Coquihalla River Crossing 16 Pipeline Replacement Project. Fish Habitat Assessment

Transcription

1 Coquihalla River Crossing 16 Pipeline Replacement Project Fish Habitat Assessment Westcoast Energy Inc., doing business as Spectra Energy Transmission nd Avenue, Prince George, BC V2N 3A1 tel fax triton-env.com

2 This document is formatted for double-sided printing. Fish Habitat Assessment Page i

3 Disclaimer This report is rendered solely for the use of Westcoast Energy Inc., carrying on business as Spectra Energy Transmission (Westcoast) in connection with the Coquihalla River Crossing 16 Pipeline Replacement Project, and no person may rely on it for any other purpose without Triton Environmental Consultants Ltd. s (Triton) prior written approval. Should a third party use this report without Triton s approval, they may not rely upon it. Triton accepts no responsibility for loss or damages suffered by any third party as a result of decisions made or actions taken based on this report. This report is based on facts and opinions contained within the referenced documents, including the results of any data collection programs carried out in relation to this report. We have attempted to identify and consider facts and documents relevant to the scope of work, accurate as of the time period during which we conducted this analysis. However, the results, our opinions, or recommendations may change if new information becomes available or if information we have relied on is altered. The following assumptions were relied on during the preparation of this report: all information provided by Westcoast (i.e. engineering details, construction methodology and timing, footprint, and archaeological studies) are accurate and current at the date of this report. We applied accepted professional practices and standards in developing and interpreting data. While we used accepted professional practices in interpreting data provided by Westcoast or third party sources we did not verify the accuracy of any such data. This report must be considered as a whole; selecting only portions of this report may result in a misleading view of the results, our opinions, or recommendations. Fish Habitat Assessment Page ii

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5 TABLE OF CONTENTS Disclaimer... ii 1.0 Project Overview Background Fish Species Information Fish Habitat Assessment Coquihalla River Sowaqua Creek Proposed Project Works Site Preparation and Mobilization Stream Diversion Trench Excavation and Pipeline Construction Potential Effects to Fish and Fish Habitat Riparian Clearing Instream Work Regional Timing Windows Mitigation Measures Summary of Project Effects to Fish and Fish Habitat References LIST OF FIGURES Figure 1. Project location map... 2 LIST OF APPENDICES Appendix 1. Representative photographs Appendix 2. Self-assessment of serious harm to fish Fish Habitat Assessment Page iv

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7 1.0 Project Overview Westcoast Energy Inc., doing business as Spectra Energy Transmission (Westcoast), is applying to the National Energy Board (NEB) under section 45.1 of the NEB Onshore Pipeline Regulations (OPR) and section 58 of the NEB Act for authorization to replace approximately 450 m of the existing 8AL1/8AL2 914 mm (36 inch) and 762 mm (30 inch) outside diameter (O.D.) pipelines at the Coquihalla River crossing #16, approximately 15 km northeast of Hope, BC (the Project). Re-routing of the Coquihalla River during construction of Highway 5 resulted in increased flow velocities and scour. Despite previous armouring to protect the exposed 36 inch pipe, engineering assessments have concluded that the pipelines are still at risk from scouring. The new 500 m pipeline crossings will be constructed within new statutory ROW contiguous to the existing Westcoast ROW, 50 m upstream of the existing crossing with an isolated open cut approach, using a diversion through the side channel or a superflume in the main or side channel of the Coquihalla River. Approximately 350 m of each of the existing pipes will be capped and decommissioned in place, and approximately 50 m of both the 36 inch and 30 inch pipe will be removed at each end of the replacement to accommodate tie-ins. The installation of the new crossing and removal of old pipe are currently scheduled for the summer of The Project includes temporary bridges across the main and side channels. Project elements are located on the existing ROW as well as new Crown and private land. Fish Habitat Assessment Page 1

8 Figure 1. Project location map Fish Habitat Assessment Page 2

9 2.0 Background Fish Species Information The Coquihalla River is utilized by several fish communities for migration, spawning, rearing and overwintering. These include: Bull Trout (Salvelinus confluentus), Coastrange Sculpin (Cottus aleuticus), Dolly Varden (Salvelinus malma), Leopard Dace (Rhinichthys falcatus), Longnose Sucker (Catostomus catostomus), Northern Pikeminnow (Ptychocheilus oregonensis), Rainbow Trout (Oncorhynchus mykiss), Largescale Sucker (Catostomus macrocheilus), Longnose Dace (Rhinichthys cataractae), Mountain Whitefish (Prosopium williamsoni), Sculpin (Cottus spp), and Steelhead (Oncorhynchus mykiss) (BC MOE, 2016a). Pacific Salmon (Oncorhynchus spp.) and Coastal Cutthroat Trout (Oncorhynchus clarkii clarkii) are documented in the Coquihalla River, but only utilize habitat up to Othello Tunnels, which is located roughly 12 km downstream of the Project location and is where an obstruction (cascade/falls/canyon) prevents the migration upstream of these species (Whelen, 1998). Steelhead and Bull Trout, which is Blue-listed, are documented upstream and downstream of the Project location. Fish species documented in Sowaqua Creek include Steelhead (summer run), Bull Trout, Rainbow Trout, and Dolly Varden. Fish Habitat Assessment Page 3

10 3.0 Fish Habitat Assessment 3.1 Coquihalla River The Coquihalla River flows between the Coquihalla Lakes and the Fraser River, running parallel to the Coquihalla Highway and through Hope, BC. The Coquihalla River is an important habitat for several fisheries, including Bull Trout, a provincially Blue-listed species, and also a rare, native, summer-run of Steelhead, which spawns in the spring, and requires rearing and overwintering habitat during the fall and winter months. In the vicinity of the crossing, the Coquihalla River has an average gradient of 4% boulder-cascade-pool habitat and swiftly flowing water (Photos 1-2). The stream bed consists primarily of boulders and cobbles (Photo 3). Based on criteria in BC OGC (2016) a S1-B fish stream classification would apply, along with a corresponding Riparian Management Area (RMA) of 70 m, composed of a 50 m Riparian Reserve Zone (RRZ) and 20 m Riparian Management Zone (RMZ). Rearing habitat was rated high based on the perennial flows and abundant cover provided by boulders and deep pools. Potential spawning habitat is limited, with only occasional pockets of suitable substrate immediately behind large boulders. Overwintering habitat was rated high due to the perennial flow and depth (Photo 4). As a migration corridor, this stretch of river was rated high, with deep continuous flow and a lack of barriers. While all life history activities could potentially occur within the ROW, the absence of spawning substrate and deep pools would likely limit fish usage to juvenile rearing and migration. The main channel is separated from an ephemeral side channel by a partially vegetated island (Photo 5). The channel width is approximately 20.3 m with an average gradient of 3.5% at the current pipeline crossing location (Photo 6). The bed elevation of the side channel is considerably higher than the Coquihalla River main stem (Photo 7). When the Coquihalla is at its peak flows (bankfull height) the channel may become active, providing rearing and migratory habitat on a seasonal basis. Based on the lack of perennial flows, the side channel does not provide opportunities for spawning or overwintering habitat. Riparian vegetation is composed of big-leaf maple (Acer macrophyllum), western red cedar (Thuja plicata), Douglas fir (Pseudostuga menziesii), red alder (Alnus rubra), black cottonwood (Populus balsamifera ssp. trichocarpa), and willow species (Salix spp.) (Photo 8). All tree species are at an early successional stage and are located along the margins of the current ROW. Outside the ROW, the vegetation is comprised of mature cedars, cottonwoods, and alders (Photo 9). 3.2 Sowaqua Creek Sowaqua Creek (Photo 10) is a direct tributary to the Coquihalla River; the confluence is approximately 90 m upstream from the side channel (260 m upstream from the current Fish Habitat Assessment Page 4

11 ROW crossing). The average channel width is 26 m, and it has an average gradient of 3%. Habitat in the vicinity of the proposed Project is boulder-cascade-pool habitat with swiftly flowing water. The stream bed consists primarily of cobbles and gravels. At the confluence with the Coquihalla River (Photo 11), the creek is classified as S1-B, with a 50 m RRZ (BC OGC, 2016). Sowaqua Creek lies within steep, vegetated slopes (slopes greater than 60%). Riparian vegetation consists of mature big-leaf maple, western red cedar, Douglas fir, red alder, black cottonwood, and willow species. Fish Habitat Assessment Page 5

12 4.0 Proposed Project Works The proposed works entail the replacement of the pipelines at the Coquihalla 16 crossing at a new location 50 m upstream of the current crossing. The new crossings will be constructed using an open cut approach, under isolation of flow via a diversion through the ephemeral side channel or a superflume placed in the main channel or side channel of the Coquihalla River. The general work sequence is described in the following subsections. 4.1 Site Preparation and Mobilization Site preparation of the Project area and access routes includes clearing and grubbing of all workspaces, as well as salvage of topsoil and shrubby vegetation. Temporary workspace is required in the riparian areas of both the Coquihalla River and Sowaqua Creek. Riprap will be dismantled at the existing crossing and temporary bridges will be installed across the Coquihalla River and the side channel for construction activities. An additional temporary bridge crossing at Coquihalla Crossing 17 is required to mobilize equipment to the Project footprint. The temporary crossing is within the existing Westcoast right-of-way. Fording of equipment will be necessary to install the bridges. 4.2 Stream Diversion Two options are proposed for isolating the instream work area; a diversion channel or superflume. If the diversion channel is selected, an Aquadam would be installed in the main channel to divert flow through the natural side channel, which will be excavated for approximately 50 m of its length to lower the bed level and accommodate the flows. Alternatively, the instream work area may be isolated using a superflume placed in the main channel or side channel, spanning across the proposed ditch. Pumps and dig sumps will be assembled to address seepage in the isolated area. A fish salvage will be completed in accordance with provincial permit conditions during the drawdown of isolated areas. Pumped seepage water will be diverted to a pre-determined upland vegetated area to prevent turbid water from entering the river. 4.3 Trench Excavation and Pipeline Construction The new sections of pipe will be assembled on temporary workspaces and hydrostatically tested. The trench for the new pipelines will be excavated under isolation of flows. Substrate layers will be removed separately, stockpiled, and replaced in the same order during backfill following lowering in of the new pipes. Due to the coarseness of the substrates, there is a potential that blasting may be required to facilitate excavation of the pipe trench. Following installation of the new pipes, the excavated side channel will be restored to pre-construction levels and contours to the extent practical before removing the Fish Habitat Assessment Page 6

13 instream isolation. Disturbed terrestrial areas will be backfilled with separated soil layers, restored to natural contours, and seeded where indicated. Salvaged shrubby vegetation will be replaced, and disturbed riparian areas (i.e., within the 50 m RRZ) will be supplemented with locally sourced rooted stock where necessary. Temporary structures and crossings will be removed following construction. The site will be left in a stable, non-erosive condition. Fish Habitat Assessment Page 7

14 5.0 Potential Effects to Fish and Fish Habitat Construction activities associated with an open cut methodology that have the potential to result in adverse effects on fish and fish habitat include the removal of riparian vegetation, instream isolation, fish salvage, trench excavation, and backfilling, as well as the release of a deleterious substance (e.g., sediment and hydrocarbons). These effects may be temporary (i.e., removal of riparian vegetation, the potential for elevated local turbidity during construction, and the temporary displacement of fish from the isolated area) or longer term (i.e., alteration of mesohabitat distribution and instream habitat features, and fish mortality). 5.1 Riparian Clearing Temporary workspace is currently proposed in the RRZ of the Coquihalla River to facilitate preparation of the diversion channel. The new permanent ROW (50 m wide) will also occupy the riparian area within the new alignment, resulting in the displacement of mixed mature forest vegetation by a mixed shrub community that will be subject to ongoing vegetation management. The total riparian footprint, including temporary workspace and permanent ROW, in the RRZ of the Coquihalla River and side channel is approximately 3.98 ha. The majority of this footprint is temporary as riparian revegetation is proposed following construction. Approximately 0.97 ha of this total will be occupied by the new permanent ROW, although the decommissioned ROW will no longer be managed and will be allowed to regenerate naturally. 5.2 Instream Work Instream works include installation of the new pipelines via isolated open cut as described in Section 4.0 above. Potential adverse effects include the introduction of suspended sediments and other deleterious substances, as well as alteration of instream habitats and fish mortality associated with isolation, fish salvage, and the potential for blasting. The approximate temporary instream footprint associated with installing the new pipelines is approximately 1,200 m 2, in addition to the excavation of the side channel (approximately 50 m of its length). Conducting a fish salvage prior to complete drawdown of the isolated site will mitigate the potential for fish mortality within the work area. Following placement of the pipes, the trench will be backfilled with separated substrate layers and graded to pre-construction contours to the extent practical. The side channel will also be restored to pre-construction contours, to the extent practical. Fish Habitat Assessment Page 8

15 5.2.1 Regional Timing Windows The timing of the proposed instream works has been scheduled within the Least Risk Timing Window for spring and fall spawning species of August 1 to August 31 (BC MOE, 2006) Fish Habitat Assessment Page 9

16 6.0 Mitigation Measures Protection of fish and fish habitat involves timing instream works during periods of reduced sensitivity for fish, implementing measures to reduce potential for physical harm to fish, maintenance of water quality, and reducing the duration of instream works to the extent practical. All applicable mitigation in DFO s Measures to Avoid Causing Harm to Fish and Fish Habitat (DFO, 2013) will be implemented during construction. The general principles and objectives of the fish and fish habitat protection plan are to: Complete the works as quickly as practical; Adjust work plans and activities as necessary to reduce sediment risks during periods of inclement weather; Minimize the disturbance within the RRZ of the Coquihalla River and Sowaqua Creek; Ensure sufficient equipment and materials are present onsite to address any environmental emergencies or contingencies (e.g., spills, heavy rains); and Ensure the site is left in a stable, non-erosive condition. Mitigation measures in place to reduce the effects of the Project on vegetation (e.g., replacement of all salvage strippings and plants to original locations as soon as possible, utilizing existing access routes) will also ensure that potential effects on riparian areas are reduced. As well, considerations of water quality and quantity (e.g., maintaining sediment barriers, working in the dry, managing waste materials, water quality monitoring during instream works) will mitigate the effects on fish and fish habitat during construction. Timing of works and following other BMPs, including appropriate and effective erosion and sediment control, will further reduce the magnitude and duration of potential aquatic effects. The following site-specific mitigation will be followed: All instream works will be completed in isolation of flow. The crossing of the Coquihalla River will be isolated via a diversion into the existing elevated side channel, which will be excavated to accommodate flows (as described in Section 4.0 above). Alternatively, the instream work site may be isolated via a superflume placed in the side or main channel of the river. Prior to complete dewatering of the isolated site, the Environmental Inspector (EI) will conduct a fish salvage following Scientific Fish Collection Permit conditions. The EI will document the species/numbers caught before releasing to a suitable habitat downstream of the construction site. When fording: o Minimize the turning of tracks instream to reduce the mobilization of sediment; Fish Habitat Assessment Page 10

17 o o Ensure machinery is in good working order free of drips and leaks; and Ensure environmentally safe fluids are utilized. In the unlikely event that blasting is required instream due to large substrates, applicable mitigation in DFO s Measures to Avoid Serious Harm will be followed, including the following: o o o o o o Blasting will only be completed within the Least Risk Timing Window. Blasting will only be completed within the isolated work site. Blast charge weights will be minimized. Each charge will be subdivided into a series of smaller charges in blast holes with a minimum 25 millisecond delay between detonations. Blasting mats will be placed over holes to minimize scattering of debris. Any debris and equipment will be removed from the area following blasting. Ammonium nitrate based explosives will not be used. Blasting will only be utilized where necessary. Substrate layers removed from the instream trench will be stockpiled separately, and replaced in the same order. The disturbed channel bed will be restored to pre-construction conditions prior to removal of isolation structures. The side channel will be restored to pre-existing contours, to the extent practical. Water intakes placed in fish bearing waters will not disturb the channel bed and will be screened in accordance with DFO s Freshwater Intake End-of-Pipe Fish Screen Guidelines (1995). Disturbed banks and approaches will be stabilized and restored to preconstruction conditions to the extent practical. Restoration of previously disturbed vegetated riparian areas will proceed following construction. Locally sourced rooted stock of a species composition appropriate to the riparian area (i.e., comparable to undisturbed riparian areas) will be planted to achieve a minimum overall target density of one plant per square metre (including both planted and naturally regenerating stems). Environmental management practices for working around fish and fish habitat are detailed in Section 6.6 of the Environmental Manual (SET, 2014). Additional general fish and fish habitat mitigation measures are summarized below: Environmentally sensitive areas (e.g., riparian areas, root wads, log overhang) will be flagged/fenced prior to commencement of clearing and construction near watercourses. Trees will be felled away from watercourses to reduce damage to stream banks and beds. To maintain bank stability, trees within 10 m of watercourses will be Fish Habitat Assessment Page 11

18 close cut with stumps left in place except along the trench line or where grading is required. Slash will be prevented from entering the watercourse. Any trees or slash inadvertently introduced will be removed. Stump removal will be limited to over the trench line and required graded areas in riparian areas. Grading will be minimized on steep watercourse approach slopes. Prior to commencing instream works, the EI will monitor local weather stations to determine if precipitation is forecast. If necessary, construction works will be delayed or altered until weather conditions are more favourable. Unnecessary activity outside of designated access corridors and temporary workspaces indicated on the environmental alignment sheets will be prohibited. Works below the high water mark will be scheduled to be completed in the shortest practical time period. The onsite EI will inspect any secondary habitats (e.g., side channels, ponds) that exist within 500 m of the Project footprint prior to and throughout the duration of instream isolation to ensure they are not impacted during construction. Travel by heavy machinery in wetted areas within the high water mark (i.e., fording) will be restricted to once over and back as necessary for temporary bridge installation and installation/removal of the instream isolation. Erosion and sediment control and spill control and response measures (detailed in the Environmental Protection Plan (EPP)) will be implemented to prevent the release of a deleterious substance into the Coquihalla River or other watercourses. Sumps/berms will be constructed if required to contain excavated materials from watercourses so that silty run-off does not re-enter the watercourse. Fish Habitat Assessment Page 12

19 7.0 Summary of Project Effects to Fish and Fish Habitat Section 35(1) of the Fisheries Act prohibits serious harm to fish that are part of a commercial, recreational, or Aboriginal (CRA) fishery, or fish that support such a fishery. Serious harm is defined as the death of a fish, or permanent alteration or destruction of fish habitat at a spatial scale, duration, or intensity that limits or removes the ability of fish to use such habitats as spawning grounds, nursery, rearing, food supply areas, or as a migratory corridor. The Project is not expected to permanently reduce or eliminate the ability of fish habitat in the vicinity of the Project to directly or indirectly support the life processes of fish, or result in the death of a fish. The construction approach will minimize the potential for effects to instream habitats and fish that may be present at the time of construction. Construction is currently scheduled to occur within the Least Risk Timing Window for fish, which will protect sensitive life stages of fish during instream works. Water quality monitoring during instream works and other mitigation measures described in the EPP will reduce the likelihood of the release of a deleterious substance. Disturbance to the riparian area will largely be temporary; temporary workspaces will be revegetated, and, although riparian vegetation in the new ROW will be displaced by a managed shrub community, the decommissioned ROW will no longer be managed and will be allowed to regenerate naturally. The assessment of serious harm is provided in Appendix 2. With the application of standard BMPs and site-specific mitigation measures described above and in the EPP, the proposed works are not expected to have adverse effects to CRA fish species potentially residing in the vicinity of the pipeline crossing, nor is it expected to result in disruption to spawning activities or the death of eggs. Therefore, the Project as proposed is not likely to result in serious harm to fish and fish habitat. Fish Habitat Assessment Page 13

20 8.0 References [BC MOE] British Columbia Ministry of Environment. 2016a. Fisheries Inventory Data Queries. Fisheries Information Summary System Fish Distribution Query. Accessed November 23, 2016: [BC MOE] BC Ministry of Environment Guidelines for Reduced Risk Instream Work Windows. Ministry of Environment, Lower Mainland Region. Accessed March, 2016: [BC MOE] British Columbia Ministry of Environment. 2014b. Habitat Wizard. Accessed February 15, 2016: [BC OGC] British Columbia Oil and Gas Commission Environmental Protection and Management Guideline v2.2. Available from [DFO] Department of Fisheries and Oceans Freshwater Intake End-of-Pipe Fish Screen Guideline. Communications Directorate. Ottawa, ON. [DFO] Department of Fisheries and Oceans Measures to Avoid Causing Harm to Fish and Fish Habitat. Accessed Novemeber 23, [SET] Spectra Energy Transmission (Spectra) Environmental Manual for Construction Projects in Canada, 3rd Edition. December Submitted to NEB March Whelen, Mike Reconnaissance (1:20 000) Fish and Fish Habitat Inventory of Upper Coquihalla River Watershed WSC: Prepared for International Forest Products Ltd. (Interfor). Hope, BC. Fish Habitat Assessment Page 14

21 APPENDIX 1 REPRESENTATIVE PHOTOGRAPHS Fish Habitat Assessment Appendix 1

22 Fish Habitat Assessment Appendix 1

23 Photo 1. Looking southwest showing the morphology of the Coquihalla River at the pipeline crossing location, taken February 17 th Photo 2. Looking upstream from the ROW showing the morphology of the Coquihalla River, taken February 17 th Fish Habitat Assessment Appendix 1 Page 1

24 Photo 3. Looking southwest across ROW showing the substrate present at the crossing location, taken August Photo 4. Looking at confluence of Sowaqua Creek and the Coquihalla River showing the large pool approximately 260 m upstream of ROW crossing, taken February 17 th Fish Habitat Assessment Appendix 1 Page 2

25 Photo 5. Looking northeast showing the vegetated island separating the main stem from the side channel, taken February 17 th Photo 6. Looking upstream on the side channel, taken February 17 th Fish Habitat Assessment Appendix 1 Page 3

26 Photo 7. Looking downstream at the start of the side channel showing the stream bed elevation difference from the mainstem, taken February 17 th Photo 8. Looking south along left bank showing the riparian vegetation dominated by Red Alder, taken February 17 th, Fish Habitat Assessment Appendix 1 Page 4

27 Photo 9. Looking north from ROW showing the adjacent forest ecosystem, taken February 17 th, Photo 10. Looking downstream (north) on Sowaqua Creek from privately owned bridge, taken February 17 th, Fish Habitat Assessment Appendix 1 Page 5

28 Photo 11. Confluence of Sowaqua Creek with the Coquihalla River (approximately 260 m upstream of Project crossing, taken February 17 th, Fish Habitat Assessment Appendix 1 Page 6

29 APPENDIX 2 SELF-ASSESSMENT OF SERIOUS HARM TO FISH Fish Habitat Assessment Appendix 2

30 Fish Habitat Assessment Appendix 2