Share this Story: Big Bar blasting resumes to ensure salmon can migrate past landslide
Big Bar blasting resumes to ensure salmon can migrate past landslide
The DFO says blasting will be done until water levels rise from the spring freshet. In-river drilling and excavation are also underway.
Nick Eagland
Mar 08, 2020 • March 8, 2020 • 2 minute read
An aerial shot of the slide site showing current river flow post-blasting on March 5, 2020. Photo by Handout: Fisheries and Oceans Ca /PNG
Blasting resumes this month at the Big Bar landslide on the Fraser River to ensure salmon and steelhead can safely migrate this spring.
Fisheries and Oceans Canada said blasting will be done until water levels rise from the spring freshet which they expect to arrive by mid-March. In-river drilling and excavation are also underway.
Big Bar blasting resumes to ensure salmon can migrate past landslide Back to video
"Reduction of harm to fish, to the greatest extent possible, is one of the high priorities for this work," the department said in an email Friday.
"There is ongoing monitoring in place below the slide site to determine whether any fish are in the area."
The department said a plan was formed to reduce impacts on fish and they have a program to detect fish before the blast so they can be relocated or scared away.
Once holes are drilled into boulders and rocks, they will be loaded with water-resistant dynamite which was chosen because it is less toxic to fish than ammonia-based explosives.
There aren't any salmon trapped below the Big Bar slide right now but the departmentanticipates that hundreds of thousands of salmon will return and need to migrate through the area in 2020.
The huge remediation project is jointly managed by Fisheries and Oceans Canada, the B.C. government and B.C. First Nations, who are guided by an Indigenous leadership panel. It involves equipment operators for excavators and rock trucks, drillers and blasters, rock scalers, emergency medical, river rescue and helicopter evaluation crews, environmental specialists and archeologists.
"Blasting in waterways is not uncommon and the methods the contractor is using to drill and blast rock near and in-water are well understood," the department said.
"The challenge for this site has been to get crews and heavy equipment into this remote location so that they can work safely and build the infrastructure necessary to support blasting and excavating of material from the river."
CATs work on building access to the West Bank. Photo by Handout: Fisheries and Oceans Ca /PNG
Last November, the federal government issued a call for advice from the private sector on demolition and rock blasting services, along with excavating, rock crushing and dredging, in an official request for information.
Peter Kiewit Sons ULC, was awarded the contract on Dec. 31, 2019 to undertake extensive winter work at the landslide site.
The remediation project will occur on the traditional territories of the Secwepemc Nation, specifically High Bar First Nation and Stswecem'c Xgat'tem First Nation.
A pair of technical working groups is also coming up with a contingency plan for alternate ways to help fish safely pass through the landslide site in case the water is too high or fast to allow some salmon populations to pass through.
It is vital to remove the debris during the winter period of low water flows before the spring freshet in order to save four upper Fraser salmon runs from extirpation.
The U.S. Army Corps of Engineers and the Canadian Armed Forces have been involved in the planning process along with industry experts in the use of explosives.
The slide was first reported June 23, 2019, and work to clear a path for salmon started in mid-July. A priority has been blasting and removing the massive boulders that sheared off the 125-metre cliff above the river.
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