Hall, JW, Middlemis, H, Waters, PJ & Rozlapa, KL 2006, 'Integration of Groundwater Modelling with Mine Planning to Optimise Mine Closure Plans ⎯ The Marillana Creek (Yandi) Mine Story', in AB Fourie & M Tibbett (eds), Proceedings of the First International Seminar on Mine Closure
, Australian Centre for Geomechanics, Perth, pp. 131-137, https://doi.org/10.36487/ACG_repo/605_5
A major challenge for closure planning at mining operations below water table is evaporation from final void
pit lakes, which can impact on downstream groundwater (and surface water) flows and quality. A closure
approach that is increasingly being adopted is to infill the final voids with waste rock to above the pre-
mining water table to prevent the development of a pit lake and subsequent evaporative losses. At BHP
Billiton Iron Ore’s Marillana Creek (Yandi) mine, where the orebody is a channel iron deposit that forms the
major aquifer in the region, this approach is not practical. With a stripping ratio of less than one, there is
insufficient waste rock to infill all mine areas to the pre-mining water table. Through the integration of
hydrogeological modelling with mine planning, a cost effective solution was developed, which involved
selective infilling of all pits, largely using run-of-mine waste dumping, and some diversion of surface water
flows. This solution will result in maintenance of adequate groundwater and surface water flows to support
downstream water dependent ecosystems and maintain beneficial use.
Aquaterra (2000) Central Pilbara Study. Marillana Creek Groundwater Model. Report to Water and Rivers
Commission. November 2000.
BHP Billiton Iron Ore (2004) Marillana Creek (Yandi) Mine. Decommissioning and Final Rehabilitation Plan. January
Gilbert and Associates (2003) Yandi Iron Ore Mine. Hydrological and Hydraulic Assessment of Proposed Diversion of
Marillana Creek for Life of Mine and Closure Concept Plan. Report to BHPBIO.
Kalf and Associates (2000) Yandi Model Review. Unpublished report to BHP Iron Ore Ltd.
Middlemis, H. and Rozlapa, K.L. (1998) Stream-Aquifer Interaction Model for Mining Below the Water Table in the
Pilbara, Western Australia. Proceedings International Groundwater Conference: Groundwater: Sustainable
Solutions. International Association of Hydrogeologists, Australian Chapter.
Planning for Closure
Mine Closure 2006, Perth, Australia 137