Morton, KL 2022, '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, https://doi.org/10.36487/ACG_repo/2205_42 (https://papers.acg.uwa.edu.au/p/2205_42_Morton/) Abstract: Groundwater affects all aspects of block cave and sublevel caving. The use of gravity to drive ore into the ore passes means that all liquids including mud and water, gravitate to the drawpoints and lowest points on the mine. Mine dewatering design requires knowledge of inflows, groundwater volumes and gradients. Accurate groundwater level and pressure monitoring enables the plotting of groundwater gradients around a block cave which then allows understanding of groundwater flow directions. Once the flow directions are known they can be diverted away from the active caving areas to reduce risk of inflows, reduce mud rushes and increase production. Techniques for measuring head and the use of pressure release tests (PRTs) to obtain hydraulic parameters are given and case studies are discussed. Keywords: dewatering, pressure release tests, groundwater, inflows, mud rush, depressurisation, flood