October 15, 2015, Vancouver, BC, Canada – Knight Piésold staff from the Vancouver, North Bay, and Lima offices participated in the 2015 Canadian Dam Association (CDA) Annual Conference. The conference, held in Mississauga, Ontario on October 5-8, 2015, was well-attended by consultants, regulators, and large dam owners from across the country. 

Staff attended pre-conference workshops on tailings dam breach modelling as well as dam safety reviews. These sessions outlined the state of practice in these two fields and allowed practitioners to share experiences and challenges to provide feedback to the CDA committees developing guidelines in these areas.

During the tailings dam breach workshop, the CDA committee members presented a potential change to the methodology for completing these studies. The proposal involves decoupling dam hazard classification and emergency response studies by looking at the level of risk associated with the dam and the credible failure modes for the facility. There was general agreement that mining dams behave differently than conventional water retaining dams during a breach event and that specific guidelines should be developed for mining dams. 

During the dam safety review sessions, the committee clarified that for mining dams a minimum factor of safety of 1.3 is considered only during construction before the first fill of the dam. Discussions continued about whether the engineer of record needed to be an individual or could be a company, the difference in the responsibilities between the designer of record and engineer of record, and the responsibilities of the owner during all stages of the mine life.

The conference consisted of presentations and keynote addresses on a variety of topics ranging from dam safety and sustainability, geotechnical issues, and mining dams. Specialist Hydrotechnical Engineer Violeta Martin and Project Engineer Anna Akkerman from the Vancouver office presented the following technical papers during the tailings dam breach session:

1. Practical Tools for Conducting Tailings Dam Breach Studies
2. Assessing Credible Modes of Failure: Afton TSF Dam Breach Study