Coquitlam Dam Seismic Upgrade

Client: BC Hydro and Power Authority

Engineer: BC Hydro Engineering

December 2005 – September 2008

The original Coquitlam Dam was built in 1911 and served its owner and the GVRD continuously. In the late 1990’s BC Hydro completed seismic investigations to ensure the seismic integrity of the Coquitlam Dam. As part of BC Hydro’s ongoing dam safety program, the decision was made to upgrade the existing dam by building a new dam embankment on the downstream side of the existing Coquitlam Dam.

JJM Construction Ltd. has been awarded the majority of this upgrade project, which consists of the following works:

  • 160’000 m3 of excavation
  • 3000 m2 plastic concrete cutoff wall (up to 23 m deep)
  • 65’000 m3 of impervious core placement
  • 236’000 m3 of Sands, Gravels, rockfill and Rip Rap
  • 4’000 m3 concrete transition
  • 150 m tie down post tensioned strand anchors (61 strands)
  • Permanent Electrical and Mechanical equipment

To produce the quantities required for the new dam, JJM has developed a quarry to produce the rockfill and the rip rap.  The impermeable core is mined from a borrow area which is approx. 6 km away from the dam site within the GVRD Coquitlam Watershed. The concrete for the transition and the plastic concrete cutoff wall is produced on site with a portable batch plant. With a high focus on quality, JJM is providing the complete Quality Assurance Program and controlling the quality with a complete onsite laboratory. Working within a watershed requires special attention to the environment and work safety.  JJM Construction Ltd. established detailed procedures and plans to ensure that all precautions are taken to minimize the impact on the environment and to create a safe work environment for all.  

Project Contacts:     

Mark Stevens, Project Manager
Cameron McIntosh, Project Superintent