking Hydroacoustic BeamInside the Trail Bridge Turbine Intake ........................................................................................... 2.283.1 Plot of Average Percent Noise per Hour over all Range Strata Sampled by Two In-TurbineTransducers. Percent Noise was Calculated as the Number of Noise Echoes Dividedby the Number of Possible Noise Echoes......................................................................................... 3.13.2 Plot of Average Percent Noise per Hour over all Range Strata Sampled by Two SpillwayTransducers. Percent Noise per Stratum was Calculated as the Number of NoiseEchoes Divided by the Number of Possible Noise Echoes .............................................................. 3.23.3 Mean Target Strengthof Filtered Detections at the Trail Bridge Dam Turbine and Spillway bySeason and Associated Length Classes ............................................................................................3.33.4 Plots of Effective Beam Angle as a Function of the Integer of Target Range from theUp-Looking Transducer Inside the Turbine Intake. ......................................................................... 3.43.5 Plots of EBA as a Function of Target Range from the Down-Looking Transducer Inside theTurbine Intake .................................................................................................................................. 3.43.6 Plots of EBA as a Function of Target Range from the Transducer Sampling the NW Halfof the Spillway.................................................................................................................................. 3.53.7 Plots of EBA as a Function of Target Range from the Transducer Sampling the NW Half of theSpillway............................................................................................................................................ 3.5xviii

3.8 Plot of the Percent Cumulative Frequency of the Number of Echoes per Trace.............................. 3.63.9 Echogram from the Down-Looking Transducer Sampling the Southeast Half of the Spillwayat Trail Bridge Dam.......................................................................................................................... 3.63.10 Echogram from the Down-Looking Transducer Sampling the Turbine at Trail Bridge Dam.......... 3.73.11 Echogram Showing a Short Range Trace Detected by the Up-Looking Transducer in theTurbine Intake .................................................................................................................................. 3.73.12 Plots of the Distribution of Target Strengths for the Turbine Intake and the Spillway ofTrail Bridge Dam.............................................................................................................................. 3.83.13 Radial and Standard Frequency Distribution Plots of the Azimuth Direction of Travel forEach of the Transducers Sampling at Trail Bridge Dam.................................................................. 3.93.14 Plot of Forebay Elevation and MW of Power Generated During the Period of Study atTrail Bridge Dam............................................................................................................................ 3.103.15 Discharge from the McKenzie River Below Trail Bridge Dam and from the Trail BridgeSpillway During the Study ............................................................................................................. 3.103.16 Forebay Elevation from 1200 Hours on May 23 Through 1100 Hours on May 25, 2004 ............. 3.113.17 Estimated Annual Passage in Each of Four Length Classes by Severity of Filtering onTarget Speed. Filters indicate targets that were removed.............................................................. 3.123.18 Estimated Annual Passage in Each of Four Length Classes by Severity of Filtering onTarget Speed................................................................................................................................... 3.133.19 Hydroacoustic Estimates of Filtered Detections Through the Turbine from May 11, 2004Through May 17, 2005 by Length Class and Week ....................................................................... 3.133.20 Hydroacoustic Estimates of Mean Hourly Rate of Passage Through the Turbine fromMay 11, 2004 Through May 17, 2005 by Length Class and Week................................................ 3.143.21 Hydroacoustic Estimates of Median Hourly Rate of Passage Through the Turbine fromMay 11, 2004 Through May 17, 2005 by Length Class and Week................................................ 3.143.22 Hydroacoustic Estimates of Median Hourly Rate of Passage Through the Turbine fromMay 11, 2004 Through May 17, 2005 by Length Class and Week................................................ 3.153.23 Estimated Mean Hourly Rate of Detections of all Length Classes of Targets by Hour of Dayfor the Trail Bridge Turbine Intake Based on Sampling from May 11, 2004 ThroughMay 17, 2005.................................................................................................................................. 3.163.24 Hydroacoustic Estimates of Mean Number of Detections per Hour Through Turbine Intakefrom May 11, 2004 Through May 17, 2005 by Length Class and Hour of Day ............................ 3.163.25 Regression of the Mean Hourly Rate of Passage of 38- to 100-mm Fish Through the TurbineIntake on Mean Hourly Forebay Elevation .................................................................................... 3.173.26 Diel Pattern in Mean Forebay Elevation and the Mean Hourly Rate of Passage of 38- to100-mm Fish Through the Turbine Intake ..................................................................................... 3.173.27 Percent Vertical Distribution of all Sizes of Targets Detected Passing Inside the TurbineIntake.............................................................................................................................................. 3.183.28 Hydroacoustic Estimates of Passage Through the Spillway from May 11, 2004 ThroughMay 17, 2005 by Length Class and Day ........................................................................................ 3.19xix

3.29 Hydroacoustic Estimates of the Mean Hourly Rate of Passage Through the Spillway fromMay 11, 2004 Through May 17, 2005 by Length Class and Day .................................................. 3.193.30 Paired Hydroacoustic Estimates of Passage Through the SE and NW Halves of the Spillwayby Month for Three Length Classes of Targets.............................................................................. 3.203.31 Hydroacoustic Estimates of Mean Hourly Rate of All Filtered Detections at the Spillway fromMay 11, 2004 Through May 17, 2005 Versus Hour of Day........................................................... 3.213.32 Hydroacoustic Estimates of Mean Hourly Rate of Filtered Hydroacoustic Detections Throughthe Spillway from May 11, 2004 Through May 17, 2005 by Length Class and Hour of Day ....... 3.213.33 Hydroacoustic Estimates of the Spill Passage Efficiency by Month and Length Class ................. 3.223.34 Hydroacoustic Estimates of the Spill Passage Efficiency by Date and Length Class Based onHours when Detections Were Greater than 0 for both routes......................................................... 3.223.35 Hydroacoustic Estimates of Spill Passage Effectiveness by Season .............................................. 3.234.1 Diel Trends in Passage Above and Below an Extended Length Bar Screen at Intake 8B atBonneville Dam in Spring and Summer 1998.................................................................................. 4.64.2 Diel Trends in the Number of Smolt-Sized Targets Passing into the 22-ft Deep Corner Collectorat Bonneville Dam Second Powerhouse in Spring 2004.................................................................. 4.64.3 Vertical Distribution of Smolt-Sized Targets Inside Modified Intake 15B for Spring andSummer 2001. Normal pool elevation is about 74 ft MSL.............................................................. 4.74.4 Estimated Sluiceway Effectiveness for the Bonneville Project and Each Powerhouse forSpring and Summer 2004 ................................................................................................................. 4.8xx

TablesS.1 Project Spill Passage Efficiency, Turbine Intake Detections, Spill Passage Detections, andTotal Detections During a 1-yr Hydroacoustic Study Based on Filtering Targets Moving>50% of the Median Speed of Small Targets..................................................................................... viS.2 The Mean and Median Hourly Rates of Passage Through the Turbine and Spillway........................ vi2.1 Calibration Statistics and Calculated Receiver Gains Sufficient to Detect a -56 dB Target in theCenter of the Acoustic Beam Cross Section for the Trail Bridge Hydroacoustic System................ 2.22.2 Input Data for the Detectability Model by Channel and Length Class............................................. 2.72.3 Coefficients for Estimating Effective Beam Angle from the Midpoint Range of a Target froma Transducer ................................................................................................................................... 2.102.4 Definitions of Autotracking Software Parameters Used for Processing Hydroacoustic Data........ 2.112.5 Autotracking Software Settings Used to Process Trail Bridge Dam in 2004 and 2005 ................. 2.122.6 Definitions of Variables Used for Filtering Echo Traces Selected by Autotracking Software ...... 2.222.7 SAS Code Used to Eliminate Echo Traces That Did Not Meet Echo Trace Criteria for EachChannel........................................................................................................................................... 2.222.8 SAS Code for Defining Echo Traces as Fish Because They Had more than the MaximumNumber of Echoes Expected at a Given Range.............................................................................. 2.263.1 ProjectSpill Passage Efficiency, Turbine Intake Detections, Spill Passage Detections, andTotal Detections During a One-Year Hydroacoustic Study Based on Filtering Targets Moving>50% of the Median Speed of Small Targets................................................................................. 3.124.1 Comparison of Passage Estimates Through the Trail Bridge Spillway Based on Samplingboth Halves Versus just the NW Half, Which was Less Plagued by Debris Loading than theSW Half............................................................................................................................................ 4.3xxi

1.0 Introduction1.1 BackgroundThe Eugene Water and Electric Board (EWEB) is seeking to relicense the Carmen-Smith HydroelectricProject with the Federal Energy Regulatory Commission so that the project can continue tooperate in an environmentally, socially, and economically sustainable manner. The project consists ofthree dams and their associated impoundments, Carmen Diversion Dam and Reservoir, Smith River Damand Reservoir, and Trail Bridge Dam and Reservoir. The Carmen-Smith Project can provide a maximum114 megawatts (MW) of electric power, and the associated reservoirs and land offer recreationalopportunities that include camping, picnicking, fishing, and boating. The EWEB seeks to identify andinvestigate possible environmental effects of the project and identify cost-effective protection, mitigation,and enhancement measures based on scientific study and investigation.Trail Bridge Dam (Figure 1.1) creates a 73.4 acre re-regulating reservoir and has bull trout (Salvelinusconfluentus) and juvenile Chinook salmon (Oncorhynchus tshawytscha) that presumably pass through thespillway (Figure 1.2) and turbine (Figure 1.3) at unknown rates at certain times of the year. The top ofthe turbine intake (Figure 1.1) is about 40 ft deep when the forebay water elevation is at 2085 ft MSL.Juvenile spring Chinook (progeny of adults transported from the McKenzie River Hatchery to above TrailBridge Dam) must pass through one of these exit routes to migrate downstream past the dam. Other fishthat may be entrained include native coastal cutthroat trout (Oncorhynchus clarki clarki), residentrainbow trout (Oncorhynchus mykiss) (both hatchery and native stocks), and non-native brook trout(Salvelinus fontinalis) (EWEB 2004). The Oregon Department of Fish and Wildlife stocking schedule for2004 called for adding about 3,000 rainbow trout on May 17, 3,000 on July 12, and 2,000 on August 2.1.2 GoalsThere were two goals for this study. The first goal was to assess the feasibility of using fixed-locationhydroacoustic methods to estimate fish-entrainment rates through the turbine intake and spillway of TrailBridge Dam. This pilot study was conducted from May 11, 2004 through May 16, 2004 by Battelle –Pacific Northwest Division in Richland, Washington, for Stillwater Sciences Incorporated, the primecontractor to the EWEB. After the feasibility of sampling was established by the pilot study, the secondgoal was to sample with consistent methods for one year to determine seasonal, diel, and spatial trends inthe entrainment of four length classes of fish through the turbine and spillway.1.3 ObjectivesThe feasibility study of a hydroacoustic approach to estimate fish entrainment rates at Trail BridgeDam was one step in the process to acquire information to relicense the Carmen Smith HydroelectricProject. The first five days of study were used to assess the feasibility of using hydroacoustic methods bydetermining the distribution of structural and volume-reverberation noise in the intake and spill bay thatcould impair or preclude hydroacoustic detection of fish. We modeled the probability of detection basedon aiming angles, beam angles, range, ping rates, and target size and trajectory, and we examined echocountstatistics of tracked targets by range strata to determine whether trends supported conclusions basedon detection modeling.1.1

This Figure is designated as Critical Infrastructure Information(CEII) FERC Only

Hydroacoustic Evaluation of Fish Passage Through Trail Bridge Dam (2004-2005)Figure 1.2.Photograph of the Single-Bay Spillway at the Southeast End of Trail Bridge DamFigure 1.3.Photograph of the Single-Turbine Powerhouse just Below Trail Bridge Dam1.3

Hydroacoustic Evaluation of Fish Passage Through Trail Bridge Dam (2004-2005)The objectives of the feasibility study were to:1. Collect and process hydroacoustic data to examine the amount of volume reverberation fromentrained air and structure that could preclude or limit detection of targets.2. Determine average trace characteristics from targets passing through hydroacoustic beams and usethese statistics to model and assess hydroacoustic detectability.3. Calibrate the autotracker tracking software developed by Battelle and demonstrate its effectiveness bycorrelating counts of manually tracked targets with counts of autotracked targets.4. Draw conclusions about the probability of hydroacoustic methods providing a reasonable index tofish passage at Trail Bridge Dam.After the pilot study established the feasibility of sampling with hydroacoustic methods, a one-yearstudy was conducted to:1. Estimate passage through the turbine intake and spillway for four length classes of targets on hourly,daily, weekly, monthly, and annual time scales.2. Provide estimates of spill passage efficiency, which is the proportion of fish passing by the only nonturbineroute (spill efficiency = fish-passage efficiency at Trail Bridge Dam) for times when theturbine and spillway were both passing water.3. Estimate the vertical distribution of passage into the turbine intake by season.This study used fixed-location hydroacoustic methods to estimate the number and timing of passagefor four length classes of fish (38–100 mm, >100–200 mm, > 200–350 mm, and > 350 mm). In a parallelstudy, Stillwater Sciences deployed underwater video cameras and infrared lights to identify fish speciespassing into the turbine intake. Hydroacoustics cannot identify which species are being entrained exceptto the extent that smaller targets can be classified as juvenile Chinook salmon or that peaks in passagenumbers closely follow stocking dates of known fish.1.4

Hydroacoustic Evaluation of Fish Passage Through Trail Bridge Dam (2004-2005)2.0 Methods2.1 ApproachSplit-beam, fixed-aspect hydroacoustic methods were used to sample the turbine intake and spill bayat Trail Bridge Dam from May 11 through May 16, 2004 to assess the feasibility of using hydroacousticmethods to estimate rates of passage. Feasibility was assessed by mapping acoustic noise in samplevolumes and by modeling acoustic detectability to ensure that targets were adequately detected. Inmapping noise, we examined the proportion of time that 1-m range strata could be tracked (i.e., notobscured by noise from turbulence or entrained air). In general, a deployment is unacceptable if echoesfrom structure or volume reverberation obscure traces more than 50% of the time. A trace is a linear orcurvilinear arrangement of successive echoes from a target passing through the acoustic beam. From thedistribution of target strengths from noise and passing targets, we determined that the most appropriatedetection threshold was -56 dB for an on-axis target. Target speed, trajectory, and strength provided inputfor modeling detectability, which yielded detection curves in the form of effective-beam angle as afunction of range from the transducer. Distribution statistics on the number of echoes per trace providedanother way to assess the adequacy of detection. After the feasibility of sampling with hydroacousticmethods was established in the pilot study, we continued sampling using the same methods from May 17,2004 through May 17, 2005.2.2 Equipment and CalibrationsA hydroacoustic system consists of a transceiver (echosounder), a multiplexer, cables, transducers, anoscilloscope, and a computer system. The transceiver and computer are plugged into an uninterruptiblepower supply. The echosounder generates electric signals at the required pulse durations and repetitionrates, and cables conduct those transmit signals from the echosounder to a multiplexer and transducers.Transducers convert the electrical energy to acoustic energy of specific frequency and amplitude andtransmit the sound into the water. Targets with densities different than that of water reflect a portion ofthis acoustic energy back in the direction of transmission, where it is detected by the transducers, convertedback to electrical energy, and returned to the echosounder. Amplitudes of echoes that meet targetacquisitioncriteria and exceed some preset threshold are then recorded to a hard drive. The multiplexer isa switch box that allows the user to sample different transducers according to sequences set up in dataacquisitionsoftware. An oscilloscope displays echo voltages and calibration tones as a function of time.The computer system controls echosounder and multiplexer activity and records data to a hard disk. Thesplit-beam echosounder, multiplexer, and 420 kHz circular split-beam transducers are controlled by dataacquisition software running on an acquisition computer.In this study, we used a 420 kHz split-beam hydroacoustic system manufactured by PrecisionAcoustic Systems (PAS), Seattle, Washington. Before deployment, PAS electronically checked andcalibrated the echosounder and transducers. After calibration, we calculated receiver gains to equalize theoutput voltages among transducers for on-axis targets ranging in hydroacoustic size from about –56 to –26 dB || 1 μPa at 1 m (Table 2.1). Lengths of fish corresponding to that acoustic size range would beabout 1.7 and 40 inches, respectively, if insonified within 30 degrees of their dorsal or ventral aspect(Love 1977).2.1

2.2Table 2.1.Echo-TransducerSounderNumberNumber Channel and PhaseCalibration Statistics and Calculated Receiver Gains Sufficient to Detect a -56 dB Target in the Center of the Acoustic Beam CrossSection for the Trail Bridge Hydroacoustic System. Bolded statistics are the average for the x and y phases. The source level wasat a -5 dB transmit level.CalibratedCableLength(ft)SourceLevel(dB)MaximumOutputVoltage(dB)40 logRReceiverSensitivity(dB)Strength ofLargest On-AxisTarget ofInterest(dB)CalculatedReceiverGain(dB)Receiver GainAdjusted forDifferencein Cable Length(dB)Strength ofSmallestOn-AxisTarget(dB)Voltage ofSmallestOn-AxisTarget(dB)Voltage ofSmallestOn-Axis Targetat 20 dB/volt(V)1 457 (x) 385 209.19 80 -111.02 -26 7.83 7.83 -56 50 2.501 457 (y) 385 209.31 80 -110.98 -26 7.67 7.67 -56 50 2.501 0 457 385 209.25 80 -111.00 -26 7.75 7.75 -56 50 2.501 465 (x) 385 208.91 80 -111.52 -26 8.61 8.61 -56 50 2.501 465 (y) 385 208.81 80 -111.62 -26 8.81 8.81 -56 50 2.501 1 465 385 208.86 80 -111.57 -26 8.71 8.71 -56 50 2.501 472 (x) 285 211.24 80 -111.78 -26 6.54 6.54 -56 50 2.501 472 (y) 285 211.00 80 -111.78 -26 6.78 6.78 -56 50 2.50Hydroacoustic Evaluation of Fish Passage Through Trail Bridge Dam (2004-2005)1 2 472 285 211.12 80 -111.78 -26 6.66 6.66 -56 50 2.501 476 (x) 285 212.18 80 -110.64 -26 4.46 4.46 -56 50 2.501 476 (y) 285 212.19 80 -110.6 -26 4.41 4.41 -56 50 2.501 3 476 285 212.19 80 -110.62 -26 4.44 4.44 -56 50 2.50

Hydroacoustic Evaluation of Fish Passage Through Trail Bridge Dam (2004-2005)2.3 DeploymentsA computer was used to control one split-beam transceiver, which in turn controlled two to four splitbeamtransducers using a remote four-channel multiplexer and associated cables. Two split-beam transducerswere deployed at the spill bay upstream of the tainter gate (Figures 2.1 and 2.2), and the other twotransducers were deployed in the turbine intake (Figure 2.3).Figure 2.1.Spillway Transducer Mounts Showing 3-inch-Diameter Aluminum Pipe Extending downinto the Water from the Upstream Side of the Roadway Above the Tainter Gate at theSpillway. Transducers were located at the ends of 8.5-ft-long horizontal pipes extendingdownstream from the vertical pipes toward the tainter gate.This Figure is designated as Critical Infrastructure Information(CEII) FERC OnlyFigure 2.2.Cross-Section (top) and Front View (bottom) of the Spill Bay at Trail Bridge DamShowing the Aiming Angles of Two 12-Degree Split-Beam Transducers Deployed on3-inch-Diameter Aluminum Pipe Mounts. The heavily shaded area of the acoustic beam ofthe upper diagram shows the volume in which echo traces were counted (4.0 to 5.6 m fromthe transducers).2.3

Hydroacoustic Evaluation of Fish Passage Through Trail Bridge Dam (2004-2005)This Figure is designated as Critical Infrastructure Information(CEII) FERC OnlyFigure 2.3.Plan View (top) and Cross-Section View (bottom) of the Turbine Intake at Trail BridgeDam Showing the Deployment of Two 12-Degree Split-Beam Transducers. Heavilyshaded beam volumes indicate where targets traces were counted.2.4 Spatial ExpansionsEach spillway transducer sampled one-half of the 30-ft-wide spill bay. Acoustic counts of targetsfrom each spillway transducer were expanded based on the ratio of one-half the bay width to beamacoustic diameter at the range of detection:2.4

Hydroacoustic Evaluation of Fish Passage Through Trail Bridge Dam (2004-2005)4.57EC =EBAMRiTAN( ) i22(1)where EC is the expanded count, 4.57 is one-half the bay width in m, MR is the mid-point range of a tracein m, TAN is the tangent, and EBA is effective-beam angle in degrees, as determined by detectabilitymodeling (see Section 2.5). Expanded counts from each half of the spill bay were summed to estimatepassage for the entire spill bay.Each in-turbine transducer sampled about half of the circular intake opening (Figure 2.3). Acousticcounts from each intake transducer were expanded based on the ratio of the chord length across thecircular penstock entrance to the diameter of the acoustic beam at the range of detection:CLEC =EBAMRiTAN( ) i22(2)where CL is the length of a chord across the penstock entrance perpendicular to the main axis of theacoustic beam at the range of detection, and MR is the midpoint range of echoes forming a trace in m.Figure 2.4 illustrates this expansion. The position of a target at the 15-ft-diameter circular entrance to thepenstock downstream of the trash racks was determined from trajectories of targets passing through thehydroacoustic beams (Figure 2.5).The aiming angles of in-turbine transducer beams insonified fish from about 41° off the head aspectin the horizontal plane and either 35° off the ventral aspect (the up-looker) or 41° off the dorsal aspect(the down-looker) in the vertical plane. Therefore, the smallest fish that could be detected would be about1.5 inches long, according to empirical data of Love (1977).Figure 2.4.Illustration of Spatial Expansion of Detection at Turbine Intake Based on the Ratio ofChord Length Across the Circular Penstock Entrance to Acoustic Beam Diameter at theRange of Detection2.5

Hydroacoustic Evaluation of Fish Passage Through Trail Bridge Dam (2004-2005)Figure 2.5.Diagram Illustrating Trajectories of Targets Passing Through Up- and Down-LookingHydroacoustic Beams Inside the Turbine Intake at Trail Bridge Dam. Average trajectorieswere calculated from all detections in each 1-m stratum of range from the transducers.2.5 Detectability ModelingEffective beam angle in Equations 1 and 2 depends on the detectability of targets of different sizes inthe acoustic beam and is a function of nominal beam angle, ping rate (pings/sec), and target size, aspect,trajectory, velocity, and range. We modeled detectability to determine effective beam angle using targetvelocity data by 1-m strata and mean target strength data for each length class detected by the split-beamtransducers. These and other hydroacoustic acquisition data (Table 2.2) were entered into a stochasticdetectability model. Some of the inputs, such as target plunge and speed, are a function of range from thetransducers (Figures 2.6 and 2.7). Beam patterns, which describe the fall-off in echo strength withincreasing angle off the main axis of the acoustic beam, also were input to the model (e.g., Figure 2.8).2.6

2.7 2.7ChannelOrientationLengthClass(mm)Table 2.2.Max.RangeMin.RangeInput Data for the Detectability Model by Channel and Length ClassMax. PingGapThreshold(dB)BeamAngleBeamTiltPingRateMeanTargetStrengthTS (e)STD (f)Ping to PingCorrelationPolynomialEnd Range(cm)T00 (a) DOWN 38-100 7.6 1 4 -56 12 35 30 -48.9 2.191 0.380 760 6>100-200 7.6 1 4 -56 12 35 30 -42.7 1.578 0.460 760 6>200-350 7.6 1 4 -56 12 35 30 -37.6 1.240 0.460 760 6>350 7.6 1 4 -56 12 35 30 -32.7 1.657 0.440 760 6T01 (b) UP 38-100 6.87 1 4 -56 12 41 30 -48.9 2.191 0.370 687 6>100-200 6.87 1 4 -56 12 41 30 -42.7 1.578 0.410 687 6>200-350 6.87 1 4 -56 12 41 30 -37.6 1.240 0.350 687 6>350 6.87 1 4 -56 12 41 30 -32.7 1.657 0.400 687 6T02 (c) DOWN 38-100 5.6 1 4 -56 12 20 30 -49.3 2.271 0.600 560 6>100-200 5.6 1 4 -56 12 20 30 -42.5 1.637 0.630 560 6>200-350 5.6 1 4 -56 12 20 30 -37.1 1.245 0.580 560 6>350 5.6 1 4 -56 12 20 30 -32.5 1.899 0.630 560 6T03 (d) DOWN 38-100 5.55 1 4 -56 12 20 30 -49.3 2.271 0.640 550 6>100-200 5.55 1 4 -56 12 20 30 -42.5 1.637 0.700 550 6>200-350 5.55 1 4 -56 12 20 30 -37.1 1.245 0.610 550 6>350 5.55 1 4 -56 12 20 30 -32.5 1.899 0.570 550 6(a)(b)(c)(d)(d)(e)T00 = the in-turbine down-looking transducer.T01 = in-turbine up-looking transducer.T02 = SE spillway transducer.T03 = NW spillway transducer.TS = target strength.STD = standard deviation.Min.Number ofEchoesHydroacoustic Evaluation of Fish Passage Through Trail Bridge Dam (2004-2005)

Hydroacoustic Evaluation of Fish Passage Through Trail Bridge Dam (2004-2005)Plunge (Degrees)605040302010086420Turbine DownlookerTurbine Uplooker`-2706050403020100Spillway Downlookers1 2 3 4 5 6 7 8RangeFigure 2.6.Plots of Plunge as a Function of Range from Transducers, Where Plunge is the Angle Offof a Line Perpendicular to the Main Axis of the Acoustic BeamSpeed (m / s)1.00.90.80.70.60.50.42.01.61.20.8Turbine TransducersSpillway TransducersFigure 2.7.0.41 2 3 4 5 6 7 8Range (m)Plots of Target Speed as a Function of Range from Transducers2.8

Hydroacoustic Evaluation of Fish Passage Through Trail Bridge Dam (2004-2005)Drop in dB0-2-4-6-8-10-120 5 10 15Angle Off AxisFigure 2.8.Acoustic Beam Pattern for Transducer 457 Deployed Down-Looking Inside Trail BridgeDam Turbine Intake. Drop in dB is decrease in echo strength referenced to 1 µPa at 1 m asa target moves across the acoustic beam, and angle off axis is the angle of a standard targetto either side of the center of the 12-degree acoustic beam.We know of no other detectability model that incorporates all of these factors into a stochastic framework.One important factor affecting estimates of effective beam width is the minimum echo patterncriterion (a core of four echoes in five pings, used in this study), which can be modeled only stochastically.An effective beam angle for a nominal 12-degree beam may become asymptotic with increasingrange at 12 or 13 degrees if an echo-pattern criterion is not modeled. However, modeling detectability fora core pattern of four colinear echoes in five pings (allowing a one-ping gap) may provide an effectivebeam angle of 11 or 12 degrees. Requiring four colinear echoes in four pings (allowing no gap in the coreof a trace) may provide an effective angle of only 5 degrees. Target strength also has a major effect ondetectability and effective beam angle; it is deployment dependent because target strength depends in parton the orientation of targets as they pass through a hydroacoustic beam. We modeled detectability foreach length class of interest because mean target strength varied more by length class than by season.Results of detectability modeling are polynomials for calculating effective beam angle as a functionof the midpoint range of a target from a transducer (Table 2.3) for use in Equations 1 and 2.2.6 Sampling Schemes and Temporal ExpansionsThree setup files were created to allow sampling of 1) all four transducers for simultaneous spill andturbine operations, 2) two spillway transducers (spill only), or 3) two turbine intake transducers (turbineintake only). During any simultaneous turbine and spill operations, four transducers were repeatedlysampled sequentially for one minute each, so 15 one-minute samples were obtained from each transducer.This provided one-quarter time sampling for each half of the spill bay and the upper and lower halves ofthe turbine intake. During spill-only operations, spillway transducers were continuously sequentiallymultiplexed to provide 30 one-minute samples per hour from each transducer (i.e., 60 min/hr of samplingprovides 1/2-time sampling of each half of the spill bay). During turbine-only operations, intake transducerswere sequentially sampled during 15 randomly selected pairs of minutes per hour (30 min/hr), sothe upper and lower halves of the circular intake were each sampled for 15 min/hr or one-quarter time. In2.9

Hydroacoustic Evaluation of Fish Passage Through Trail Bridge Dam (2004-2005)Table 2.3.Coefficients for Estimating Effective Beam Angle from the Midpoint Range of a Targetfrom a Transducer (a)Length Classmm)MinimumRangeMaximumCoefficientsRange C1 C2 C3 C4 C5Turbine Intake (Down-looking Transducer)38-100 1 7.60 0.0064 -0.2766 2.8013 -10.1922 26.0000>100-200 1 7.60 0.0222 -0.4631 3.3917 -10.2220 25.9307>200-350 1 7.60 0.0197 -0.4318 3.3130 -10.3965 26.9880>350 1 7.60 0.0252 -0.5169 3.7392 -11.2095 27.5957Turbine Intake (Up-looking Transducer)38-100 1 6.87 0.0241 -0.4490 2.8646 -6.8295 15.3729>100-200 1 6.87 0.0064 -0.2766 2.8013 -10.1922 26.0000>200-350 1 6.87 0.0064 -0.2766 2.8013 -10.1922 27.4043>350 1 6.87 0.0064 -0.2766 2.8013 -10.1922 28.4032SE Half of Spillway (Down-looking Transducer)38-100 4 5.60 0.0371 -0.6586 4.1696 -11.0404 20.3600>100-200 4 5.60 0.1123 -1.8824 11.2781 -28.4044 38.0000>200-350 4 5.60 0.1123 -1.8824 11.2781 -28.4044 40.0000>350 4 5.60 0.1123 -1.8824 11.2781 -28.4044 41.1450NW Half of Spillway (Down-looking Transducer)38-100 4 5.55 0.0633 -0.9757 5.4144 -12.7936 21.0067>100-200 4 5.55 0.0881 -1.5331 9.3501 -23.2816 32.0000>200-350 4 5.55 0.0881 -1.5331 9.3501 -23.2816 33.8800>350 4 5.55 0.0881 -1.5331 9.3501 -23.2816 34.8817(a) The equation for estimating effective beam angle from polynomial coefficients is2 3 4EA = C5+ C4⋅ R + C3⋅ R + C2⋅ R + C1⋅Rwhere R = range from the transducer and C1, C2, C3, C4, and C5 are coefficients in the table.passage reports, spatially expanded fish counts from the spillway and turbine intake were temporallyexpanded to the whole hour by multiplying counts by 60 divided by the number of minutes each transducersampled per hour. Sample variances also were temporally expanded to the whole hour using theformula:2VAR _ AH (60 (1 N / 60) VAR _ AM= − i (3)where VAR _ AH = variation among minutes sampled, N = the number of minutes sampled per hour, andVAR _ AH = variation for the hour.Sequential sampling of 2 to 4 transducers allowed us to maximize the pulse repetition rate at 30pulses per second to ensure adequate detectability of the fastest-moving target passing through theacoustic beams.2.7 Autotracker CalibrationAutotracking software was used to detect echo traces and record trace statistics to a comma-separatedvariable file for further processing. The channel specific parameters set in the autotracking software aredefined in Table 2.4, and values used for Trail Bridge in 2004 and 2005 are presented in Table 2.5. Theautotracker software tells the processing computer to:2.10

Hydroacoustic Evaluation of Fish Passage Through Trail Bridge Dam (2004-2005)Table 2.4.Definitions of Autotracking Software Parameters Used for Processing Hydroacoustic DataParameterDefinitionBlockSizeMaximum number of ping of data to process as a sampleMaxRangeRange (cm) to end autotrackingMinRangeRange (cm) to begin autotrackingStructureThresholdFraction of possible echoes in a range bin that triggers assignment as structureRangeNoiseRange (cm) uncertainty in the position of an echo in rangeGateSizeMaximum range about the predicted position of the next echo in which an encounter echowill be added to a trackDKMaxThe maximum ping difference the autotracker will check to find the next ping in a tracksegmentAlphaParameter used in an alpha-beta tracking formula; beta was calculated from alpha asfollows: beta = 2(2 –alpha) –4(1 –alpha)0.5LinkGateRange (cm) over which two colinear tracked segments will be linkedLinkDKMaxThe maximum ping difference the autotracker will span to link segments into a trackMaximum Echo or Target Strength Largest acoustic size acceptable for autotracking. This may be based on echo strength(dB) from single beams or target strength (dB) from split beamsMinimum Echo or Target Strength Smallest acoustic size acceptable for tracking. Also known as the on-axis strength of anecho.NoiseThe number of dilates and erodes used to identify noise regions (greater than 0) (-1 meansdo not do noise for a channel)BottomStartRangeThe range (in cm) to begin the routine to identify the surface or bottom range (should bebetween min and max range) (if bottom identification is not needed, set value greater thanmax range)BottomCtTholdThe proportion of a range that must be occupied by echoes > than the bottom amplitudethreshold to be marked as bottom. (0 –1)BottomAmplTholdThe minimum echo strength (in decibels) above which echoes will be tallied as bottom orsurface echoes1. Identify and remove echoes at constant range from structure.2. Find seed echoes for candidate tracks.- Go to every echo.- Define a 10-ping by 1-m window centered on that echo.- Place all echoes in the window into 5-degree angle bins.- If any bin-count is greater than 3, flag the center echo as a candidate seed.3. Re-examine candidate seed echoes.- Go to every seed-echo window.- Count echoes in all possible line features (Hough transform).- If no echoes in the window are part of a strong line feature, drop the seed echo (to distinguishbetween dense noise and dense tracks).4. Initiate alpha-beta tracking.- Track forward, starting at each seed echo.- Track backward from the same seed echo after forward tracking has ended.- Check the track segment against criteria (echo density; minimum and maximum gap).5. Link colinear track segments into single tracks. This involves projecting the first track segmentforward and the second segment backward and linking them into one track if the ping gap ≤20 pings andthe two segments line up and meet a track link criteria.6. Write out track statistics (echo statistics optional).2.11

2.12SystemandChannelDataBlockSize(pings)Max.Range(m)Table 2.5. Autotracking Software Settings Used to Process Trail Bridge Dam in 2004 and 2005Min.Range(m)StructureThresholdRangeNoise(cm)VerticalGateSize(cm)DK-MaxAlphaLinkGate(cm)LinkDKMax(pings)Max.Echo orTargetStrength(dB)Min.Echo orTargetStrength(dB)NoiseLevelRange toStartBottomDetect(cm)BottomCountThresholdBottomAmplitudeThreshold(dB)T00 (a) 2000 9 1 0.08 0.2 0.03 4 0.4 0.12 20 -26 -56 6 36 0.3 -25.99T01 (b) 2000 9 1 0.08 0.2 0.03 4 0.4 0.12 20 -26 -56 6 36 0.3 -25.99T02 (c) 2000 6 1 0.08 0.2 0.03 4 0.4 0.18 20 -26 -56 6 36 0.3 -25.99T03 (d) 2000 6 1 0.08 0.2 0.03 4 0.4 0.18 20 -26 -56 6 36 0.3 -25.99(a) T00 = the in-turbine down-looking transducer.(b) T01 = in-turbine up-looking transducer.(c) T02 = SE spillway transducer.(c) T03 = NW spillway transducer.Hydroacoustic Evaluation of Fish Passage Through Trail Bridge Dam (2004-2005)

Hydroacoustic Evaluation of Fish Passage Through Trail Bridge Dam (2004-2005)To evaluate and fine-tune the autotracker and develop post-processing filters for eliminating falsetraces from the autotracker’s output, we reviewed samples of its performance for every deployment on atrack-by-track basis. We released the autotracker to process data for a given deployment only after wedetermined that it was missing few of the echo patterns that we would have tracked manually. Wemanually tracked 33 hours of data from in-turbine transducers and 7 hours of data from spillwaytransducers and found highly significant correlations between manual tracker counts and filteredautotracker counts (Figure 2.9). We pooled data for the two in-turbine transducers because there werefew counts higher than 1/hr. Data from spillway transducers were treated separately, but correlation lineshad slopes that did not differ significantly.4TurbineManual Count / Hour321y = xr 2 = 1; n = 66 Hoursn = 1n = 1n = 12n = 5200 1 2 3 4Autotracker Count / Hour60SpillwayManual Count / Hour50403020SE Half of SpillwayNW Half of Spillwayy = 0.9325xr 2 = 0.98; n = 7 Hours10y = 0.9601xr 2 = 0.99; n = 7 Hours00 10 20 30 40 50 60Autotracker Count / HourFigure 2.9.Correlations of Manual Tracker Counts with Autotracker Counts for TransducerDeployments at Trail Bridge Dam2.13

Hydroacoustic Evaluation of Fish Passage Through Trail Bridge Dam (2004-2005)2.8 Processing Echograms ManuallyManual tracking is done using software that displays echograms, which are images of all echoes thatexceed the voltage threshold by range from the transducer on the y axis and through time on the x axis(e.g., Figure 2.10). Echograms presented in Figures 2.10 through 2.22 illustrate many features such as aflat series of echoes from structure, sloped echo traces, tracked echo traces, selected traces showing a boxwith an x-y “barrel” view of echo movement across the beam, selected traces with a box with tracestatistics that are available from the manual and autotracker software, and noise events caused by airentrained in vortexes. These echograms all have the following characteristics in common:1. Echograms are created, displayed, and processed using proprietary Battelle software.2. Time is labeled in pings from 0 to 300 in the white horizontal bar across the top. At 30 pings/secused for sampling at Trail Bridge Dam, each screen displays 10 seconds of data.3. Range in meters is displayed from the thin white horizontal bar across the bottom of the echogram upto the white horizontal bar that displays pings across the top. It may be labeled in 1-m increments orjust at the 5-m increment, which also is indicated by the + sign inside the image.4. Echo colors vary depending on echo strength, and the color range is dark blue (about -54 dB), lightblue (about -50 dB), light green (about -46 dB), dark green (about -40 dB), yellow (-33 dB), orange (-31 dB), and red (-26 dB).5. A user may page through files and screens, zoom in or out, display an x-y barrel view of a selectedarea, or display echo-trace statistics using the control buttons at the bottom left.6. The status bar at the bottom of the window displays statistics for the last location pointed to with themouse, including ping number, range, echo strength (if mouse is over an echo), progress (filesprocessed out of files opened), channel number, section, time, and screen number within a file.7. The status bar at the right presents statistics for the last echo that the mouse cursor was over.In Figure 2.10, which displays a typical echogram from the in-turbine up-looking transducer, highamplitudered echoes begin to occur at about 7.94 m of range and are from the intake ceiling. Just belowthe intake ceiling, from about 7.94 m down to about 6.90 m, there is a gradation of structural echoes thatare orange, yellow, green, light blue, and blue. These result from acoustic shading and multipath echoesas the sound wave front encounters the curved ceiling of the circular intake. The first structure of thecurved ceiling is detected at the edges of the 12-degree acoustic beam at about 6.97 m, and thus echostrengths are lower than echo strengths from structure detected at subsequently greater ranges that areincreasingly closer to the center of the 12-degree acoustic beam. In contrast, the ceiling of the intake at7.91 m is on the center axis of the beam and yields the highest echo strength. Figure 2.8 shows the falloffof echo strength with increasing angle off the main axis of the acoustic beam. Low-amplitude echoesfrom structure also are evident between about 2.8 and 3.4 m of range (Figure 2.10), but these were shortof the minimum tracking range of 4.6 m for the up-looking beam sampling the upper half of the intake.The down-looking transducer inside the Trail Bridge Dam intake began detecting the structure of thecircular intake on the edges of the 12-degree beam at about 7.60 m of range from the transducer(Figure 2.11). Structural echoes from 7.60 m to about 8.53 m were of increasing strength as structures2.14

Hydroacoustic Evaluation of Fish Passage Through Trail Bridge Dam (2004-2005)Figure 2.10. Image of an Echogram from the Up-Looking In-Turbine Transducer at Trail Bridge Dam.The axes display time in pings across the top (ping rate was 30/sec) and range in metersupward along the right side.Figure 2.11. Echogram from the Down-Looking In-Turbine Transducer at Trail Bridge Dam. The axesdisplay time in pings across the top and range in meters along the right side.detected at greater ranges were nearer to the center of the acoustic beam than those at shorter range. Thesurface of the circular intake perpendicular to the main axis of the acoustic beam returned a stronger echothan surfaces detected at glancing angles > 90 degrees. The range from 1 to 7.6 m was free fromstructural echoes, but tracking was limited to the bottom half of the intake at ranges >5.5 m.2.15

Hydroacoustic Evaluation of Fish Passage Through Trail Bridge Dam (2004-2005)The down-looking transducers deployed at the Trail Bridge Dam spillway began detecting the ogee atabout 5.6 m of range from the transducer (Figures 2.12 and 2.13). The range from 1 to 5.6 m was freefrom structural echoes on both transducers.Figure 2.12. Echogram from the Down-Looking Spillway Transducer Sampling the Southeast Half ofthe Spillway at Trail Bridge Dam. The axes display time in pings across the top and rangein meters upward along the right side.Figure 2.13. Echogram from the Northwest Down-Looking Spillway Transducer at Trail Bridge Dam.The axes display time in pings across the top and range in meters upward along the rightside.2.16

Hydroacoustic Evaluation of Fish Passage Through Trail Bridge Dam (2004-2005)When fish pass through one of the acoustic beams, successive echoes form linear echo traces(Figure 2.14) that are easily tracked manually or with an autotracking program. In most cases, traces haveslopes that clearly distinguish them from flat structural echoes. An echo trace can be selected by drawinga box around it with the mouse cursor to either display the x-y view down the acoustic beam (Figure 2.15)or trace statistics (Figures 2.16 and 2.17).Figure 2.14. Echogram from the Down-Looking Transducer Sampling the Southeast Half of theSpillway at Trail Bridge Dam. Three traces composed of colinear sequences of echoes arevisible between 0 and 100 pings and 3 and 4 m of range.Figure 2.15. Echogram from the Down-Looking Transducer Sampling the Northwest Half of theSpillway at Trail Bridge Dam. One trace composed of 28 colinear echoes is visible insidethe box formed with a white dashed line. The x-y display box on the lower right shows thebarrel view of the trace in the beam and that the direction of travel across the beam wasdownward toward the curved tainter gate. Statistics for this trace include an estimate of x-y azimuth direction of travel of about 185 degrees.2.17

Hydroacoustic Evaluation of Fish Passage Through Trail Bridge Dam (2004-2005)Figure 2.16. Echogram from the Down-Looking Transducer Sampling the Turbine at Trail Bridge Dam.One trace composed of 22 colinear echoes is visible inside the box formed with a whitedashed line. Statistics for the traces are displayed in the Track ID box on the lower left.Figure 2.17. Echogram from the Down-Looking Transducer Sampling the Turbine at Trail Bridge Dam.One trace composed of 20 colinear echoes is visible at short range where the acoustic beamis only about 0.47 m in diameter.2.18

Hydroacoustic Evaluation of Fish Passage Through Trail Bridge Dam (2004-2005)When an echo trace is tracked manually or automatically, echoes are highlighted in white (e.g., seeFigures 2.18 through 2.20) and all trace statistics are written to a file so they can be analyzed later alongwith those for all other traces to develop filters for eliminated non-fish traces or evaluate detectability.Figure 2.18. Echogram from the Down-Looking Transducer Sampling the Turbine at Trail Bridge DamShowing a Tracked Echo Trace with Echoes Highlighted in White and Trace StatisticsDisplayed in the Track ID BoxFigure 2.19. Echogram From the Up-Looking Transducer Sampling the Turbine at Trail Bridge DamShowing Two Tracked Echo Traces with Echoes Highlighted in White2.19

Hydroacoustic Evaluation of Fish Passage Through Trail Bridge Dam (2004-2005)Figure 2.20. Echogram from the Down-Looking Transducer Sampling the Southeast Half of theSpillway at Trail Bridge Dam Showing Nine Tracked Echo Traces with Individual EchoesHighlighted in WhiteTracking echo traces is challenging when an echogram has scattered echoes from noise events such asa bubble-shedding vortex, which occurred occasionally at the Trail Bridge spillway (e.g., Figure 2.21) andturbine intake. The application of filters to exclude traces associated with noise events is critical. Figure2.22 shows the same echogram as Figure 2.21 after applying a noise identification routine. GrayedFigure 2.21. Echogram from the Down-Looking Transducer Sampling the Southeast Half of theSpillway at Trail Bridge Dam Showing Echoes from Entrained Air Associated with aVortex2.20

Hydroacoustic Evaluation of Fish Passage Through Trail Bridge Dam (2004-2005)Figure 2.22. Same Echogram as Figure 2.21 After Noise Processing, Tracking, and Filtering. Grayechoes were classified as noise, tracked traces were highlighted in green or white; greenindicates traces that were tracked but filtered out and white indicates an unfiltered trace.echoes in Figure 2.22 were classified as noise, and filters were applied to exclude as many noiseassociatedtraces as possible. Unfiltered traces are highlighted in white and filtered traces in green.Estimates of fish passage from hydroacoustics and netting like those presented by Ploskey and Carlson(1999) are most highly correlated when noise events are identified and excluded from processing or areheavily filtered.2.9 Filtering to Eliminate Poor Echo TracesPoor echo traces are those that are outside the range of interest, from intermittent structural echoesthat occur 0.5% within any1-m range strata from 4 to 6.99 m on the intake down- and up-looking transducers and > 4 m at eitherspillway transducer. All hours with dropped samples had sufficient samples remaining with which toestimate passage and its variance.2.21

Hydroacoustic Evaluation of Fish Passage Through Trail Bridge Dam (2004-2005)Table 2.6.Definitions of Variables Used for Filtering Echo Traces Selected by Autotracking SoftwareParameterDefinitionMux_Channel Corresponds to a single transducer attached to one specific echosounder channel.First_PingThe absolute ping number for the first echo in a series of echoes forming an echo trace.Last_PingThe absolute ping number for the last echo in a series of echoes forming an echo trace.Last_Ping/Group_Size is the total number of pings in an echo trace.Group_Size Describes the number of transducers sampled simultaneously (1=slow multiplex; 2=fast).Linearity1Mean cm deviation of echoes from line fit through a series of echoes forming a trace.Linearity2Mean cm deviation of echoes from parabola fit through a series of echoes forming a trace.Number of noise echoes in a window around an echo trace. The window began five pingsNoise_Count_Average before the first echo and ended five pings after the last echo in the trace and was ± 0.5 m inrange.Slope(last range - first range)/(last relative ping - first relative ping)First_Range The ranges of the first echoes in an echo trace.Last_Range The ranges of the last echoes in an echo trace.Echo_Count Number of echoes in a track.Noise_Index Noise Sum/Track echo countNoise_Count_ Average Count of noise echoes/count of track echoesXY_Azimuth Azimuth direction of travel where 90 and 270 degrees define a line plane perpendicular tothe upstream-downstream direction, so angles > 90 and =8.69) OR(Last_Range >=8.69) OR(LAST_RANGE > 7 AND Track_Type = 1) OR(Echo_Count = 4 AND ((Linearity1 / Echo_Count) > 0.25)) OR(Echo_Count = 5 AND ((Linearity1 / Echo_Count) >= 0.34)) OR((Echo_Count = 6 OR Echo_Count = 7) AND ((Linearity1 / Echo_Count) >= 0.38)) OR((Linearity2 / Echo_Count) > 0.4) OR(Noise_Count_Average >= 3) OREcho_Count < 6) THEN DELETE;END;IF MUX_CHANNEL=1 THEN DO;IF (((First_Range + Last_Range)/2 < 4.6) OR(First_Range >=7.69) OR(Last_Range >= 7.69) OR(LAST_RANGE > 5 AND Track_Type = 1) OR(Echo_Count = 4 AND ((Linearity1 / Echo_Count) > 0.25)) OR(Echo_Count = 5 AND ((Linearity1 / Echo_Count) >= 0.34)) OR((Echo_Count = 6 OR Echo_Count = 7) AND ((Linearity1 / Echo_Count) >= 0.38)) OR((Linearity2 / Echo_Count) > 0.4) OR(Noise_Count_Average >= 3) OREcho_Count < 6) THEN DELETE;END;2.22

Hydroacoustic Evaluation of Fish Passage Through Trail Bridge Dam (2004-2005)Table 2.7. (contd)IF MUX_CHANNEL=2 THEN DO;IF ((LAST_RANGE < 4) OR(FIRST_RANGE > 5.60 OR LAST_RANGE > 5.60) OR(LAST_RANGE < 4.5 AND SLOPE < 0.35) OR(Echo_Count = 4 AND ((linearity1 / Echo_Count) > 0.25)) OR(Echo_Count = 5 AND ((Linearity1 / Echo_Count) >= 0.34)) OR(Echo_Count = 4 AND (ECHO_COUNT / ((LAST_PING / GROUP_SIZE + 1) - (FIRST_Ping / GROUP_SIZE)) < 0.8)) OR(Echo_Count = 5 and (ECHO_COUNT / ((LAST_PING / GROUP_SIZE + 1) - (FIRST_Ping / GROUP_SIZE)) < 0.7)) OR((Echo_Count= 6 OR Echo_Count = 7) AND (Linearity1 / Echo_Count >= 0.3)) OR(Echo_Count < 7 AND (((Noise_Count_Average) / ((Echo_Count + 12) * 18)) > 0.005)) OR(Echo_Count >=7 AND (((Noise_Count_Average) / ((Echo_Count + 12) * 18)) > 0.008)) OR(Noise_Count_Average >= 3) OR(Linearity2 / Echo_Count > 0.4) OR(XY_Azimuth =270) OREcho_Count < 6 OR(Track_Type = 1)) THEN DELETE;END;IF MUX_CHANNEL=3 THEN DO;IF ((LAST_RANGE < 4) OR(FIRST_RANGE > 5.55 OR LAST_RANGE > 5.55) OR(LAST_RANGE < 4.5 AND SLOPE < 0.35) OR(Echo_Count = 4 AND ((linearity1 / Echo_Count) > 0.25)) OR(Echo_Count = 5 AND ((Linearity1 / Echo_Count) >= 0.34)) OR(Echo_Count = 4 AND (ECHO_COUNT / ((LAST_PING / GROUP_SIZE + 1) - (FIRST_Ping / GROUP_SIZE)) < 0.8)) OR(Echo_Count = 5 and (ECHO_COUNT / ((LAST_PING / GROUP_SIZE + 1) - (FIRST_Ping / GROUP_SIZE)) < 0.7)) OR((Echo_Count= 6 OR Echo_Count = 7) AND (Linearity1 / Echo_Count >= 0.3)) OR(Echo_Count < 7 AND (((Noise_Count_Average) / ((Echo_Count + 12) * 18)) > 0.005)) OR(Echo_Count >=7 AND (((Noise_Count_Average) / ((Echo_Count + 12) * 18)) > 0.008)) OR(Noise_Count_Average >= 3) OR(Linearity2 / Echo_Count > 0.4) OR(XY_Azimuth =270) OREcho_Count < 6 OR(Track_Type = 1)) THEN DELETE;END;(a) Mux_channel = 0 = in-turbine down-looking transducer.(b) Mux_channel = 1 = in-turbine up-looking transducer.(c) Mux_channel = 2 = SE spillway transducer.(d) Mux_channel = 3 = NW spillway transducer.2.10 Filtering to Eliminate Non-Fish Echo TracesAfter filtering to eliminate poor echo traces, we were conservative in accepting echo traces as fishbecause a meaningful index to fish passage must have a lot more fish than non-fish. Hydroacousticsampling at Trail Bridge Dam was a challenge because the small reservoir provided relatively few fish tobe entrained relative to the potential number of non-fish targets. Hydroacoustic sampling works bestwhen the number of fish passing by a given route is very high. For example, the number of juvenilesalmonids passing Bonneville Dam on the Columbia River is >20 million in each migration season. Tohave a meaningful index to fish passage for Trail Bridge Dam, we needed to eliminate a high proportionof non-fish targets from samples, and the speed of targets proved to be a useful discriminator.We arbitrarily assigned a probability to every echo trace based on its speed relative to the medianspeed of the smallest targets detected (Figure 2.23), and we retained only traces with a “fish probability”>90%. The smallest detected targets (< -50 dB or < 72 mm in equivalent fish length) could either be2.23

Hydroacoustic Evaluation of Fish Passage Through Trail Bridge Dam (2004-2005)1.11.0Fish Probability0.90.80.70.60.50.40.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0Relative SpeedFigure 2.23. Arbitrarily Assigned Probabilities That a Target Was a Fish as a Function of RelativeSpeed (m/s). Relative speed was calculated as target speed divided by the median speed ofthe smallest targets (< -50 dB or about 72 mm fish-equivalent length), which had limitedswimming capability (the smallest fish) or none (debris or bubbles).non-fish targets moving the same speed as the entraining flow or could be small fish moving about thespeed of flow because of limited swimming capability. We eliminated traces moving faster than 50% ofthe median speed of the smallest targets (< -50 dB). We chose 50% of the median speed of small targetsafter plotting the frequency of target speeds for two groups of targets—small targets < -50 dB and largetargets > -50 dB (Figure 2.24). Plots revealed that below about 50% of the median speed, the large-targetgroup had a relatively high frequency of slow-moving targets that was noticeably absent from the smalltargetgroup. However, the frequency of targets moving faster than the median speed of small targets wassimilar for both groups (Figure 2.24). Underwater video revealed that nearly 100% of fish swept into theturbine intake were oriented upstream and swimming against the flow and therefore were moving slowerthan the water surrounding them.We assigned a “fish probability” of 100% whenever the mean echo count exceeded the maximumexpected echo count for target moving through the center of the beam. Mean echo count is anotherindicator of speed that is independent of the phase information used to calculate target speed, when weassume that targets moved through the center of the acoustic beam. Basically, any trace that had morethan the maximum expected number of echoes at a given range was moving too slow to be anything but afish. This assignment kept fish that might have been excluded based solely upon speed, which can beinaccurate if phase data were corrupt. The SAS code used to define the maximum expected number ofechoes per trace and to assign a fish probability is in Table 2.8.2.24

Hydroacoustic Evaluation of Fish Passage Through Trail Bridge Dam (2004-2005)Proportion of DetectionsProportion of DetectionsProportion of Detections0.300.250.200.150.100.050.000.200.150.100.050.000.350.300.250.200.150.100.050.00< -50 dB> -50 dB0 0.3 0.6 0.9 1.2 1.5Speed (m / s)< -50 dB> -50 dB0 0.3 0.6 0.9 1.2 1.5 1.8 2.1Speed (m / s)> -50 dB< -50 dB0 0.3 0.6 0.9 1.2 1.5 1.8Speed (m / s)Figure 2.24. Proportion of Detections of Targets < -50 dB and ≥ -50 dB as a Function of Speed ofMovement Through Acoustic Beams. From top to bottom the plots are for the downlookingtransducer, the up-looking transducer, and the spillway transducers, respectively.2.25

Hydroacoustic Evaluation of Fish Passage Through Trail Bridge Dam (2004-2005)Table 2.8.SAS Code for Defining Echo Traces as Fish Because They Had more than MaximumNumber of Echoes Expected at a Given Range. Maximum expected number was based onregression equations for targets moving through the center of the acoustic beam (greatestdiameter) at a given range for each transducer. The last line of code assigns the probabilityused to keep the observation (a,b,c,d).IF A TARGET HAS MORE THAN THE MAXIMUM NUMBER OF ECHOES AT RANGE THEN IT IS A FISHREGARDLESS OF SPEED OR XY PHASE FIT;IF MUX_CHANNEL=0 THEN DO;MAX_ECHO_COUNT=-0.1667*MID_RANGE**2 + 5.2889*MID_RANGE + 5.6242;END;IF MUX_CHANNEL=1 THEN DO;MAX_ECHO_COUNT=-0.432*MID_RANGE**2 + 7.7319*MID_RANGE + 2.2987;END;IF MUX_CHANNEL=2 THEN DO;MAX_ECHO_COUNT=0.6049*MID_RANGE**3 - 7.1177*MID_RANGE**2 + 25.27*MID_RANGE - 4.9556;END;IF MUX_CHANNEL=3 THEN DO;MAX_ECHO_COUNT=0.5732*MID_RANGE**3 - 6.8725*MID_RANGE**2 + 25.075*MID_RANGE - 6.5229;END;IF ECHO_COUNT GT MAX_ECHO_COUNT THEN PROB_FISH=1;(a) Mux_channel = 0 = in-turbine down-looking transducer.(b) Mux_channel = 1 = in-turbine up-looking transducer.(c) Mux_channel = 2 = SE spillway transducer.(d) Mux_channel = 3 = NW spillway transducer..The median speed of small targets was calculated differently for the spillway and turbine. For thespillway, median speed was either the hourly median if at least 10 targets were detected and the differencein the hourly and daily median was 75% of the median speed of small targets5. Removal of traces moving >50% of the median speed of small targets.We plotted target-passage estimates by passage route, length class, and filter to illustrate filter effects(see Figures 3.16 and 3.17). Other than those two figures, all figures and tables in this report were basedon data remaining after the application of Filter 5 above. We chose to use Filter 5 for several reasons.2.26

Hydroacoustic Evaluation of Fish Passage Through Trail Bridge Dam (2004-2005)Speed (m / s)2.01.81.61.41.21.00.80.6y = 0.12x + 0.0473r 2 = 0.50574-5 m0.40.20.00 2 4 6 8 10MWSpeed (m / s)2.05-6 m1.8y = 0.149x + 0.07661.6r 2 = 0.64521.41.21.00.80.60.40.20.00 2 4 6 8 10MWSpeed (m / s)2.01.81.61.41.21.00.80.60.40.20.0y = 0.152x + 0.1061r 2 = 0.54876-7 m0 2 4 6 8 10MWFigure 2.25. Regression Plots of the Speed of Small Targets (< -50 dB) as a Function of Megawatts(MW) of Power Generated for Each of Three 1-m Range Strata (individual plots) from theDown-Looking Hydroacoustic Beam Inside the Trail Bridge Turbine IntakeFirst, the proportion of slow-moving, targets > -50 dB was high relative to the proportion of small(< -50 dB) targets when speed was < 50% of the median speed of the small targets (Figure 2.24). Inaddition, the proportion of large fast-moving targets was similar to that of small fast-moving targets.Second, nearly 100% of the fish observed passing through the trash racks and into the turbine intakein underwater video recordings were swimming against the flow and therefore would have been movingslower than the water and entrained non-fish objects. Third, passage estimates based on Filter 5 were themost reasonable relative to the size of the fishery resource, as indicated by conventional fish samplingmethods. For an index to fish passage to be of value for describing seasonal, diel, vertical, and routespecifictrends, it must contain more fish than non-fish targets, which is why a strong filter was absolutelycritical for Trail Bridge Dam. As an index to fish passage, the estimates should accurately indicatetemporal and spatial trends, although they may not estimate the magnitude of fish passage accurately.Errors in speed estimates based upon acoustic phase data make it very probable that not all non-fishtargets were eliminated by Filter 5, and it is also likely that Filter 5 eliminated some fish that were notactively swimming when they were detected.2.27

Hydroacoustic Evaluation of Fish Passage Through Trail Bridge Dam (2004-2005)Speed (m / s)2.01.81.61.41.21.00.84-5 my = 0.1387x + 0.0426r 2 = 0.70850.60.40.20.00 2 4 6 8 10MWSpeed (m / s)2.05-6 m1.8y = 0.1217x + 0.07341.6r 2 = 0.57861.41.21.00.80.60.40.20.00 2 4 6 8 10MWSpeed (m / s)2.06-7 m1.8y = 0.1061x + 0.1031.6r 2 = 0.39011.41.21.00.80.60.40.20.00 2 4 6 8 10MWFigure 2.26. Regression Plots of the Speed of Small Targets (< -50 dB) as a Function of PowerGenerated (MW) for Each of Three 1-m Range Strata (individual plots) from the Up-Looking Hydroacoustic Beam Inside the Trail Bridge Turbine Intake2.11 Dam Operations DataHourly estimates of forebay elevation and MW of power generated by the turbine were obtained fromStillwater Sciences. We explored possible effects of dam operations on diel and seasonal trends inpassage by regressing hourly estimates of passage on MW and forebay elevation. Significantrelationships would illustrate effects as well as the amount of unexplained variation.2.12 Missing DataFor forebay elevation, we estimated missing values by interpolating estimates by hour of the day fromnon-missing hours on the day before and the day after. This approach preserved the distinctive dielpattern in forebay elevation better than simply averaging estimates before and after one to four missinghours of data. For MW data, we averaged non-missing data from one hour before and one hour after amissing estimate, two hours before and after two missing estimates, and so on up to six consecutivemissing hours. The range in estimates over 24 hours usually was

Hydroacoustic Evaluation of Fish Passage Through Trail Bridge Dam (2004-2005)data were downloaded and cleaned off the drive. Downloads were conducted every 3-4 days; when thehard drive was full the last several hours of data were missed. These hourly estimates were interpolatedby simple averaging for less than five hours and by among-day linear interpolation by hour of the day forperiods longer than 5 hours. There was only one failure of hydroacoustic equipment during the study. Inearly 2005, the echo sounder malfunctioned when a circuit board failed, and the system did not samplecorrectly for several days until it was repaired. Hours of spill made up only 5.8% of the hours of study,and the remaining 94.2% were assigned missing values instead of zeros to indicate that no spill passagesamples were collected. This approach ensured that mean and median hourly rates of spill passage wouldnot be biased by a preponderance of zeros in the dataset. Every hour the turbine was shut down wasassigned a zero for fish passage so that fish detected in the intake by the continuously sampling hydroacousticgear would not be incorrectly counted. The assignment of zeros for the hours the turbine was offdid not overly bias mean and median estimates of hourly passage because off hours were rare.2.13 Fish Passage MetricsWe estimated project spill passage efficiency, or the percent of fish passing the dam by non-turbineroutes for every hour in which spill passage was not missing using the following equation:⎡Sˆ⎤SPE = FPE =⎣ ⎦⎡ T + Sˆ⎤⎣ ⎦× 100 (4)where SPE = spill passage efficiency, FPE = fish passage efficiency, T = sum of fish passage throughthe turbine, and Ŝ = sum of fish passage through the spillway. The variance of SPE was estimated bywhere ( ) ( ) ( T )⎡( 22 Var SˆVarVar SPE ) = SPE ( 1− SPE)⎢ +⎢ ˆ 2S T⎣Var S is the variance in fish passage through the spillway, and Var T is the variance in fishpassage through the turbine on an hourly, daily, weekly, monthly, or annual basis (after Skalski et al.1996). Estimates of spill passage efficiency for any periods other than those concurrent with turbineoperation are biased by the proportion of spill and turbine operations and discharge. For example, spillpassage efficiency for 38- to 100-mm fish was 51.5% for the entire study, but the spillway was open only6.2% of the hours of >3.2 MW turbine operation. Spill passage efficiency would have been higher if thespillway ran more or the turbine ran less.Spill passage effectiveness, SPS , was calculated as SPESPS =PSwhere SPE is spill passage efficiency, as defined above, and PS is percent spill.2⎤⎥⎥⎦( )(5)2.29

Hydroacoustic Evaluation of Fish Passage Through Trail Bridge Dam (2004-2005)3.0 Results3.1 Noise FrequencyFew one-minute samples were dropped because noise was >0.5% within any 1-m range stratasampled, but eliminating such samples removed a lot of false targets from noise. The percent of samplesunaffected by these criteria was very high: 99.96% of intake down-looker, 99.90% of intake up-looker,96.5% of SE spillway, and 99.5% of NW spillway samples had noise densities < 0.5% at ranges ofinterest (Figures 3.1 and 3.2).Cumulative Frequency (%)100.0099.9999.9899.9799.9699.9599.9499.9399.9299.9199.90100.0099.9999.9899.9799.9699.9599.9499.9399.9299.9199.90Turbine Intake Down-lookerR = 1-1.99 mR = 2.00-2.99R = 3.00-3.99R = 4.00-4.99R = 5.00-5.99R = 6.00-6.99R = 7.00-7.990 5 10 15 20Turbine Intake Up-lookerR = 1.00-1.99R = 2.00-2.99R = 3.00-3.99R = 4.00-4.99R = 5.00-5.99R = 6.00-6.990 5 10 15 20Noise Density (%)Figure 3.1.Plot of Average Percent Noise per Hour over all Range Strata Sampled by Two In-TurbineTransducers. Percent Noise Was Calculated as Number of Noise Echoes Divided by theNumber of Possible Noise Echoes; noise density >0.5% from 4 to 6.99 m was used to dropone-minute samples.3.1

Hydroacoustic Evaluation of Fish Passage Through Trail Bridge Dam (2004-2005)Cumulative Frequency (%)100.0099.0098.0097.0096.0095.0094.0093.0092.0091.0090.00100.0099.0098.0097.0096.0095.0094.0093.0092.0091.0090.00SE Half of SpillwayR = 2.00-2.99R = 3.00-3.99R = 4.00-4.99R = 5.00-5.990 5 10 15 20NE Half of SpillwayR = 2.00-2.99R = 3.00-3.99R = 4.00-4.99R = 5.00-5.990 5 10 15 20Noise Density (%)Figure 3.2.Plot of Average Percent Noise per Hour over all Range Strata Sampled by Two SpillwayTransducers. Percent Noise per Stratum Was Calculated as the Number of Noise EchoesDivided by the Number of Possible Noise Echoes; noise density >0.5% from 4 to 5.99 mwas used to drop one-minute samples.3.2 DetectabilityWe modeled detectability by the length class of targets because there were greater differences inmean target strength among length classes than there were among seasons (Figure 3.3). Average targetstrengths were near -49 dB for fish ≤ 100 mm long, -43 dB for fish >100 to 200 mm long, -38 dB for fish>200 to 350 mm, and -33 dB for fish >350 mm long.Plots of effective-beam angle versus range from each of the four transducers are presented inFigures 3.4 through 3.7. Effective beam angle generally increases with target size, but the greatestincrease was between length groups (LG) 1 and 2. For the target tracking range, effective beam anglesnear or exceeding the nominal beam angle are considered adequate, as was the case for all length groupsof targets. In the figures, LG 1 = 38–100, LG 2 = >100–200, LG 3 = >200–350, and LG 4 = >350 mm.3.2

Hydroacoustic Evaluation of Fish Passage Through Trail Bridge Dam (2004-2005)-26Trail Bridge TurbineMean Target Strength (dB)-32-38-44-50-56SPRINGSUMMERAUTUMNWINTERSPRINGSPRINGSUMMERAUTUMNWINTERSPRINGSPRINGSUMMERAUTUMNWINTERSPRINGSPRINGSUMMERAUTUMNWINTERSPRING100-200mm>200-350mm>200-350mm>200-350mm>200-350mm>200-350mm> 350mm> 350mm> 350mm> 350mm> 350mmSeason (2004-2005) and Length Class-20Trail Bridge SpillwayMean Target Strength (dB)-26-32-38-44-50-56SPRINGSUMMERAUTUMNWINTERSPRINGSPRINGSUMMERAUTUMNWINTERSPRINGSUMMERAUTUMNWINTERSPRINGSUMMERAUTUMNWINTERSPRING100-200mm>200-350mm>200-350mm>200-350mm>200-350mm> 350mm> 350mm> 350mm> 350mmSeason (2004-2005) and Length ClassFigure 3.3.Mean Target Strength (dB || µ1 Pa at 1 m) of Filtered Detections at the Trail Bridge DamTurbine and Spillway by Season and Associated Length Classes. Vertical bars indicate80% confidence limits about the means.The number of echoes per trace is an empirical indication of the adequacy of detectability. For alltargets detected in the intake, 98% had > 10 echoes, 95% had >30 echoes, 75% had >40, and 50% had>50 (Figure 3.8). Less than 1% was eliminated by the six-echo minimum filter that was required duringprocessing. For the spillway, 98% of targets detected had > 19 echoes, 95% had >20, 75% had > 37, and50% had >48 (Figure 3.8). These empirical results clearly indicate that detectability was not limitinginside the turbine intake or at the spillway, as was the number of echoes on targets detected at short range.For example, see the 12-echo trace detected at 2.8 m by a spillway transducer (Figure 3.9), a 20-echo3.3

Hydroacoustic Evaluation of Fish Passage Through Trail Bridge Dam (2004-2005)Figure 3.4.Plots of Effective Beam Angle (EBA) as a Function of Integer of Target Range from theUp-Looking Transducer Inside the Turbine Intake. Targets were tracked at ranges >4.6 .Figure 3.5.Plots of EBA as a Function of Target Range from the Down-Looking Transducer Insidethe Turbine Intake. Targets were tracked at ranges >5.5 m.3.4

Hydroacoustic Evaluation of Fish Passage Through Trail Bridge Dam (2004-2005)Figure 3.6.Plots of EBA as a Function of Target Range from the Transducer Sampling the NW Halfof the Spillway. Targets were tracked at ranges >4 m.Figure 3.7.Plots of EBA as a Function of Target Range from the Transducer Sampling the NW Halfof the Spillway. Targets were tracked at ranges > 4 m.3.5

Hydroacoustic Evaluation of Fish Passage Through Trail Bridge Dam (2004-2005)1009080Cumulative Percent7060504030In-turbine DownlookerIn-Turbine UplookerSE Half of SpillwayNW Half of Spillway201000 50 100 150 200 250Number of Echoes per TraceFigure 3.8.Plot of the Percent Cumulative Frequency of the Number of Echoes per TraceFigure 3.9.Echogram from the Down-Looking Transducer Sampling the Southeast Half of theSpillway at Trail Bridge Dam. One trace composed of colinear sequences of 12 echoesis visible at about ping 190 and range 2.8 m.3.6

Hydroacoustic Evaluation of Fish Passage Through Trail Bridge Dam (2004-2005)trace detected at 2.22 m by the down-looking, in-turbine transducer (Figure 3.10), and the 15-echo tracetracked at 2.12 m by the up-looking transducer in the turbine (Figure 3.11). All of these detections wereat ranges shorter than the minimum tracking range where acoustic beams were quite narrow.Figure 3.10. Echogram from the Down-Looking Transducer Sampling the Turbine at Trail Bridge Dam.One trace composed of 20 colinear echoes is visible at short range where the acoustic beamis only about 0.47 m in diameter.Figure 3.11. Echogram Showing a Short Range Trace Detected by the Up-Looking Transducer in theTurbine Intake. The trace has 15 colinear echoes and a midrange of 2.12 m, as indicated inthe trace statistics box, where the beam diameter is only about 0.45 m wide.3.7

Hydroacoustic Evaluation of Fish Passage Through Trail Bridge Dam (2004-2005)A plot of target strength distributions for the entire study clearly indicates that the -56-dB on-axisthreshold used for acquiring data at Trail Bridge Dam was sufficiently low so that small fish were notmissed (Figure 3.12). The number of targets with -55 dB mean target strengths was near zero at alllocations, and the median was about -49 dB. There were more large targets (> -40 dB) detected at thespillway than there were in the turbine intake.Turbine Intake Down-lookerSE Half of Spillway1212101088Percent64Percent642200-60 -55 -50 -45 -40 -35 -30 -25Target Strength (dB)-60 -55 -50 -45 -40 -35 -30 -25Target Strength (dB)Turbine Intake Up-lookerNW Half of Spillway1212101088Percent64Percent642200-60 -55 -50 -45 -40 -35 -30 -25Target Strength (dB)-60 -55 -50 -45 -40 -35 -30 -25Target Strength (dB)Figure 3.12. Plots of the Distribution of Target Strengths for the Turbine Intake (left) and the Spillway(right) of Trail Bridge Dam3.3 Direction of TravelWithin hydroacoustics sample volumes, over 98% of targets were moving in a downstream direction(Figure 3.13), and any that were moving upstream were eliminated by an azimuth direction filter thatexcluded targets with headings less than 90 degrees or greater than 270 degrees.3.4 Dam OperationsDam operations data for the Trail Bridge Project indicated that pool elevation varied about 6 to 7 ftover most diel cycles and that power generation (MW) varied more among than within days, ranging from0 to about 9 MW overall (Figure 3.14). The common operating range was about 4 to 7 MW. Dischargebelow Trail Bridge Dam had seasonal peaks in spring and winter (Figure 3.15), closely paralleling thetrend in MW (Figure 3.14). In the typical diel cycle, minimum elevations were reached around 0600hours and were about 6 ft lower than maximum elevations at 2200 hours (Figure 3.16). Thus the poolusually was declining between 2200 and 0600 hours and rising or stable between 0600 and 2200 hours.3.8

Hydroacoustic Evaluation of Fish Passage Through Trail Bridge Dam (2004-2005)Turbine Down-lookerTurbine Up-looker20 10 20330 340350 3030 330 340350320 1540320250020 10 20 2530320 330340350330 3403501540 320 2031050310153001060300290280270260250240230220507080901001101201301402902802702602502402302201050210150210200190 170160200190180180Spillway NWSpillway SE00310503102030010603001529028027026025024023022021020019050180708090100110120130140150160170290280270260250240230220210200190105018010 20 3040506070809010011012013014015016017010 20 30405060708090100110120130140150160170252520Turbine Down-looker20Turbine Up-looker15151010Percent of Targets5025200306090120150Spillway NW1802102402703003305025200306090120150Spillway SE18021024027030033015151010550003060901201501802102402703003300306090120150180210240270300330Azimuth Direction (Degrees)Figure 3.13. Radial and Standard Frequency Distribution Plots of the Azimuth Direction of Travel(degrees) for Each of the Transducers Sampling at Trail Bridge Dam. Headings greaterthan 90 and less than 270 degrees were in a downstream direction.3.9

Hydroacoustic Evaluation of Fish Passage Through Trail Bridge Dam (2004-2005)Figure 3.14. Plot of Forebay Elevation and MW of Power Generated During the Period of Study at TrailBridge Dam2500Discharge (ft 3 /sec)200015001000500McKenzie RiverTrail Bridge Spillway05/04 6/04 7/04 8/04 9/04 10/04 11/04 12/04 1/05 2/05 3/05 4/05 5/05Date (Month / Year)Figure 3.15. Discharge from the McKenzie River Below Trail Bridge Dam and from the Trail BridgeSpillway During the Study3.10

Hydroacoustic Evaluation of Fish Passage Through Trail Bridge Dam (2004-2005)2,090Julian Day 144-145 Julian Day 145-1462,0882,086Elevation (ft)2,0842,0822,0802,07812 14 16 18 20 22 0 2 4 6 8 10HourFigure 3.16. Forebay Elevation from 1200 Hours on May 23 Through 1100 Hours on May 25, 20043.5 Effects of Speed FiltersStrong filtering on target speed was necessary to ensure that observed temporal and spatial trendswere meaningful for fish, but it relegated the magnitude of passage estimates to a relative index that wasnot quantitative. Trends in seasonal and diel passage, as described in the next section, were based ontrace-detection data remaining (Table 3.1) after application of the strongest speed filter to eliminate asmany non-fish targets as possible. The strongest filter produced an estimate of total project passage(44,867) that was about 28.7% of the unfiltered estimate (155,983). Remaining detection data yielded anoverall spill passage efficiency estimate of 49% for the 38 to 100-mm length class, which made up 58%of detections at the turbine and 64% of spillway detections (Table 3.1). Spill passage efficiency waslowest (38%) for the >100–200 mm length class, which made up 33% of turbine and 24% of spillwaydetections. The highest efficiencies (53 and 57%) were for the >200–350 mm length class, which madeup 8 to 10% of all detections and the >350 mm class, which made up 1 to 2% of all detections (Table 3.1).The effect of various speed filters on the number of detections in four size classes is illustrated in Figure3.17 for the turbine and in Figure 3.18 for the spillway. Without filtering on target speed, the annualpassage estimate for the turbine was very high (>95,000), but filtering on the speed of hydroacoustictargets reduced the totals to 23,979, which was 25% of unfiltered estimates (Figure 3.17). Most targetswere less than 100 mm long, and numbers in this length class were most reduced by filtering. Unfilteredannual estimates for the spillway also were very high (59,941), although spill only occurred during about5.9% of study hours. At the spillway, speed filters also had the greatest relative effect on targets less than100 mm long. The strongest speed filter reduced the total for all length classes to about 20,897, or about35% of unfiltered estimates (Figure 3.18).3.11

Hydroacoustic Evaluation of Fish Passage Through Trail Bridge Dam (2004-2005)Table 3.1.Project Spill Passage Efficiency (or fish-passage efficiency), Turbine Intake Detections,Spill Passage Detections, and Total Detections During a One-Year Hydroacoustic StudyBased on Filtering Targets Moving >50% of the Median Speed of Small Targets(350 57 5.6 359 70.6 1 480 139 2 839Total 47 2.9 23,978 1168.8 20,898 1562 44,876Number of Fish70,00060,00050,00040,00030,000Effect of Speed Filters onTurbine-Intake PassageNo Filter+- 15% of Median Speed+- 25% of Median Speed> 75% of Median Speed> 50% of Medain SpeedTotalsbyFilter96,04253,11644,11835,80623,97920,00010,000038-100 mm 100-200 mm 200-350 mm >350 mmLength Class (mm)Figure 3.17. Estimated Annual Passage in Each of Four Length Classes by Severity of Filtering onTarget Speed. Filters indicate targets that were removed. Vertical error bars are 80%confidence intervals.3.6 Trends in Passage After Filtering3.6.1 Turbine Intake Passage3.6.1.1 Seasonal TrendsMost passage through the Trail Bridge turbine intake occurred from November through February,according to weekly estimates of numbers (Figure 3.19), mean hourly rates (Figures 3.20 and 3.21), andmedian hourly rates (Figures 3.22). There was a high day-to-day variation in passage and rates ofpassage, particularly in the fall and winter months when passage was highest. Passage and rates of3.12

Hydroacoustic Evaluation of Fish Passage Through Trail Bridge Dam (2004-2005)50,000Effect of Speed Filters onSpillway PassageNumber of Fish40,00030,00020,000No Filter+- 15% of Median Speed+- 25% of Median Speed> 75% of Median Speed> 50% of Median SpeedTotalsbyFilter59,94143,33438,53535,53420,89710,000038-100 mm 100-200 mm 200-350 mm >350 mmLength Class (mm)Figure 3.18. Estimated Annual Passage in Each of Four Length Classes by Severity of Filtering onTarget Speed. Vertical error bars are 80% confidence intervals.Figure 3.19. Hydroacoustic Estimates of Filtered Detections Through the Turbine from May 11, 2004Through May 17, 2005 by Length Class and Week (x axis within plots). Vertical bars are80% confidence limits.3.13

Hydroacoustic Evaluation of Fish Passage Through Trail Bridge Dam (2004-2005)Figure 3.20. Hydroacoustic Estimates of Mean Hourly Rate of Passage Through the Turbine fromMay 11, 2004 Through May 17, 2005 by Length Class and Week (x axis within plots).Vertical bars are 80% confidence limits.5.04.5Turbine IntakeMean Hourly Rate4.03.53.02.52.01.51.038-100 mm>100-200 mm>200-350 mm>350 mm0.50.0May-Oct Nov-Feb Mar-MayTime FrameFigure 3.21. Hydroacoustic Estimates of Median Hourly Rate of Passage Through the Turbine fromMay 11, 2004 Through May 17, 2005 by Length Class and Week (x axis within plots).Vertical bars are 80% confidence limits.3.14

Hydroacoustic Evaluation of Fish Passage Through Trail Bridge Dam (2004-2005)passage were highest for the smallest length class and lower for successively larger length classes. Oftotal numbers detected, 58% were 38 to 100 mm long, 33% were >100 to 200 mm, 8% were >200 to350 mm, and 1% were larger than 350 mm. For three length classes, mean hourly rates of passage werelower before November 2004 and after February 2005 than they were from in the fall and winter period(Figures 3.20 and 3.21). Median hourly estimates were much lower than mean hourly estimates, andhourly medians were zero before November and after February for all length classes (Figure 3.22).Figure 3.22. Hydroacoustic Estimates of Median Hourly Rate of Passage Through the Turbine fromMay 11, 2004 Through May 17, 2005 by Length Class and Week (x axis within plots).Vertical bars are 80% confidence limits.3.6.1.2 Diel TrendsWe found that the highest mean hourly rates of detection were at night and in the morning and thatthere was a decline in the hourly rate from about 0100 through 2100 hours (Figure 3.22). The trend wasmost evident for the two smaller size classes, which made up 91% of the detections (Figure 3.23).The mean hourly rate of detection was weakly and inversely correlated with mean hourly forebayelevation, with elevation explaining about 21% of the variation in detection rate (Figure 3.25). However,an examination of the hourly trends reveals the rate of detection was high from 0200 through 1100 hourswhen elevation was first declining for 5 consecutive hours and then increasing for four consecutive hours(Figure 3.26).3.15

Hydroacoustic Evaluation of Fish Passage Through Trail Bridge Dam (2004-2005)4.0TurbineMean Number / Hour3.53.02.52.01.50 1 2 3 4 5 6 7 8 9 101112131415161718192021222324Hour of the DayFigure 3.23. Estimated Mean Hourly Rate of Detections of All Length Classes of Targets by Hour ofDay for the Trail Bridge Turbine Intake Based on Sampling from May 11, 2004 ThroughMay 17, 2005. The line is a 2-hour moving average.Figure 3.24. Hydroacoustic Estimates of Mean Number of Detections per Hour Through Turbine Intakefrom May 11, 2004 Through May 17, 2005 by Length Class and Hour of Day (x axiswithin plots).3.16

Hydroacoustic Evaluation of Fish Passage Through Trail Bridge Dam (2004-2005)4.54.0y = -0.2364x + 495.38r 2 = 0.213.5Mean Hourly Rate3.02.52.01.51.00.50.02081 2082 2083 2084 2085 2086Elevation (ft)Figure 3.25. Regression of the Mean Hourly Rate of Passage of 38- to 100-mm Fish Through theTurbine Intake on Mean Hourly Forebay Elevation4.52,0864.02,0853.5Mean Hourly Rate3.02.52.01.51.00.5TargetsElevation2,0842,0832,0822,0812,080Elevation (ft)0.01 2 3 4 5 6 7 8 9 1011121314151617181920212223242,079HourFigure 3.26. Diel Pattern in Mean Forebay Elevation and the Mean Hourly Rate of Passage of 38- to100-mm Fish Through the Turbine Intake3.6.1.3 Vertical Distribution of PassageMost hydroacoustic detections were above the centerline of the circular penstock opening in turbineintake, and vertical distribution patterns were similar each season (Figure 3.27). All detections weremade 10.5 to 15 ft downstream of intake trash racks (Figure 2.3). The peak in distributions was two feetabove the center line near elevation 2,028 ft every season. Eighty percent of detections were made inautumn and winter (see the inset in Figure 3.27).3.17

Hydroacoustic Evaluation of Fish Passage Through Trail Bridge Dam (2004-2005)2,0342,0322,030WinterAutumnSpringSummerElevation (ft)2,0282,0262,0242,0222,020%50.040.030.020.010.00.0Spring Summer Autumn WinterSeason2,0180 5 10 15 20 25 30 35 40 45Percent of DetectionsFigure 3.27. Percent Vertical Distribution of All Sizes of Targets Detected Passing Inside the TurbineIntake. The heavy line at 2026 ft elevation is the center line of the 15-ft-diameter penstockopening downstream of the trash racks.3.6.2 Spillway Passage3.6.2.1 Seasonal TrendsDaily and hourly rates of passage through the spillway were highly variable, higher than passage ratesthrough the turbine intake, and positively related to spill durations (Figures 3.28 through 3.29). The datado not suggest a strong dominance of passage in fall and winter, as was observed in the turbine, but spillwas not sampled often or long enough for confidence about seasonal trends in passage. We intentionallydid not connect estimates for different days of spill with lines to illustrate patterns because spill was notsampled often or long enough for confidence about seasonal trends. Seasonal patterns were highlydependent on the frequency, timing, and duration of spill events. The number of spill hours per dayexplained 61% of the variation in the number of detections per day.3.6.2.2 Lateral DistributionWhen differences in the expanded estimates of passage were indicated by non-overlapping 80%confidence limits, passage usually was higher through the southeast half of the spillway than it wasthrough the northwest half (Figure 3.30). The largest differences occurred during June and July 2004.The highest passage occurred during 11 days of continuous spill during June 2004. There were nosignificant differences in passage between spillway locations for fish greater than 350 mm long becauseof low numbers and high variability. These data were not plotted.3.18

Hydroacoustic Evaluation of Fish Passage Through Trail Bridge Dam (2004-2005)Figure 3.28. Hydroacoustic Estimates of Passage Through the Spillway from May 11, 2004 ThroughMay 17, 2005 by Length Class and Day (x axis within plots). Error bars are 80%confidence limits.Figure 3.29. Hydroacoustic Estimates of the Mean Hourly Rate of Passage Through the Spillway fromMay 11, 2004 Through May 17, 2005 by Length Class and Day (x axis within plots). Errorbars are 80% confidence limits.3.19

Hydroacoustic Evaluation of Fish Passage Through Trail Bridge Dam (2004-2005)14,00012,00010,0008,0006,0004,0002,00038-100 mmSpillwaySE HalfNW HalfExpanded Number of Fish03,0002,5002,0001,5001,000500080070060050040030020010005 6 7 8 9 10 11 12 1 2 3 4 5100-200 mmSE HalfNW Half5 6 7 8 9 10 11 12 1 2 3 4 5200-350 mmSE HalfNW Half5 6 7 8 9 10 11 12 1 2 3 4 5Month in 2004-05Figure 3.30. Paired Hydroacoustic Estimates of Passage Through the SE and NW Halves of theSpillway by Month for Three Length Classes of Targets. Error bars are 80%confidence intervals.3.6.2.3 Diel TrendsThe mean hourly number of detections was clearly higher during the day than at night for all lengthclasses pooled (Figure 3.31) and for individual length classes (Figure 3.32). For the two smallest lengthclasses, there also appeared to be a brief, minor peak around sunset. Unlike the mean hourly rate, the dielpattern in the sum of spillway passage was dependent upon the frequency, timing, and duration of spillevents. The observed for the number of hours of spill operations was higher during the day than it was atnight, and hours of spill explained 54% of the variation in the hourly sum of detections at the spillway.3.20

Hydroacoustic Evaluation of Fish Passage Through Trail Bridge Dam (2004-2005)76Percent of Detections5432100 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23HourFigure 3.31. Hydroacoustic Estimates of Mean Hourly Rate of All Filtered Detections at the Spillwayfrom May 11, 2004 Through May 17, 2005 versus Hour of Day. The fitted line is a 2-hourmoving average.Figure 3.32. Hydroacoustic Estimates of Mean Hourly Rate of Filtered Hydroacoustic DetectionsThrough the Spillway from May 11, 2004 Through May 17, 2005 by Length Class andHour of Day (x axis within plots). Error bars are standard error of the mean estimate.3.6.3 Spill Passage EfficiencySpill passage efficiency and fish-passage efficiency are identical for Trail Bridge Dam because thespillway is the only non-turbine route of passage. For the entire one-year study, spill passage efficiencywas 51.5% for fish 100 mm or less, 41.5% for fish from 100 to 200 mm, 55% for fish 200 to 350 mm, and58.3% for fish longer than 350 mm, even though the project spilled water about 6% of the time. Spillpassage efficiency had the potential to be high when turbine passage was low (e.g., May–October) and the3.21

Hydroacoustic Evaluation of Fish Passage Through Trail Bridge Dam (2004-2005)project spilled water in June, July, and September (Figure 3.32). Spill passage efficiency was zero inAugust and February when there was no spill, and in May 2005 spill was not sampled when transducerswere removed from the turbine. Hourly spill passage efficiency during simultaneous turbine and spillwayoperation was 100% 96% of the time because hourly spillway detections were more frequent than hourlyturbine detections, but when it was less than 100% it was weakly correlated with the hour of the day(Figure 3.33).100Spill Passage Efficiency (%)908070605040302038-100 mm>100-200 mm>200-350 mm>350 mm1005 6 7 8 9 10 11 12 1 2 3 4 5MonthFigure 3.33. Hydroacoustic Estimates of the Spill Passage Efficiency by Month (x axis) and LengthClass (four bar shadings). Error bars are 80% confidence limits.10090y = 1.1243x + 43.137r 2 = 0.14Spill Passage Efficiency (%)807060504030201000 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23Hour of the DayFigure 3.34. Hydroacoustic Estimates of the Spill Passage Efficiency by Date and Length Class Basedon Hours when Detections were Greater than 0 for both routes (i.e., simultaneousoperations during part or all of each hour). Error bars are 80% confidence limits.3.6.4 Spill Passage EffectivenessSpill passage effectiveness is the ratio of the proportion of fish to the proportion of water spilled. Itranged from 4.5 to 20.1 among seasons and was 9.6 ± 0.2 for the year.3.22

Hydroacoustic Evaluation of Fish Passage Through Trail Bridge Dam (2004-2005)Spill Passage Effectiveness302520151050AUTUMN SPRING SUMMER WINTERSeasonFigure 3.35. Hydroacoustic Estimates of Spill Passage Effectiveness by Season. The annual estimatefor May 2004 to May 2005 is indicated by the horizontal line at 9.6. Line thicknessillustrates the ± 80% confidence limit of 0.2. Bars show estimates by season; error bars are± 80% confidence limits.3.6.5 AppendixesTemporally and spatially expanded counts of filtered detections are in Appendix A, mean hourly ratesof detection are in Appendix B, and median hourly rates are in Appendix C. All data were filtered toexclude targets moving >50% of the median speed of the smallest targets to eliminate as many non-fishtargets as possible and provide meaningful spatial temporal trends in fish passage. As such, themagnitude of passage estimates is a relative index to fish passage and not a quantitative measure.Appendixes include many tables with filtered detection data for four length classes of targets by year,month, and week.3.23

Hydroacoustic Evaluation of Fish Passage Through Trail Bridge Dam (2004-2005)4.0 Discussion4.1 Passage Estimates4.1.1 Effect of Filters on the Magnitude of PassageThe hydroacoustic estimates of fish passage in this report represent a relative index rather than anabsolute estimate because of very intensive filtering to eliminate targets moving >50% of the speed offlow, as indexed by the median speed of the smallest targets. Eliminated targets were mostly non-fishdebris moving about the same speed as the flow but likely included small fish with limited swimmingability (e.g., 38–50 mm long), and some larger fish that were not swimming against the flow. Underwatervideo at intake trash racks revealed that nearly 100% of the fish swam against entraining flows as theypassed into the intake and therefore were moving slower than the water around them. The number ofdetections remaining after filtering on target speed at the turbine entrance (Figures 3.17 and 3.18) wasmost sensitive to the initial filter (±15% of median speed) than it was to successively stronger filters (e.g.,±25% of median speed, >75%, and >50%). For the spillway, the initial filter (± 15% of median speed)and the final filter had the most impact on the number of detections remaining. Filtering reduced passageestimates for small targets more than it did for large targets. Not only are small targets much moreabundant than large targets, but they also tend to include a much higher proportion of non-fish targets.Strong filtering of non-fish targets ensured that observed temporal and spatial trends would be meaningfulfor fish. The strongest speed filter reduced unfiltered passage estimates for the spillway and turbine fromabout 156,000 to about 45,000 per year, with about 24,000 detected inside the turbine intake.With no speed filter or weak filters, we had to question high annual passage estimates that likelyexceeded the number of fish in Trail Bridge Reservoir and especially the very high rates of passage in falland winter. At all levels of filtering (Figures 3.17 and 3.18), the number of hydroacoustic detections atthe turbine was 6 to 10 times higher in fall and winter than it was in spring and summer. The >75% ofmedian speed filter, for example, produced an annual passage estimate of 71,340 and a turbine estimate of35,800 per year, with two-thirds of passage occurring in fall and winter. The high annual estimates madeus question the appropriateness of hydroacoustic sampling of the turbine entrance in fall and winter.With the strongest speed filter, we had to conclude that seasonal trends were the result of fish passagebecause few non-fish targets could survive such a stringent filter. We only retained targets with estimatedspeeds 50%-of-median-speed filter was applied we noticed that thefrequency of traces with high echo counts increased dramatically (Figure 3.8), and this could only happenif targets were moving slower and staying in the hydroacoustic beams longer. After the filter, only 5% ofin-turbine targets had fewer than 30 echoes. We also noticed that spillway passage did not have a strongseasonal bias favoring fall and winter (Figures 3.28 and 3.29). If leaf litter detections were a problem, wewould have expected the most detections in fall and winter at both turbine and spillway locations. Third,passage estimates of 45,000 per year with 24,000 through the turbine began to seem reasonable relative tothe size of the potential fishery resource in Trail Bridge Reservoir.Based on conventional fish-sampling methods, Stillwater Sciences estimated that there were about50,000 chinook salmon fry and 75 bull trout larger than 150 mm in the reservoir. There also should be4.1

Hydroacoustic Evaluation of Fish Passage Through Trail Bridge Dam (2004-2005)bull trout smaller than 150 mm and probably other species of fish as well. According to the schedules for2004 and 2005, the Oregon Department of Fish and Wildlife stocked about 8,000 trout during the study.There also should have been some trout from the previous year and some moving down from Smith andCarmen Reservoirs, but it is doubtful that these numbers would double the number of trout in thereservoir. A liberal summing of these estimates would suggest that the population of fish could be65,000.We also made other estimates of the number of fish that might inhabit Trail Bridge reservoir (46,500to 61,246) by multiplying the volume or area of Trail Bridge Reservoir by the density estimates obtainedin mobile hydroacoustic surveys in forebay areas of two lower Columbia River dams. The maximumdensity of fish detected in the forebay of The Dalles Dam during mobile hydroacoustic surveys was about20 fish per 1,000 m 3 of water sampled (Faber et al. 2005), and there was about 2,324.4 x 10 3 m 3 of waterin Trail Bridge Reservoir at maximum pool elevation (2087.5 ft). The product of this maximum densityestimate and maximum volume is about 46,500 fish. The average density of fish in mobile surveys ofBonneville Dam forebay areas was about 0.24 fish / m 2 , respectively (Ploskey et al. 1998), and at anaverage pool elevation of 2,084 ft at Trail Bridge Dam, there is about 255,191 m 2 of water. The productof the mean densities and the mean surface area would be 61,246 fish.Clearly, we did not eliminate all false targets during processing. If the number of fish available forpassage was 47,000, as suggested by densities of fish at The Dalles Dam, then our passage estimate of45,000 would indicate that most of the fish left the reservoir over a one-year period, and that seems veryunlikely. If the population was about 65,000, as suggested by conventional sampling methods andaverage densities per m 2 in Bonneville Dam forebay areas, 47,000 detections would represent 72% of thepopulation, which also would make our passage estimates seem high.The challenge in applying hydroacoustic methods to sample fish passage at Trail Bridge Dam was infiltering acquired data to eliminate as many non-fish targets as possible without filtering fish. Hydroacousticsampling is most effective for indexing fish passage when the number of fish passing is high andless effective when fish passage is low. The numbers of fish available for passage at Trail BridgeReservoir was very small relative to numbers typically sampled at Columbia River Dams, where morethan 20 million juvenile salmonids are known to pass through each migration season, particularly atdownstream projects like Bonneville Dam.4.1.2 Effects of Expansion on Passage Estimates for Fish >200 mmPassage estimates for the two larger size classes in this study likely were overestimated by a factor of10 for several reasons. First, speed filtering is not as effective on large debris as it is on small pointscatterers of sound. Second, large fish with strong swimming ability can be detected multiple timesbefore actually passing, while fish < 200 mm usually are detected only once. Third, assumptionsunderlying spatial and temporal expansions are not as appropriate for large fish as they are for small fish.These expansions work for small targets that are more likely to be randomly distributed in time and spacethan large ones. In contrast, large targets pass rarely and yet have a much higher probability of beingdetected than small targets because of their size. Nevertheless, counts of large targets were dutifullyexpanded just like those of the small targets. For example, the count of one large fish detected in thecenter of the up-looking beam inside the turbine intake at a range of 5 m was expanded by a factor of4.2

Hydroacoustic Evaluation of Fish Passage Through Trail Bridge Dam (2004-2005)three (i.e., the ratio of the diameter of the circular opening to the acoustic beam diameter). Thisexpansion assumes that targets are randomly distributed across the opening. The assumption of a randomdistribution is much better for a small fish than for large fish, which have greater ability to detect andavoid walls. The same fish that was expanded to a count of three next is expanded by another factor of 3(to 9 fish) because the transducer sampled only one-third of the time. This temporal expansion assumesthat fish passage is random throughout an hour, an assumption that is much more appropriate for smallfish than for large fish, whose passage likely is sporadic and rare. Alternative methods for expandingdetections of large targets at turbines and spillways have not yet been developed by researchers usinghydroacoustic methods. However, the distribution of fish across a hydroacoustic beam is used forspatially expanding counts of adult salmonids in side-looking riverine deployments (Ploskey et al. 2001).Dividing annual passage estimates for the two largest length classes by 10 would reduce the total annualpassage estimate by 9 to 12%, which was the contribution of those length classes to total number ofdetections. Revised estimates would be 40,614 (total), 22,040 (turbine), and 18574 (spillway).4.1.3 Effect of Location and Debris on Spillway Passage EstimatesPassage estimates were very high at the spillway relative to the turbine in all seasons, and some of thedifference may have resulted from false detections of debris at the spillway. During spill, flotsam usuallywas observed accumulating in the spillway area upstream of the tainter gate, especially on the southeastside. As these materials sank and passed under the gate, some would have been detected by the hydroacousticbeams. The number of detections by the acoustic beam sampling the southeast half of thespillway was 2.2 times higher than the number detected by the beam sampling the northwest half,suggesting that debris loading was still a problem even after the strongest target-speed filter was applied.Large debris like that accumulating on the southeast side of the spillway is difficult to filter based ontarget speed because phase information often is corrupt when targets are not small point scatterers ofsound. Hourly rates of passage through the northwest half of the spillway probably are more reasonablethan those for the southeast half. If we recalculate passage based upon twice the number of detections inthe NW beam, the spillway passage estimates would be reduced to 62.6% of the two-beam estimate(Table 4.2). The effect of a sampling-location adjustment would reduce estimates in Table 3.1 to 37,000per year (total), 23,979 (turbine), and 13,076 (spillway).4.1.4 Addressing Uncertainties in Passage EstimatesThe true magnitude of fish passage through Trail Bridge Dam is unknown, even though we cancalculate that the large-fish and spillway-location adjustments (Sections 4.12 and 4.13 above) wouldreduce annual passage estimates to 33,421 (total), 22,040 (turbine), and 11,381 (spillway). We simplycannot determine how many small, weak-swimming fish or larger non-swimming fish might haveTable 4.1.Comparison of Passage Estimates Through Trail Bridge Spillway Based on Sampling BothHalves Versus only NW Half, Which was Less Plagued by Debris Loading than SW HalfLength ClassTwo Beam EstimateSE and NWNW BeamEstimate x 238-100 mm 13,427 7,932100-200 mm 4,934 3,244200-350 mm 2057 1,566> 350 mm 480 334All 20,898 13,0764.3

Hydroacoustic Evaluation of Fish Passage Through Trail Bridge Dam (2004-2005)been eliminated by speed filtering or how much large debris was not eliminated because of inaccuratespeed estimates from non-point or multipoint scatterers of sound. Only simultaneous sampling withhydroacoustics and netting could conclusively resolve uncertainty about filter effects, and we do notrecommend such an expensive study. Only about 5% of the echo traces detected inside the turbine intakehad fewer than 30 echoes (see the strong inflection at 5% and 30 echoes in Figure 3.8), and this suggeststhat the speed filter was very effective at eliminating non-fish echoes from the turbine data. In contrast,30% of the echo traces detected at the spillway had fewer than 30 echoes, suggesting that either targetswere moving faster or the speed filter was less effective at the spillway than it was at the turbine. Thiswould suggest that the spillway adjustment described in Section 4.13 above may be appropriate.A DIDSON acoustic camera should be deployed for a few days at each location when water is beingpassed to resolve uncertainties about fish and debris. The DIDSON is a nonintrusive device that is notlimited by turbidity or light. The DIDSON was developed by the Applied Physics Laboratory (APL) atthe University of Washington (Belcher et al. 1999) for the Space and Naval Warfare Systems Centerharbor surveillance program. It operates at 1 or 1.8 MHz depending on whether range or resolution ismore important; and in the lower, longer range mode, it can receive echoes from objects out to 48 m. Inthe higher-frequency mode it can provide animated images of fish out to about 12 m. The DIDSON wasdesigned to bridge the gap between existing sonar, which can detect acoustic targets at long ranges butcannot record the shapes or sizes of targets, and optical systems, which can videotape fish in clear waterbut are limited at low light levels or turbidity. Images within about 18 m of the device are clear enoughthat undulating movements of fish and swimming direction can be discerned, and this would allow realtimediscrimination between fish and non-fish targets. Given the wide field of view (30 degreeshorizontal and 12 degrees vertical), the DIDSON could image most of the spillway gate or turbine intakeat Trail Bridge Dam.Having a good idea of the size of the fishery resource in Trail Bridge Reservoir would help put thehydroacoustic passage estimates into perspective. Several mobile hydroacoustic surveys using split-beamtransducers or a DIDSON could be conducted to estimate the density of fish in the reservoir. This wouldprovide a check on the estimated size of the fishery resource.4.2 Season TrendsAfter the strongest speed filter did not remove the fall and winter peaks in hydroacoustic detections,we concluded that fish passage was much higher in fall and winter than during spring and summer (seeFigures 3.19 - 3.22). Regardless of the filtering method (see Figures 3.17 and 3.18), fall and winterpassage was 6-10 times higher than passage in spring and summer. However, without filtering on targetspeed, or after the application of weaker speed filters, we could not be certain that peaks in fall and winterwere due to fish passage and not due to leaf litter. In deciduous forest areas, very large numbers of falsehydroacoustic targets can be contributed by leaf litter in fall and winter. In a year-round study of fishpassage through Richard B. Russell Dam on the Savannah River between Georgia and South Carolina,hydroacoustic sampling had to be abandoned for fall and early winter because very high hydroacousticcounts did not match fish catches in a full-recovery net (Ploskey et al. 1995). The single-beam transducersused in the Richard B. Russell study could not provide target-speed estimates, so there was noreliable way to discriminate between fish and debris.4.4

Hydroacoustic Evaluation of Fish Passage Through Trail Bridge Dam (2004-2005)For this Trail Bridge Dam study, split-beam transducers and the ability to estimate and filter on targetspeed allowed us to eliminate most targets that were moving >50% of the median speed of flow. Thispowerful debris filter was not perfect because speed estimates can be inaccurate for larger non-pointscatterers, but the strong speed filter did increase our confidence that the seasonal trends were producedby fish. With weak speed filters, we were more confident in annual passage estimates based on hourlyrates of passage in spring and summer than on the sum of detections throughout the year. In short, we hadto ignore high fall and winter rates to obtain reasonable estimates relative to the size of the fisheryresource in the reservoir. However, with the strongest speed filter, we believe the fall and winter rates ofpassage are reasonable because few non-fish targets could have remained in the filtered dataset.Dam operations and river discharge peaked in May and December 2004 and March, April, and May2005 (Figures 3.14 and 3.15), so hydrology did not explain the large number of false targets in the turbineintake in fall and winter. Vortices that occasionally form above the turbine intake and near the spillwaycan contribute false targets in the form of bubbles, but several factors strongly suggest that vortices werenot responsible for high passage estimates in fall and winter. First, there was a very weak correlationbetween passage indexes and dam operations data. Hourly estimates of MW and pool surface elevationexplained < 1% of the variation in hydroacoustic detections in a multiple-regression model. Second, anexamination showed that echo traces detected during the hours of highest passage were very rarelyassociated with noise events like vortices. Third, speed filters used in processing the data should havebeen nearly 100% effective for eliminating small point-source echoes from bubbles.4.3 Diel TrendsFor small targets, the hourly rate of pattern of higher passage through the turbine at night than duringthe day (Figures 3.23 and 3.24) was consistent with what has been observed at Bonneville Dam forturbines (e.g., Figure 4.1). Diel changes in forebay elevation explained only 21% of the diel variation inthe passage of small targets (Figure 3.25), leaving 79% to be explained by something else like fishbehavior. Higher nighttime passage seems to be common for deep passage routes.Diel variation in passage through the Trail Bridge Spillway, with higher passage during the day thanat night (Figure 3.30), was consistent with diel patterns of passage for surface bypass routes such as theBonneville Second Powerhouse sluiceway (Figure 4.2), which has a depth similar to that of the TrailBridge Dam spillway.4.4 Vertical Distribution in the Turbine IntakeVertical distributions of detections inside the turbine at Trail Bridge Dam were similar to those oftenreported for turbines on the lower Columbia River (compare Figure 3.27 with Figure 4.3). Given thedepth of most turbine intakes and relative shallow vertical distributions of fish at most locations, it is notsurprising that passage would be skewed upward.4.5 Spill Passage EfficiencySpill passage efficiency at Trail Bridge Dam depended upon the number of hours of turbineoperations versus spill operations and the relative rate of passage through each route. Spill and fishpassage efficiency are identical for Trail Bridge Dam because the spillway is the only non-turbine route of4.5

Hydroacoustic Evaluation of Fish Passage Through Trail Bridge Dam (2004-2005)600SpringGUIDEDUNGUIDED400Number / Hour2000600Summer40020008 10 12 14 16 18 20 22 0 2 4 6HourFigure 4.1.Diel Trends in Passage Above (guided) and Below (unguided) an Extended Length BarScreen at Intake 8B at Bonneville Dam in Spring and Summer 1998 (figure from Ploskeyet al. 2001)Figure 4.2.Diel Trends in the Number of Smolt-Sized Targets Passing into the 22-ft Deep CornerCollector at Bonneville Dam Second Powerhouse in Spring 2004 (Ploskey et al. 2005)4.6

Hydroacoustic Evaluation of Fish Passage Through Trail Bridge Dam (2004-2005)3525In-Turbine Elevation (ft)155-5SpringSummer-15Figure 4.3.-250 1 2 3 4 5 6 7PercentVertical Distribution of Smolt-Sized Targets Inside Modified Intake 15B for Spring andSummer 2001. Normal pool elevation is about 74 ft MSL (Ploskey et al. 2002).passage. The relatively high rate of passage through the spillway meant that just a few hours of operationwere required to achieve passage comparable to that of the turbine. For the entire one-year study, spillpassage efficiency was 51.5% for fish ≤100 mm, 41.5% for fish >100 to 200 mm, 55% for fish 200 to350 mm, and 58.3% for fish >350 mm, even though the project spilled water just 6% of the time (522hours). Even after reducing spillway estimates by the sampling location adjustment described inSection 4.1.3, spill passage efficiency was 35.3% for the year.During simultaneous spill and turbine operations, spill passage efficiencies < 100% were weaklycorrelated with the hour of the day (r 2 =0.14; Figure 3.33), which has implications for management. Therelationship results from differential diel patterns of passage at the spillway and turbine, with highestturbine passage at night and in the morning and highest spillway passage during the afternoon. Therefore,nighttime spill should provide higher spill passage efficiency than daytime spill, perhaps by attracting fishaway from the turbine intake when they are most likely to pass there. During most simultaneous turbineand spillway operation, hourly spill passage efficiency was 100%, because hourly spillway detectionswere more frequent than hourly turbine detections and turbine discharge was throttled back toaccommodate spill.Whether spill is desirable compensation for turbine passage at a project like Trail Bridge Damdepends on fishery management goals. If maintenance of the reservoir fishery is important, spilling maynot be desirable. In addition, assessing tradeoffs is difficult because the risk of injury during passage hasnot been established for either passage route.4.7

Hydroacoustic Evaluation of Fish Passage Through Trail Bridge Dam (2004-2005)4.6 Spill Passage EffectivenessSpill passage effectiveness, which is the proportion of fish relative to the proportion of water that isspilled, is highly affected by the frequency and duration of spill during any time frame of interest. On anannual scale, effectiveness was 9.6 because spill occurred during just 6% of the hours sampled, andseasonally, effectiveness ranged from 4.5 to 20.1. Seasonal and annual estimates for Trail Bridge Damwere similar to effectiveness estimates for surface flow outlets at Bonneville Dam (Figure 4.4) but muchhigher than Bonneville spill effectiveness, which ranged from 0.8 to 1 in 2004 (Ploskey et al. 2005).During the fish-passage season in 2004, 39 to 42% of flow was directed through the Bonneville spillway,and fish-passage efficiency was similar to the percent of water spilled. At Trail Bridge Dam, spilldischarge averaged just 5.5% of project flow, which was closer to the 3% of project flow passed bysurface flow outlets at Bonneville Dam than it was to the spill proportion at Bonneville Dam in 2004.Other similarities between the Trail-Bridge spillway and surface-flow outlets at Bonneville Dam includeproximity to a turbine and shallow depth. In contrast, spill bays at Bonneville Dam are 50 ft deep atnormal pool elevation and in a different forebay from the turbine intakes.Ratio (% Passage: % Flow)14121086420Project SluiceEffectiveness (B1+ B2CC)Project B1SluicewayEffectivenessProject B2CCSluicewayEffectivenessSpringSummerB1 Sluiceway B2CCEffectiveness Re: Effectiveness Re:B1B2Sluiceway MetricsFigure 4.4.Estimated Sluiceway Effectiveness for the Bonneville Project and Each Powerhouse forSpring and Summer 2004 (from Ploskey et al. 2005) (B1 = powerhouse 1; B2 =powerhouse 2; B2CC = B2 corner collector)4.8

Hydroacoustic Evaluation of Fish Passage Through Trail Bridge Dam (2004-2005)5.0 ReferencesBelcher EO, HQ Dinh, DC Lynn, and TJ Laughlin. September 1999. “Beam forming and imaging withacoustic lenses in small, high-frequency sonar.” Proceedings of Oceans ’99, Seattle, Washington.EWEB. March 2004. Fish entrainment: final study plan. Eugene Water and Electric Board, Eugene,Oregon.Faber DM, ME Hanks, SA Zimmerman, JR Skalski, and PW Dillingham. 2005. The distribution andflux of fish in the forebay of The Dalles Dam in 2003. PNNL-14628, prepared for the U.S. ArmyCorps of Engineers, Portland District, by Pacific Northwest National Laboratory, Richland,Washington.Love RH. 1977. “Target Strength of an Individual Fish at any Aspect.” Journal of the AcousticalSociety of America, 62(6):1397-1403.Ploskey GR and TJ Carlson. 1999. “Comparison of hydroacoustic and net estimates of fish guidanceefficiency of an extended submersible bar screen at John Day Dam.” North American Journal ofFisheries Management, 19: 1066-1079.Ploskey GR, G Weeks, S Scherck, C Shilt, P Johnson, and JM Nestler. 1995. Richard B. Russell PhaseII Completion Report: Impacts of two-unit pumpback operation. Prepared by the U. S. ArmyEngineer Waterways Experiment Station for the U. S. Army Engineer District, Savannah, Georgia.Ploskey GR, LR Lawrence, PN Johnson, WT Nagy, and MG Burczynski. 1998. HydroacousticEvaluations of Juvenile Salmonid Passage at Bonneville Dam including Surface-CollectionSimulations. EL-98-4, prepared for the U.S. Army Corps of Engineers, Portland District, by the U.S.Army Corps of Engineers Waterways Experiment Station, Vicksburg, Mississippi.Ploskey GR, DS Patterson, CR Schilt, and ME Hanks. 2000. Workshop on standardizing hydroacousticmethods of estimating fish passage for lower Columbia River dams. ERDC/EL SR-00-10, U.S. ArmyEngineer Research and Development Center, Vicksburg, Mississippi.Ploskey GR, WT Nagy, LR Lawrence, DS Patterson, CR Schilt, PN Johnson, and JR Skalski. 2001.Hydroacoustic Evaluation of Juvenile Salmonid Passage through Experimental Routes at BonnevilleDam in 1998. ERDC/EL TR-01-2, prepared for the U.S. Army Corps of Engineers, Portland District,by the U.S. Army Corps of Engineers Research and Development Center Environmental Laboratory,Vicksburg, Mississippi.Ploskey GR, CR Schilt, ME Hanks, PN Johnson, J Kim, JR Skalski, DS Patterson, WT Nagy, andLR Lawrence. 2002. Hydroacoustic Evaluation of Fish Passage Efficiency at Bonneville Dam in2001. PNNL-14047, prepared for the U.S. Army Corps of Engineers, Portland District, by PacificNorthwest National Laboratory, Richland, Washington.Ploskey GR, MA Weiland, CR Schilt, J Kim, PN Johnson, ME Hanks, DS Patterson, JR Skalski, andJ Hedgepeth. 2005. Hydroacoustic Evaluation of Fish Passage through Bonneville Dam in 2004.PNNL-15249, prepared for the U.S. Army Corps of Engineers, Portland District, by PacificNorthwest National Laboratory, Richland, Washington.5.1

Hydroacoustic Evaluation of Fish Passage Through Trail Bridge Dam (2004-2005)Skalski JR, GE Johnson, CM Sullivan, E Kudera, and MW Erho. 1996. “Statistical evaluation of turbinebypass efficiency at Wells Dam on the Columbia River, Washington.” Canadian Journal ofFisheries and Aquatic Sciences, 53:2188-2198.5.2

Appendix APassage Estimates Based on Filtering of TargetsMoving >50% of the Median Speed of theSmallest Detected Targets

Appendix APassage Estimates Based on Filtering of TargetsMoving >50% of the Median Speed of theSmallest Detected TargetsTable A.1. Passage of 38-100 mm, Slow-Moving Targets Through the Trail Bridge DamTurbine and Spillway from May 11, 2004 Through May 17, 2005. Estimates arefollowed by their respective 80% confidence limits.Length +- +- +-Class Project 80% Intake 80% Spill 80%mm FPE (%) CL Passage CL passage CL38-100 48.94 1.329 14007.4 447.9 13427.1 570.5>100-200 38.69 1.698 7818.6 299.0 4933.6 298.5>200-350 53.41 2.870 1793.7 133.6 2056.5 181.0>350 57.21 5.586 358.9 54.1 479.7 82.2A.1

Table A.2. Passage of 38-100 mm, Slow-Moving Targets Through the Trail Bridge Dam Turbine and Spillway by Month. First and last monthshad only 21 and 17 days, respectively. Lone decimals indicate missing values for spill in August, February, and May.Project +- +- Turbine +- Turbine +- +- Spill +- Spill +-FPE (%) 80% Turbine 80% Passage 80% Passage 80% Spillway 80% Passage 80% Passage 80%YEAR MONTH 38-100 mm CL Passage CL (W Half) CL (E Half) CL Passage CL (NW Half) CL (SE Half) CLA.22004 5 49.82 27.87 65.9 26.3 35.7 18.6 30.3 18.6 65.5 68.1 31.4 20.5 34.0 65.02004 6 99.04 0.362 84.2 31.7 19.2 14.2 64.9 28.3 8648.4 394.9 2364.0 207.6 6284.3 336.02004 7 88.10 2.564 281.0 61.9 115.6 33.0 165.4 52.3 2080.9 221.9 435.7 135.8 1645.2 175.52004 8 . . 287.8 58.2 126.9 36.0 160.9 45.8 . . . . . .2004 9 68.18 6.039 424.2 75.2 263.9 58.9 160.3 46.7 908.9 195.1 333.8 150.6 575.1 124.02004 10 9.56 11.85 543.6 77.9 311.6 54.9 231.9 55.3 57.5 78.3 43.1 32.0 14.4 71.52004 11 19.99 4.028 3225.7 224.8 1364.4 142.3 1861.3 174.0 806.0 195.0 342.4 139.0 463.6 136.82004 12 17.56 3.486 2638.7 192.9 875.4 101.4 1763.3 164.1 561.9 128.9 222.9 83.2 339.0 98.52005 1 3.06 2.010 2975.8 211.1 694.4 83.4 2281.4 193.9 94.1 63.3 69.3 57.0 24.8 27.52005 2 . . 2214.0 167.6 606.8 85.7 1607.2 144.0 . . . . . .2005 3 8.19 6.085 462.0 87.9 130.1 40.1 331.9 78.2 41.2 32.4 21.9 24.4 19.3 21.42005 4 17.71 9.913 756.8 106.5 269.5 53.4 487.3 92.1 162.9 108.4 101.1 77.5 61.8 75.82005 5 . . 47.9 23.2 8.3 8.7 39.5 21.5 . . . . . .

Table A.3.Passage of 100-200 mm, Slow-Moving Targets Through the Trail Bridge Dam Turbine and Spillway by Month. First and lastmonths had only 21 and 17 days, respectively. Lone decimals indicate missing values for spill in August, February, and May.Project +- +- Turbine +- Turbine +- +- Spill +- Spill +-FPE (%) 80% Turbine 80% Passage 80% Passage 80% Spillway 80% Passage 80% Passage 80%YEAR MONTH 100-200 mm CL Passage CL (W Half) CL (E Half) CL Passage CL (NW Half) CL (SE Half) CLA.32004 5 14.93 8.887 175.7 44.2 48.2 24.8 127.5 36.6 30.8 20.1 13.8 12.9 17.1 15.52004 6 95.43 1.320 111.9 32.8 16.0 9.7 95.9 31.3 2335.0 177.5 628.8 88.7 1706.2 153.82004 7 81.65 4.188 242.2 61.1 70.7 27.0 171.5 54.8 1077.5 129.5 294.9 73.9 782.7 106.32004 8 . . 196.0 57.0 95.6 34.3 100.5 45.5 . . . . . .2004 9 60.59 5.691 439.2 62.5 142.0 35.1 297.1 51.8 675.0 129.0 407.3 111.9 267.8 64.12004 10 9.06 6.313 299.3 52.8 226.9 42.6 72.4 31.2 29.8 22.2 0.0 0.0 29.8 22.22004 11 17.42 3.789 1848.4 147.4 758.6 87.8 1089.8 118.4 389.8 97.9 139.9 56.7 249.9 79.82004 12 11.34 3.511 1723.8 139.5 596.2 80.0 1127.6 114.3 220.4 74.9 62.0 40.6 158.4 62.92005 1 4.05 3.321 1323.8 115.8 456.8 65.5 866.9 95.5 55.8 47.5 39.6 43.9 16.2 18.02005 2 . . 954.4 108.4 309.6 57.2 644.8 92.0 . . . . . .2005 3 14.92 14.43 198.6 48.4 46.0 19.8 152.6 44.2 34.8 38.7 0.0 0.0 34.8 38.72005 4 24.55 15.03 259.9 58.4 105.6 38.6 154.3 43.7 84.6 66.0 36.0 28.3 48.5 59.62005 5 . . 45.3 24.2 0.0 0.0 45.3 24.2 . . . . . .

Table A.4.Passage of 200-350 mm, Slow-Moving Targets Through the Trail Bridge Dam Turbine and Spillway by Month. First and lastmonths had only 21 and 17 days, respectively. Lone decimals indicate missing values for spill in August, February, and May.Project +- +- Turbine +- Turbine +- +- Spill +- Spill +-FPE (%) 80% Turbine 80% Passage 80% Passage 80% Spillway 80% Passage 80% Passage 80%YEAR MONTH 200-350 mm CL Passage CL (W Half) CL (E Half) CL Passage CL (NW Half) CL (SE Half) CLA.42004 5 16.91 15.20 41.6 20.3 13.6 10.4 28.0 17.4 8.5 8.2 8.5 8.2 0.0 0.02004 6 99.10 0.938 5.1 5.4 5.1 5.4 0.0 0.0 565.9 75.8 197.8 41.2 368.1 63.62004 7 81.40 5.033 121.7 33.3 63.4 22.4 58.3 24.6 532.5 100.8 218.1 72.6 314.4 69.92004 8 . . 138.9 38.3 45.8 20.1 93.1 32.6 . . . . . .2004 9 89.71 3.400 65.5 21.8 50.0 18.4 15.6 11.6 571.3 91.0 265.2 63.5 306.1 65.22004 10 0.00 . 151.8 39.5 64.9 22.1 87.0 32.7 0.0 0.0 0.0 0.0 0.0 0.02004 11 35.64 7.532 462.0 67.3 86.4 27.0 375.5 61.7 255.8 75.3 78.2 45.6 177.6 59.92004 12 19.42 8.515 384.6 62.8 69.2 24.0 315.4 58.1 92.7 48.1 14.8 16.4 77.9 45.22005 1 7.81 8.172 180.1 42.5 61.9 23.0 118.2 35.8 15.3 16.9 0.0 0.0 15.3 16.92005 2 . . 129.2 36.9 60.4 23.9 68.7 28.2 . . . . . .2005 3 0.00 . 53.4 23.9 17.7 13.2 35.7 20.0 0.0 0.0 0.0 0.0 0.0 0.02005 4 19.56 18.60 59.9 24.4 14.7 10.9 45.2 21.8 14.6 16.2 0.0 0.0 14.6 16.22005 5 . . 0.0 0.0 0.0 0.0 0.0 0.0 . . . . . .

Table A.5.Passage of >350 mm, Slow-Moving Targets Through the Trail Bridge Dam Turbine and Spillway by Month. First and last monthshad only 21 and 17 days, respectively. Lone decimals indicate missing values for spill in August, February, and May.Project +- +- Turbine +- Turbine +- +- Spill +- Spill +-FPE (%) 80% Turbine 80% Passage 80% Passage 80% Spillway 80% Passage 80% Passage 80%YEAR MONTH >350 mm CL Passage CL (W Half) CL (E Half) CL Passage CL (NW Half) CL (SE Half) CLA.52004 5 . . 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.02004 6 100.0 . 0.0 0.0 0.0 0.0 0.0 0.0 98.6 28.7 15.1 9.7 83.4 27.12004 7 84.47 7.832 30.6 15.6 30.6 15.6 0.0 0.0 166.6 52.0 83.5 36.2 83.0 37.42004 8 . . 40.0 18.2 40.0 18.2 0.0 0.0 . . . . . .2004 9 78.32 9.668 34.2 16.4 34.2 16.4 0.0 0.0 123.6 37.8 39.5 22.9 84.1 30.02004 10 0.00 . 40.5 18.0 30.1 14.7 10.4 10.4 0.0 0.0 0.0 0.0 0.0 0.02004 11 50.11 15.07 76.9 24.5 28.2 15.0 48.8 19.5 77.3 39.5 15.2 16.9 62.1 35.72004 12 17.81 17.04 63.6 22.3 25.9 14.5 37.7 17.0 13.8 15.3 13.8 15.3 0.0 0.02005 1 0.00 . 20.9 14.5 12.4 9.2 8.5 11.3 0.0 0.0 0.0 0.0 0.0 0.02005 2 . . 24.5 15.0 10.7 9.8 13.9 11.4 . . . . . .2005 3 0.00 . 12.5 9.3 0.0 0.0 12.5 9.3 0.0 0.0 0.0 0.0 0.0 0.02005 4 0.00 . 13.3 11.0 9.7 8.9 3.6 6.6 0.0 0.0 0.0 0.0 0.0 0.02005 5 . . 1.7 3.6 1.7 3.6 0.0 0.0 . . . . . .

Table A.6. Passage of 38-100 mm, Slow-Moving Targets Through the Trail Bridge Dam Turbine andSpillway by Week. First and last weeks had only 5 and 3 days, respectively. Missingvalues are indicated by lone decimals.Week Project +- Intake +- Spill +-Beginning FPE 80% Passage 80% passage 80%Sunday 38-100 mm CL 38-100 mm CL 38-100 mm CL05/09/04 85.05 18.77 11.5 12.0 65.5 68.105/16/04 . . 45.0 21.2 . .05/23/04 . . 9.4 9.8 . .05/30/04 . . 0.0 0.0 . .06/06/04 0.00 . 8.0 8.4 0.0 0.006/13/04 . . 44.3 23.5 . .06/20/04 99.36 0.394 31.8 19.5 4911.2 318.306/27/04 100.0 . 0.0 0.0 5625.8 306.707/04/04 . . 89.6 40.9 . .07/11/04 91.24 7.288 18.5 13.9 192.4 99.207/18/04 . . 72.9 29.8 . .07/25/04 . . 100.0 32.8 . .08/01/04 . . 28.0 17.5 . .08/08/04 . . 90.6 34.2 . .08/15/04 . . 38.5 20.7 . .08/22/04 . . 61.8 26.6 . .08/29/04 . . 105.0 35.7 . .09/05/04 96.61 2.668 22.6 17.8 643.7 136.009/12/04 . . 57.7 28.3 . .09/19/04 76.60 11.74 81.0 31.5 265.2 139.909/26/04 . . 249.7 57.4 . .10/03/04 . . 194.9 48.4 . .10/10/04 . . 41.6 19.3 . .10/17/04 . . 102.3 36.6 . .10/24/04 26.78 27.18 157.1 39.5 57.5 78.310/31/04 . . 723.6 104.1 . .11/07/04 44.14 6.810 1019.8 135.8 806.0 195.011/14/04 . . 836.1 111.3 . .11/21/04 . . 375.9 73.2 . .11/28/04 . . 675.6 90.9 . .12/05/04 . . 446.3 74.9 . .12/12/04 57.88 7.354 408.8 80.1 561.9 128.912/19/04 . . 903.5 114.9 . .12/26/04 . . 624.8 103.4 . .01/02/05 . . 252.7 55.1 . .01/09/05 13.94 8.311 580.9 96.0 94.1 63.301/16/05 . . 959.6 115.9 . .01/23/05 . . 803.2 100.9 . .01/30/05 . . 1158.7 134.3 . .02/06/05 . . 912.9 104.7 . .02/13/05 . . 396.8 67.2 . .02/20/05 . . 0.0 0.0 . .02/27/05 10.30 10.68 191.1 61.6 21.9 24.403/06/05 . . 57.9 25.0 . .03/13/05 . . 22.9 17.3 . .03/20/05 . . 137.4 45.7 . .03/27/05 26.76 24.52 52.7 30.4 19.3 21.404/03/05 . . 0.0 0.0 . .04/10/05 23.40 12.34 533.1 94.0 162.9 108.404/17/05 . . 210.8 48.8 . .04/24/05 . . 12.8 11.0 . .05/01/05 . . 7.7 9.4 . .05/08/05 . . 21.6 16.1 . .05/15/05 . . 18.6 13.8 . .A.6

Table A.7. Passage of >100-200 mm, Slow-Moving Targets Through the Trail Bridge Dam Turbine andSpillway by Week. First and last weeks had only 5 and 3 days, respectively. Missingvalues are indicated by lone decimals.Week Project +- Intake +- Spill +-Beginning FPE 80% Passage 80% passage 80%Sunday 100-200 mm CL 100-200 mm CL 100-200 mm CL05/09/04 100.0 . 0.0 0.0 30.8 20.105/16/04 . . 106.0 35.4 . .05/23/04 . . 55.3 24.3 . .05/30/04 . . 51.0 20.5 . .06/06/04 0.00 . 43.5 21.6 0.0 0.006/13/04 . . 23.3 14.8 . .06/20/04 99.37 0.661 8.5 8.9 1328.4 139.606/27/04 99.17 0.617 14.6 10.8 1738.4 146.607/04/04 . . 39.6 27.4 . .07/11/04 91.53 5.230 32.0 20.1 345.8 85.407/18/04 . . 41.0 21.7 . .07/25/04 . . 115.0 44.7 . .08/01/04 . . 76.0 42.8 . .08/08/04 . . 27.5 21.9 . .08/15/04 . . 37.9 17.8 . .08/22/04 . . 13.9 10.3 . .08/29/04 . . 56.3 25.2 . .09/05/04 90.57 4.095 39.4 16.9 378.9 81.309/12/04 . . 39.5 16.9 . .09/19/04 58.33 9.849 211.5 47.2 296.1 100.209/26/04 . . 138.6 31.9 . .10/03/04 . . 89.9 26.8 . .10/10/04 . . 41.9 19.4 . .10/17/04 . . 58.9 23.4 . .10/24/04 25.26 15.59 88.3 31.4 29.8 22.210/31/04 . . 654.1 91.2 . .11/07/04 40.47 6.943 573.4 81.1 389.8 97.911/14/04 . . 436.4 68.4 . .11/21/04 . . 103.3 32.8 . .11/28/04 . . 206.5 49.0 . .12/05/04 . . 396.4 66.9 . .12/12/04 35.57 8.687 399.2 67.0 220.4 74.912/19/04 . . 566.1 80.5 . .12/26/04 . . 311.6 58.2 . .01/02/05 . . 208.0 47.1 . .01/09/05 17.21 12.43 268.4 51.4 55.8 47.501/16/05 . . 239.4 49.0 . .01/23/05 . . 445.0 66.9 . .01/30/05 . . 499.1 82.7 . .02/06/05 . . 387.7 64.1 . .02/13/05 . . 163.3 42.8 . .02/20/05 . . 7.4 7.7 . .02/27/05 29.56 24.53 83.0 32.8 34.8 38.703/06/05 . . 29.6 18.5 . .03/13/05 . . 7.8 8.2 . .03/20/05 . . 53.9 24.3 . .03/27/05 0.00 . 24.2 16.5 0.0 0.004/03/05 . . 0.0 0.0 . .04/10/05 35.88 19.38 151.1 48.1 84.6 66.004/17/05 . . 75.1 26.6 . .04/24/05 . . 33.7 19.5 . .05/01/05 . . 12.3 12.9 . .05/08/05 . . 33.0 20.5 . .05/15/05 . . 0.0 0.0 . .A.7

Table A.8. Passage of >200-350 mm, Slow-Moving Targets Through the Trail Bridge Dam Turbine andSpillway by Week. First and last weeks had only 5 and 3 days, respectively. Missingvalues are indicated by lone decimals.Week Project +- Intake +- Spill +-Beginning FPE 80% Passage 80% passage 80%Sunday 200-350 mm CL 200-350 mm CL 200-350 mm CL05/09/04 62.99 33.19 5.0 5.2 8.5 8.205/16/04 . . 10.4 10.9 . .05/23/04 . . 17.6 13.6 . .05/30/04 . . 13.7 10.5 . .06/06/04 100.0 . 0.0 0.0 12.3 12.706/13/04 . . 0.0 0.0 . .06/20/04 100.0 . 0.0 0.0 327.6 59.406/27/04 100.0 . 0.0 0.0 449.2 74.607/04/04 . . 0.0 0.0 . .07/11/04 95.25 3.570 15.4 11.5 309.4 81.507/18/04 . . 52.8 21.5 . .07/25/04 . . 53.5 22.6 . .08/01/04 . . 45.3 22.6 . .08/08/04 . . 21.1 16.3 . .08/15/04 . . 28.8 17.9 . .08/22/04 . . 28.9 15.8 . .08/29/04 . . 29.4 15.5 . .09/05/04 94.73 3.816 13.6 10.1 245.0 46.609/12/04 . . 5.8 6.1 . .09/19/04 98.30 1.793 5.6 5.9 326.4 78.209/26/04 . . 27.4 13.8 . .10/03/04 . . 61.9 26.4 . .10/10/04 . . 49.0 21.5 . .10/17/04 . . 16.2 13.9 . .10/24/04 0.00 . 14.8 11.0 0.0 0.010/31/04 . . 138.2 35.3 . .11/07/04 61.96 9.395 157.0 42.2 255.8 75.311/14/04 . . 90.1 29.2 . .11/21/04 . . 39.9 17.6 . .11/28/04 . . 132.7 36.0 . .12/05/04 . . 70.5 25.6 . .12/12/04 40.88 14.37 134.0 38.9 92.7 48.112/19/04 . . 67.8 25.6 . .12/26/04 . . 32.0 17.4 . .01/02/05 . . 32.5 19.2 . .01/09/05 22.56 20.72 52.4 21.8 15.3 16.901/16/05 . . 13.5 13.0 . .01/23/05 . . 74.6 27.2 . .01/30/05 . . 13.2 9.8 . .02/06/05 . . 92.7 32.7 . .02/13/05 . . 23.3 14.1 . .02/20/05 . . 0.0 0.0 . .02/27/05 0.00 . 31.0 19.6 0.0 0.003/06/05 . . 6.7 7.0 . .03/13/05 . . 0.0 0.0 . .03/20/05 . . 6.7 7.0 . .03/27/05 0.00 . 9.0 9.5 0.0 0.004/03/05 . . 0.0 0.0 . .04/10/05 42.80 33.02 19.5 14.9 14.6 16.204/17/05 . . 40.4 19.3 . .04/24/05 . . 0.0 0.0 . .05/01/05 . . 0.0 0.0 . .05/08/05 . . 0.0 0.0 . .05/15/05 . . 0.0 0.0 . .A.8

Table A.9. Passage of >350 mm, Slow-Moving Targets Through the Trail Bridge Dam Turbine andSpillway by Week. First and last weeks had only 5 and 3 days, respectively. Missingvalues are indicated by lone decimals.Week Project +- Intake +- Spill +-Beginning FPE 80% Passage 80% passage 80%Sunday >350 mm CL >350 mm CL >350 mm CL05/09/04 62.99 33.19 5.0 5.2 8.5 8.205/16/04 . . 10.4 10.9 . .05/09/04 . . 0.0 0.0 0.0 0.005/16/04 . . 0.0 0.0 . .05/23/04 . . 0.0 0.0 . .05/30/04 . . 0.0 0.0 . .06/06/04 . . 0.0 0.0 0.0 0.006/13/04 . . 0.0 0.0 . .06/20/04 100.0 . 0.0 0.0 46.9 22.206/27/04 100.0 . 0.0 0.0 78.4 25.707/04/04 . . 0.0 0.0 . .07/11/04 89.46 7.357 16.5 11.5 139.8 48.807/18/04 . . 7.7 8.0 . .07/25/04 . . 6.5 6.8 . .08/01/04 . . 4.4 7.9 . .08/08/04 . . 6.5 6.8 . .08/15/04 . . 12.8 9.5 . .08/22/04 . . 3.0 5.8 . .08/29/04 . . 19.9 12.1 . .09/05/04 94.82 5.344 5.9 6.2 107.7 31.609/12/04 . . 14.3 11.1 . .09/19/04 100.0 . 0.0 0.0 15.8 20.709/26/04 . . 9.1 8.5 . .10/03/04 . . 25.6 14.6 . .10/10/04 . . 2.7 4.9 . .10/17/04 . . 1.6 3.3 . .10/24/04 0.00 . 9.0 8.2 0.0 0.010/31/04 . . 33.5 16.5 . .11/07/04 77.10 13.60 22.9 13.2 77.3 39.511/14/04 . . 7.3 7.7 . .11/21/04 . . 2.3 4.2 . .11/28/04 . . 30.9 15.1 . .12/05/04 . . 13.9 11.3 . .12/12/04 57.16 34.17 10.3 8.7 13.8 15.312/19/04 . . 16.0 11.1 . .12/26/04 . . 3.3 4.9 . .01/02/05 . . 0.0 0.0 . .01/09/05 . . 0.0 0.0 0.0 0.001/16/05 . . 3.2 5.8 . .01/23/05 . . 17.7 13.3 . .01/30/05 . . 10.6 9.7 . .02/06/05 . . 2.8 5.1 . .02/13/05 . . 11.1 10.2 . .02/20/05 . . 0.0 0.0 . .02/27/05 . . 0.0 0.0 0.0 0.003/06/05 . . 6.3 6.6 . .03/13/05 . . 0.0 0.0 . .03/20/05 . . 6.3 6.6 . .03/27/05 . . 0.0 0.0 0.0 0.004/03/05 . . 0.0 0.0 . .04/10/05 0.00 . 2.9 5.2 0.0 0.004/17/05 . . 3.6 6.6 . .04/24/05 . . 6.8 7.2 . .05/01/05 . . 1.7 3.6 . .05/08/05 . . 0.0 0.0 . .05/15/05 . . 0.0 0.0 . .A.9

Appendix BMean Hourly Rates of Passage Based on Filteringof Targets Moving >50% of the Median Speed of theSmallest Detected Targets

Appendix BMean Hourly Rates of Passage Based on Filteringof Targets Moving >50% of the Median Speedof the Smallest Detected TargetsTable B.1. Mean Hourly Rate of Passage of 38-100 mm, Slow-Moving Targets Through theTrail Bridge Dam Turbine and Spillway from May 11, 2004 Through May 17, 2005.Estimates are followed by their respective 80% confidence limits.Length +- +-Class Intake 80% Spill 80%mm Passage CL Passage CL38-100 1.57 0.09 25.72 2.04>100-200 0.88 0.05 9.45 0.80>200-350 0.20 0.02 3.94 0.47>350 0.04 0.01 0.92 0.18B.1

Table B.2. Mean Hourly Rate of Passage of 38-100 mm, Slow-Moving Targets Through the Trail Bridge Dam Turbine and Spillway by Month.First and last months had only 21 and 17 days, respectively. Lone decimals indicate missing values for spill in August, February, andMay.B 2+- Turbine +- Turbine +- +- Spill +- Spill +-Turbine 80% Passage 80% Passage 80% Spillway 80% Passage 80% Passage 80%YEAR MONTH Passage CL Lower Half CL Upper Half CL Passage CL NW Half CL SE Half CL2004 5 0.13 0.07 0.07 0.06 0.06 0.05 8.18 5.73 3.93 3.30 4.25 5.452004 6 0.12 0.05 0.03 0.02 0.09 0.05 38.27 3.49 10.41 1.89 27.81 2.502004 7 0.38 0.11 0.16 0.05 0.22 0.08 32.51 5.98 6.81 2.69 25.71 5.392004 8 0.39 0.10 0.17 0.06 0.22 0.07 . . . . . .2004 9 0.59 0.25 0.37 0.17 0.22 0.10 18.93 5.16 6.95 3.71 11.74 3.482004 10 0.73 0.16 0.42 0.11 0.31 0.10 28.73 36.83 21.55 27.62 7.18 9.212004 11 4.48 0.50 1.89 0.28 2.59 0.33 15.21 5.51 6.46 3.97 8.75 3.262004 12 3.55 0.41 1.18 0.21 2.37 0.31 10.81 3.46 4.29 1.87 6.52 2.832005 1 4.00 0.46 0.93 0.16 3.07 0.41 10.45 10.16 7.70 6.93 2.75 3.532005 2 3.29 0.50 0.90 0.22 2.39 0.40 . . . . . .2005 3 0.62 0.18 0.17 0.09 0.45 0.15 1.42 1.27 0.76 0.97 0.66 0.852005 4 1.05 0.26 0.37 0.14 0.68 0.18 5.25 5.01 3.26 2.62 1.99 2.552005 5 0.12 0.07 0.02 0.03 0.10 0.06 . . . . . .

Table B.3.Mean Hourly Rate of Passage of 100-200 mm, Slow-Moving Targets Through the Trail Bridge Dam Turbine and Spillway byMonth. First and last months had only 21 and 17 days, respectively. Lone decimals indicate missing values for spill in August,February, and May.B 3+- Turbine +- Turbine +- +- Spill +- Spill +-Turbine 80% Passage 80% Passage 80% Spillway 80% Passage 80% Passage 80%YEAR MONTH Passage CL Lower Half CL Upper Half CL Passage CL NW Half CL SE Half CL2004 5 0.36 0.11 0.10 0.06 0.26 0.10 3.85 3.26 1.72 2.21 2.13 2.732004 6 0.16 0.06 0.02 0.02 0.13 0.06 10.33 1.16 2.77 0.61 7.55 0.932004 7 0.33 0.11 0.10 0.05 0.23 0.10 16.84 2.90 4.61 1.42 12.23 2.412004 8 0.26 0.09 0.13 0.06 0.14 0.07 . . . . . .2004 9 0.61 0.12 0.20 0.08 0.41 0.10 14.06 3.30 8.48 2.15 5.46 2.042004 10 0.40 0.10 0.30 0.08 0.10 0.05 14.91 19.11 0.00 0.00 14.91 19.112004 11 2.57 0.31 1.05 0.17 1.51 0.23 7.35 2.17 2.64 1.13 4.72 1.822004 12 2.32 0.23 0.80 0.14 1.52 0.18 4.24 1.64 1.19 0.88 3.05 1.302005 1 1.78 0.22 0.61 0.11 1.17 0.18 6.20 5.82 4.40 5.64 1.80 2.312005 2 1.42 0.24 0.46 0.12 0.96 0.19 . . . . . .2005 3 0.27 0.08 0.06 0.03 0.21 0.07 1.20 1.54 0.00 0.00 1.20 1.542005 4 0.36 0.10 0.15 0.06 0.21 0.08 2.73 2.21 1.16 1.04 1.57 2.012005 5 0.11 0.07 0.00 0.00 0.11 0.07 . . . . . .

Table B.4.Mean Hourly Rate of Passage of 200-350 mm, Slow-Moving Targets Through the Trail Bridge Dam Turbine and Spillway byMonth. First and last months had only 21 and 17 days, respectively. Lone decimals indicate missing values for spill in August,February, and May.B 4+- Turbine +- Turbine +- +- Spill +- Spill +-Turbine 80% Passage 80% Passage 80% Spillway 80% Passage 80% Passage 80%YEAR MONTH Passage CL Lower Half CL Upper Half CL Passage CL NW Half CL SE Half CL2004 5 0.08 0.05 0.03 0.03 0.06 0.04 1.06 1.36 1.06 1.36 0.00 0.002004 6 0.01 0.01 0.01 0.01 0.00 0.00 2.50 0.42 0.87 0.25 1.63 0.362004 7 0.16 0.05 0.09 0.04 0.08 0.04 8.32 2.17 3.41 1.24 4.91 1.252004 8 0.19 0.06 0.06 0.03 0.13 0.05 . . . . . .2004 9 0.09 0.04 0.07 0.04 0.02 0.02 11.90 2.30 5.53 1.55 6.25 1.582004 10 0.20 0.06 0.09 0.03 0.12 0.05 0.00 0.00 0.00 0.00 0.00 0.002004 11 0.64 0.11 0.12 0.04 0.52 0.10 4.83 1.39 1.48 0.86 3.35 1.152004 12 0.52 0.09 0.09 0.04 0.42 0.08 1.78 1.14 0.28 0.36 1.50 1.092005 1 0.24 0.07 0.08 0.04 0.16 0.05 1.69 2.17 0.00 0.00 1.69 2.172005 2 0.19 0.06 0.09 0.04 0.10 0.05 . . . . . .2005 3 0.07 0.04 0.02 0.02 0.05 0.03 0.00 0.00 0.00 0.00 0.00 0.002005 4 0.08 0.05 0.02 0.02 0.06 0.04 0.47 0.60 0.00 0.00 0.47 0.602005 5 0.00 0.00 0.00 0.00 0.00 0.00 . . . . . .

Table B.5.Mean Hourly Rate of Passage of >350 mm, Slow-Moving Targets Through the Trail Bridge Dam Turbine and Spillway by Month.First and last months had only 21 and 17 days, respectively. Lone decimals indicate missing values for spill in August, February,and May.+- Turbine +- Turbine +- +- Spill +- Spill +-Turbine 80% Passage 80% Passage 80% Spillway 80% Passage 80% Passage 80%YEAR MONTH Passage CL Lower Half CL Upper Half CL Passage CL NW Half CL SE Half CLB 52004 5 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.002004 6 0.00 0.00 0.00 0.00 0.00 0.00 0.44 0.15 0.07 0.06 0.37 0.142004 7 0.04 0.02 0.04 0.02 0.00 0.00 2.60 0.88 1.31 0.59 1.30 0.582004 8 0.05 0.03 0.05 0.03 0.00 0.00 . . . . . .2004 9 0.05 0.03 0.05 0.03 0.00 0.00 2.57 0.98 0.82 0.49 1.72 0.702004 10 0.05 0.03 0.04 0.02 0.01 0.01 0.00 0.00 0.00 0.00 0.00 0.002004 11 0.11 0.04 0.04 0.02 0.07 0.03 1.46 0.71 0.29 0.37 1.17 0.622004 12 0.09 0.03 0.03 0.02 0.05 0.02 0.27 0.34 0.27 0.34 0.00 0.002005 1 0.03 0.02 0.02 0.02 0.01 0.01 0.00 0.00 0.00 0.00 0.00 0.002005 2 0.04 0.02 0.02 0.02 0.02 0.02 . . . . . .2005 3 0.02 0.02 0.00 0.00 0.02 0.02 0.00 0.00 0.00 0.00 0.00 0.002005 4 0.02 0.01 0.01 0.01 0.01 0.01 0.00 0.00 0.00 0.00 0.00 0.002005 5 0.00 0.01 0.00 0.01 0.00 0.00 . . . . . .

Table B.6.Mean Hourly Rate of Passage of 38-100 mm, Slow-Moving Targets Through the TrailBridge Dam Turbine and Spillway by Week. First and last weeks had only 5 and 3 days,respectively. Missing values are indicated by lone decimals.Week Intake +- Spill +-Beginning Passage 80% Passage 80%Sunday 38-100 mm CL 38-100 mm CL05/09/04 0.096 0.123 4.675 5.99405/16/04 0.268 0.269 . .05/23/04 0.056 0.072 . .05/30/04 0.000 0.000 . .06/06/04 0.048 0.061 0.000 .06/13/04 0.264 0.182 . .06/20/04 0.189 0.243 42.964 10.06606/27/04 0.000 0.000 44.128 7.24407/04/04 0.533 0.337 . .07/11/04 0.110 0.093 6.778 3.99207/18/04 0.434 0.238 . .07/25/04 0.595 0.219 . .08/01/04 0.167 0.154 . .08/08/04 0.539 0.329 . .08/15/04 0.229 0.106 . .08/22/04 0.368 0.143 . .08/29/04 0.625 0.300 . .09/05/04 0.135 0.121 35.160 17.33709/12/04 0.343 0.252 . .09/19/04 0.482 0.204 8.250 7.77309/26/04 1.486 1.254 . .10/03/04 1.160 0.372 . .10/10/04 0.247 0.186 . .10/17/04 0.609 0.284 . .10/24/04 0.935 0.385 28.728 .10/31/04 4.307 1.531 . .11/07/04 6.070 2.948 11.853 8.78811/14/04 4.977 1.489 . .11/21/04 2.238 0.882 . .11/28/04 4.021 1.365 . .12/05/04 2.657 0.463 . .12/12/04 2.434 0.951 9.948 8.27612/19/04 5.378 2.225 . .12/26/04 3.719 0.637 . .01/02/05 1.504 0.821 . .01/09/05 3.458 1.233 10.450 .01/16/05 5.712 1.604 . .01/23/05 4.781 1.386 . .01/30/05 6.897 1.386 . .02/06/05 5.434 1.480 . .02/13/05 2.362 1.118 . .02/20/05 0.000 0.000 . .02/27/05 1.137 1.007 0.844 1.08203/06/05 0.345 0.224 . .03/13/05 0.136 0.116 . .03/20/05 0.818 0.438 . .03/27/05 0.314 0.325 3.853 .04/03/05 0.000 0.000 . .04/10/05 3.173 1.769 30.529 37.70004/17/05 1.255 0.571 . .04/24/05 0.076 0.068 . .05/01/05 0.046 0.028 . .05/08/05 0.128 0.108 . .05/15/05 0.258 0.331 . .B.6

Table B.7.Mean Hourly Rate of Passage of >100-200 mm, Slow-Moving Targets Through the TrailBridge Dam Turbine and Spillway by Week. First and last weeks had only 5 and 3 days,respectively. Missing values are indicated by lone decimals.Week Intake +- Spill +-Beginning Passage 80% Passage 80%Sunday 100-200 mm CL 100-200 mm CL05/09/04 0.000 0.000 2.202 2.82305/16/04 0.631 0.193 . .05/23/04 0.329 0.218 . .05/30/04 0.304 0.193 . .06/06/04 0.259 0.182 0.000 .06/13/04 0.139 0.091 . .06/20/04 0.050 0.065 10.675 1.17006/27/04 0.087 0.111 14.465 4.90407/04/04 0.236 0.233 . .07/11/04 0.190 0.161 12.908 1.15607/18/04 0.244 0.172 . .07/25/04 0.685 0.245 . .08/01/04 0.453 0.393 . .08/08/04 0.164 0.150 . .08/15/04 0.225 0.142 . .08/22/04 0.083 0.106 . .08/29/04 0.335 0.184 . .09/05/04 0.235 0.118 20.436 9.20209/12/04 0.235 0.119 . .09/19/04 1.259 0.334 11.414 2.21009/26/04 0.825 0.454 . .10/03/04 0.535 0.209 . .10/10/04 0.249 0.193 . .10/17/04 0.351 0.174 . .10/24/04 0.525 0.282 14.910 .10/31/04 3.893 1.630 . .11/07/04 3.413 1.822 6.137 3.25211/14/04 2.598 0.707 . .11/21/04 0.615 0.223 . .11/28/04 1.229 0.406 . .12/05/04 2.360 0.680 . .12/12/04 2.376 0.683 3.681 1.65712/19/04 3.369 0.922 . .12/26/04 1.855 0.441 . .01/02/05 1.238 0.696 . .01/09/05 1.597 0.362 6.200 .01/16/05 1.425 0.934 . .01/23/05 2.649 0.816 . .01/30/05 2.971 0.752 . .02/06/05 2.308 0.616 . .02/13/05 0.972 0.415 . .02/20/05 0.044 0.056 . .02/27/05 0.494 0.427 1.584 2.03003/06/05 0.176 0.113 . .03/13/05 0.047 0.060 . .03/20/05 0.321 0.292 . .03/27/05 0.144 0.129 0.000 .04/03/05 0.000 0.000 . .04/10/05 0.900 0.545 12.698 15.33204/17/05 0.447 0.306 . .04/24/05 0.200 0.109 . .05/01/05 0.073 0.048 . .05/08/05 0.197 0.124 . .05/15/05 0.000 0.000 . .B.7

Table B.8.Mean Hourly Rate of Passage of >200-350 mm, Slow-Moving Targets Through the TrailBridge Dam Turbine and Spillway by Week. First and last weeks had only 5 and 3 days,respectively. Missing values are indicated by lone decimals.Week Intake +- Spill +-Beginning Passage 80% Passage 80%Sunday 200-350 mm CL 200-350 mm CL05/09/04 0.041 0.053 0.604 0.77505/16/04 0.062 0.080 . .05/23/04 0.105 0.092 . .05/30/04 0.082 0.071 . .06/06/04 0.000 0.000 6.126 .06/13/04 0.000 0.000 . .06/20/04 0.000 0.000 2.388 0.38006/27/04 0.000 0.000 3.767 1.32607/04/04 0.000 0.000 . .07/11/04 0.092 0.077 11.415 0.50407/18/04 0.315 0.136 . .07/25/04 0.318 0.162 . .08/01/04 0.270 0.181 . .08/08/04 0.126 0.110 . .08/15/04 0.171 0.105 . .08/22/04 0.172 0.112 . .08/29/04 0.175 0.081 . .09/05/04 0.081 0.104 11.608 0.21609/12/04 0.034 0.044 . .09/19/04 0.034 0.043 11.492 2.94509/26/04 0.163 0.147 . .10/03/04 0.368 0.177 . .10/10/04 0.292 0.205 . .10/17/04 0.096 0.088 . .10/24/04 0.088 0.073 0.000 .10/31/04 0.823 0.308 . .11/07/04 0.935 0.549 5.043 1.04211/14/04 0.536 0.257 . .11/21/04 0.237 0.153 . .11/28/04 0.790 0.215 . .12/05/04 0.419 0.218 . .12/12/04 0.798 0.386 1.846 0.91712/19/04 0.403 0.260 . .12/26/04 0.190 0.088 . .01/02/05 0.193 0.165 . .01/09/05 0.312 0.178 1.695 .01/16/05 0.080 0.068 . .01/23/05 0.444 0.243 . .01/30/05 0.079 0.101 . .02/06/05 0.552 0.219 . .02/13/05 0.139 0.084 . .02/20/05 0.000 0.000 . .02/27/05 0.184 0.156 0.000 0.00003/06/05 0.040 0.051 . .03/13/05 0.000 0.000 . .03/20/05 0.040 0.051 . .03/27/05 0.053 0.069 0.000 .04/03/05 0.000 0.000 . .04/10/05 0.116 0.096 0.280 0.35904/17/05 0.241 0.159 . .04/24/05 0.000 0.000 . .05/01/05 0.000 0.000 . .05/08/05 0.000 0.000 . .05/15/05 0.000 0.000 . .B.8

Table B.9.Mean Hourly Rate of Passage of >350 mm, Slow-Moving Targets Through the TrailBridge Dam Turbine and Spillway by Week. First and last weeks had only 5 and 3 days,respectively. Missing values are indicated by lone decimals.Week Intake +- Spill +-Beginning Passage 80% Passage 80%Sunday >350 mm CL >350 mm CL05/09/04 0.000 0.000 0.000 0.00005/16/04 0.000 0.000 . .05/23/04 0.000 0.000 . .05/30/04 0.000 0.000 . .06/06/04 0.000 0.000 0.000 .06/13/04 0.000 0.000 . .06/20/04 0.000 0.000 0.326 0.19606/27/04 0.000 0.000 0.655 0.26907/04/04 0.000 0.000 . .07/11/04 0.098 0.103 5.353 2.02807/18/04 0.046 0.059 . .07/25/04 0.039 0.050 . .08/01/04 0.026 0.033 . .08/08/04 0.039 0.049 . .08/15/04 0.076 0.063 . .08/22/04 0.018 0.023 . .08/29/04 0.118 0.072 . .09/05/04 0.035 0.045 5.049 0.31409/12/04 0.085 0.071 . .09/19/04 0.000 0.000 0.466 0.59709/26/04 0.054 0.056 . .10/03/04 0.152 0.116 . .10/10/04 0.016 0.021 . .10/17/04 0.009 0.012 . .10/24/04 0.053 0.049 0.000 .10/31/04 0.199 0.147 . .11/07/04 0.137 0.068 1.240 0.92311/14/04 0.044 0.056 . .11/21/04 0.014 0.017 . .11/28/04 0.184 0.095 . .12/05/04 0.083 0.061 . .12/12/04 0.061 0.047 0.418 0.53512/19/04 0.095 0.064 . .12/26/04 0.020 0.012 . .01/02/05 0.000 0.000 . .01/09/05 0.000 0.000 0.000 .01/16/05 0.019 0.024 . .01/23/05 0.106 0.064 . .01/30/05 0.063 0.060 . .02/06/05 0.017 0.022 . .02/13/05 0.066 0.059 . .02/20/05 0.000 0.000 . .02/27/05 0.000 0.000 0.000 0.00003/06/05 0.037 0.048 . .03/13/05 0.000 0.000 . .03/20/05 0.037 0.048 . .03/27/05 0.000 0.000 0.000 .04/03/05 0.000 0.000 . .04/10/05 0.017 0.022 0.000 0.00004/17/05 0.022 0.028 . .04/24/05 0.041 0.052 . .05/01/05 0.010 0.013 . .05/08/05 0.000 0.000 . .05/15/05 0.000 0.000 . .B.9

Appendix CMedian Hourly Rates of Passage Based on Filteringof Targets Moving >50% of the Median Speedof the Smallest Detected Targets

Appendix CMedian Hourly Rates of Passage Based on Filteringof Targets Moving >50% of the Median Speedof the Smallest Detected TargetsTable C.1.Median Hourly Rate of Passage of 38-100 mm, Slow-Moving Targets Through the TrailBridge Dam Turbine and Spillway from May 11, 2004 Through May 17, 2005. Estimatesare followed by their respective 80% confidence limits.Length +- +-Class Intake 80% Spill 80%mm Passage CL Passage CL38-100 0.00 0.09 12.16 2.04>100-200 0.00 0.05 0.00 0.80>200-350 0.00 0.02 0.00 0.47>350 0.00 0.01 0.00 0.18C.1

Table C.2.Median Hourly Rate of Passage of 38-100 mm, Slow-Moving Targets Through the Trail Bridge Dam Turbine and Spillway byMonth. First and last months had only 21 and 17 days, respectively. Lone decimals indicate missing values for spill in August,February, and May.+- Turbine +- Turbine +- +- Spill +- Spill +-Turbine 80% Passage 80% Passage 80% Spillway 80% Passage 80% Passage 80%YEAR MONTH Passage CL Lower Half CL Upper Half CL Passage CL NW Half CL SE Half CLC 22004 5 0.00 0.07 0.00 0.06 0.00 0.05 0.00 5.73 0.00 3.30 0.00 5.452004 6 0.00 0.05 0.00 0.02 0.00 0.05 26.43 3.49 0.00 1.89 20.65 2.502004 7 0.00 0.11 0.00 0.05 0.00 0.08 22.01 5.98 0.00 2.69 5.87 5.392004 8 0.00 0.10 0.00 0.06 0.00 0.07 . . . . . .2004 9 0.00 0.25 0.00 0.17 0.00 0.10 0.00 5.16 0.00 3.71 0.00 3.482004 10 0.00 0.16 0.00 0.11 0.00 0.10 28.73 36.83 21.55 27.62 7.18 9.212004 11 0.00 0.50 0.00 0.28 0.00 0.33 0.00 5.51 0.00 3.97 0.00 3.262004 12 0.00 0.41 0.00 0.21 0.00 0.31 0.00 3.46 0.00 1.87 0.00 2.832005 1 0.00 0.46 0.00 0.16 0.00 0.41 0.00 10.16 0.00 6.93 0.00 3.532005 2 0.00 0.50 0.00 0.22 0.00 0.40 . . . . . .2005 3 0.00 0.18 0.00 0.09 0.00 0.15 0.00 1.27 0.00 0.97 0.00 0.852005 4 0.00 0.26 0.00 0.14 0.00 0.18 0.00 5.01 0.00 2.62 0.00 2.552005 5 0.00 0.07 0.00 0.03 0.00 0.06 . . . . . .

Table C.3.Median Hourly Rate of Passage of 100-200 mm, Slow-Moving Targets Through the Trail Bridge Dam Turbine and Spillway byMonth. First and last months had only 21 and 17 days, respectively. Lone decimals indicate missing values for spill in August,February, and May.+- Turbine +- Turbine +- +- Spill +- Spill +-Turbine 80% Passage 80% Passage 80% Spillway 80% Passage 80% Passage 80%YEAR MONTH Passage CL Lower Half CL Upper Half CL Passage CL NW Half CL SE Half CLC 32004 5 0.00 0.11 0.00 0.06 0.00 0.10 0.00 3.26 0.00 2.21 0.00 2.732004 6 0.00 0.06 0.00 0.02 0.00 0.06 3.84 1.16 0.00 0.61 0.00 0.932004 7 0.00 0.11 0.00 0.05 0.00 0.10 12.91 2.90 0.00 1.42 4.55 2.412004 8 0.00 0.09 0.00 0.06 0.00 0.07 . . . . . .2004 9 0.00 0.12 0.00 0.08 0.00 0.10 4.50 3.30 0.00 2.15 0.00 2.042004 10 0.00 0.10 0.00 0.08 0.00 0.05 14.91 19.11 0.00 0.00 14.91 19.112004 11 0.00 0.31 0.00 0.17 0.00 0.23 0.00 2.17 0.00 1.13 0.00 1.822004 12 0.00 0.23 0.00 0.14 0.00 0.18 0.00 1.64 0.00 0.88 0.00 1.302005 1 0.00 0.22 0.00 0.11 0.00 0.18 0.00 5.82 0.00 5.64 0.00 2.312005 2 0.00 0.24 0.00 0.12 0.00 0.19 . . . . . .2005 3 0.00 0.08 0.00 0.03 0.00 0.07 0.00 1.54 0.00 0.00 0.00 1.542005 4 0.00 0.10 0.00 0.06 0.00 0.08 0.00 2.21 0.00 1.04 0.00 2.012005 5 0.00 0.07 0.00 0.00 0.00 0.07 . . . . . .

Table C.4.Median Hourly Rate of Passage of 200-350 mm, Slow-Moving Targets Through the Trail Bridge Dam Turbine and Spillway byMonth. First and last months had only 21 and 17 days, respectively. Lone decimals indicate missing values for spill in August,February, and May.+- Turbine +- Turbine +- +- Spill +- Spill +-Turbine 80% Passage 80% Passage 80% Spillway 80% Passage 80% Passage 80%YEAR MONTH Passage CL Lower Half CL Upper Half CL Passage CL NW Half CL SE Half CLC 42004 5 0.00 0.05 0.00 0.03 0.00 0.04 0.00 1.36 0.00 1.36 0.00 0.002004 6 0.00 0.01 0.00 0.01 0.00 0.00 0.00 0.42 0.00 0.25 0.00 0.362004 7 0.00 0.05 0.00 0.04 0.00 0.04 0.00 2.17 0.00 1.24 0.00 1.252004 8 0.00 0.06 0.00 0.03 0.00 0.05 . . . . . .2004 9 0.00 0.04 0.00 0.04 0.00 0.02 9.71 2.30 0.00 1.55 0.00 1.582004 10 0.00 0.06 0.00 0.03 0.00 0.05 0.00 0.00 0.00 0.00 0.00 0.002004 11 0.00 0.11 0.00 0.04 0.00 0.10 0.00 1.39 0.00 0.86 0.00 1.152004 12 0.00 0.09 0.00 0.04 0.00 0.08 0.00 1.14 0.00 0.36 0.00 1.092005 1 0.00 0.07 0.00 0.04 0.00 0.05 0.00 2.17 0.00 0.00 0.00 2.172005 2 0.00 0.06 0.00 0.04 0.00 0.05 . . . . . .2005 3 0.00 0.04 0.00 0.02 0.00 0.03 0.00 0.00 0.00 0.00 0.00 0.002005 4 0.00 0.05 0.00 0.02 0.00 0.04 0.00 0.60 0.00 0.00 0.00 0.602005 5 0.00 0.00 0.00 0.00 0.00 0.00 . . . . . .

Table C.5.Median Hourly Rate of Passage of >350 mm, Slow-Moving Targets Through the Trail Bridge Dam Turbine and Spillway byMonth. First and last months had only 21 and 17 days, respectively. Lone decimals indicate missing values for spill in August,February, and May.+- Turbine +- Turbine +- +- Spill +- Spill +-Turbine 80% Passage 80% Passage 80% Spillway 80% Passage 80% Passage 80%YEAR MONTH Passage CL Lower Half CL Upper Half CL Passage CL NW Half CL SE Half CLC 52004 5 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.002004 6 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.15 0.00 0.06 0.00 0.142004 7 0.00 0.02 0.00 0.02 0.00 0.00 0.00 0.88 0.00 0.59 0.00 0.582004 8 0.00 0.03 0.00 0.03 0.00 0.00 . . . . . .2004 9 0.00 0.03 0.00 0.03 0.00 0.00 0.00 0.98 0.00 0.49 0.00 0.702004 10 0.00 0.03 0.00 0.02 0.00 0.01 0.00 0.00 0.00 0.00 0.00 0.002004 11 0.00 0.04 0.00 0.02 0.00 0.03 0.00 0.71 0.00 0.37 0.00 0.622004 12 0.00 0.03 0.00 0.02 0.00 0.02 0.00 0.34 0.00 0.34 0.00 0.002005 1 0.00 0.02 0.00 0.02 0.00 0.01 0.00 0.00 0.00 0.00 0.00 0.002005 2 0.00 0.02 0.00 0.02 0.00 0.02 . . . . . .2005 3 0.00 0.02 0.00 0.00 0.00 0.02 0.00 0.00 0.00 0.00 0.00 0.002005 4 0.00 0.01 0.00 0.01 0.00 0.01 0.00 0.00 0.00 0.00 0.00 0.002005 5 0.00 0.01 0.00 0.01 0.00 0.00 . . . . . .

Table C.6.Median Hourly Rate of Passage of 38-100 mm, Slow-Moving Targets Through theTrail Bridge Dam Turbine and Spillway by Week. First and last weeks had only 5and 3 days, respectively. Missing values are indicated by lone decimals.Week Intake +- Spill +-Beginning Passage 80% Passage 80%Sunday 38-100 mm CL 38-100 mm CL05/09/04 0.000 0.000 0.000 0.00005/16/04 0.000 0.000 . .05/23/04 0.000 0.000 . .05/30/04 0.000 0.000 . .06/06/04 0.000 0.000 0.000 .06/13/04 0.000 0.000 . .06/20/04 0.000 0.000 25.384 10.08606/27/04 0.000 0.000 34.977 9.39507/04/04 0.000 0.000 . .07/11/04 0.000 0.000 0.000 0.00007/18/04 0.000 0.000 . .07/25/04 0.000 0.000 . .08/01/04 0.000 0.000 . .08/08/04 0.000 0.000 . .08/15/04 0.000 0.000 . .08/22/04 0.000 0.000 . .08/29/04 0.000 0.000 . .09/05/04 0.000 0.000 31.821 24.54409/12/04 0.000 0.000 . .09/19/04 0.000 0.000 0.000 0.00009/26/04 0.000 0.000 . .10/03/04 0.000 0.000 . .10/10/04 0.000 0.000 . .10/17/04 0.000 0.000 . .10/24/04 0.000 0.000 28.728 .10/31/04 0.000 0.000 . .11/07/04 0.000 2.580 0.000 0.00011/14/04 0.000 0.000 . .11/21/04 0.000 0.000 . .11/28/04 0.000 0.778 . .12/05/04 0.000 0.000 . .12/12/04 0.000 0.000 0.000 9.38512/19/04 0.000 2.320 . .12/26/04 0.000 0.800 . .01/02/05 0.000 0.000 . .01/09/05 0.000 0.000 0.000 .01/16/05 0.000 0.000 . .01/23/05 0.000 1.592 . .01/30/05 0.000 0.000 . .02/06/05 0.000 0.000 . .02/13/05 0.000 0.704 . .02/20/05 0.000 0.000 . .02/27/05 0.000 0.000 0.000 0.00003/06/05 0.000 0.000 . .03/13/05 0.000 0.000 . .03/20/05 0.000 0.000 . .03/27/05 0.000 0.000 0.000 .04/03/05 0.000 0.000 . .04/10/05 0.000 0.000 0.000 38.04904/17/05 0.000 0.000 . .04/24/05 0.000 0.000 . .05/01/05 0.000 0.000 . .05/08/05 0.000 0.000 . .05/15/05 0.000 0.000 . .C.6

Table C.7.Median Hourly Rate of Passage of >100-200 mm, Slow-Moving Targets Throughthe Trail Bridge Dam Turbine and Spillway by Week. First and last weeks hadonly 5 and 3 days, respectively. Missing values are indicated by lone decimals.Week Intake +- Spill +-Beginning Passage 80% Passage 80%Sunday 100-200 mm CL 100-200 mm CL05/09/04 0.000 0.000 0.000 0.00005/16/04 0.000 0.000 . .05/23/04 0.000 0.000 . .05/30/04 0.000 0.000 . .06/06/04 0.000 0.000 0.000 .06/13/04 0.000 0.000 . .06/20/04 0.000 0.000 4.397 2.78506/27/04 0.000 0.000 11.107 6.23807/04/04 0.000 0.000 . .07/11/04 0.000 0.000 8.774 11.24907/18/04 0.000 0.000 . .07/25/04 0.000 0.000 . .08/01/04 0.000 0.000 . .08/08/04 0.000 0.000 . .08/15/04 0.000 0.000 . .08/22/04 0.000 0.000 . .08/29/04 0.000 0.000 . .09/05/04 0.000 0.000 12.966 16.62209/12/04 0.000 0.000 . .09/19/04 0.000 0.000 8.518 10.92009/26/04 0.000 0.000 . .10/03/04 0.000 0.000 . .10/10/04 0.000 0.000 . .10/17/04 0.000 0.000 . .10/24/04 0.000 0.000 14.910 .10/31/04 0.000 0.000 . .11/07/04 0.000 1.599 0.000 0.00011/14/04 0.000 0.000 . .11/21/04 0.000 0.000 . .11/28/04 0.000 0.252 . .12/05/04 0.000 0.727 . .12/12/04 0.000 0.655 0.000 0.00012/19/04 0.000 0.000 . .12/26/04 0.000 0.532 . .01/02/05 0.000 0.000 . .01/09/05 0.000 0.000 0.000 .01/16/05 0.000 0.000 . .01/23/05 0.000 0.339 . .01/30/05 0.000 0.000 . .02/06/05 0.000 0.000 . .02/13/05 0.000 0.000 . .02/20/05 0.000 0.000 . .02/27/05 0.000 0.000 0.000 0.00003/06/05 0.000 0.000 . .03/13/05 0.000 0.000 . .03/20/05 0.000 0.000 . .03/27/05 0.000 0.000 0.000 .04/03/05 0.000 0.000 . .04/10/05 0.000 0.000 0.000 15.55704/17/05 0.000 0.000 . .04/24/05 0.000 0.000 . .05/01/05 0.000 0.000 . .05/08/05 0.000 0.000 . .05/15/05 0.000 0.000 . .C.7

Table C.8.Median Hourly Rate of Passage of >200-350 mm, Slow-Moving Targets Throughthe Trail Bridge Dam Turbine and Spillway by Week. First and last weeks hadonly 5 and 3 days, respectively. Missing values are indicated by lone decimals.Week Intake +- Spill +-Beginning Passage 80% Passage 80%Sunday 200-350 mm CL 200-350 mm CL05/09/04 0.000 0.000 0.000 0.00005/16/04 0.000 0.000 . .05/23/04 0.000 0.000 . .05/30/04 0.000 0.000 . .06/06/04 0.000 0.000 6.126 .06/13/04 0.000 0.000 . .06/20/04 0.000 0.000 0.000 0.00006/27/04 0.000 0.000 0.000 0.00007/04/04 0.000 0.000 . .07/11/04 0.000 0.000 2.202 2.82307/18/04 0.000 0.000 . .07/25/04 0.000 0.000 . .08/01/04 0.000 0.000 . .08/08/04 0.000 0.000 . .08/15/04 0.000 0.000 . .08/22/04 0.000 0.000 . .08/29/04 0.000 0.000 . .09/05/04 0.000 0.000 9.661 1.49909/12/04 0.000 0.000 . .09/19/04 0.000 0.000 7.369 9.44609/26/04 0.000 0.000 . .10/03/04 0.000 0.000 . .10/10/04 0.000 0.000 . .10/17/04 0.000 0.000 . .10/24/04 0.000 0.000 0.000 .10/31/04 0.000 0.000 . .11/07/04 0.000 0.000 0.000 0.00011/14/04 0.000 0.000 . .11/21/04 0.000 0.000 . .11/28/04 0.000 0.000 . .12/05/04 0.000 0.000 . .12/12/04 0.000 0.000 0.000 0.00012/19/04 0.000 0.000 . .12/26/04 0.000 0.000 . .01/02/05 0.000 0.000 . .01/09/05 0.000 0.000 0.000 .01/16/05 0.000 0.000 . .01/23/05 0.000 0.000 . .01/30/05 0.000 0.000 . .02/06/05 0.000 0.000 . .02/13/05 0.000 0.000 . .02/20/05 0.000 0.000 . .02/27/05 0.000 0.000 0.000 0.00003/06/05 0.000 0.000 . .03/13/05 0.000 0.000 . .03/20/05 0.000 0.000 . .03/27/05 0.000 0.000 0.000 .04/03/05 0.000 0.000 . .04/10/05 0.000 0.000 0.000 0.00004/17/05 0.000 0.000 . .04/24/05 0.000 0.000 . .05/01/05 0.000 0.000 . .05/08/05 0.000 0.000 . .05/15/05 0.000 0.000 . .C.8

Table C.9.Median Hourly Rate of Passage of >350 mm, Slow-Moving Targets Through theTrail Bridge Dam Turbine and Spillway by Week. First and last weeks had only5 and 3 days, respectively. Missing values are indicated by lone decimals.Week Intake +- Spill +-Beginning Passage 80% Passage 80%Sunday >350 mm CL >350 mm CL05/09/04 0.000 0.000 0.000 0.00005/16/04 0.000 0.000 . .05/23/04 0.000 0.000 . .05/30/04 0.000 0.000 . .06/06/04 0.000 0.000 0.000 .06/13/04 0.000 0.000 . .06/20/04 0.000 0.000 0.000 0.00006/27/04 0.000 0.000 0.000 0.00007/04/04 0.000 0.000 . .07/11/04 0.000 0.000 1.288 1.65207/18/04 0.000 0.000 . .07/25/04 0.000 0.000 . .08/01/04 0.000 0.000 . .08/08/04 0.000 0.000 . .08/15/04 0.000 0.000 . .08/22/04 0.000 0.000 . .08/29/04 0.000 0.000 . .09/05/04 0.000 0.000 0.000 0.00009/12/04 0.000 0.000 . .09/19/04 0.000 0.000 0.000 0.00009/26/04 0.000 0.000 . .10/03/04 0.000 0.000 . .10/10/04 0.000 0.000 . .10/17/04 0.000 0.000 . .10/24/04 0.000 0.000 0.000 .10/31/04 0.000 0.000 . .11/07/04 0.000 0.000 0.000 0.00011/14/04 0.000 0.000 . .11/21/04 0.000 0.000 . .11/28/04 0.000 0.000 . .12/05/04 0.000 0.000 . .12/12/04 0.000 0.000 0.000 0.00012/19/04 0.000 0.000 . .12/26/04 0.000 0.000 . .01/02/05 0.000 0.000 . .01/09/05 0.000 0.000 0.000 .01/16/05 0.000 0.000 . .01/23/05 0.000 0.000 . .01/30/05 0.000 0.000 . .02/06/05 0.000 0.000 . .02/13/05 0.000 0.000 . .02/20/05 0.000 0.000 . .02/27/05 0.000 0.000 0.000 0.00003/06/05 0.000 0.000 . .03/13/05 0.000 0.000 . .03/20/05 0.000 0.000 . .03/27/05 0.000 0.000 0.000 .04/03/05 0.000 0.000 . .04/10/05 0.000 0.000 0.000 0.00004/17/05 0.000 0.000 . .04/24/05 0.000 0.000 . .05/01/05 0.000 0.000 . .05/08/05 0.000 0.000 . .05/15/05 0.000 0.000 . .C.9

FINAL REPORT Carmen-Smith Hydroelectric Project (FERC No. 2242)Fish Entrainment Technical ReportExhibit 4Video footage of fish entrainmentVideoCopyright © 2006 Eugene Water & Electric Board - the following Exhibit 4 for the Fish Entrainment Technical Report:Exhibit 4Video footage of fish entrainment