Phytocaps in mine waste landforms: a nature-based approach to sustainable rehabilitation

Authors: Salt, M; Hume, T Download Paper Open access courtesy of:

DOI https://doi.org/10.36487/ACG_repo/2615_64

Cite As:
Salt, M & Hume, T 2026, 'Phytocaps in mine waste landforms: a nature-based approach to sustainable rehabilitation', 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. 1-13, https://doi.org/10.36487/ACG_repo/2615_64



Abstract:
This paper examines the application of phytocaps as final cover systems for mine waste landforms, presenting them as a robust, sustainable alternative to conventional compacted clay barrier covers. Traditional low‑permeability barrier systems have been widely adopted to limit percolation and oxidation; however, long‑term field studies in both landfill and mining contexts have demonstrated that their hydraulic performance can deteriorate rapidly due to desiccation cracking, root penetration and soil structure changes. Drawing on long‑term field monitoring and applied rehabilitation experience from multiple sites in Victoria and South Australia, this paper demonstrates that phytocaps – cover systems that rely on soil water balance processes and healthy vegetation communities – can achieve equal or superior hydraulic performance compared with compacted clay barrier systems. Data from a decade‑long field trial show that phytocaps achieved lower net percolation than a compacted clay barrier despite being constructed without a low‑permeability layer. The paper further demonstrates that vegetation selection, soil preparation and ongoing vegetation management are critical determinants of phytocap performance and long‑term stability. Several case studies illustrate how inappropriate soil material selection, seedbed preparation or species selection can undermine rehabilitation outcomes, while adaptive management and the use of indigenous vegetation communities can result in resilient, self‑sustaining landforms. The findings support a shift in mine closure practice away from reliance on high-specification engineered barriers toward vegetation-led, nature-based systems that reduce long-term closure risk, improve sustainability and better align with post-closure land use objectives.

Keywords: phytocaps, mine closure, rehabilitation, evapotranspiration covers, vegetation establishment

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