Work at the Big Bar landslide site northwest of Clinton is continuing, and the COVID-19 outbreak has not caused significant delays. The Department of Fisheries and Oceans (DFO) says that prime contractor Peter Kiewit Sons ULC (Kiewit) is taking additional health and safety precautions, including tightening site access to limit the risk to workers.
The landslide response continues to be a top priority for the DFO, with resources remaining dedicated to the work. With water levels remaining low, and the addition of a swift water rescue night-shift, crews are tackling crucial in-river work around the clock. Crews recently removed additional rock from the river, installed supports for the West Bank canopy, and improved the access route in multiple locations.
Kiewit is also preparing for a second East Toe blast. Crews have detonated charges to create a plateau on the rock outcropping to use as a drilling platform. They will move an air track drill to this shelf by heavy lift helicopter in the coming days. Drilling will then commence, with a blast scheduled in April.
Since mid-January, Kiewit has made steady progress at the site despite challenging weather and difficult access. Although crews have been successful in meeting the winter work objectives, including removing large boulders and debris, recent modeling done at low water shows that a mass of slide debris situated elsewhere in the river will cause heavy flows at high water, stopping fish passage.
A team of internal and external experts has been developing contingency plans and designing alternative fish passage systems to move fish during high water, when passage will not be possible for an extended period of time. The plans include constructing a “nature-like” fishway, installing a pneumatic fish lift system, and developing a trap and transport option to collect salmon below the slide and release them upriver.
Contingency planning for the enhancement of stocks returning to the upper Fraser watershed is also ongoing. A monitoring program will be implemented throughout the salmon migration period to gather as much information as possible and to aid the implementation of the contingency plans.
For more information about the Big Bar landslide and ongoing work at the site, please visit https://bit.ly/3bzPSar.