Photo: Contributed

Bastion Mountain

A study of a Shuswap mountain where a fatal slide took place has come up with a dozen recommendations.

This assessment was conducted on Bastion Mountain following three landslides in 2014 and 2017 which destroyed homes and killed one man.

A geomorphic study into the future landslide risk on the mountain is a starting point for additional action to make residents of the Sunnybrae area aware of potential hazards.

The study will also help various agencies determine the next steps to mitigate possible threats to people or property.

Columbia Shuswap Regional District directors received a report from Kerr Wood Leidal Consulting Engineers, assisted by Westrek Geotechnical Services, which made a dozen recommendations for consideration.

Sophisticated Lidar mapping, aerial mapping, a review of historical landslide data and an analysis of water flows were used to draft the recommendations.

The report will be used to help manage land development with regard to landslide risk in the Bastion Mountain area. 

Some of the recommendations include developing an acceptable and tolerable level of risk for both proposed and existing developments.

Simon Gautschi from Westrek, said most local governments in BC do not have these types of risk thresholds, so standards for these risk levels would have to be developed by the CSRD.

Additional assessments are also recommended for areas with logging or which have been affected by wildfire, as this can increase the potential for landslides.

It was also recommended all creek fan areas identified in the report be designated as Development Permit Areas within the CSRD.

"There are incredible implications if it should collapse for hundreds or even thousands of people," said Electoral Area C Director Paul Demenok. "What is acceptable risk? What do the people who live there think is acceptable risk?"

The reports notes culverts along Sunnybrae-Canoe Point Road are significantly undersized, with the exception of the recently replaced Robinson Creek culverts, and are susceptible to blockage from sediment and possible flooding or debris flow.

It recommends these culverts be upgraded, which would fall to the provincial Ministry of Transportation and Infrastructure, as they are responsible for road maintenance. Board Chair Rhona Martin said the report will be forwarded to the ministry for their review.

Only a portion of the Reinecker Creek watershed, which includes Herald Provincial Park and Campground, was assessed as part of this study due to cost and complexity.

The report, however, is recommending an assessment of this entire watershed for debris flood potential.

Derek Sutherland, Team Leader of Protective Services, said while the CSRD has already started working on resolving a number of the recommendations, some of them are not in the CSRD's jurisdiction or involve private property.

"We are taking the report very seriously and are working towards implementing those processes that are necessary," he said, noting the complete report is available on the CSRD's website for the public to review.

A communications strategy will also be developed to ensure residents in the area are aware of potential risks.