What is a Run-of-River Project?
The type of hydroelectric project that is commonly used today in British Columbia is the run-of-river project. It is deemed as a significant contributor to green power because it requires little or no storage to generate the electricity that is needed. Unlike large hydro projects that have been built traditionally in B.C., no large dam, reservoir or flooding will result from the Ashlu project. The energy produced will come from the naturally flowing mountain waters.
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Here is how the Ashlu Creek Project would work:
Weir and Intake
Located 8 kilometres upstream of the confluence with the Squamish River, a 3 metre high inflatable rubber weir sitting on top of an approximately 3 metre high sill will divert some of the water from Ashlu Creek into an intake structure, which subsequently directs the water into an underground tunnel. The rubber weir is inflated to slow down the water in the creek so that some of the water can be diverted into the tunnel. A fish ladder will be installed at the weir to allow any fish to pass upstream of the weir.
Intake structure at Rutherford Creek
Tunnel
A 4 metre diameter, underground tunnel will be built through solid granite. It will transport the diverted water over 4 kilometres downstream to the powerhouse. The tunnel will be built entirely underground so that there is no disturbance to wildlife.
Soo River Hydro Electric Project Powerhouse
Powerhouse
Inside the powerhouse, the incoming water from the tunnel will turn the turbines to generate electricity. The powerhouse is the size of a large, residential house and is well insulated to minimise any noise. There is only a minimal amount of lighting on the outside of the powerhouse; there are lights on the inside for a worker to monitor the turbines. Lights and noise from the Ashlu powerhouse will not be visible nor audible from the Squamish Valley.
Turbine Generator
Water Return Channel
After passing through the turbines, the water returns, clean and unchanged, through a channel and back into the natural creek. The returning water is several hundreds of metres upstream of the salmon habitat area on the Ashlu delta to ensure no disturbance to the salmon during spawning season. There is no net loss of water to the creek as all of the diverted water is returned to the creek.
Powerline
An overhead powerline will be installed and will follow the existing logging road for 2.5 kilometres to connect to BC Hydro's existing powerlines from the Cheakamus Generating Station. By tying into the existing power lines, there is no new power line down the Upper Squamish Valley and no visual impact to the local area residents.
