Skip to content

MLA Report: How to ensure a dam never fails

Norm Macdonald discusses dams in this week's MLA report.

When the Mount Polley tailings pond retaining wall collapsed this past summer, the BC Liberals said the failure was completely unpredictable. That is not true. If BC Hydro operated their dams the same way the government allows mining companies to manage their retaining walls, the entire Columbia Basin would be under threat all the way to the city of Portland, Oregon.

BC Hydro provides an example of how to manage these structures when failure is not an option. Mica Dam is an earth filled dam north of Revelstoke, and at full pond holds back so much water that the very fate of the whole Columbia River Valley depends upon it never failing.

BC Hydro does daily visual checks, weekly site inspections by trained inspectors, bi-annual inspections by specifically trained dam safety engineers, and every five years an independent set of dam safety consulting engineers visits from other jurisdictions in the world. This is how you ensure a dam never fails.

Compare that to Mount Polley. The government knew there were problems with expansion of the tailings pond. The government knew that there were signs of cracks in the structure. The government knew that there was improper management of water levels, and that, at times, 40% of Mount Polley’s automated measurement devices did not work.

The government chose to have absolutely no geotechnical engineers on mines ministry staff and do no inspections of Mount Polley for years at a time.

If the government had the attitude that tailings ponds can never be allowed to fail, we would use our ability and technology to ensure that these accidents never happen.

This government’s sloppiness made this failure completely predictable, yet the BC Liberals still feign shock and surprise. And the sad fact is that there will be no political consequences for their failure to ensure our environment is protected.

If there were serious political consequences, future Ministers and governments would do their jobs properly. It’s up to citizens to ensure that this is the case.