Risk reduction becomes focus at Colliery dams over winter

NANAIMO – City staff looking at all options to mitigate flooding and quake hazard during rainy season

Nanaimo city officials will consider changes to its emergency notification program and dam spillways as part of new short-term mitigation measures for Colliery Dam Park.

City staff is working with Snuneymuxw First Nation on short-term fixes to address flood safety issues at Colliery Dam Park this winter, including altering spillways so they can take on more water.

Officials say all risk- mitigation options are on the table, but top picks include improved emergency notification for downstream residents, increased water-level monitoring, and drainage of a portion of the dams. They are no longer looking at completely dewatering the two swimming holes, calling the move expensive and impractical.

The push to come up with mitigation measures was spurred by city council last Wednesday, which voted unanimously to cancel tenders to demolish the lower and middle Colliery dams this summer. More than $2 million has been made available for future mitigation work and city staff members have been tasked with finding short-term solutions within the next 60 days. The century-old dams are considered a public safety hazard by the B.C. Dam Safety Branch, unable to withstand a major earthquake or flood. City officials had planned to take out the dams this summer and rebuild sometime next year to eliminate risk, but they said an 11th-hour consultation with Snuneymuxw First Nation precluded any reasonable attempt to deconstruct the structures this season.

“Certainly short-term mitigation is our first priority and staff will be looking for input,” said Susan Clift, Nanaimo’s director of engineering and public works. “I think mostly we are going to be focusing on our emergency response for this winter and minor physical changes…because of the lack of time remaining.”

The City of Nanaimo has been working with the B.C. Dam Safety Branch on deciding the fate of the structures and they are not happy with the new direction, according to Clift. They wanted the city to consider draining the dams this winter to cut out risk, but Clift said it would have been too difficult for city workers to constantly pump out water flowing into the vacant space.

The province  sent a letter to council before Wednesday’s meeting, expressing their views on the city’s potential new direction and suggesting they find an alternative as soon as possible. The letter was not made public before press time, despite assurances it would be made available online.

Ted Swabey, Nanaimo’s general manager of development, said everyone wishes the risk would have been mitigated permanently before now but “we are, where we are at. We couldn’t get everything done,” he said.

The Snuneymuxw and City of Nanaimo will be collaborating on options and rolling out potential short-term and permanent solutions to stakeholders. The city will remain liable for structural damage done by a major quake until the city takes action with long term solutions next spring.