Mitigation for the Construction and Operation of Libby Dam

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index (e.g., contribution of EPT-taxa), Simpsons Diversity (D), the ratio of Baetidae: Ephemeroptera, the contribution of Diptera, the proportional abundance of burrowers and sprawlers (sediment tolerant), and the contribution of collector-gatherers. At the Libby Creek Upper Cleveland Project site, 3 of the 7 metrics had values in 2003 that were significantly different from the values attained from the pre-restoration values. However, they were all in the opposite direction expected. We specifically expected the relative abundance of sensitive organisms (% EPT) to increase and the dominance of tolerant organisms (% Diptera and % Collector-gatherers) to decrease as conditions become more natural. We observed the opposite and this usually indicates an ecosystem is that has been recently disturbed. None of the Grave Creek metrics tested showed a statistically significant difference between the pre- and post-restoration samples. Results indicate that a longer-term monitoring program will be necessary to document changes as the streams recover. We conducted juvenile salmonid population estimates within reference reaches on Sinclair, Therriault, Grave, Young, Libby, Parmenter, and Pipe creeks. Trend analyses relevant to stream restoration projects are presented for Grave, Libby, and Parmenter creeks. Montana FWP has documented the changes in species composition, and species size and abundance within Libby Reservoir since the construction of Libby Dam. We continued monitoring fish populations within the reservoir using spring and fall gill netting and present the results and trend analyses for 11 fish species. Our spring gill net catch of bull trout has especially increased since 1990. We were able to improve the linear regression model for bull trout gillnet catch between years by adjusting the mean bull trout catch per net by reservoir volume at the time the nets were fished each year. This adjustment substantially improved the regression model’s fit to the data. Bull trout redd counts in both the Wigwam River and Grave Creek are both significantly and positively correlated to the spring gill net catch rates for bull trout adjusted for reservoir elevation. Montana FWP has also monitored zooplankton species composition, abundance and size of zooplankton within the reservoir since the construction and filling of Libby Dam. Zooplankton abundance, species composition, and size distribution have also all been similar during the second half of the reservoir’s history. Since 1997, Cyclops and Daphnia have been the first and second most abundant genera of zooplankton present in the reservoir. Introduction The primary objectives of the Libby Mitigation Project are to 1) Correct deleterious effects caused by hydropower operations and mitigate for fisheries losses attributed to the construction and operation of Libby Dam using watershed-based, habitat enhancement, fish passage improvements, and offsite fish recovery actions, 2) Integrate computer models into a watershed framework using Montana FWP’s quantitative reservoir model (LRMOD), Integrated Rule Curves (IRC), Instream Flow Incremental Methodology (IFIM) and Libby Dam fish entrainment model (ENTRAIN), to improve biological production by modifying dam operation, and 3) Recover native fish species including the endangered Kootenai River white sturgeon, threatened bull trout, westslope cutthroat trout, interior redband rainbow trout, and burbot. A loss statement, site-specific mitigation actions and monitoring strategies were documented in the Libby Mitigation and Implementation Plan (MFWP, CSKT and KTOI. 1988). 39
Biological monitoring data was proven to be critical for empirically calibrating computer models used in management of water resources and operation of Libby Dam. The quantitative biological model LRMOD was calibrated using field data collected by project personnel from 1983 through 1990. Field data from 1991 through 1995 were used to refine and correct uncertainties in the model and add a white sturgeon component (Marotz et al. 1996 and 1999). These models include Integrated rule curves (IRC’s), the Libby Reservoir model (LRMOD) and an alternate flood control strategy called VARQ, which stands for variable flow (Q). The ultimate result has been the integration of fisheries operations with power production and flood control to reduce the economic impact of basin-wide fisheries recovery actions. Investigations into the factors limiting native fish populations require a combination of diverse field evaluation techniques. Characteristics evaluated include population densities, species assemblages and composition, fish length-at-age (otolith and scale aging), growth, condition factors, indices of abundance and biomass estimates. In this chapter we describe the results of the field activities required to gather this information. In addition, habitat enhancement and fish passage improvement measures may be the most promising methods for recovering native resident stocks. This project has embraced this approach and implemented several restoration projects on a basin wide priority basis using a step-wise, adaptive management approach to correct limiting factors for bull trout, burbot, white sturgeon, and redband trout in the Kootenai Basin (see chapter 2). Biological and physical monitoring is critical to assess the effectiveness of restoration or management actions designed to restore native fishes and their habitats. Evaluation of restoration activities and pilot projects will continue to determine the most cost-effective methods for enhancing these diverse populations. This chapter describes the physical and biological monitoring activities necessary to achieve the activities described above. Bull Trout Redd Counts Methods Redd surveys were conducted in October after bull trout spawned in the Wigwam and West Fisher rivers, Grave, Quartz, Bear (a tributary to Libby Creek), Keeler, Pipe, and O’Brien creeks. MFWP and U.S. Forest Service (USFS) personnel walked streams in the United States and personnel from the British Columbia Ministry of Water, Land, and Air Protection walked the Wigwam River and associated tributaries. Observers enumerated “positive” and “possible” redds. “Possible” redds were those that did not have fully developed pits and gravel berms. Since 1993, only “positive” redds have been counted, and are included in tables and figures for this report. In addition to counting redds, size and location of redds were also noted. Surveyors recorded suitable habitat and barriers to spawning bull trout when a stream was surveyed for the first time. We used linear regression of redd counts to assess population trends. Kootenai River Adult Bull Trout Population Estimate 40
Page 1 and 2: Mitigation for the Construction and
Page 3 and 4: MITIGATION FOR THE CONSTRUCTION AND
Page 5 and 6: depth of burbot that were relocated
Page 7 and 8: ACKNOWLEDGEMENTS We are thankful to
Page 9 and 10: Juvenile Salmonid Population Estima
Page 11 and 12: deviation from reference conditions
Page 13 and 14: Figure 46. Minimal detectible diffe
Page 15 and 16: Chapter 2 Tables Table 1. Design sp
Page 17 and 18: INTRODUCTION Libby Reservoir was cr
Page 19 and 20: PROJECT HISTORY Montana Fish, Wildl
Page 21 and 22: 2002 - Montana FWP collaborated wit
Page 23 and 24: DESCRIPTION OF STUDY AREA Subbasin
Page 25 and 26: Table 1. Current relative abundance
Page 27 and 28: Similar impacts have been observed
Page 29 and 30: 2460 2440 2420 2400 2380 2360 2340
Page 31 and 32: construction and operation of Libby
Page 33: Chapter 1 Physical and Biological M
Page 37 and 38: Figure 1. An aerial photograph of L
Page 39 and 40: antenna located approximately 5 cm
Page 41 and 42: We compared samples collected in Se
Page 43 and 44: extends downstream 131 m. This sect
Page 45 and 46: and reduced again to 28 ganged floa
Page 47 and 48: Results Bull Trout Redd Counts Grav
Page 49 and 50: Table 1. Bull trout redd survey sum
Page 51 and 52: Quartz Creek Bull trout redd counts
Page 53 and 54: Bull Trout Redds 40 35 30 25 20 15
Page 55 and 56: Keeler Creek Bull trout that spawn
Page 57 and 58: Burbot Monitoring Below Libby Dam T
Page 59 and 60: Table 2. Summary information for th
Page 61 and 62: 7000 6000 5000 Y = 45.246e 0.0055x
Page 63 and 64: The Libby FWP Mitigation Staff surg
Page 65 and 66: Table 2. (Continued) Capture locati
Page 67 and 68: Figure 18. Capture locations for a
Page 69 and 70: Table 4. T-test results. This table
Page 71 and 72: Figure 19. Montana Mountain Metrics
Page 73 and 74: Table 5. T-test results. This table
Page 75 and 76: Juvenile Salmonid Population Estima
Page 77 and 78: Grave Creek Juvenile salmonid monit
Page 79 and 80: Number Fish per 1000 Feet 100 80 60
Page 81 and 82: Libby Creek Section 1 of Libby Cree
Page 83 and 84: Figure 28. Rainbow trout, brook tro
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Pipe Creek Juvenile rainbow trout w
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Table 6. Average length and weight
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Catch per Net A. Mountain Whitefish
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Table 8. Kamloops rainbow trout cap
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25000.0 20000.0 15000.0 10000.0 500
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Burbot per Trap Day 3 2.5 2 1.5 1 0
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Table 9. Average catch per net for
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Table 11. Percent composition of ma
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deviation = 0.052; Figure 43), with
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Table 12. Individual probability va
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Discussion Long-term monitoring of
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We believe that Libby Reservoir dur
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Figure 47. Minimal detectible diffe
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References Bahls, L., R. Bukantis,
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trout status report (below Kootenai
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Chapter 2 Stream Restoration and Mi
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food sources, as evidenced by the l
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Methods and Results Eureka Pond The
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spacing was 172.8 feet, which repre
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Figure 2. Vicinity Map for Upper Li
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Table 1. Design specifications for
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70 60 50 40 30 20 10 0 500 1000 150
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Grave Creek Phase I Restoration Pro
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Table 4. Design specifications for
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190.0 185.0 180.0 175.0 170.0 165.0
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educed the mean width and width to
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Table 7. Mean cross sectional area,
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Discussion The Grave Creek Phase I
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References Chisholm, I.M., M.E. Hen
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Appendix 148
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Table A2. Lower Grave Creek Demonst
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Table A4. Libby Creek depletion pop
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Table A7. Mean zooplankton densitie
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Table A9. Mean zooplankton densitie
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Table A13. Yearly mean total zoopla
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Mitigation for the Construction and Operation of Libby Dam

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