Big Bar Emergency Fish Passage

Fisheries and Oceans Canada,
Lillooet, BC, Canada

Consulting Role

  • Designer
  • Alternatives Analysis
  • Civil Engineering
  • Structural Engineering
  • Mechanical Engineering
  • Hydraulic Analysis
  • Construction Support

Project Members

  • Jason Hill, P. Eng.
  • Eric Orton, P. Eng

Project Phase

  • Completed 2020

Key Elements

  • Emergency Upstream Adult Passage
  • Whoosh System
  • Denil Ladder
  • Precast Building Materials
Big Bar Emergency Fish Passage
On June 23, 2019, a landslide in a remote canyon along the Fraser River, north of Lillooet, was reported in B.C. Over 85,000 cubic meters of rock had sheared off a 125-meter-high cliff and fallen into the river. This slide created a five-meter waterfall, trapping migrating salmon below the slide.
Our engineers worked closely with the Department of Fisheries and Oceans to develop an adult fish passage integrated technological solutions in an extremely remote location to move adult Chinook and Sockeye Salmon past the slide to not lose a year class of adult spawner.
Big Bar Emergency Fish Passage
Big Bar Emergency Fish Passage

The design that was implemented utilized the vertical slot ladder concept constructed with precast ecology blocks arranged from the river to a receiving pool where a Whoosh Passage Portal System was placed. Pump systems were used to provide fishway flow as well as attraction water to entice the adults to ascend a denil ladder into the whoosh transport system. The transport tubes were hung from the side of the canyon wall above high water extending above the slide where the fish exited the tubes to continue upriver to natal spawning grounds. As part of the team, we developed multiple concepts for evaluations, coordinated river hydraulics with the team, sized and arranged the fishway receiving structure, designed the cliff Whoosh support frames, coordinated design concepts and supported construction of the system.