B.C. allows Mount Polley tailings dam to go higher, a decade after massive spill

VICTORIA — The British Columbia government is allowing the height of the Mount Polley tailings dam to be raised an extra four metres, a decade after a similar storage site burst in one of the province’s biggest environmental disasters.

A statement from the Mining and Environment ministers says the extra height is to ensure that spring runoff can be safely managed.

Environment Minister Tamara Davidson and Mines Minister Jagrup Brar say their decision was informed by the Environmental Assessment Office and they are satisfied that safety issues have been assessed thoroughly.

The tailings dam at the open-pit gold and copper mine in B.C.’s Cariboo region gave way in August 2014, spilling mine waste into nearby waterways and causing widespread environmental damage.

Two reviews led to changes in 2016 on how tailings ponds are regulated, and the government says the proposed dam height increase — from 60 to 64 metres — meets or exceeds all requirements.

The ministers say that they recognize there are significant concerns around the operation of the mine, and since 2016 there are “significantly stronger environmental standards.”

“Approvals for this change come after comprehensive technical reviews by experts, including external engineers, as well as consultation with First Nations,” they say.

Their statement says that what happened in 2014 can never happen again.

“Our strong requirements (for) protecting the environment are non-negotiable,” the statement says.

This report by The Canadian Press was first published March 27, 2025.

The Canadian Press