A case study for rock clad, non-topsoiled native woodland rehabilitation in Central Queensland

Authors: Roddy, B; Berghofer, P Download Paper Open access courtesy of:

DOI https://doi.org/10.36487/ACG_repo/2615_127

Cite As:
Roddy, B & Berghofer, P 2026, 'A case study for rock clad, non-topsoiled native woodland rehabilitation in Central Queensland', 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. 1-16, https://doi.org/10.36487/ACG_repo/2615_127



Abstract:
For many years, conventional rehabilitation of spoil on Central Queensland coal mines involved dozing slopes down to 10–15%, applying up to 300 mm of topsoil, fertilising, and sowing predominantly grass species for an eventual grazing post mining land use (PMLU). Monitoring indicates that this method is often not successful in achieving a grazing outcome, mainly due to erosional instability of the sandy loam topsoils in a climate dominated by summer storms. Progressive rehabilitation and closure plans (PRCPs), recently introduced in Queensland, require mine operators to comply with a quantitative schedule for rehabilitation, based on measurable milestones. The transition to PRCPs has led to consideration of woodland habitat as an alternative PMLU. Woodland habitat has the potential advantage of not requiring the same level of inputs, including high-quality topsoil, as an agricultural PMLU. While rehabilitation to woodland habitat has been undertaken sporadically in the past, the details of design and performance were not captured in a way that enables accepted good practice to be established. An area of native woodland was established on rock clad problematic bucket wheel excavator (BWE) spoil as part of set of trials in the early 1990s. The area has gradients ranging from 23% to 40% and was rehabilitated without constructed erosion controls, without topsoil, and with a single aerial application of seed. Monitoring has shown a sustainable mix of grasses, shrubs and trees for many years. This case study describes key elements about materials, construction techniques and seeding, gleaned from historical reports and from observations. These may provide a template for a rehabilitation methodology applicable to areas constrained by steeper slopes or limited topsoil.

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