Assessment of the distribution of 2014 brood coho adult migration below and above the Salmon River diversion dam

Transcription

1 Assessment of the distribution of 2014 brood coho adult migration below and above the Salmon River diversion dam FWCP Project 14.CBR.04 Prepared for: Fish and Wildlife Compensation Program Prepared by: E. Guimond 1 and M. Sheng 2 On behalf of: Campbell River Salmon Foundation 100 St. Ann's Rd. Campbell River, BC V9W 4C4 Prepared with financial support of: Fish and Wildlife Compensation Program on behalf of its program partners BC Hydro, the Province of B.C., Fisheries and Oceans Canada, First Nations and public stakeholders April E. Guimond Leighton Ave., Courtenay, BC V9N 2Z5 2 M. Sheng - Fisheries and Oceans Canada, 3225 Stephenson Point Rd., Nanaimo, BC V9T 1K3

2 EXECUTIVE SUMMARY In 2012 BC Hydro approved funding for a new or improved fishway at the diversion dam, and construction was scheduled to be completed before the 2015 coho migration season. This date has now been postponed to This decision resulted from 4 years of effort by the Salmon River Diversion Dam Fish Passage Consultative Committee on the Fish Passage Decision Framework process. The Campbell River Salmon Foundation (CRSF), as well as federal and provincial fisheries agency representatives, recommended a pre- and post- monitoring study be incorporated as a component of the fishway upgrade/replacement project. Monitoring coho distribution and escapement prior to fishway construction will be a key element in the performance evaluation of the overall project, which requires a more accurate assessment of the distribution and number of coho salmon that are above and below the diversion dam. In 2013, CRSF received funding from the Fish and Wildlife Compensation Program (FWCP) Coastal Region to implement a pre-construction monitoring program. This report summarizes activities in the second year of the 2 year monitoring program to assess coho salmon migration at the Salmon River diversion dam. Coho spawners in the Salmon River and tributaries were enumerated during five low-level aerial surveys conducted between September 15 and December 3, 2014, with peak counts observed during the third survey on October 7, The aerial survey data was combined with snorkel survey data collected by the A-Tlegay Fisheries Society in order calculate an Area-Under-the-Curve (AUC) escapement estimate for the system of 5,485 coho adults. The number of coho that accessed habitat above the dam was 60 adults observed on the final survey in December. This represents less than 2% of the total escapement. In November 2012, BC Hydro received a new Water Licence for the Campbell River Watershed which required the under-sluice gate to be set to 0.35 m (14 in.) open, which would provide the new minimum flow of 4 m 3 /s downstream when naturally available, without head build-up in the canal. However, field monitoring in 2013 determined that a setting of 0.35 m (14 in.) provided a minimum flow downstream of the dam that was greater than 4 m 3 /s. Therefore a range between 0.25 and 0.35 m (9.75 and 14 in.) was implemented in During the coho migration period, the undersluice gate was increased from a minimum setting of 0.25 m (9.75 in.) to 0.35 m (14 in.) on 31 October Water level data referenced to invert elevations of various key structures at the Salmon River diversion dam was used to assess fish passage through the under-sluice gate, fishway and canal trash rack by calculating the head difference upstream and downstream of each of these structures. Out of a total of 2905 hourly water level ii

3 records between 1 September and 31 December 2014, fish passage was accessible at the under-sluice 37.5% of the time based on a conservative maximum burst speed estimate for coho adults. Similarly, passage through the fishway was accessible 7.5% of the time based on the fishway orifice head drop threshold values. Passage is further reduced to 32.9% and 1.9%, respectively, if the minimum temperature threshold limitations (4.4 o C) are included. iii

4 TABLE OF CONTENTS Executive Summary... ii Table of Contents... iv List of Figures... v List of Tables... vi List of Appendices... vi 1 INTRODUCTION Background Goals and Objectives STUDY AREA METHODS Coho salmon aerial survey and escapement estimate Water level monitoring Communication Plan RESULTS AND DISCUSSION Coho salmon aerial survey and escapement estimate Water level monitoring Communications RECOMMENDATIONS ACKNOWLEDGEMENTS REFERENCES iv

5 LIST OF FIGURES Figure 1. Salmon River watershed Figure 2. Salmon River diversion system (from Anderson 2009) Figure 3. Location of the water level recorders at the diversion dam: A - diversion dam forebay, B - canal at fishway outlet (upstream end), and C - entrance of the river (downstream end). The barometer is also located at site A Figure 4. View of the canal and fishway and the location of the lower (downstream) and upper (upstream) water level recorders (arrows). (Photo credit S. Anderson)... 8 Figure 5. Salmon River hourly discharge and temperature data from WSC Gauge No. 08HD015, above the Salmon River diversion dam, for the coho salmon migration period. Aerial survey dates and associated coho counts, expanded for OE, are denoted by symbols Figure 6. Distribution of coho salmon upstream and downstream of the Salmon River diversion dam, during five aerial surveys (bars). Total coho counted has been expanded for observer efficiency (OE) Figure 7. Water level data (referenced to elevation) relative to key BC Hydro project elevations at the Salmon River diversion dam for the period September 1 to December 31, Salmon River discharge (above the dam) and the Salmon diversion flow is included for comparison Figure 8. Head difference at the under-sluice gate versus Salmon River discharge (from WSC gauge 08HD015 above the dam). Relationship in a) above was calculated in 2013 when under-sluice was at 0.35 m (14 in.) while b) was calculated from 2014 data Figure 9. Velocity through the under-sluice gate at two gate settings, when forebay water levels were less than m (i.e. when the water level was below the canal intake invert and all river discharge flows through the under-sluice). Data points below the red line indicate hourly periods when fish passage was possible Figure 10 a & b. Velocity / discharge relationship of the under-sluice at the 0.35 m (14 in.) gate setting and the 0.25 m (9.75 in.) gate setting to achieve the minimum licensed discharge requirement of 4 m 3 /s downstream of the dam Figure 11. Mean head drop over the 8 cells in the Salmon River diversion dam fishway for the period 1 Sept 31 Dec 2014 (preferred target head drop between fishway cells for an orifice fishway is 0.3 m). Black symbols are calculated from recorded river WL data while pink symbols are using estimated river WL data. Data points below the red line indicate hourly periods when fish passage was likely possible Figure 12. Trash racks over the entrance to the canal looking upstream (left), and the outlet of the fishway in the canal (right). Partial obstruction with debris may impede fish passage for adult migration through the fishway and into the forebay Figure 13. Head difference between forebay water level and canal water level (blue line) compared to Salmon River discharge above the diversion dam v

6 Figure 14. Salmon River temperature profile during the period of water level monitoring at the diversion dam. Coho passage at the fishway has been observed to cease at temperatures below 4.4 o C (Damborg and Pellett 2012) Figure 15. Water level data referenced to elevation from the Forebay and Canal loggers, and associated discharge in the Salmon River upstream of the dam Figure 16. Pipe housing the water lever logger in the Forebay adjacent the canal trash rack LIST OF TABLES Table 1. Salmon River and tributary survey segment locations and boundary coordinates Table 2. Under-sluice gate settings during the 2014 coho migration period Table 3. Estimated abundance (expanded for observer efficiency), based on live counts for all species observed during four aerial surveys of the Salmon River Table 4. Summary of fish passage at the under-sluice and fishway, as a percentage of the total coho migration period (1 Sept 31 Dec) Table 5. Compilation of adult salmon inspections at the Salmon River diversion dam from September 2013 to January LIST OF APPENDICES APPENDIX A. Fish Activity Log data sheet APPENDIX B. Salmon River 2014 Coho distribution aerial survey data APPENDIX C. DFO South Coast 2014 coho escapement for Salmon River APPENDIX D. Calculation of water level data for the recorder at the entrance to the Salmon River fishway vi

7 1 INTRODUCTION Resolving fish passage issues at BC Hydro's Salmon River diversion dam on Vancouver Island has been the focus of the Salmon River Diversion Dam Fish Passage Consultative Committee since January This Committee, made up of representatives from BC Hydro, Fisheries and Oceans Canada (DFO), Ministry of Forests, Lands & Natural Resource Operations (FLNRO), First Nations and other community stakeholder groups, was established to complete the steps in the Fish Passage Decision Framework. Fish passage at the Salmon River diversion dam has been identified as a footprint impact and is a high priority for federal and provincial agencies, as well as a concern for local stewardship groups, all of whom recognize the upper Salmon River as valuable and underutilized spawning and rearing habitat. It is acknowledged that coho salmon and steelhead trout will benefit substantially from improved passage at the Salmon River diversion and that optimum coho production in this system will not be achieved until fish passage improvements are made at the diversion dam. In 2012 BC Hydro approved funding for a new or improved fishway at the diversion dam, and construction was scheduled to be completed before the 2015 coho migration season. This date has now been postponed to 2016 or later. The Campbell River Salmon Foundation (CRSF), as well as federal and provincial fisheries agency representatives, recommended a pre- and post- monitoring study be incorporated as a component of the fishway upgrade/replacement project. Monitoring coho distribution and escapement prior to fishway construction will be a key element in the performance evaluation of the overall project, which requires a more accurate assessment of the distribution and number of coho salmon that are above and below the diversion dam. In 2013, CRSF received funding from the Fish and Wildlife Compensation Program (FWCP) Coastal Region to implement a pre-construction monitoring program. This report summarizes activities in the second year of the 2 year monitoring program to assess coho salmon migration at the Salmon River diversion dam. 1.1 Background A fishway was added to the Salmon River diversion dam in 1992 to facilitate coho salmon and winter steelhead trout passage into the upper Salmon River. The fishway consists of a series of eight submerged orifices with a small entrance at its downstream end and an intake which connects upstream into the BC Hydro diversion canal. It has been well documented that the existing Salmon River diversion dam 1

8 fishway provides only intermittent access (Anderson 2009, Damborg and Pellett 2012). During the spring freshet period, when peak adult steelhead migration occurs, the fishway has little attraction flow in comparison to overall discharge over the dam trimming weir, spillway and through the dam s under-sluice gate. At higher flows during the fall and winter period, only a limited number of coho are able to successfully migrate through the fishway due to excessive turbulence and velocities (Damborg and Pellett 2012). A key concern is the upstream end of the fishway which exits directly into the diversion canal. The canal is a rectangular smooth-sided concrete flume that diverts a portion of the Salmon River to the Campbell River watershed when flows are available. When diversion canal flows are released under the radial arm gate located a few metres downstream of the fishway exit, adults that exit the fishway into the canal must immediately turn 90 degrees, swim upstream against diversion canal flows, through the concrete orifices and then the diversion intake trash rack which occasionally plugs with wood debris during high flow events (McCubbing 2003). Returning adults are attracted to the sluice gate, fishway outlet, spills over the trimming weir and the diversion dam spillway as river discharges increase. Furthermore, coho salmon that enter the fishway during high discharges are impeded by velocity barrier conditions at some of the submerged fishway orifices (McCubbing and Burroughs 2009; McCubbing 2010). All of these conditions impose significant challenges to salmon migration above the dam. In the last 3 years ( ), when coho adult escapements were over 4,000, only 3-8% of the returns were observed above the diversion dam, yet 30% of the available coho habitat in the watershed is located above the dam. During this period, increased effort was made jointly by DFO and BC Hydro to facilitate coho access through the under-sluice gate by increasing the opening of the under-sluice when possible. Increased effort was also made enumerating adults upstream and downstream of the diversion (i.e. over-flights conducted in 2009, 2010 and 2011). Prior to 2009, the effort towards managing the gate for coho access outside of normal maintenance schedules was limited. Although there are no accurate records, adult migration above the diversion dam was likely significantly lower. In contrast, efforts made by BC Hydro and agency staff to increase opportunities for adult passage through the under-sluice gate in the last 4-5 years likely had a positive influence on the number of adults that accessed habitat above the diversion dam. The upper Salmon River escapement is far below the habitat capacity available upstream of the diversion dam. Based on a conservative bio-standard loading rate of 50 adults per kilometer, the 44 kilometers of accessible stream length above the diversion dam (Burt, 2010a) should support 2,500 adults. This represents approximately 30% of the Salmon River watershed capacity. The total length of accessible stream habitat in 2

9 the entire watershed is conservatively estimated at 156 km which should support a total of 7,800 adults. This does not include over 50 km habitat in the White River, a major tributary that joins the Salmon River a few kilometres from tide water. This method provides a reasonable estimate of coho adult capacity for B.C watersheds (Marshall and Britton 1990; Bradford et al. 1997; Bradford et al. 2000). The distribution of fish within the main-stem appears to be increasing at, and above, the diversion dam. Between 2001 and 2008, mean adult escapement to the Salmon River was approximately 6,100 adults (Burt 2010b). The estimated capacity of the Lower Salmon River is 5583 adults. The observed shift in adult distribution is probably the result of hatchery fry out-plants (by the Sayward Fish and Game Association) to the upper watershed between 1986 and This presumably increased upper watershed smolt production and subsequent homing of returning adults to their natal habitats above the diversion. The Salmon River coho population is now considered a wild population under Fisheries and Oceans Canada s Wild Salmon Policy (WSP). Hundreds of coho adults already hold below the diversion dam pool every year, many making it upstream when conditions allow. Improving fish passage at the dam would increase the opportunity for a larger number of adults accessing habitat in the upper river. This is strategically more sustainable than fry out-planting and provides B.C. Hydro a rare opportunity to establish a sustainable natural population of coho above one of its Hydro facilities without the need to enhance. 1.2 Goals and Objectives The goal of this study is to monitor coho salmon abundance and distribution in the Salmon River for two years prior to the planned fishway upgrade/replacement project to provide pre-construction baseline data for comparison to post construction assessments on habitat utilization and fish passage above the diversion dam. The objectives of Year 2 of the monitoring program are as follows: i. Conduct up to 6 helicopter over-flight surveys to enumerate the coho salmon population of the Salmon River and its tributaries (lower White River, Memekay River and Grilse Creek) over the course of the coho salmon residence timing (late September to mid-november) in order to a) assess the proportion of the coho salmon population that utilize habitat above the Hydro diversion versus below, and b) obtain counts of the coho salmon population over the course of the migration and spawning period in order to calculate an Area-Under-the- Curve (AUC) escapement estimate for the system. ii. Review and refine a communication plan with the Province, DFO and B.C. Hydro to determine when coho are present at the diversion dam, the river 3

10 discharge at that time, the weather conditions and forecast and decision rules for opening and closing the under-sluice gate to improve coho adult access above the diversion dam. iii. Install and monitor water level and temperature recorders in the headpond, canal and fishway outlet to track the hydraulic and water temperature condition during coho migration. This information will add to the existing database and be used for developing the design criteria for the new fishway. 2 STUDY AREA The Salmon River watershed encompasses a 1300 km 2 area, approximately 65 km north of Campbell River on northeastern Vancouver Island (Figure 1). It is the fourth largest river system on Vancouver Island, flowing for about 80 km from its headwaters in Strathcona Provincial Park to Johnstone Strait. Major tributaries to the Salmon River include the White and Memekay rivers with confluences in the lower 30 km, and Grilse Creek in the upper river. The Salmon River diversion works is one of three diversion systems of BC Hydro s Campbell River Hydroelectric Project. This system includes the Salmon River diversion dam and canal, located approximately 58 km upstream from the mouth, which diverts a portion of the flow from the Salmon River to the Lower Campbell Reservoir, when conditions warrant as per the provincially licensed agreement (BC Hydro 2012). Constructed in 1958 with no fish passage structure, the diversion dam historically acted as a barrier to most upstream fish passage except under rare flow conditions. In the mid-1970s, a 5 m high rock and debris obstruction located 12 km downstream of the diversion dam was removed from the river, improving salmonid migration to the dam. A fishway was retrofitted to the Salmon diversion canal in 1992 to facilitate coho salmon and winter steelhead trout passage into the upper Salmon River (Figure 2). The Salmon River supports a healthy population of coho salmon. This species has colonized habitat niches throughout the Salmon River watershed and are using habitats located up to and above the Salmon River diversion dam. Approximately 30% of the available coho habitat in the watershed is located above the diversion dam (Burt, 2010a). As such, unimpeded access to the upper watershed will be critical to the longterm adaptability, resiliency and sustainability of this population and the East Vancouver Island/Johnstone Strait-Southern Fjords) conservation unit (Holtby and Ciruna, 2007). 4

11 Figure 1. Salmon River watershed. Figure 2. Salmon River diversion system (from Anderson 2009). 5

12 3 METHODS 3.1 Coho salmon aerial survey and escapement estimate Coho spawners in the Salmon River were enumerated during five low-level aerial surveys conducted between September 15 and December 3, 2014 using an AStar helicopter out of Campbell River (West Coast Helicopters Maintenance and Contracting Ltd.). The Salmon River was divided into six distinct segments (Table 1), and all segments were surveyed during each flight. In addition, the lower ~10 km of the White River, largest of the tributaries to the Salmon River, was surveyed in 2014, due to the lower water levels early in the season which affected pink (and coho) distribution. Counts of other species present in the system were also recorded. Table 1. Salmon River and tributary survey segment locations and boundary coordinates. Segment Description Latitude (deg) Start Longitude (deg) Latitude (deg) End Longitude (deg) 1 Estuary to Highway Crossing Highway crossing to Memekay River Memekay River (confluence only in 2013) Grilse Creek to Salmon River Junction Salmon R/Grilse Ck junction to Diversion dam Diversion dam to Memekay River Two observers from DFO were present on each flight (P. Van Will and D. Ewart or another experienced crew from Quinsam Hatchery). Each observer made independent counts of all species (live counts only) in a segment, and the two counts were averaged for each segment by species, following each flight. Subjective assessments of observer efficiency (OE), or the accuracy of counts, were made based on each observer s experience. Estimated abundance (Live only) takes into account observer efficiency based on the viewing conditions (weather, water levels, shadows, wind, etc.), and the behaviour of the fish at the time of the observations. OE was then used to expand the counts for each segment. An estimate of the percent of the population covered on the flight was made based on observations of fish distribution from previous flights, and the counts were expanded based on OE and the percent of the population assumed not to be covered due to the flight conditions. For each survey, a final estimate of abundance for each species was calculated by summing the expanded counts in all segments surveyed. The proportion of coho observed above the diversion 6

13 dam on each survey date was calculated based on the escapement estimated in segments 4 and 5 (upstream of the dam) to the total estimate for the entire survey area. 3.2 Water level monitoring Three water level monitoring stations established for the 2013 Coho enumeration project (13.CBR.04), and previously used by Damborg and Pellett (2012), were used to track the hydraulic conditions at the diversion dam over the coho migration period (Figure 3). The stations were located in the diversion dam Forebay, the Canal at the fishway outlet (upstream end), and in the River downstream of the dam at the entrance of the fishway (downstream end). Each station was equipped with a water level recorder/transducer (Levelogger Model 3001; Solinst Canada Ltd., ON) suspended on a stainless steel cable in a perforated steel standpipe. In addition, a barometer (Barologger Model 3001; Solinst Canada Ltd., ON) was suspended at the top of the standpipe in the diversion dam forebay, to monitor local atmospheric pressure which was used to correct total pressure data from the three submerged water level recorders. All loggers were installed on 23 July, C B A Figure 3. Location of the water level recorders at the diversion dam: A - diversion dam forebay, B - canal at fishway outlet (upstream end), and C - entrance of the river (downstream end). The barometer is also located at site A. 7

14 The loggers were downloaded periodically during the coho migration period (9 September and 17 November 2014) and removed after the end of the migration (17 February 2015). During the final 17 Feb visit, the logger in the river (entrance to the fishway) was found to be missing, (either displaced during an extreme high flow event or from theft), and the logger in the canal could not be removed because it was embedded in silt/sand. The latter was recovered a few weeks later by BC Hydro staff. Figure 4. View of the canal and fishway and the location of the lower (downstream) and upper (upstream) water level recorders (arrows). (Photo credit S. Anderson) 3.3 Communication Plan During the coho migration period, DFO and/or BC Hydro conducted weekly (or biweekly) site visits at the diversion dam to inspect the gate settings, debris accumulation, the number of coho holding below the dam and at other locations downstream. Information from regular inspections were fed into a larger Communications Strategy that has been developed over the past few years to facilitate in-season decisions on flow regulation options for improving passage at the dam. Fish Activity Logs were completed by designated staff during each visit on-site (Appendix A), and circulated to DFO, FLNRO and BC Hydro personnel. In November 2012, BC Hydro received a new Water Licence for the Campbell River Watershed which required the under-sluice gate to be set to 0.35 m (14 in.) open, which would provide the new minimum flow of 4 m 3 /s downstream when naturally available, without head build-up in the canal. However, in 2013, field monitoring determined that a setting of 0.35 m (14 in.) provided a minimum flow downstream of 8

15 the dam that was greater than 4 m 3 /s (Guimond and Sheng 2014). Therefore a range between 0.25 and 0.35 m (9.75 and 14 in.) was implemented in During the coho migration period, the under-sluice gate was increased from a minimum setting of 0.25 m (9.75 in.) to 0.35 m (14 in.) on 31 October 2014 (Table 2). The under-sluice gate may be adjusted depending on river conditions, fish presence or debris management concerns. Table 2. Under-sluice gate settings during the 2014 coho migration period. Date Under-sluice Gate Setting 30-Apr-14 Reduced from 0.35 m to 0.32 m open (14" to 12 ½ ) 4-Jun-14 Reduced to 0.25 m (9 ¾ ") 31-Oct Jan-15 Increased from 0.25 m to 0.86 m (9 ¾ " to 34") for fish, then lowered to 0.35 m (14") at end of day Reduced to 0.32 m (12 ½ ") open 4 RESULTS AND DISCUSSION 4.1 Coho salmon aerial survey and escapement estimate Discharge in the Salmon River during the coho migration period and the five aerial surveys are illustrated in Figure 5. For most flights visibility was good under the lower flow conditions. A survey originally scheduled for mid-october was cancelled due to high river levels and poor weather. During the first two surveys, the majority of fish were observed in the lower river up to or just above the Memekay confluence due to low water conditions. Significant concentrations of pink salmon were observed in the lower river, including the White River, which affected observations of other species (P. Van Will, personal communication, February 2015). By the third survey (7 Oct), coho were distributed up to the Salmon River dam, with only one coho observed above the dam. Table 3 provides a summary of counts (live adults only) for all species recorded on each helicopter flight, which includes adjustments for observer efficiency. 9

16 1-Sep 6-Sep 11-Sep 16-Sep 21-Sep 26-Sep 1-Oct 6-Oct 11-Oct 16-Oct 21-Oct 26-Oct 31-Oct 5-Nov 10-Nov 15-Nov 20-Nov 25-Nov 30-Nov 5-Dec 10-Dec 15-Dec 20-Dec 25-Dec 30-Dec Discharge (m 3 /s) No. fish (x 1000); Temperature ( o C) 2014 Salmon River Coho Distribution Assessment 14.CBR Salmon R Q Above Diversion Salmon River Diversion Q River Temperature Aerial survey and associated Coho count Figure 5. Salmon River hourly discharge and temperature data from WSC Gauge No. 08HD015, above the Salmon River diversion dam, for the coho salmon migration period. Aerial survey dates and associated coho counts, expanded for OE, are denoted by symbols. Table 3. Estimated abundance (expanded for observer efficiency), based on live counts for all species observed during four aerial surveys of the Salmon River. Survey Date Species 15-Sep 26Sep 7-Oct 14 Nov 3 Dec Coho ,144 1, Pink 56,000 40,000 13, Chinook Chum Sockeye The estimated number of coho and the proportional distribution below and above the diversion dam is illustrated in Figure 6. The highest count of coho above the dam was 60 adults observed during the final aerial survey on 3 December 2014, representing approximately 35% of the total population on this survey date, but less than 2% of the total escapement (Appendix B). 10

17 % Distribution Number of fish 2014 Salmon River Coho Distribution Assessment 14.CBR.04 Below Diversion Above Diversion Total Count Sept 15 Sept 26 Oct 7 Nov 14 Dec 3 Survey Date 0 Figure 6. Distribution of coho salmon upstream and downstream of the Salmon River diversion dam, during five aerial surveys (bars). Total coho counted has been expanded for observer efficiency (OE). Additional information on coho salmon abundance from snorkel surveys conducted in the lower river by others (A-Tlegay Fisheries Society), was used to improve the numbers throughout the coho migration season, allowing a more accurate Area-Under-the-Curve (AUC) escapement estimate for the system (Appendix C). The AUC method generates an estimate of escapement using periodic estimates of fish numbers and an estimate on the length of time fish are alive in the survey area, (residence time or survey life). The AUC software program used by DFO Stock Assessment, modified from Irvine et al. (1993) calculates a 2014 coho escapement estimate of 5,485 adults (range 4571 to 6,856), using a 25 day survey life based on past studies of coho residence time (D. Nagtagaal, personal communication May 2014). 4.2 Water level monitoring Water level (WL) data (referenced to invert elevations on as-built BC Hydro drawings) from the three recorders at the diversion dam, in relation to the elevation of various key structures, was used to assess fish passage through the under-sluice gate, fishway and canal trash rack by calculating the head difference upstream and downstream of each of these structures (Figure 7). 11

18 1-Sep 6-Sep 11-Sep 16-Sep 21-Sep 26-Sep 1-Oct 6-Oct 11-Oct 16-Oct 21-Oct 26-Oct 31-Oct 5-Nov 10-Nov 15-Nov 20-Nov 25-Nov 30-Nov 5-Dec 10-Dec 15-Dec 20-Dec 25-Dec 30-Dec Discharge (m 3 /s) 2014 Salmon River Coho Distribution Assessment 14.CBR.04 The following section evaluates passage under various water level and discharge conditions at the dam, regardless of fish presence below the dam during the time the data was collected, and other factors such as temperature and/or fish condition that may have influenced passage Salmon River Discharge SR Diversion flow Forebay WL Elevation Canal WL Elevation River WL Elevation Elevation (m) Crest of Spillway m Crest of trimming weir 223.8m Canal Intake m Fishway at Canal 220.8m Under-sluice sill m Figure 7. Water level data from 3 water level recorders (referenced to elevation) relative to key BC Hydro project elevations at the Salmon River diversion dam for the period September 1 to December 31, Salmon River discharge (above the dam) and the Salmon diversion flow is included for comparison. Under-sluice gate fish passage: Similar to 2013, our analysis focussed on fish passage at the Salmon River dam under-sluice during low flow periods, when all river discharge is through the undersluice, and there is no flow down the canal (and therefore no flow through the fishway). Once the river begins to flow into the canal, the fishway becomes operational, allowing fish access above the dam through the fishway. At forebay elevations less than m, the invert of the canal intake, all river discharge is flowing through the undersluice gate. The head difference upstream and downstream of the under-sluice gate is directly related to river discharge and can be calculated by subtracting the water level readings recorded by the logger in the river (logger C at the downstream entrance of the fishway in Figure 3) from the readings by the logger in the forebay (logger A in Figure 3; all 12

19 Discharge m 3 /s Discharge (m 3 /s) 2014 Salmon River Coho Distribution Assessment 14.CBR.04 readings referenced to elevation). Discharge data for the Salmon River upstream of the diversion dam (from WSC gauge 08HD015) provides the total discharge flowing through the under-sluice gate for forebay elevations less than m, the invert of the canal intake (Figure 8a & b). Over the period of our analysis, the under-sluice was set at 0.25 m (9.75 in.) open from 1 September to 31 October, and 0.35 m (14 in.) open from 31 October to 31 December The sill of the under-sluice gate is m, thus the under-sluice opening elevation ranged from m to m. The minimum water level downstream of the under-sluice, as recorded by the lower fishway logger (C in Figure 3) is m indicating that the under-sluice gate was always submerged. From this analysis, illustrated in Figure 8a & b, the maximum head drop that could occur before water begins to enter the canal intake elevation is ~1.1 m at an under-sluice opening of 0.35 m (14 in.) and ~1.3 m at an opening of 0.25 m (9.75 in.). 1 a. 7.0 Under-sluice setting at 0.35 m (14 in.) open y = x R 2 = Head difference (m) b. Under-sluice setting at 0.25 m (9.75 in.) open y = x R 2 = Head Difference (m) Figure 8. Head difference at the under-sluice gate versus Salmon River discharge (from WSC gauge 08HD015 above the dam). Relationship in a) above was calculated in 2013 when under-sluice was at 0.35 m (14 in.) while b) was calculated from 2014 data. 1 The discharge vs. head drop relationship developed in this study is significantly lower than those provided on pg. 10 in NHC (2010), Salmon River Diversion Dam Conceptual Fish Passage Options Assessment, letter report to Harry Brownlow, B.C. Hydro. 13

20 1-Sep 7-Sep 13-Sep 19-Sep 25-Sep 1-Oct 7-Oct 13-Oct 19-Oct 25-Oct 31-Oct 6-Nov 12-Nov 18-Nov 24-Nov 30-Nov 6-Dec 12-Dec 18-Dec 24-Dec 30-Dec Orifice velocity (m/s) Discharge (m 3 /s) 2014 Salmon River Coho Distribution Assessment 14.CBR.04 The area of the sluice gate opening (orifice) at an under-sluice setting of 0.25 m (9.75 in.) is m 2, and m 2 for an under-sluice setting of 0.35 m (14 in.). The calculated velocity through the orifice for various river discharges (below the canal intake elevation of m) at these gate settings over the coho migration period is presented in Figure 9. Access through the under-sluice gate is probable for adult coho at velocities less than 4 m/s, (burst speed m/s; Bjornn and Reiser 1991). A conservative burst speed estimate was used, given that adults approaching the undersluice gate must first travel up a 10 m long by 3.2 m wide canal or chamber before reaching the gate orifice. The burst speed estimate does not take into consideration the effects of turbulence and air entrainment which is also common downstream of the under-sluice, further reducing the swimming efficiency of adults Orifice 0.35 m (14") Orifice 0.25 m (9.75") Salmon River Discharge Maximum burst speed 4 m/s Figure 9. Velocity through the under-sluice gate at two gate settings, when forebay water levels were less than m (i.e. when the water level was below the canal intake invert and all river discharge flows through the under-sluice). Data points below the red line indicate hourly periods when fish passage was possible. This burst speed velocity correlates to a maximum river discharge of ~4.5 m 3 /s at an under-sluice setting of 0.35 m (14 in.) and ~3.25 m 3 /s at an under-sluice setting of 0.25 m (9.75 in.; Figure 10 a & b). 14

21 Orifice Velocity (m/s) Orifice Velocity (m/s) 2014 Salmon River Coho Distribution Assessment 14.CBR.04 a) Undersluice Setting = 0.35 m (14") b) Undersluice Setting = 0.25 m (9.75") Max coho burst speed = 4 m/s y = x Discharge (m 3 /s) Max Q (5.5 m 3 /s) and corresponding V when river reaches canal intake invert Max coho burst speed = 4 m/s y = x Max Q (4.5 m 3 /s) and corresponding V when river reaches canal intake invert Discharge (m 3 /s) Figure 10 a & b. Velocity / discharge relationship of the under-sluice at the 0.35 m (14 in.) gate setting and the 0.25 m (9.75 in.) gate setting to achieve the minimum licensed discharge requirement of 4 m 3 /s downstream of the dam. Based on the discharge vs head drop relationships in Figures 8a and 8b, this maximum burst speed velocity is exceeded prior to the river flowing into the diversion canal, and consequently, the fishway, during both gate settings (~5.5 m 3 /s at the 0.35 m setting and ~4.5 m 3 /s at the 0.25 m setting; Figure 10 a & b). Therefore there are brief periods during low river discharges, when fish passage is not possible at either the under-sluice or through the fishway at the current under-sluice gate settings. Furthermore, at the smaller (0.25 m) under-sluice setting, fish passage becomes impassable at lower discharges compared to the 0.35 m setting. In the past, BC Hydro often opened the under-sluice to nearly 1 meter during low flows (<4 m 3 /s), especially in late August and September to facilitate the early coho migrants access to the upper river (S. Anderson, personal communications, May 29, 2015). Fishway passage: Based on previous fishway passage studies using PIT (passive integrated transponder) and acoustic tag technology it was determined that passage through the fishway was either difficult or appeared to cease when the canal depth exceeded 3.3 m or an elevation of m (Damborg and Pellett 2012), which coincides with the crest of the trimming weir at the upstream end. The difference in water level (head) between the water level recorder in the canal (upstream exit of the fishway) and the water level in the river (entrance of the fishway) provides an overall head drop through the fishway. By dividing the total head drop by 8, the number of cells/orifices in the fishway, we can illustrate when the fishway provided passage opportunity (Figure 11). Due to the loss of 15

22 1-Sep 6-Sep 11-Sep 16-Sep 21-Sep 26-Sep 1-Oct 6-Oct 11-Oct 16-Oct 21-Oct 26-Oct 31-Oct 5-Nov 10-Nov 15-Nov 20-Nov 25-Nov 30-Nov 5-Dec 10-Dec 15-Dec 20-Dec 25-Dec 30-Dec Mean orifice head drop (m) Discharge (m3/s) 2014 Salmon River Coho Distribution Assessment 14.CBR.04 the river water level recorder at the entrance of the fishway, water elevation data was estimated for the latter period of the coho migration, from 17 Nov to 31 Dec (Appendix D). The preferred maximum head drop between fishway cells for an orifice fishway is 0.3 m (NHC 2011). For this analysis, only forebay water levels greater than the canal intake invert ( m) and less than the crest of the trimming weir (223.8 m) were included. During previous fish passage studies at the diversion dam, no fish passage was recorded at forebay water level elevations above the trimming weir (Anderson 2009). For the period of our analysis, the Salmon River diversion fishway exceeded the design target for optimum passage by approximately 0.18 m per orifice when there was a 3.86 m total head drop for the fishway mean drop per cell (measured) Salmon River Q above diversion mean drop per cell (estimated) Salmon River Diversion Q Maximum target orifice head drop is 0.3 m for fish passage (NHC 2011) Figure 11. Mean head drop over the 8 cells in the Salmon River diversion dam fishway for the period 1 Sept 31 Dec 2014 (preferred target head drop between fishway cells for an orifice fishway is 0.3 m). Black symbols are calculated from recorded river WL data while pink symbols are using estimated river WL data. Data points below the red line indicate hourly periods when fish passage was likely possible. Canal trash rack passage: During high or extreme river discharges, debris loading has been observed on the canal trash racks to the degree that fish passage could be compromised (Figure 12). The difference in the water level elevation in the forebay and canal can provide an indication 16

23 of the head drop over the trash rack and the degree of debris build-up. This difference, recorded by the loggers, is influenced by flow over the trimming weir and diversion through the radial arm gate, but is presumed to still provide a reasonably accurate measure of head drop at the trash rack. The analysis included water level data in the forebay and the canal that was greater than the canal intake invert ( m) and less than the crest of the trimming weir (223.8 m) for canal WL data. Figure13 illustrates the head drop at the trash rack as the discharge in the Salmon River upstream of the dam increases and decreases. The Diversion discharge (i.e. flow down the canal) is shown to indicate that an observed head drop across the trash rack may have been due to or exacerbated by diversion flows. Large elevation differences (head drop > 0.5 m), as observed around Nov and Dec 1 4, coincide to some extent with diversion flows, but more notably, occur following extremely high river discharges when debris loading on the trash rack may have been more extensive. A head drop greater than 0.3 m may present a challenge for adult passage at the trash rack. Moreover, coho adults attempting to pass above the dam through the fishway during these periods would have been subjected to greater challenges once entering the canal, by the open radial arm gate in addition to the head drop at the canal trash rack and the fishway trash rack. Figure 12. Trash racks over the entrance to the canal looking upstream (left), and the outlet of the fishway in the canal (right). Partial obstruction with debris may impede fish passage for adult migration through the fishway and into the forebay. 17

24 1-Sep 6-Sep 11-Sep 16-Sep 21-Sep 26-Sep 1-Oct 6-Oct 11-Oct 16-Oct 21-Oct 26-Oct 31-Oct 5-Nov 10-Nov 15-Nov 20-Nov 25-Nov 30-Nov 5-Dec 10-Dec 15-Dec 20-Dec 25-Dec Elevation Difference (m) Discharge (m 3 /s) 2014 Salmon River Coho Distribution Assessment 14.CBR.04 3 Forebay WL - Canal WL elevation difference Salmon R Q above diversion Salmon River Diversion Q m head drop across trash rack Figure 13. Head difference between forebay water level and canal water level (blue line) compared to Salmon River discharge above the diversion dam. Fish Passage Overview: We can summarize the opportunity that fish passage was possible at the undersluice and through the fishway by using the water level information, and fish passage thresholds we used in the above analyses. Our data set includes a total of 2905 hourly water level records between 1 September and 31 December The total number of hours fish passage was accessible at the under-sluice, based on the conservative maximum burst speed estimate for coho adults (4 m/s) was 1088 hours of 2905 hours, or 37.5% of the coho migration period examined (Table 4). Similarly, the total number of hours passage was accessible through the fishway based on the fishway orifice head drop threshold values used in this report (0.3 m), was 219 hours of a total of 2905 hours, or 7.5% of the coho migration period examined (Table 4). Table 4. Summary of fish passage at the under-sluice and fishway, as a percentage of the total coho migration period (1 Sept 31 Dec). With head drop and velocity thresholds With head drop, velocity and temperature thresholds % Passage % NO Passage % Passage % NO Passage Under-Sluice Fishway

25 1-Sep 6-Sep 11-Sep 16-Sep 21-Sep 26-Sep 1-Oct 6-Oct 11-Oct 16-Oct 21-Oct 26-Oct 31-Oct 5-Nov 10-Nov 15-Nov 20-Nov 25-Nov 30-Nov 5-Dec 10-Dec 15-Dec 20-Dec 25-Dec 30-Dec Temperature ( o C) 2014 Salmon River Coho Distribution Assessment 14.CBR.04 Coho passage at the Salmon River diversion dam during the period of monitoring would have also been negatively influenced by low temperatures which can decrease maximum burst speeds of salmonids (Figure 14). Damborg and Pellett (2012) noted that coho were unable to ascend the Salmon River diversion dam fishway at temperatures below 4.4 o C. If we include this temperature threshold limitation into the analysis, fish passage at each location is further reduced (Table 4). However the observation of increasing numbers of coho adults above the dam during the last two aerial surveys (14 Nov and 3 Dec) would indicate that passage may not have been completely restricted at this temperature threshold. 18 Salmon River Temperature Observed minimum temperature threshold for coho migration Figure 14. Salmon River temperature profile during the period of water level monitoring at the diversion dam. Coho passage at the fishway has been observed to cease at temperatures below 4.4 o C (Damborg and Pellett 2012). As mentioned earlier, the water level data analysis to evaluate fish passage did not take into consideration the presence of adults below the dam. However, it is worth noting that opportunity for adult coho passage at the under-sluice was primarily during the month of September to early October. Unfortunately the low river flows influenced coho distribution in 2014, with only a few adults observed upstream of the confluence of the Memekay River during the survey on 26 September (Appendix B). Overall, in consideration of the discharges, water levels, and environmental parameters included in the analyses, and other unassessed limitations (fish presence, physiological condition), adult coho passage at the Salmon diversion dam was significantly lower in 2014 throughout the migration period compared to 2013 (Guimond and Sheng 2014). This is reflected in the low numbers of coho observed 19

26 above the dam during low level aerial surveys in 2014, an order of magnitude lower than in Data Quality: There is some question on the quality of the data recorded by the loggers and the degree to which this may affect the above analysis. The potential errors identified in 2013 (Guimond and Sheng 2014), associated with compensating and correcting the water level logger data with barometric pressure data, and adjusting the data with each logger s unique offset correction value, was addressed through strict instrument programming and testing prior to the coho migration period. In 2014 we were faced with other issues that may have affected the accuracy of the data. As mentioned in Section 3.2, the logger that was installed in a perforated standpipe in the canal could not be removed during the last two site visits to download and/or recover the data loggers. When BC Hydro finally recovered the logger, it was found to be embedded in sand/silt. How this may affect the logger s ability to accurately measure Total Pressure is not clear. Figure 15 shows that the Canal WL logger seems to track, for the most part, with the Forebay WL logger, despite being embedded. This likely would have occurred sometime before the site visit on 17 November, during the many high flow events in October and early November. Secondly, an irregularity in the data collected by the Forebay WL logger occurred in early December (Figure 15), around the same time as an extreme flow event (peak Salmon River discharge was 394 m 3 /s). Although he Canal WL was increasing, as would be expected with an increasing river discharge, the Forebay WL logger stayed level until 15 December when it increased suddenly to a level similar to the Canal WL. A probable explanation is that the 12 diameter pipe in which the Forebay WL logger is suspended may have become plugged with debris and gravel, and then cleared itself (or as a result of BC Hydro debris maintenance activities). This pipe is not perforated, extends to near the river bottom, and is located in proximity to an area where gravel/debris can accumulate (Figure 16). This latter issue would likely not influence our evaluation of fish passage as both the under-sluice and the fishway would have been impassable at these discharges and water levels. However, it does underscore the importance of proper stationing and frequent monitoring of instrumentation to ensure data is accurately recorded and not lost. 20

27 1-Sep 6-Sep 11-Sep 16-Sep 21-Sep 26-Sep 1-Oct 6-Oct 11-Oct 16-Oct 21-Oct 26-Oct 31-Oct 5-Nov 10-Nov 15-Nov 20-Nov 25-Nov 30-Nov 5-Dec 10-Dec 15-Dec 20-Dec 25-Dec 30-Dec Elevation (m) Discharge (m 3 /s) 2014 Salmon River Coho Distribution Assessment 14.CBR.04 Forebay WL Elevation Canal WL Elevation Salmon R Discharge Possible plugging of the 12" standpipe housing the Forebay WL logger Figure 15. Water level data referenced to elevation from the Forebay and Canal loggers, and associated discharge in the Salmon River upstream of the dam. 12 diameter pipe extending to river bed Figure 16. Pipe housing the water lever logger in the Forebay adjacent the canal trash rack. 4.3 Communications In the 3 years leading up to the decision to replace the fishway at the Salmon River diversion dam, intensive monitoring and assessment of coho migration at the dam and management of the diversion dam operations was conducted, forging a cooperative partnership among BC Hydro, DFO, FLNRO and local stewardship groups. Information 21

28 on the presence and behaviour of coho at the dam by various partners was promptly communicated to BC Hydro staff, which resulted in improved operation of the facility, and fish migration through the under-sluice gate, the primary access route for coho and steelhead above the dam. The partners demonstrated that this more vigilant approach led to improved migration success above the diversion dam. Under-sluice Settings: Historically, during diversion operations, the under-sluice gate was set to 0.15 m (6 in.) to maintain minimum Salmon River flow and divert flow through the canal. Even while not diverting, since 2010, the under-sluice was kept at 0.15 m (6 in.) open. When water is not being diverted, the under-sluice setting can be adjusted based on a need to minimize risks to BC Hydro infrastructure (from debris jams) and providing opportunities for fish passage which is dependent on availability of staff. During the coho migration period, one adjustment to the under-sluice was performed on 31 October This adjustment was preceded by a larger, temporary increase to allow fish passage. Overall however, inspection logs document very few observations of coho holding below the dam (Table 5). 5 RECOMMENDATIONS A third year of coho enumeration in the Salmon River and water level monitoring at the diversion dam was proposed due to the delay in the construction of a new or improved fishway at the Salmon River diversion dam. Unfortunately the proposal was not approved. However, post-construction monitoring will be a key element in the fishway upgrade/replacement project. The following recommendations have been developed as a result of the knowledge gained over the two years of coho enumeration and water level monitoring in the Salmon River. 1. Any instrumentation used to remotely monitor the performance of fish passage structures (present and future) should be fastidiously stationed, monitored and maintained to ensure accuracy and validity of the data collected. Back-up equipment may also be useful if site visits are infrequent. The data that has been collected from water level recorders over the past 2 years may be useful for future modelling of fish passage at the Salmon diversion dam. 2. Coho enumeration surveys should begin early in the season (beginning of September or sooner) in order to capture the beginning of the coho migration timing and possible distribution upstream during wet summers. 22

29 Table 5. Compilation of adult salmon inspections at the Salmon River diversion dam from September 2013 to January Debris No. Adults Date 2014 Time Agency Crew initials Salmon R Discharge (cms) Div. Q US Setting Weather Purpose Div. TR FW Div. Pool Under Log bridge Under- Sluice Left Under- Sluice Tailout Comments 3-Sep BCH GR 1.2 clear check site conditions clear clear 9-Sep 10:00 DFO MS/EG cloudy download WL loggers clear clear 11-Sep BCH LA clear check site conditions clear clear 18-Sep BCH LA cloudy check site conditions clear clear 23-Sep BCH LA cloudy check site conditions clear clear 24-Sep 13:00 DFO SA/LF rain inspect for CO clear clear poor visibility; u-s some head - vel not high, WL below canal entrance. RA gate open, fishscreen in fishing position. No flow. 1-Oct BCH GR cloudy check site conditions clear clear 8-Oct BCH GR pt cloud check site conditions clear clear reset fish screen; 13-Oct 15:00 BCH GR/LA rain closed radial gate some clear 2 water dirty Visibility poor; fish trying to get 16-Oct DFO SA inspect for CO ~100?? through u-s 22-Oct BCH GR/S 100 rain close radial gate Heavy clear 29-Oct BCH LA cloudy check site conditions some clear 31-Oct BCH Increased US from 9.75" to 34", then reset to 14" 4-Nov BCH LA clear check site conditions some clear 13-Nov BCH LA 7 0 clear check site conditions some blocked 17-Nov 12:30 DFO SA/EG cloudy download WL loggers some ptly blckd Nov 10:00 BCH SJ cloudy check site conditions some ptly blckd Nov BCH clear check site conditions some ptly blckd 4-Dec BCH LA 0 cloudy check site conditions some blocked 11-Dec 13:00 BCH GB rain check site conditions Heavy ptly blckd check site conditions, 15-Dec BCH LA/AG 13 0 cloudy clear debris clear ptly blckd 23-Dec BCH LA 15 0 cloudy check site conditions clear ptly blckd 24-Dec BCH GR clear check site conditions clear ptly blckd 7-Jan BCH GR/S 27 0 clear check site conditions clear ptly blckd Open radial gate, 13-Jan 9:35 BCH GR/S cloudy close U-S gate clear clear US decreased from 14" to 12.5" 23

30 6 ACKNOWLEDGEMENTS We are grateful for the financial support for this study from the Fish and Wildlife Compensation Program (FWCP), on behalf of its program partners BC Hydro, the Province of B.C., Fisheries and Oceans Canada, First Nations and public stakeholders. The project could not have proceeded without the support and involvement of Fisheries and Oceans Canada personnel at every stage. We wish to acknowledge DFO STAD staff P. Van Will and D. Nagtegaal for coordination and implementation of the coho enumeration surveys and escapement data analysis, and observers D. Ewart and other staff at Quinsam Hatchery. Special thanks to S. Anderson and L. Frisson for making site visits and inspections at the diversion dam, and assisting with water level instrument data retrieval. We also acknowledge BC Hydro staff for assistance with installation and recovery of water level recorders, provision of discharge data records and inspection logs. 7 REFERENCES Anderson, S Salmon River Adult Fish Passage Assessment Study. Report Prepared by Fisheries & Oceans Canada for BC Hydro Bridge Coastal Fish and Wildlife Restoration Program, Burnaby BC. 45p+ appendices. BC Hydro Campbell River System Water Use Plan, November 21, 2012: Revised for Acceptance for the Comptroller of Water Rights. g_regulatory/wup/vancouver_island/2012q4/campbell_river_wup_accept_2012_1 1_21.pdf Bradford, M.J., Taylor, G.C., and Allan, J.A Empirical review of coho salmon smolt abundance and the prediction of smolt production at the regional level. Trans. Am. Fish. Soc.126: Bradford, M.J. R.A. Myers, and J. R. Irvine Reference points for coho salmon (Oncorhynchus kisutch) harvest rates and escapement goals based on freshwater production. Can. J. Fish. Aquat. Sci. 57: Bjornn, T. C., and D. W. Reiser Habitat requirements of salmonids in streams. American Fisheries Society Special Publication 19: Burt, D.W. 2010a Fisheries and Aquatic Resources of the Salmon River, Vancouver Island Literature Review Update Prepared for: British Columbia Hydro and Power Authority, Burnaby, BC 24

31 Burt, D.W. 2010b. Salmon River upstream fish passage Step 3 Environmental Feasibility Assessment. Draft MS. Prepared for Campbell River Salmon Foundation and Salmon River Diversion Fish Passage Committee.25pp. Burt, D.W. and C.B. Robert Fisheries and aquatic resources of the Salmon River, Vancouver Island. A review of existing information. Prepared for BC Hydro, Burnaby, BC. 84p. Craig, James, R. Ferguson, M. McCulloch, and H. Wright A synoptic survey of potential habitat of coho salmon in the upper Salmon River Watershed, Vancouver Island. Damborg J. and K. Pellett 2012 Salmon River Diversion Steelhead and Coho Passage Evaluation 2011/12 FWCP #11CBR Habitat and Enhancement Branch, Fisheries & Oceans Canada, Campbell River, BC.vi.+53p. + app. Guimond, E. and M. Sheng Assessment of the distribution of 2013 brood coho adult migration below and above the Salmon River diversion dam. FWCP Project 13.CBR.04. Prepared for the Fish and Wildlife Compensation Program, Burnaby, BC. Holtby, L.B. and K.A. Ciruna Conservation Units for Pacific Salmon under the Wild Salmon Policy. Irvine, J. R., J. F. T. Morris, and L. M. Cobb Area-under-the-curve salmon escapement estimation manual. Canada Department of Fisheries and Oceans, Canadian Technical Report of Fisheries and Aquatic Sciences 1932, Nanaimo, British Columbia. Marshall, D.E., and Britton, E.W Carrying capacity of coho salmon streams. Can. MS Rep. Fish. Aquat. Sci. 2058: 32 p. McCubbing. D.J.F 2003 Fish counter enumeration of Steelhead and Rainbow trout on the Bonaparte River in 2003 post fishway redesign and operational improvements. Report to MoE for HCTF. McCubbing. D.J.F Salmon River (BC Hydro) Diversion Coho Salmon Fishway Passage Study Resistivity Counter Evaluation. Report to BCRP in prep. McCubbing. D.J.F and Burroughs L Salmon River (BC Hydro) diversion coho salmon fishway passage study resistivity counter evaluation. Report to BCRP 07.cbr p. NHC Salmon River Diversion Dam Conceptual Fish Passage Options Assessment. Letter Report. Prepared for BC Hydro by Northwest Hydraulic Consultants Ltd. March 31, NHC Salmon River Diversion: Upstream Adult Fish Passage Study Final Report. Prepared for BC Conservation Foundation by Northwest Hydraulic Consultants Ltd. July

32 Personal Communications Dave Nagtegaal - Stock Assessment Technician, DFO (May 2014). Pieter VanWill - Stock Assessment Biologist, DFO (Feb 2015). APPENDICES 26

33 APPENDIX A. Fish Activity Log data sheet. Salmon River Diversion Adult Salmon Survey Activity Log Book 2013 BC Hydro Staff Contractor DFO Technician (circle option that applies) Date: Time: PDT /PST Crew Name(s): River Discharge (cms estimate) Diversion Canal (cms estimate)?changed to Weather : Clear Cloudy Rain Snow Wind Lock out required Yes No Purpose of Site Visit: (ie check site conditions, open/close/adjust radial arm gate, clear debris, monitor screen, check monitoring equipment) Observations Sketch for detailed observations notes next page 1. Debris build up on diversion trashrack Clear Some debris Lots of debris?passable 2. Debris Fishway at diversion canal Clear Partly Blocked Mostly Blocked?Passable Adult Salmon observed Yes None Where? #, Where? #, Where? #, Where? #, (or note on sketch next page) Activity Open Undersluice? Debris cleaning or Fish passage a. Did fish go through? b. Undersluice opened to inches c. Undersluice opened for minutes Additional Comments 27

34 Salmon River Coho Distribution Assessment 13.CBR.04 APPENDIX B. Salmon River 2014 Coho distribution aerial survey data 28

35 Salmon River Coho Distribution Assessment 13.CBR.04 APPENDIX B. Cont d 29

36 Salmon River Coho Distribution Assessment 13.CBR.04 APPENDIX C. DFO South Coast 2014 coho escapement for Salmon River 30