BC Hydro has completed a C$65 million (US$54 million) seismic upgrade that included construction of a backup dam immediately downstream of Coquitlam Dam, serving the 55-MW Buntzen Lake 1 project.
The backup dam, 30 kilometers north of Vancouver, was needed to upgrade the existing 30-meter-tall earthfill structure, built in 1913. The backup dam was completed in 2007, with BC Hydro declaring the entire seismic improvement project complete in October.
More than 4,000 cubic meters of concrete, 65,000 kilograms of steel, and 300,000 cubic meters of glacial till, sand, gravel, and rock were used to build the new 30-meter-tall, 300-meter-long earth and rockfill embankment dam.
Water from Coquitlam Lake Reservoir powers Buntzen Lake 1. A second hydropower plant, 18-MW Buntzen Lake 2, no longer is operational.
The seismic improvement project ensures Vancouver’s first hydropower supplier will continue to provide clean, reliable power for generations, BC Hydro said. The system first generated power in 1903.
�Investing in this heritage asset helps secure a reliable supply of clean energy for the Lower Mainland,� Energy Minister Richard Neufeld said. �Much of the growth in electricity demand will be in Metro Vancouver, so ensuring the longevity of a power system so close the province’s major population center is important in helping us meet our current and future energy needs.�
Coquitlam Dam and reservoir are located within Metro Vancouver’s Coquitlam watershed, providing water for power generation, municipal drinking water, recreational opportunities, and fisheries and wildlife habitat.
Kwikwetlem First Nation, Metro Vancouver, regulatory agencies, local governments, local stakeholders, and BC Hydro staff supported construction of the new dam. JJM Construction Ltd. built the backup structure under a C$25 million (US$21 million) contract.
BC Hydro pursued the seismic improvement project after discovering a zone of loose fill within the dam could liquefy during a moderate to large earthquake. It included Coquitlam Dam in plans to spend C$3.4 billion (US$2.9 billion) over two years to renew and upgrade hydroelectric projects and electricity infrastructure. (HNN 3/4/08)