Watton, JW & Fowler, MJ 2020, 'Slope performance monitoring and management of a pit wall experiencing large-scale deformations near Kalgoorlie, Western Australia', in PM Dight (ed.), Slope Stability 2020: Proceedings of the 2020 International Symposium on Slope Stability in Open Pit Mining and Civil Engineering, Australian Centre for Geomechanics, Perth, pp. 889-900, https://doi.org/10.36487/ACG_repo/2025_58 (https://papers.acg.uwa.edu.au/p/2025_58_Watton/) Abstract: This case study demonstrates the successful geotechnical slope performance monitoring and management of an excavated pit slope undergoing large-scale ductile deformations at the Teal open pit gold mine near Kalgoorlie, Western Australia. Most of the eastern wall of the open pit deformed as mining progressed to the target depth of 50 m. Total displacements at the conclusion of mining were in the order of tens of metres and cracking was observed up to 90 m behind the crest of the pit. Rates of wall displacement in excess of 10 mm per hour were experienced during mining. The slope deformations experienced at the Teal open pit were successfully managed as a result of highly responsive expert geotechnical slope performance monitoring and management. Slope performance management tools applied at the site included design modifications, a carefully developed trigger action response plan (TARP) and equally importantly, proactive mining operations. Pit slope monitoring comprised prism and slope stability radar monitoring. The application of slope stability radar monitoring and effective slope performance management enabled mining operations to safely continue with slope deformations in excess of conventionally accepted open pit slope performance criteria. The pit was successfully completed at the planned metal grades, with a 5% surplus in ore mined. Keywords: slope performance management, monitoring, deformation, radar, open pit