Campbell River Elk Falls #3 Intake and Connector Channel Construction Summary

Transcription

1 Campbell River Elk Falls #3 Intake and Connector Channel Construction Summary Prepared for: Campbell River Salmon Foundation 920 Alder Street Campbell River, BC V9W 2P8 Prepared by: Northwest Hydraulic Consultants Ltd. # Island Hwy North Nanaimo, BC V9T IV9 File no and, R. Wong Consulting 6050 Aldergrove Drive Courtenay, BC, V9J 1 W3 Prepared with financial assistance from: BCHydro Bridge Coastal Fish and Wildlife Restoration Program 6911 Southpoint Drive (E 14) Bu),naby, BC V3N 4X8 BCRP Report No. 08.CBR.Ol March 2009

2 DISCLAIMER This document has been prepared by Northwest Hydraulic Consultants and R. Wong Consulting in accordance with generally accepted engineering and geoscience practices and is intended for the exclusive use and benefit of the client for whom it was prepared and for the particular purpose for which it was prepared. No other warranty, expressed or implied, is made. Northwest Hydraulic Consultants and R. Wong Consulting and its officers, directors, employees, and agents assume no responsibility for the reliance upon this document or any of its contents by any party other than the client for whom the document was. prepared. The contents of this document are not to be relied upon or used, in whole or in part, by or for the benefit of others without specific written authorization from Northwest Hydraulic Consultants and R. Wong Consulting. Campbell River Salmon Foundation Elk Falls Intake and Connector Channel Construction Summary i

3 TABLE OF CONTENTS List of Photos... iii List of Figures... iv Appendices... iv 1.0 Background Introduction Construction Week 1 (Aug 25-Aug 29)...: Week 2 (Sept 2 - Sept 5)...; Week 3 (Sept 7- Sept 11)...; Week 4 (Sept 15- Sept 19) Week 5 (Sept 22- Sept 26) Week 6 (Sept 29- Oct 2) Re-vegetation Phase (Oct 14- Oct 21) Project Budget...: Fisheries Biology Future Performance Monitoring References...; Campbell River Salmon Foundation Elk Falls Intake and Connector Channel Construction Summary ii

4 LIST OF PHOTOS Photo 1. The Elk Falls #3 Side Channel dried out in the summer when the BC Hydro flows dipped below approximately 60 m 3 /s. Photo 2. Prior t6 construction, the site was vegetated with a mixed second growth deciduous/coniferous forest. Photo 3. Approximately 450 ill of snow fencing was used to cordon of the construction site and the EF trail system was intermittently closed during construction. Photo 4. The site was cleared and grubbed with a Cat 330 excavator Photo 5. The 600 mm diameter intake pipe, intake screen, and concrete headwall were staged on site in preparation of installation. Photo 6. The intake trench was excavated to grade and the intake pipe was installed in one segment with the screen and concrete headwall attached. Photo 7. The Cat 330 excavator and two 25 tonne off-road haul trucks were used to excavate the channel and move the material to the spoil site.. Photo 8. The spoil site was at the same location as for the original EF3 construction. The spoil site was raised approximately 10m. Invasive species such as Scotch Broom and Himalayan Blackberry, were destroyed. Photo 9. The bulk excavation was performed by the Cat 330 while the JD 135 placed boulders, shaped the banks, and placed L WD. Photo 10. Bird nesting cavities were carved in approximately six artificial snags constructed along the length of the channel. Photo 11. The 1200 mm diameter CMP under the pumphouse road was 26 m long. It serves as a choke point to restrict flooding into the wetland. Photo 12. The wetland outlet was reconfigured such that inspecting potential beaver dam activity, and maintenance, would be easier. About 30 tonnes of spawning gravel was also added. Photo 13. The pumphouse road was remediated at the end of the project. Photo 14. The completed channel immediately downstream of the new intake. The LWD increases the fish habitat value for juvenile Coho salmon. Photo 15. The flow is much improved with the new intake system. A spawning platform was installed immediately upstream of the riffle crest. Photo 16. The EF3 wetland filled within several hours of opening the intake valve. Photo 17. Planting crews unloaded 2,777 rooted stock at the site. Photo 18. Deer repellent was applied to improve plant survival. Photo 19. The riparian planting prescriptions were implemented along the disturbed banks of side channel, near the intake, and on the spoil site near the pumphouse. Photo 20. Adult salmon utilized the spawning gravel installed downstream of the culvert and at the wetland outlet in the fall. Campbell River Salmon Foundation Elk Falls Intake and Connector Channel Construction Summary

5 LIST OF FIGURES Sheet 1: As-Built Plan and Profile Sheet 2: As-Built Intake Manifold, Culvert Baffle, and Typical Section ApPENDICES Appendix A: Contact List Appendix B: Riparian Planting Appendix C:,Financial Summary Appendix D: Performance Measures Appendix E: Media Coverage Campbell River Salmon Foundation Elk Falls Intake and Connector Channel Construction Summary iv

6 1.0 BACKGROUND The Campbell River has limited habitat available for anadromous salmonids. The river is only 6.5 km from the estuary to the impassable Elk Falls, including 2 km of canyon habitat. The remnant channels and wetlands on the north side of the Campbell River, upstream and downstream of the Elk Falls pump house, were created many years ago when the river meandered naturally. Prior to construction of the hydro dams, the river recruited more gravel thus maintaining the riverbed at a higher elevation. Through an altered flow regime and impoundment, the gravel bars in the lower river have degraded to an extent where the flood plain and natural side channels are mostly hydraulically disconnected from the main river. Impoundment has also reduced the opportunity for organics and fish food items to be added to the system. Furthermore, the high kinetic energy associated with the single-threaded river channel disconnected from the floodplain rapidly flushes the limited nutrient and food supply through to the ocean. The lack of rearing and over wintering habitat has been identified as a limit to the salmonid production in the Campbell (BC Hydro 2000, Burt & Bums, 1995, Burt 2004). The development and implementation of the Campbell River Interim Flow Management Strategy (CRlFMS 1997) has been successful in limiting the magnitude of high flows associated with hydro spills, and returning the river to a more natural flow regime by increasing flows during spawning periods and reducing flows for summer rearing opportunities. While beneficial to fish inthe mainstem of the Campbell River, this has further reduced Coho access to off-channel rearing sites. There is a major initiative underway to rebuild Coho stocks in Georgia Strait. One key Coho rebuilding strategy is to re-establish off-channel habitat on systems that have continuous summer flow as there are a limited number of such systems on the East Coast of Vancouver Island. Considerable restoration work has been completed on the Campbell River, the majority of which has focused on other salmon species. The construction of Elk Falls #3 (EF3) project in (Anderson & Norgan, 2001) has improved the very limited Coho habitat on the Campbell River. This channel and wetland project has added about 19,000 m 2 of Coho and trout rearing habitat to the system. Based on biostandard estimates, the channel has the potential to support about 9000 Coho smolts, and produce Coho adults (Reiser & Bjomn, 1979), or 12,667 Coho smolts by currently recognized DFO bio-standards (Keeley et. ai, 1997). The EF3 channel functioned as designed for about 10 months of the year until flows in the mainstem Campbell River were less than about 60 m 3 /s. During periods from July to September inflows to the EF3 channel were significantly reduced and approximately 89% of the wetland habitat dewatered with a high potential for fish stranding in isolated pools. Inflows to the side channel were reduced when the invert elevation of the upper channel was higher than the mainstem Campbell River. A small degree of groundwater seepage continued to charge the wetland over the summer but the majority of suitable rearing habitat for fish and amphibians in the EF3 complex was lost (Photo 1). In order to improve the functionality of the EF3 channel, the Bridge Coastal Restoration Program (BCRP) provided funding (07_ CBR _02) to the Campbell River Gravel Committee/Campbell River Salmon Foundation (CRSF) to analyze options to retrofit the existing project. Part of the options analysis process involved identifying, quantifying and Campbell River Salmon Foundation Elk Falls Intake and Connector Channel Construction Summary 1

7 comparing impacted 'values' to the Elk Falls Park. These options included the following concepts, and variations of these; pumping water into the wetland during low flow periods, excavating a dendritic drainage channel through the wetland, installing a new river intake 50 m upstream of the current intake, installing a rock weir in the Campbell River to increase the water depth over the intake, constructing a new 400 m long channel with a new intake upstream of the current intake, connecting to EF3, managing the infrastructure as is, status quo. An iterative process amongst the working group, which included DFO, MoE, CRSF, BC Parks, and others, resulted in identifying the best long term solution as constructing a new 400 m long channel, installing a new intake, and connecting to EF3. A detailed Environmental Impact Assessment (EIA) was prepared as part of the BCRP 2007 project. The impact assessment process ensured that the stewardship of British Columbia's system of protected areas was included in all activities and practices were conducted within these areas. Its purpose was to provide for the assessment of all potential impacts of proposed actions in provincial protected areas; ensure provincially consistent standards are followed; provide an open and accountable assessment process; provide a forum for standardized and documented decision-making; and, provide for participation in the review process by the proponent, other agencies, First Nations, and the public, where required. The EIA documented elements and biophysical features that had potential conservation value including native plant communities, aquatic and terrestrial habitats, species (including rare and endangered species), sensitive ecosystems, site hydrology and flood issues, and other environmental features affecting sensitivity of the site. Field surveys for any rare or endangered species that could potentially be present in the vicinity of the side channel site were conducted using standardized methodology for each suspected species or group. The EIA described the anticipated effects of the side channel development both in the short and long term and discuss how adverse effects will be minimized. The EIA also outlined critical mitigative measures that could be implemented to ensure construction activities meet or exceed all guidelines, codes and regulations A detailed topographic survey was carried out as part of the 2007 work (BCRP 07_ CBR _02). The survey area encompassed the new intake area, side channel, and parts ofef3 (Photo 2). The survey was tied into the coordinate system and datum used for other restoration efforts on the river. Final plans and specifications were completed in the spring of 2008 for the construction of a new intake pipeline and a 400 m long connector channel. Several permits were required prior to starting construction. A water license amendment was applied for and issued by MoE (File no , Conditional Lic ). The. Section 9 permit was integrated in the water license. The existing EF3 Park Use Permit was also amended and issued (ST ), and a Transport Canada Navigable-Waters Protection Division permit was applied for and issued. Campbell River Salmon Foundation Elk Falls Intake and Connector Channel Construction Summary 2

8 2.0 INTRODUCTION The project saw the construction of a new 650 mm diameter by 30 m long pipeline installed between the river and a new side channel starting on the left bank near the downstream end of First Island. A new 400 m long trapezoidal channel was excavated to connect the new intake to the upstream end of the existing EF3 channel. The new project provides up to 700 Lis of flow year round to the pre-existing channels and EF3 wetland. Additional work included installing a 1200 mm diameter culvert under the Catalyst pumphouse road, improving 800 m of the Elk Falls trails (widening and resurfacing), improving to the EF3 wetland outlet, and extensively planting 2,777 riparian species over a 0.87 ha area. The side channel now provides year round flows to the EF3 (2000) channel and wetland, and at the same time increases wetted habitat for fish and amphibians by 2,700 m 2 for a total of 19,700 m 2 (approximately) of improved or new fish habitat. The incremental increase of wetted stream habitat has the potential to increase amphibian production, as well as Coho production by over 2,700 smolts per year (1 smolt/m 2 for channels) in the project footprint. Additionally, this project has the potential to increase productivity an additional 6800 Coho smolts year (0.4 smolts I m 2 for wetlands) when including the benefits of improving the pre-existing EF3 channel function. Funding for constructing the project was provided by the Campbell River Salmon Foundation and BC Hydro BCRP($304,097.90). CRSF, DFO and BC Parks had in-kind contributions in the form of staff time ($10,500). The total value of the construction project was $314, Campbell River Salmon Foundation Elk Falls Intake and Connector Channel Construction Summary 3

9 3.0 CONSTRUCTION Prior to the start of construction, materials were sourced and staged for the project. Sixty meters of recycled 660 mm (26") diameter pipe was purchased from Can-Am Recycling and delivered to Southside Welding in Campbell River for the intake. Southside Welding fabricated the intake screen and welded flanges onto 15 m pipe segments. Key Mill Construction built a concrete headwall to support the valve on the downstream end of the intake pipe. Armtec supplied 26 m of 1200 mm corrugated metal pipe (CMP) for the Catalyst pumphouse road crossing. Uplands Excavating supplied crushed rock for improving the trail surfaces. A. Wood Bulldozing supplied coniferous tree stumps for L WD complexing. Approximately 500 m of snow fencing was rented from various sources for securing the construction site. Streamside Native Plants supplied the rooted native stock for re-vegetating the disturbed areas, and live stakes were supplied by R. Wong Consulting.. The prime contractor was A. Wood Bulldozing which supplied most of the excavation equipment and articulating off-road haul trucks. Dig Dug Excavating provided a small excavator, and Uplands Excavating provided an articulating haul truck for several days. Tuttle Trucking, Bobcat, and Excavating provided a bobcat for improving the EF trails. The Altegay Fisheries Society and DFO supplied a labour crew for maintaining trail closures. Altegay Fisheries Society also provided general site labour tasks throughout the various phases of construction and reclamation. KML Forestry performed the construction supervision duties. Park trail closure notification and communications were coordinated by BC Parks, DFO, and the CRSF. R.Wong Consulting provided the biology support and performed the environmental monitoring duties. Northwest Hydraulic Consultants was responsible for engineering and the overall project coordination. A project contact list is provided in Appendix A. 3.1 WEEK 1 (AUG 2S-AUG 29) Constructiori started on August 25 th, A tailgate safety meeting was held prior to starting work, and typically at the start of every week. The EF trail was closed during the clearing and brushing stage for approximately 2 days. Members of Altegay Fisheries Society and DFO staff were stationed at critical locations during the clearing phase to ensure public safety and provide information as required. Approximately 450 m of snow fencing was installed along the edge of the trail to restrict public access to the site (Photo 3). A Cat 330 excavator cleared the channel right-of-way (Photo 4). The excavator and 25 tonne off-road truck were used to construct a tote road to the upstream end of the site in preparation for installing the intake. The dump site near the Catalyst pumphouse was also cleared and prepared for receiving the excavated overburden and gravel and sorting large wood re-used for channel complexing and wildlife trees. Campbell River Salmon Foundation Elk Falls Intake and Connector Channel Construction Summary 4

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