Project Update - Site C Clean Energy Project

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If we build a 200-foot dam to create 1,100 MW of energy, how can the fish continue to migrate to their spawning grounds upstream?

McMillen Jacobs’ Water Resources Division is in the final stages of developing fish passage solutions to accommodate the construction of a 200-foot tall dam on the Peace River in northeast British Columbia, Canada for BC Hydro. A 3,450-foot long x 200-foot high earthfill dam will connect to a 2,600-foot long combination roller-compacted and cast-in-place concrete dam and include a 1,100 MW hydroelectric generating station, BC Hydro’s largest substation, and all supporting infrastructure.

The addition of the dam will result in a reservoir that creates a 165-foot change in elevation, resulting in the need for an upstream fish passage/trap and haul facility to allow fish to continue their migration upstream past the dam. McMillen Jacobs designed two fish passage facilities for this project including a temporary structure that will operate during construction when the Peace River is diverted through two 36-foot diameter tunnels. Following the closure of the diversion tunnels and reservoir filling, the permanent upstream fish passage facility will be constructed at the outlet of the generating station and the temporary structure will be decommissioned.

The journey for Peace River Bull Trout will begin when they are attracted to a fish ladder entrance at the foot of the Site C Dam. Fish will ascend a series of pools in a ladder until they reach a trapping pool. From there, they will travel in a “fish lift” to a sorting area, where they will be classified by species and counted, then placed in aerated tanks that are loaded onto trucks and driven to upstream release sites.

McMillen Jacobs’ scope of work includes an alternatives analysis with considerations for potential fish passage risks, technical feasibility, biological benefits, and capital and operating costs; discussions with regulators and 13 local indigenous groups; a biological monitoring plan; constructability reviews; hydrologic and hydraulic analysis with CFD modeling; geotechnical review; and full drawings, specs, construction cost estimates, and schedules. We are currently serving as the Owner’s Engineer during the construction and commissioning of the temporary fish passage facility. Elements of the projects includes an auxiliary water supply system, an entrance pool containing 2 entrances with 6-foot wide slide gates and stop logs, fishway pools, a vee-trap, a fish lock gate, a sorting facility (65’ x 42’), and PLC-based instrumentation and controls system to allow full operation from the sorting facilities.

Currently, the excavation of two diversion tunnels (36-foot in diameter x 2,460-foot long) is near completion, the spillway foundations and the roller compacted concrete buttresses are complete, the left bank mass excavation is ongoing, and penstocks continue to be assembled. The construction for the temporary fish passage facility is nearing completion and the design for the permanent fish passage facility is complete.











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