From risk to relinquishment: adaptive pathways for the Hazelwood mine

Authors: McKenzie-McHarg, A; Chong, R; Missen, J Download Paper Open access courtesy of:

DOI https://doi.org/10.36487/ACG_repo/2615_136

Cite As:
McKenzie-McHarg, A, Chong, R & Missen, J 2026, 'From risk to relinquishment: adaptive pathways for the Hazelwood 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_136



Abstract:
Planning for the rehabilitation of the Hazelwood mine required a rigorous and transparent risk‑assessment approach to support the site’s transition to a safe, stable and sustainable final landform. The risk assessment process is fundamental to achieving ENGIE’s aspirations for the future use of the site while meeting statutory mine closure obligations. The work was undertaken by GHD, a global engineering and advisory firm, in collaboration with ENGIE, an international energy company and asset owner responsible for the site. GHD supported ENGIE to update the 2025 Hazelwood Risk Assessment and Management Plan (ENGIE 2025a) for the proposed rehabilitation and the aftercare period. In doing so GHD has utilised a range of risk assessment techniques to consider rehabilitation planning, technical understanding, stakeholder expectations, the regulatory environment and long‑term relinquishment outcomes. Adaptive pathway planning (APP) (ENGIE 2025b) is a relatively common tool in other industries including healthcare, financial services and industrial manufacturing but has not been widely adopted in the mine closure context. APP can provide a dynamic and flexible approach to risk designed to support decision-making in uncertainty and particularly useful for evaluating long-term scenarios and risk mitigation strategies. APP was essential to the risk assessment process, incorporating long-term uncertainty associated with components such as water sourcing, the geotechnical behaviour of mine batters, compliance and regulation. APP enabled the Hazelwood mine to demonstrate how risks will be managed to meet regulatory obligations and maintain community and stakeholder objectives. The APP process assessed 3 alternate closure pathways – namely, the preferred, the contingency and the non-preferred – which included a range of triggers and mitigation measures. To ensure a reasonably broad scope of risks, the assessment actively utilised internal specialists, independent reviewers and regulatory authorities. Critical controls for key risks were identified (International Council on Mining and Metals 2015), including the definition of performance standards essential for demonstrating that critical controls remained effective and were periodically reviewed. APP is intended to demonstrate how risks are managed under alternate rehabilitation scenarios and, in turn, increase positive community and stakeholder sentiment. This provides a defensible, stakeholder‑aligned, statutorily‑considered pathway towards relinquishment.

Keywords: adaptive pathway planning; mine closure, risk assessment, rehabilitation

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