Powell River is a city on the northern Sunshine Coast of southwestern British Columbia, Canada. With two intervening long, steep sided fjords inhibiting the construction of a contiguous road connection with Vancouver to the south, the project’s location complexity required equipment, supplies and workers access only by multiple ferries to the project.
A 36-in. water main, initially installed in 1964, is Powell River’s only water supply, running 4,396 ft from Haslam Lake to the new UV treatment Plant and located in remote area requiring equipment, supplies and workers access only by multiple ferries to project.
Environmental protection was critical. The original large trench excavated to achieve the desired elevation profile remained following the initial water main installation and subsequently filled with water. A wetland formed in the trench following initial construction. This wetland is over 3,280 ft long and up to 5 ft deep, and supports a number of amphibian and bird species, as well as beavers. The wetland is a headwater source for Miller Creek, which flows downstream to Cranberry Lake, which are both fish-bearing.
The entire length of water transmission main was sliplined in one continuous pull of 4,180 ft from entry to exit pit. Sliplining the entire length in one pull allowed the wetland to remain untouched. This project represents one of the longest continuous pulls utilizing the sliplining method to replace a water transmission main in North America.
The complexity of the pull required significant advancement in sending the cable from the launch pit to the receiving pit, including preparation of the host pipe with cleaning and CCTV.
Project Owner: City of Powell River, BC Canada
Contractor: Murphy Pipeline Contractors
Value of Trenchless Project (US$): $2,680,450