About The Project

Day to day BC Hydro’s dams, like the John Hart Dam, are safe and functioning normally.  

Vancouver Island is within the most seismically active zone in BC. For many decades we have been assessing earthquake hazards at our dams, related facilities, and upgrading the dams as required. In 2007, we launched a six-year, $10 million ‘Probabilistic Seismic Hazard Analysis’ study with the results released in 2014. The purpose for this investment? To create a best-in-class model for calculating earthquake hazards for BC, with the results used to better evaluate dam assessments and validate the resulting upgrades. The study outcome was that significant capital upgrades would be required. 

 Project objectives: 

• Upgrade the earthfill and concrete dam to improve seismic performance, including:
  • Placing upstream and downstream earthfill berms.
  • Adding a seepage cutoff wall (impermeable wall) where required within the earthfill sections to act as the seepage barrier.
  • Anchoring of the concrete dam structures.
  • Upgrading the concrete roadway.
• Construct permanent flood and flow imbalance risk mitigation upgrades including:
  • Adding an overflow spillway below the road deck.
  • Replacing the three spillway gates and related works, such as the hoist system, so they can safely and more reliably pass water in a controlled manner downstream post-earthquake.
  • Install new equipment and upgrades to the existing protection and control equipment to meet current reliability standards, including improved post-earthquake operation.