Wilson, S, Snyman, J, McGuinness, M, Albrecht, J & De Vries, J 2015, 'Gwalia mine – backfill system operational review', in R Jewell & AB Fourie (eds), Paste 2015: Proceedings of the 18th International Seminar on Paste and Thickened Tailings, Australian Centre for Geomechanics, Perth, pp. 341-355, https://doi.org/10.36487/ACG_rep/1504_26_Wilson (https://papers.acg.uwa.edu.au/p/1504_26_Wilson/) Abstract: The Gwalia gold mine located in Western Australia has been operating its current backfill system since 2009. The backfill system prepares a paste fill from harvested mine tailings, blending these with water and binder before discharging into a gravity driven reticulation system. Currently the backfill plant operates at approximately 185 tph, delivering 130 m3/h of paste fill to a depth of approximately 1,500 m below surface. In line with good operational practice, and as a reaction to a series of borehole blockages, Gwalia has undertaken an operational review of its backfill system. The system review considered all aspects of the operation from tailings harvesting through to plant operation procedures, maintenance planning and paste distribution, as well as establishing the root cause of the borehole failures. The overall backfill management system was also reviewed, and recommendations made. In addition, a life of mine review has considered the requirements and implications of extending the reticulation system to 1,800 m below surface. This paper presents an overview of the review along with an assessment of the current and future reticulation systems, concluding from it a number of value-adding recommendations. Additionally, comment is made on best practice in paste fill system management.