Campbell River Water Supply Intake
Since 1947, the city of Campbell River, located on Vancouver Island in British Columbia, has accessed the majority of their water from a manmade lake, John Hart Lake, through a hydroelectric generation plant owned by BC Hydro. To provide safer, efficient and more reliable service, BC Hydro embarked on the construction of a new underground hydropower generation facility. The change required the City of Campbell River to devise an independent means for sourcing its drinking water.
This new system consists of nearly two miles of connecting lines and a raw water intake. The design team selected Permalok® casing pipe for a new 380 linear feet intake. The 60” ID Permalok® carries a fused HDPE liner and attaches to a submerged intake screen system at a depth of over 45 feet. The efficient upgrade supplies water while reducing impact to the surrounding provincial park at a reduced cost.
Microtunneling is an installation method for this project. The closed slurry system continually supports the Microtunnel Boring Machine (MTBM) by balancing groundwater and soil pressure during excavation. With an operator at the surface level controlling the MTBM via remote, this approach is very safe to use in high water environments.
The team faced a few complications including the logistics of reaching a remote jobsite that required truck, barge, and heavy lift equipment. The restricted shaft space of the intake structure limited the length of Permalok pipe and the final flotation, in addition to the attachment of the HDPE pipeline, which subsequently sank, coupled with contractor’s first wet retrieval.