Bridge River Water Use Plan Lower Bridge River Aquatic Monitoring Implementation Year 1 Reference: BRGMON-1 2012 Annual Data Report Study Period: January 1, 2012 – December 31, 2012 Coldstream Ecology, Ltd. PO Box 1654 Lillooet, BC V0K 1V0 Tel: 250-256-0637 Please cite as: McHugh and Soverel, 2013. Lower Bridge River Aquatic Monitoring. Year 2012 Data Report. Bridge Seton Water Use Plan. Prepared for St'at'imc Eco Resources, Ltd. and BC Hydro for submission to the Deputy Comptroller of Water Rights, August 2013. July 31, 2013 Bridge-Seton Water Use Plan Lower Bridge River Annual Data Report July 31, 2013 Bridge-Seton Watershed Lower Bridge River Aquatic Monitoring Program 2012 Annual Data Report Table of Contents 1.0 Executive Summary 5 2.0 Introduction 7 2.1 Management Questions 8 2.2 Objectives and Scope 9 2.3 Approach 9 2.4 Study Area 9 2.5 Study Period 12 3.0 Methods 12 3.1 The Aquatic Monitoring Program 12 3.1.1 Overview 12 3.1.2 Water temperature, River Stage, and Flow Release 13 3.1.3 Water Chemistry and Nutrient Sampling 13 3.1.4 Primary and Secondary Productivity Sampling 14 3.1.5 Sampling for juvenile salmonid growth data 15 3.1.6 Fall Standing Stock Assessment 15 3.2 Flow Rampdown Surveys 16 3.2.1 Overview 16 3.2.2 Communications 16 3.2.3 Terzaghi Flow Release and River Stage 17 3.2.4 Water Temperature and Turbidity 17 3.2.5 Fish Salvage 17 3.3 Chinook Life History 18 4.0 Aquatic Monitoring Results 19 4.1 Physical Conditions 19 4.1.1 River Stage 19 4.1.2 Water temperature 21 4.1.3 Water Chemistry 25 4.2 Periphyton and Macroinvertebrates 25 4.2.1 Periphyton 25 BC Hydro Page 2 Bridge-Seton Water Use Plan Lower Bridge River Annual Data Report July 31, 2013 4.2.2 Macroinvertebrates 26 4.3 Fish Sampling 27 4.3.1 Fish Growth 27 4.3.2 Standing Stock Assessment 28 5.0 Results and Discussion 30 5.1.1 Answering the Management Questions and Current Challenges 30 6.0 Flow Rampdown Survey Results 31 7.0 References Cited 31 8.0 Summary Cost Table 33 9.0 APPENDIX A 33 9.1 Additional Tables and Figures 33 10.0 APPENDIX B 34 10.1 Flow Rampdown Survey Results 34 10.1.1 Terzaghi Dam Flow Release and River Stage Results 34 10.1.2 Water Temperature and Turbidity 38 10.1.3 Physical Habitat Attributes 41 10.1.4 Fish Salvage 43 10.1.5 Recommendations and Discussion 47 11.0 APPENDIX C 48 11.1 Chinook Life History Sampling 48 12.0 APPENDIX D 49 12.1 Details regarding methods and locations of sampling sites. 49 12.1.1 Nutrient Samples Collection Procedure 49 12.1.2 Chlorophyll Sampling 54 12.1.3 Lower Bridge River Temperature Logger Locations 54 12.1.4 Photograph Reference Site Descriptions 55 List of Tables Table 1. Reach break designations and descriptions for the Lower Bridge River 10 Table 2. Schedule of Sampling Sessions, 2012. 12 Table 3. Size ranges (in mm) for each age-class of salmonids captured in the Lower Bridge River for growth information, May to November 2012. 28 Table 4. Estimated mean biomass (g/100 m2) of salmonids captured in the Lower Bridge River during the standing stock assessment, 5 September to 10 October, 2012. 29 BC Hydro Page 3 Bridge-Seton Water Use Plan Lower Bridge River Annual Data Report July 31, 2013 Table 5. Summary Cost Table: Costs per study are shown as a total per year including inflation and contingency. 33 Table 6. Summary of stage changes at various locations downstream of Terzaghi Dam on each ramping date, August and October 2012. 37 Table 7. Maximum and mean hourly stage changes at the Plunge Pool site on each ramping date, August and October 2012. 38 Table 8. Summary of site attributes for all fish salvage locations on the Lower Bridge River between Terzaghi Dam and the Yalakom River confluence. 42 Table 9. Summary of numbers of fish salvaged by ramping date, August and October 2012. 44 Table 10. Summary of numbers of fish salvaged by species and age class, August 2012. 44 Table 11. Summary of numbers of fish salvaged by species and age class, October 2012. 44 Table 12. Summary of numbers of fish salvaged by Reach, August 2012. 45 Table 13. Summary of numbers of fish salvaged by Reach, October 2012. 45 Table 14. Summary of sizes for fish that were measured for forklength, August 2012. 47 Table 15. Site names and sampling locations for water collection (i.e., nutrients and chlorophyll). 50 Table 16. Site names and sampling locations for temperature loggers 54 Table 17. Lower Bridge River Site Reference Photos Descriptions (Also refer to the set of Sample Reference Photos) taken for BRGMON-16 55 List of Figures Figure 1. The Lower Bridge River Aquatic Monitoring Program study area, including reach breaks, index sample site locations (indicated by black dots), and the locations of tributaries between Terzaghi Dam and the Fraser River. The red diamonds indicate the approximate locations of the 50 fall standing stock assessment sites. 11 Figure 2. Lower Bridge River hydrographs at the 3 m3s-1 and 6 m3s-1 water budgets. Arrow indicates the timing of the annual fall standing stock assessment sampling. 16 Figure 3. Relative river stage levels at three locations on the Lower Bridge River and mean daily flow releases from the LLO (lower level outlet) gate at Terzaghi Dam during 2012 (2° axis). 20 Figure 4. Mean daily flow releases from the LLO (lower level outlet) gate at Terzaghi Dam during 2011, 2012, and the start of 2013. 21 Figure 5. Mean daily water temperatures recorded in the Lower Bridge River, 1 January to 31 December 2012. 22 Figure 6. Mean daily temperatures for Reach 3 during fall spawning season (Sept-Dec) for Pre-Trial (1996-1999), Trial 1 (2000-2010), and Trial 2 ( 2011, 2012). 23 Figure 7. Mean daily temperatures for Reach 4 during fall spawning season (Sept-Dec) for Trial 1(2000-2010), and Trial 2 (2011, 2012). Pre-Trial data are not applicable because Reach 4 was not wetted at this time. Reache 2 is included in Appendix A, A2.4. 23 Figure 8. Mean periphyton accrual (measured as Chlorophyll a) on artificial substrates in the Lower Bridge River, during the fall series sampling in 2012. Each point represents an average accrual for all stations within a reach; bars represent +/- 1 standard dev. 26 Figure 9. Macroinvertebrate mean abundance per taxa (primary axis) and total taxa biodiversity (secondary axis) at site index locations 39.9, 36.5, 33.3, 30.4, 26.4, 23.6, and 20. 27 BC Hydro Page 4 Bridge-Seton Water Use Plan Lower Bridge River Annual Data Report July 31, 2013 Figure 10. 15 minute stage levels at or near the reach breaks on the Lower Bridge River (1° axis), and hourly flow releases from Terzaghi Dam (2° axis), August 2012. 34 Figure 11. 15 minute stage levels at or near the reach breaks on the Lower Bridge River (1° axis), and hourly flow releases from Terzaghi Dam (2° axis), October 2012. 35 Figure 12. 15 minute stage levels at or near the reach breaks on the Lower Bridge River (1° axis), and hourly flow releases from (2° axis), November, 2012. 36 Figure 13. Relative river stage levels recorded from observations of staff gauges at four locations in the Lower Bridge River, August 2012. 36 Figure 14. Hourly water temperatures recorded from the Lower Bridge River at ca. 3 km intervals downstream of Terzaghi Dam, August 2012. 39 Figure 15. Hourly water temperatures recorded from the Lower Bridge River at ca. 3 km intervals downstream of Terzaghi Dam, October 2012. 39 Figure 16. Hourly water temperatures recorded from the Lower Bridge River at ca. 3 km intervals downstream of Terzaghi Dam during most of the duration of the gate malfunction in October and November, 2012. 40 Figure 17. Mean turbidities recorded for water samples collected at the start and end of flow changes on each ramping date, August and October 2012. Black lines represent standard deviation for the individual measurements. 41 Figure 18. Range of flows where fish salvage operations were required at each site during flow ramping in 2012. The vertical light blue lines indicate the flow changes that required incidental fish captures as fish were being 'pushed' out of dewatering habitats. The solid black rectangles indicate the flow ranges where isolated habitats were observed and active fish salvaging was conducted. 43 Figure 19. Numbers of fish salvaged by condition at capture for each site during the rampdown events in August 2012. 46 Figure 20. Numbers of fish salvaged by condition at capture for each site during the rampdown events in October 2012. 46 1.0 EXECUTIVE SUMMARY Historically, the Bridge River Valley was a thriving, productive river valley that harbored a rich and abundant diversity of aquatic and terrestrial life. This diversity contributed vast benefits to local and regional culture, society and the environment. These benefits were partially the result of interconnectedness between the headwaters of the Bridge River and the confluence of the Fraser River. In 1948, the interconnectedness was broken by the building of Mission Dam, and in 1960 the system was fully fragmented by the finalization of Terzaghi Dam. Terzaghi dam blocked off all flow into the Lower Bridge River (LBR) between 1960 and 2000, converting approximately 4km of its uppermost reach from aquatic to terrestrial habitat.