Big Bar: Giving fish an assist

September 22, 2020 | Kieways 2020 Q3

As the project progressed, Kiewit’s scope of work grew to building and placing structures to help give the fish better odds of making it upriver, including:

Technical fish ladder

A technical fish ladder made of concrete blocks is a multi-tiered structure for fish to more easily reach a platform for the next part of their journey.

Fish transport system

During higher water flows, a Mechanical Fish Transport System supplied by Whooshh Innovations offers fish a way to bypass the rapids. They swim up the technical fish ladder to find their way into the Whooshh system. There, they are scanned and automatically sorted by size before being transported through pipes with a compressed air assist across the rapids.

Natural fishway

A natural fishway was constructed from large boulders retrieved from the river. Located directly below the slide site along the face, this organic fish ladder was designed to calm the waters and give the fish a resting place before they swim the rapids behind the boulders.


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