Campbell River Spawning Gravel Placement: Site 7-IV
In the lower Campbell River system, gravel recruitment is an ongoing footprint issue due to the blockage of natural gravel recruitment from the upper river, caused by the construction of the John Hart Generating Facility in 1947. This project is part of an ongoing gravel recruitment program on the Campbell River. Specifically, this project will reconstruct an approximately 1800 square-metre spawning gravel pad at “Site 7,” in order to provide critical spawning habitat for up to 180 Chinook spawning pairs at an historically significant spawning location in the river. Approximately 2100 square metres of spawning gravel was placed at this location in 2013, but it was obliterated in a disastrous flood event in December 2014.
This project will result in the reconstruction of an 1800 square-metre spawning gravel pad in an historically significant area for Chinook, Coho, Chum and Steelhead populations. In addition, the nutrient inputs from salmon carcasses will enrich the aquatic trophic system and benefit stream-dwelling juvenile salmonids of all species and other freshwater species. The proposed spawning gravel pad will provide spawning habitat for approximately 360 Chinook, and an undetermined number of Coho and Chum along the edges of the restoration site, where water velocities and depths will be more suitable. Restoration of this spawning habitat at Site 7 will create an alternate site for Chinook Salmon currently utilizing adjacent spawning areas, and reduce the likelihood of over-use at other spawning locations upstream and downstream of the proposed restoration site. The addition of suitable Chinook spawning habitat at Site 7 will also reduce intraspecific and interspecific competition for spawning habitat, thus increasing the use of suitable portions of these areas by other species (Chum and Coho Salmon). By dispersing the spawning adults over a larger area, there is the potential for increased spawning success for all species by decreasing the potential for over-spawning disturbances. Restoration of this spawning habitat will also benefit Coho, Chum, and Steelhead populations.
Final Report: Executive Summary
The Campbell River 2016 Site 7-IV gravel placement project was constructed from 8 to 12 August 2016 and involved the placement of 4,300 metric tonnes of washed and screened spawning gravel into the Campbell River. Rows of large boulders were also placed in an attempt to retain the spawning gravel during high flows. The gravel was placed at Site 7, which is 300 m downstream of the BC Hydro John Hart Generating Station between the right bank and downstream end of First Island. This project has now been completed four times since 2006, giving this latest project the title ‘Site 7-IV’.
The purpose of the project was to increase the available spawning habitat for Chinook salmon and other riverine species. Strategic placement of spawning gravel for Chinook salmon in historically important areas of the mainstem Campbell River is a priority ‘Habitat Based’ action in the Campbell River Salmonid Action Plan (FWCP, 2011). The finished spawning platform had an undulated surface, with four large boulder ‘gravel retaining structures’ spaced approximately 20 m apart on the existing river bed in an attempt to keep the gravel in place during high scouring flows. The constructed platform is approximately 100 meters long, and ranges from 20 meters wide at the upstream end to 27 meters at the downstream end, with a surveyed top area of approximately 2,250 m2 . Based on the assumption of one spawning pair of Chinook salmon per 10 m2 of gravel platform (Burt, 2004), this project supplied spawning habitat for 225 pairs of Chinook.
During construction, flows in the Campbell River were held steady at 30 m3 /s. Chinook salmon were observed spawning on the gravel pad in October 2016 at a river discharge of 130 m3 /s. Due to large amounts of rainfall, flows in the Campbell River increased to 650 m3 /s on 10 November 2016. Discharge since that time has been approximately 100 m3 /s. The high discharges make assessment of the site difficult; however, it is believed that much of the placed gravel was mobilized downstream because the design calculations showed the gravel was stable for flows up to about 260 m3 /s.
Funding for this project was supplied by the Fish and Wildlife Compensation Program (FWCP), Campbell River Salmon Foundation (CRSF), and the Department of Fisheries and Oceans’ (DFO). DFO and CRSF also provided input to the project design and construction process. Engineering services, project management, construction supervision, and reporting were provided by Northwest Hydraulic Consultants Ltd. (NHC). Materials and construction services were provided by Upland Contracting Ltd. Environmental monitoring and site security was provided by ATlegay Fisheries Society.
Click the provincial database link below to read the full final report for this project.