Internally draining rehabilitation: lessons from several decades of experience at Newlands Coal Mine

Authors: Gimber, C; Hancock, GR; Bushell, C; Baillieu, N Download Paper Open access courtesy of:

DOI https://doi.org/10.36487/ACG_repo/2615_97

Cite As:
Gimber, C, Hancock, GR, Bushell, C & Baillieu, N 2026, 'Internally draining rehabilitation: lessons from several decades of experience at Newlands Coal Mine', 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. 1-11, https://doi.org/10.36487/ACG_repo/2615_97



Abstract:
Internally draining rehabilitation (IDR) is a landform design approach applied in mine closure to enhance water retention, support vegetation establishment, and improve slope stability by reducing effective batter lengths. Variants of this concept include ‘moonscaping’ and internally draining landforms (IDLs). IDR has demonstrated potential to improve rehabilitation performance, particularly in arid and semi-arid environments where evaporation exceeds rainfall. Newlands Mine, a large-scale open cut and underground coal operation in central Queensland Australia, operated from 1983 to 2023. Over its operational life, multiple landform design strategies were trialled, creating a valuable long-term record of rehabilitation performance and evolution. Between 1991 and 2006, IDR was the preferred rehabilitation methodology at Newlands. The approach incorporated steep external batters and hummocky internal microtopography intended to maximise water retention, enhance hydrological function, and reduce sediment transport. Post-rehabilitation monitoring has shown variable performance across IDR areas, with outcomes strongly influenced by soil properties, particularly near outer batters where susceptibility to piping and erosion is elevated. Although the site transitioned to conventional externally draining landforms after 2007, Newlands now provides a rare 20–30-year dataset on IDR performance. In addition, long-term erosion trajectories have been modelled over timeframes of up to 300 years using the SIBERIA landform evolution model (LEM). Drawing on several decades of monitoring, maintenance records, and long-term geomorphic modelling, this paper evaluates the performance of IDR at Newlands and provides guidance on the conditions under which this landform design concept can be most effectively implemented.

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