Tailings are finely ground waste rock produced as a by-product of standard mining projects as well as some industrial and power plant operations. Tailings are conventionally impounded behind a dam that is raised perpetually insofar as operations continue, thus amassing large volumes of materials (sometimes including supernatant pond water) in the process. The failures of some tailings impoundments have triggered downstream mass movements that have caused human, economic and environmental impacts, thus inviting considerable public attention and scrutiny. Developing a detailed inventory of these tailings flows facilitates a better understanding of the magnitude-frequency statistics, preconditioning and trigger variables, breach-outflow processes and downstream runout behaviour. Upon screening over 350 historical waste impoundment failure incidents in pre-existing secondary datasets, we have developed a comprehensive global database of 63 tailings flows from 1928-2020 while following strict case selection criteria with the support of satellite imagery, digital elevation models (DEMs) and source literature. Using a novel runout zonation method, the satellite images and DEMs were analyzed on geographic information systems (GIS) platforms to independently estimate runout distances, inundation areas and travel path angles of tailings flows. Depending on data availability or quality, we also summarized the background information, impoundment conditions and geotechnical indices to provide site-specific context to case histories. The collated data is aimed to (i) broaden the scholarly understanding of tailings breach-runout behaviour, (ii) provide comprehensive documentation while assessing the limitations of data availability and/or quality in the public domain and (iii) establish a consistent framework for reporting various properties of tailings dam failures and tailings flows. Lastly, we note that the data should be treated with prudence. Tailings impoundments are highly variable depending on the locality, and site-specific conditions exert strong controls on post-breach behaviour. As such, it is recommended that our database be used purely as a basis for screening-level assessments, case analog comparisons and academic research. For site-specific prediction studies undertaken by practitioners, targeted field observations, laboratory investigations and numerical models are essential.
Report and appendices to the report available on the bottom of this web page. Appendices are relatively technical.
CanBreach is a NSERC-funded university-industry research team whose purpose is to equip engineers with better tools, including computer simulations, to help manage the risks associated with tailings storage facilities. Using an integrated approach to research, the team will work to develop a better understanding of the mobility of tailings flow, breach mechanisms of tailings dams and the downstream behaviour of long runout tailings flow.
Decision Support System for Water Infrastructure Security Human Consequence Module (DSS-WISETM HCOM) is an analytical module for automated assessment of the human consequences of dam-break floods. The National Center for Computational Hydroscience and Engineering (NCCHE) and the University of Mississippi developed the module with funding provided by the U.S. Federal Emergency Management Agency (FEMA) through a contract with Argonne National Laboratory.
DSS-WISE Lite is a web-based, automated two-dimensional dam-break flood modeling and mapping capability developed by the National Center for Computational Hydroscience and Engineering (NCCHE), the University of Mississippi. The development of the web-based tool and its operation and maintenance is supported by the U.S. Federal Emergency Management Agency (FEMA).
Secure, web-based graphical user interface and map server providing analytical capabilities and a decision support system for dam/levee security.
This DVD has a suite of ArcGIS tools designed to support the development of simplifed dam break studies, Risk Mapping, Assessment and Planning (Risk MAP) datasets, loss of life assessments, Emergency Action Plans (EAPs), and EAP map panel creation. This version of GeoDam-BREACH can be used for various workfows including: Simplifed Dam Break Studies, Risk MAP Datasets, Loss of Life Assessment, EAP Map Panel Creation, and EAP Development. The Users Guide is a part of the CD. Dam Safety offcials across America is the targeted audience.
While not specific to tailings, this webinar includes valuable knowledge for tailings engineers. This webinar demonstrates the differences between Level Pool reservoir routing and Dynamic reservoir routing for dam breach modeling. Though the concept would apply to any 1-d hydrodynamic model, this webinar is designed around HEC-RAS. Given its stability and ease-of-use, Level Pool routing can be a more cost effective way to simulate the drawdown of a reservoir during a dam breach event, when compared to the more accurate, yet more computationally demanding Dynamic routing. The required input is simply a definition of the reservoir's stage-storage relationship. Dynamic routing requires much more detail, including cross sections that represent the bathymetric terrain in the reservoir, and is prone to instabilities, which can require a great deal of time and effort to work out. While Level Pool reservoir routing is a convenient method to simulate dam breach reservoir drawdown, it is not always appropriate and if misused, can lead to significant errors in computing the dam breach outflow hydrograph. This webinar explains when, and under what circumstances a Level Pool analysis is appropriate for dam breach modeling and demonstrates the input requirements and geometry setup for both Level Pool and Dynamic routing in HEC-RAS.
The purpose of this document is to provide dam safety professionals with guidance on how to prepare dam breach inundation modeling studies and conduct mapping that can be used for multiple purposes, including dam safety, hazard mitigation, consequence evaluation, and emergency management including developing emergency action plans. This guidance is intended to provide a consistent approach that can be applied across the country.
BC Chief Inspector of Mines - The Mount Polley tailings dam, owned by Imperial Metals, breached 4 August 2014, releasing its free pond water and a portion of the tailings into Polley Lake. The spill flooded Polley Lake, creating a plug at Hazeltine Creek, and continued into nearby Quesnel Lake and Cariboo River. The cause of the dam breach and subsequent tailings spill has been investigated with a final report published 31 January 2015, the Independent Expert Engineering Investigation and Review Panel assessment of the Mount Polley Tailings Storage Facility Breach.