Groundwater control and mud rush prevention for caving mines
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Authors: Morton, KL; van Heerden, W Open access courtesy of:
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DOI https://doi.org/10.36487/ACG_repo/2645_76
Cite As:
Morton, KL & van Heerden, W 2026, 'Groundwater control and mud rush prevention for caving mines', in A van As, D Cumming-Potvin & J Wesseloo (eds), Caving 2026: Proceedings of the Sixth International Conference on Block and Sublevel Caving, Australian Centre for Geomechanics, Perth, pp. 1-13, https://doi.org/10.36487/ACG_repo/2645_76
Abstract:
Caving methods create drainage of all water from within a predictable radius. The diameter and shape of the radius are functions of the sources of water, the country rock hydraulic conductivity and geological structures which drain towards the caving areas (active and closed). Although some water is advantageous to production rates, too much water creates hazardous conditions and contributes to mud rushes. Understanding the sources of water and monitoring head distribution are essential for the calculation and management of water ingress. Over 45 years, the author has developed a phased approach to mine dewatering design and water management. This has been adapted to support caving operations and used to reduce mud rushes. Flood control requires a top-down approach including surface water management, flow path mapping, stormwater prediction and diversion, and modelling of flood events. This can then be incorporated in the mine’s water risk management strategy and reported in the risk register. Prevention of mud rushes requires a thorough understanding of the causes and hydrogeological environment. Mud rushes have 4 components: presence of mud-forming materials (low-friction material or fines), driving head of water (phreatic surface above a specific maximum level), discharge points present for mud to enter the workings and one or two triggers. Triggers include water pressure head exceeding a target head, seismic events, (natural or manmade), blasting pattern and overdraw. Water is the most important factor. The head of water around a caving area can be monitored, diverted and managed. Numerical modelling, based on a detailed understanding of the groundwater regime, can be used to help predict the pattern of pressure distribution and the range of maximum head for specific configurations of extraction advance. Methods are discussed for achieving improved mine dewatering design and the prevention of the ingress of both water and mud.
Keywords: mud rush, caving, monitoring, in rush, flooding, dewatering, water management, drainage, water balance
References:
Butcher, RJ, Joughin, W & Stacey, TR 2000, A Booklet on Methods of Combatting Mudrushes in Diamond and Base Metal Mines, Safety in Mines Research Advisory Committee (SIMRAC), Johannesburg.
Butcher, RJ, Stacey, TR & Joughin, WC 2005, ‘Mud rushes and methods of combating them’, Journal of the Southern African Institute of Mining and Metallurgy, vol. 105, pp. 817–824.
De Beers 1993, The Study of Critical Parameters Affecting Mud and Water Ingresses Within the Muckpile Above Subsidence Mining: Phase 1 with Appendix, confidential in-house report prepared by Ninham Shand.
De Beers 1996, The Study of Critical Parameters Affecting Mud and Water Ingresses Within the Muckpile Above Subsidence Mining: Phase 2 with Appendix, confidential in-house report prepared by Ninham Shand.
De Freitas, MH & Tellam, J 2025, ‘Engineering geological principles of groundwater’, in J Duncan & UL Lawrence (eds), Engineering Geology of Groundwater in Design and Construction: Engineering Group Working Party Report, Engineering Geology Special Publication 31, Geological Society, London, pp. 15–105.
Du Toit, C 2005, Mud Rush Accident at Dutoitspan Mine, 14 January 2005: Mining Method Recommendations to Reduce/Minimise Risk of Further Mud Rushes, internal report, De Beers, South Africa.
Freeport-McMoRan 2025, Freeport Provides Update on PT Freeport Indonesia Operations, viewed 20 June 2026,
Hilton, G, Holder, A, Rogers, AJ, Bartlett, PJ & Keyter, GJ 2012, ‘Mudrush mitigation on Kimberley’s old scraper drift block caves’, Proceedings of the 2nd Southern Hemisphere International Rock Mechanics Symposium, Sun City.
Holder, A, Rogers, AJ, Bartlett, PJ & Keyter, GJ 2013, ‘Review of mud rush mitigation on Kimberley’s old scraper drift block caves’, Journal of the Southern African Institute of Mining and Metallurgy, vol. 113, no. 7, pp. 529–537.
Morton, KL & Van Niekerk, FA 1993, ‘A phased approach to mine dewatering’, Mine Water and the Environment, vol. 12, pp. 27–34.
Morton, KL 2008, The Hydrogeology of Kimberlite Mines with Specific Reference to Finsch Mine, PhD thesis, Imperial College London, London.
Morton, KL, Muresan, MC & Ramsden, F 2008, ‘Importance of pore pressure monitoring in slope stability in surface mining’, Proceedings of the International Symposium on Slope Stability, Southern African Institute of Mining and Metallurgy, Johannesburg.
Morton, KL 2022a, ‘Accurate diamond mine water control: a historical perspective and guidelines for modern deep underground diamond mines’, Proceedings of the Southern African Institute of Mining and Metallurgy Diamond Conference 2021,
Morton, KL 2022b, ‘The use of groundwater monitoring and underground pressure release tests to benefit block caving’, in Y Potvin (ed.), Caving 2022: Proceedings of the Fifth International Conference on Block and Sublevel Caving, Australian Centre for Geomechanics, Perth, pp. 611–622,
Morton, KL & Millsteed, BD 2023, ‘Structural logging and modelling for use in simulation of inflows in mines hosted in hard rock and well-indurated rock masses’, Proceedings of the International Mine Water Association Conference 2023, Newport.
Morton, KL 2024, ‘A phased approach to mine dewatering – updated from IMWA 1993’, in B Kleinmann, J Skousen & C Wolkersdorfer (eds), West Virginia Mine Drainage Task Force Symposium and 15th International Mine Water Association Congress, International Mine Water Association, Morgantown, pp. 458–463.
Morton, KL 2026a, ‘Prevention of mud rushes in underground mines: a call to arms’, Journal of the Southern African Institute of Mining and Metallurgy, vol. 126, pp. 141–143.
Morton, KL 2026b, ‘Summary of incidents of mud and flood fatalities in underground mines since 1815’, Journal of the Southern African Institute of Mining and Metallurgy, vol. 128, in press.
SIMRAC 2000, A Booklet on Methods of Combatting Mudrushes in Diamond and Base Metal Mines, Safety in Mines Research Advisory Committee, Woodmead.
Vutukuri, VS & Singh, RN 1995, ‘Mine inundation: case histories’, Mine Water and the Environment, vol. 14, pp. 107–130.
WMC 2003, Major Hazard Audit Protocol: inrushes and Subsidence, SAFMHAP-09 Rev. 2, DOCS No. 57103, Perth.
Younger, PL 2004, ‘Making water: The hydrogeological adventures of Britain’s early mining engineers’, in JD Mather (ed.), 200 years of British hydrogeology, Geological Society Special Publication 225, Geological Society, London, pp. 121–259.
Yuan, S, Han, G, Liu, D, Li, G, Zhang, A & Li, W 2025, ‘Analysing water recharge mechanisms and predicting water inflow in deep mining based on hydrogeological structures: a case study’, Scientific Reports, vol. 15, article 44764,
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