Assessing Consequences of Potential Tailings Dam Failures on Canadian Communities.

Abstract:

The dams that retain waste materials from mining sites, called tailings storage facilities (TSF), are among some of the world's largest engineered structures. Recent, devastating TSF failures, such as the 2019 Córrego do Feijão TSF failure in Brazil, inundated large areas, killed 270 people and caused extensive environmental, social and economic consequences. Currently, the potential consequences of TSF failures are not well understood from a systems perspective, with most risk analyses focussing on site-by-site analyses at fixed points in time. There is an urgent need to better understand potential TSF consequences that may arise across different spatial and temporal scales so that management and policy interventions can be better designed. Through a case study on Canada, this study considers how potential TSF failures may impact communities and surrounding environments. By using a recalibrated Geographic Information System-based lahar-inundation model (Laharz), we simulate potential failure scenarios from selected Canadian TSF sites to create a high-level, national hazard map. Furthermore, we develop an initial methodology for a TSF failure consequence analysis by analyzing the extent to which key risk elements such as population centres, Indigenous communities, high-value land-uses, and protected areas intersect with the modelled inundation zones from potential TSF failures. The results garnered from this study can be used as a high-level guide for policymakers to understand the potential consequences of TSF failures, inform the development of a national strategy and contribute to policy interventions towards more robust tailings management.