Madzivire, G, Ramugondo, S, Sinthumule, ME, Ramatsekisa, R & Vadapalli, VRK 2026, 'Water management in interconnected underground mine voids during mine closure: lessons from the Witwatersrand Basin, South Africa', in AB Fourie, G Boggs, J Heyes & M Tibbett (eds), Mine Closure 2026: Proceedings of the 19th International Conference on Mine Closure, Australian Centre for Geomechanics, Perth, pp. 1-12, https://doi.org/10.36487/ACG_repo/2615_109 (https://papers.acg.uwa.edu.au/p/2615_109_Madzivire/) Abstract: Underground mining in the Witwatersrand Basin, South Africa, resulted in the formation of extensive, interconnected mine voids. Following mine closure and the cessation of dewatering, these voids were filled with acidic mine water enriched in sulphates and potentially toxic elements, posing substantial risks to water resources. In response, a coordinated mine water management strategy was implemented. This involved 2 key interventions: (i) ingress control measures to reduce the inflow of surface water into abandoned mine workings, and (ii) active pumping and treating of mine water to maintain levels below defined environmental critical levels. These measures have been applied in the Western, Central and Eastern interconnected mining Basins. This paper presents lessons learnt from more than 2 decades of managing rising mine water within the Witwatersrand Basin. Implementation of ingress control and managed pumping has been found to regulate the water entering the mine voids. This prevents flash flooding of the mine voids that produces highly polluted mine water. Analysis of water quality in the mine voids indicates that it gradually improves. This requires continued monitoring to adapt the water management plan according to the dynamic water quality. The experiences from the Witwatersrand Basin provide valuable science-based insights for sustainable mine water management strategies, such as nature-based technologies.