BC Hydro is increasing investments and safety measures following the release of a seismic study that pinpoints the hazards to its facilities in the event of a major earthquake.
The study - the first-of-its-kind to be applied by the hydropower industry in North America - found that the seismic hazard at the utility's largest generation facilities, in the North and Southeast, has decreased or remains the same. It also found however that ground shaking on Vancouver Island and along Bridge River could be more severe during a major earthquake than previous studies have indicated. As a result, BC Hydro is taking steps to address the increased hazard.
"BC Hydro has been assessing seismic hazards at its dams and facilities for many decades," said Chris O'Riley, executive vice-president, Generation, BC Hydro. "The new model shows us that nothing has changed for the biggest dams in the province. We have an updated action plan that addresses the hazards raised for Vancouver Island. This includes investing $700 million on Vancouver Island dam safety upgrades over the next ten years. This is in addition to the $1 billion John Hart upgrade project. It is all encompassed in the 10-year plan for BC Hydro that was introduced last fall."
The study is the culmination of six years of work by a cross-section of experts, including seismologists, physicists and geologists. They studied the history of seismic events across British Columbia and adjoining regions. BC Hydro worked to identify where major seismic activity could occur, developed prediction models and determined resulting seismic ground motions at its facilities. This methodology is now a best-in-class model for calculating earthquake hazards for utilities, the utility said.
"This information applies to what would happen in the event of a major earthquake and it is important that we respond. Our dams are safe. We have a rigorous and thorough dam safety program which includes inspections and monitoring on a daily basis and additional review from independent experts," added O'Riley.
BC Hydro is now advancing the design and review of the John Hart dam safety upgrade, and will undertake new public education and awareness campaigns in the Campbell River and the Jordan River areas. In the Bridge River system, BC Hydro is modifying operations at the Downton Reservoir for La Joie dam and undertaking further studies at Terzaghi and Seton dams to determine if action is required.
BC Hydro said the new seismic study will be made available to local governments, agencies and others who are interested in assessing ground movement and what it may mean for their infrastructure.