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Big Bar landslide response summary

On June 23, 2019, a significant landslide was reported in a remote, rugged canyon along the Fraser River near Big Bar, north of Lillooet, British Columbia, on the traditional territory of the Secwepemc Nation.

Huge pieces of rock and substantial debris sheared off from a 125-metre cliff and crashed into the river, creating a five-metre waterfall. Further analysis confirmed that approximately 110,000 cubic metres (m3) of debris fell into the river. This barrier prevented migrating Pacific Fraser salmon from moving beyond the landslide to reach their spawning grounds, thus impacting the reproductive cycle of several key Upper Fraser salmon populations.

View the Big Bar landslide response timeline of key events.

2019

2019

Emergency response

Five days after the discovery, the Big Bar Incident Command Post (ICP) was established to respond to the emergency situation. The ICP consisted of experts and specialists from First Nations, the Government of British Columbia and the Government of Canada.

Between June and September 2019, the emergency response operations were jointly led by the three levels of government, and supported by other agencies, stakeholder groups, and geotechnical and hydrological experts. Significant resources were mobilized to mitigate the impact of the landslide on migrating Fraser salmon stocks.

The response efforts included:

  • rock scaling to stabilize the cliff and establish site safety;
  • in-river rock manipulation to improve natural passage;
  • use of helicopter to transport fish past the slide site, and
  • intensive fisheries, hydrological and geotechnical monitoring.

Throughout the operation, the safety of personnel and the public remained a top priority.

As natural migration began to occur in early September 2019, transport operations stopped. By then, approximately 60,000 fish had been transported above the slide by helicopter. Work then focused on continued fish monitoring and planning future remediation efforts.

As a result of the emergency response efforts in 2019, approximately 276,000 salmon were detected passing Churn Creek, 40 km north of the slide site.

First Nations Leadership Panel

The First Nations Leadership Panel (FNLP) was established in July 2019, consisting of Indigenous leadership and delegates impacted by the landslide or those invested in Fraser River salmon stocks. The FNLP provides direction related to the protection and sustainability of fish. They are involved in decisions related to remediation of the slide area, implementation of alternative fish passage systems and other important issues related to the response. In September 2019, the FNLP endorsed options for winter construction.

Transition to project structure

In October 2019, the ICP transitioned to a new project structure with the Joint Executive Steering Committee (JESC). The landslide response team is guided by the ongoing partnership between the three levels of government and ensure the continuity of direction and knowledge retention from the emergency phase.

Technical working groups

Two technical working groups were also established in December 2019. The group consists of experts from the three levels of government, Indigenous fisheries organizations, stakeholders, non-profit organizations, and academia. They provide input for comprehensive mitigation plans for alternate fish passage methods and emergency conservation-based enhancement.

To reduce the impact of high water on salmon populations during the early part of the 2020 migration season, the groups developed three options for alternative fish passage:

  • a “nature-like” fishway;
  • a pneumatic fish pump system; and,
  • when there is a gap in pump operations, truck and transport.
2020

2020

2019/2020 winter work

In December 2019, following a competitive process, Peter Kiewit Sons ULC (Kiewit) was awarded a contract to undertake extensive winter work at the landslide site. This work began in early January 2020 and continued until the end of April 2020.

Kiewit’s winter work objectives included in-channel rock blasting and debris removal, which allowed heavy equipment to access large boulders in the middle of the river. Subsequently, crews completed multiple blasts of the East Toe, removing an estimated 14,000 m3 of rock from the river and reducing the height of the river flow at the slide site by approximately 50%.

Kiewit’s contract also included an Indigenous Benefits Plan (IBP) to provide socio-economic benefits to High Bar First Nation and Stswecem’c Xgat’tem First Nation. Training, employment and sub-contracting opportunities for both communities were key components of the IBP.

Fish passage systems

In early April 2020, DFO and provincial staff, and Indigenous JESC members met with the FNLP delegates to provide a winter work progress update and highlight upcoming plans for spring and summer work. The FNLP reached consensus and endorsed the proposed mitigation measures for fish passage and emergency conservation enhancement at the site.

During this time, Kiewit completed the construction of the “nature-like” fishway on the west side of Big Bar to allow fish to pass through the slide at different flow levels without assistance.

In mid-April, Public Services and Procurement Canada (PSPC), on behalf of DFO, awarded a contract for the lease of a pneumatic fish pump system to Whooshh Innovations Inc. By mid-May, the concrete fish ladder was completed. In addition to acting as the entrance to the pneumatic fish pump system, the temporary fish ladder supported truck and transport and emergency enhancement operations. The six-lane Whooshh Passage Portal™ was operational by July 2020.

The Gitksan, Sta’t’imc, Secwpemc and Sylx First Nation crews led fish wheel operations and transported fish collected at the slide site by truck to the French Bar Creek Holding Facility. This work was critical to the capture of salmon for radio tagging, emergency enhancement and upstream release. By mid-August, Indigenous crews had moved more than 1,500 salmon over the slide, and captured approximately 90 per cent of the early timed chinook and Early Stuart sockeye needed for the enhancement program.

Monitoring program

During the 2020 migration season, hydroacoustic sonars and radio tagging were used above and below the slide site to track and understand fish population size, movement and health in near real time. Between May and October, more than 161,000 salmon were detected moving past the barrier.

Preliminary monitoring data indicates that migrating Fraser salmon were significantly slowed by an extended period of high water throughout the Fraser River from late April to early August 2020. Hence, fish arrived at Big Bar much later than usual. However, as a direct result of the construction of the “nature-like” fishway and rock removal this past winter, salmon were able to pass through higher river volumes than in 2019. Additionally, greater numbers of salmon successfully passed the slide without assistance in 2020 as compared to 2019.

Emergency conservation enhancement program

The Big Bar Emergency Conservation Enhancement Program is critical in supporting the recovery of impacted salmon populations. Fish selected for the 2020 program have resulted in the rearing of 120,000 Early Stuart and 12,000 Bowron sockeye, and 99,000 chinook juveniles at hatcheries with their planned release in summer 2021.

This work builds on the enhancement efforts undertaken during the 2019 emergency response. In October 2020, First Nations and DFO staff successfully released 20,000 Early Stuart sockeye fry into creeks near Fort St. James and Takla Landing. The fry were reared from eggs collected from adult salmon that arrived at the slide site in 2019.

Long-term planning

Over the last several months, the landslide response team has been focused on the critical next steps of planning, evaluating and implementing a permanent solution to restore natural fish passage at the slide. An extensive options analysis, concluded in July 2020, determined that a permanent fishway is the only long-term solution which can provide reliable fish passage at Big Bar. On November 17, PSPC, on behalf of DFO, awarded the contract for the construction of a permanent fishway to Kiewit. Work on the new fishway will begin in winter 2020 and is expected to be operational in time for the 2022 Fraser salmon migration.

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