Colliery Dams Public Information Update July 9, 2014

Press Release –

Work undertaken by Golder Associates on behalf of the Technical Committee is coming to a close. Release of Golder’s technical reports, information generated by the Technical Committee, and a report to Council are being scheduled for the next two weeks. Also, a public information meeting is being scheduled, which will include Golder representatives in attendance to answer questions.

Background:

• An update on the status of the Technical Committee’s work was last provided on 2014-MAY-26. This report provides information on Golder’s analysis of the dams, proposed remediation options, estimated costs of remediation options, signage, schedule for an upcoming information meeting and Council meeting, and next steps.
• The City of Nanaimo established the Technical Committee, whose focus included development of an environmentally, minimally invasive, cost- and time-effective solution that addresses:

o   The safety of downstream residents and workers;

o   Dam Safety Section requirements;

o   The respective objectives of the City, Snuneymuxw First Nation, the Colliery Dam Park Preservation Society, and the community;

o   Environmental concerns, including fisheries habitat and ecology;

o   Cost-effectiveness; and

o   Having a timely, permanent solution in place in 2014, if possible, but no later than 2015, with shorter-term mitigation in place, if required, in 2014.

 

Dam Analysis:

• As noted in previous updates, extensive site investigation indicates that risks related to the dams are significantly lower than previously believed.

 

Though the risks are significantly lower, analysis and recommendations from Golder Associates need to be considered in planning for dam remediation and future planning in the event of an earthquake or severe storm.

• Earthquake: Analysis has confirmed that there is an extremely low probability of a dramatic rupture of the dams during an earthquake that would put public safety at risk.

 

If the dams were to be damaged in an earthquake, cracks would develop in the dam walls, resulting initially in water slowly leaking through the cracks. Leaking could continue over time, leading to destabilization of the dams/embankment. If destabilization occurred, the reservoir likely would have to be dewatered to allow for repairing, rebuilding, or removing the dams.

Read more: https://ibftoday.ca/wp-content/uploads/2014/07/140709CollieryDamsPublicInformationUpdate.pdf