MMG Advances New Rosebery Tailings Options as Tasmanian Mine Approaches 2030 Storage Limit
MMG is moving to secure the long-term operating future of its Rosebery mine in western Tasmania, exploring three tailings storage locations designed to support one of Australia’s longest-running base metals operations beyond the end of this decade. MMG is moving to secure the long-term operating future of its Rosebery mine in western Tasmania, exploring three tailings storage locations designed to support one of Australia’s longest-running base metals operations beyond the end of this decade.
The company’s approach places Rosebery’s next tailings decision within a structured planning, regulatory and community engagement process rather than a short-term storage fix. MMG has submitted two new environmental approval notices for potential long-term solutions: a conventional tailings storage facility at Exe Creek, about five kilometres southwest of Rosebery, and a filtered tailings stack near the existing Bobadil site. That’s in addition to South Marionoak, where there have been delays in progressing preliminary design and assessment works.
Rosebery has operated for more than 90 years and remains a significant regional employer on Tasmania’s west coast and is one of Australia’s longest-running mining operations, producing zinc, copper and lead concentrates as well as gold and silver, with around 650 permanent employees and contractors.
The immediate driver is tailings capacity. Rosebery currently uses the Bobadil and 2/5 Dam tailings storage facilities, but both are approaching capacity. Recent reporting indicates the existing storage pathway is available until around 2030 subject to permitting, while the mine must identify a long-term solution for more than 850,000 tonnes of tailings a year.
The Exe Creek option would provide the larger storage horizon. Tasmania’s Environment Protection Authority says the proposed Exe Tailings Storage Facility would store approximately 22.1 million tonnes of tailings, equivalent to about 26 years of storage at Rosebery’s current tailings production rate of 850,000 tonnes per year. The proposal would be subject to environmental impact assessment by the EPA Board under Tasmania’s Environmental Management and Pollution Control Act.
The Bobadil Heights option reflects a different technical pathway. This proposal is based on a filtered tailings stack adjacent to the existing Bobadil TSF, supported by a filter plant, pipeline and road infrastructure. It would process tailings into filtered material for disposal in a stack, with capacity for up to 10.45 million tonnes of filtered tailings, or around 12 years at the current production rate.
For MMG, the parallel assessment of conventional and filtered tailings options gives the company a more flexible development pathway. Conventional storage offers longer-duration capacity, while filtered tailings can reduce water content and change the physical management profile of the tailings stream. The company’s decision to progress both options through assessment provides regulators and the community with a clearer view of the other locations now being considered in addition to South Marionoak.
The shift also follows a period of significant scrutiny over previous long-term tailings proposals. Earlier options associated with South Marionoak drew environmental opposition because of concerns over the Tarkine region. More recent reporting indicates MMGhas no current plans to advance works at South Marionoak, while it awaits a decision from the Minister, and is instead progressing Exe Creek and Bobadil Heights alternatives.
MMG has also put community engagement around the process. Recent public information sessions and site visits were organised to explain the two potential storage pathways and receive feedback. Rosebery general manager, Steve Scott, said the company wanted to keep the community informed because the mine operates on the west coast and within the community, while environment and community manager, Adam Pandelis, pointed to local interest in ensuring the lowest practical community impact.
The tailings strategy is central to Rosebery’s future because this is an operating mine with established infrastructure, a skilled workforce and an existing supplier base, not an early-stage development seeking a speculative approval. The operation supports underground mining, processing, maintenance, environmental monitoring, transport, power, water management and local service activity across the west coast.
Rosebery also gives the wider mining sector a practical case study in how long-life operations are adapting tailings planning to modern regulatory and community expectations. Mine operators globally are under increasing pressure to demonstrate stronger design standards, water management, closure planning and transparent engagement around tailings infrastructure. MMG’s current pathway shows a mature mine operator working through those pressures through formal assessment, alternative design options and public consultation.
The outcome will help determine how Rosebery continues beyond 2030. For Tasmania, the decision carries importance for regional employment, base metals production and the future of mining in a region where technical capability, environmental responsibility and community confidence must be managed together.
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