Sudden underground water inrushes are an example of potentially catastrophic events that can result from lack of hazard awareness and planning, and supporting information and data, during mine operations. The iterative cycle of Monitor -> Model -> Manage that forms the basis of mine site groundwater management is effective but does not deal well with unexpected and unpredicted events that can occur under a variety of circumstances through life of mine. Such events can result in loss of production and, in the worst cases, loss of life and/or loss of the mine (i.e., a catastrophic inflow).
An ongoing awareness of potential hydrogeological hazards combined with clearly defined and structured hazard assessment methodologies and tools enable mines to mitigate these risks.
SRK has developed workflow techniques and tools to assess risks associated with specific hydrogeological hazards within the context of clear, focussed objectives. This approach has been applied on several projects and involves the following steps:
Recent examples of SRK’s involvement in inrush assessment, investigation and mitigation at operational mines include:
- Ongoing operational support to a copper-cobalt mine to develop inrush hazard management plans
- Post-event investigation and incident cause analysis at a lead-zinc mine following flooding after a raise pilot hole broke through into the underground workings of the operational mine leading to an unexpected groundwater inrush
- Review of inrush hazards and development of a GIS-based flood risk assessment tool at an underground potash mining complex
- A structured accident investigation using the Incident Cause Analysis Methodology to evaluate a catastrophic inrush of water and mud at a diamond mine
- Review of a sudden groundwater inflow at a potash mine which occurred simultaneously with surface collapse and sink hole generation
- Development of conceptual and numerical groundwater and geotechnical models to characterise the hydrogeological setting of an underground nickel mine and improve understanding of a sudden inrush event which caused significant mine flooding
