Greatland’s Telfer-Havieron 5Moz reserve: life-of-mine planning notes for engineers
Reviewed by Tom Sullivan

First reported on Australian Mining
30 Second Briefing
Greatland Resources has reported a combined Ore Reserve of 5.0Moz of gold and 196,000 tonnes of copper as at 31 March 2026 for its Telfer-Havieron complex in Western Australia, incorporating a revised Telfer reserve and the existing Havieron Ore Reserve. The update signals a multi-decade mine life strategy for the integrated gold–copper operation, supporting long-term planning for pit and underground sequencing, plant utilisation and regional infrastructure. Geotechnical and mine planning teams can now anchor slope design, ground support regimes and tailings capacity studies to a materially larger, better-defined reserve base.
Technical Brief
- Group Ore Reserve Estimate is reported as at the effective date of 31 March 2026.
- Estimate explicitly aggregates a revised Telfer reserve with the pre-existing Havieron Ore Reserve into one complex.
- Combined reporting at complex level enables integrated scheduling of Telfer open pits with Havieron underground stopes.
- Unified reserve base provides a single planning case for concentrator throughput, recovery assumptions and metallurgical blending.
- Reserve consolidation supports long-horizon planning of shared haulage, power and accommodation infrastructure across the complex.
- Long-dated reserve visibility allows staged tailings storage expansion and potential in-pit tailings options to be assessed earlier.
- Geotechnical domains for both Telfer and Havieron can now be reconciled against one mine-wide economic shell.
- For similar multi-asset hubs, complex-level reserve statements are becoming a prerequisite for regional optimisation studies.
Our Take
The 5 Moz combined Ore Reserve at the Telfer–Havieron gold–copper complex, dated to March 2026, sits alongside a recently approved $500 million corporate debt facility for Havieron, signalling lenders view this Western Australian asset as bankable over a multi-decade horizon rather than a short mine-life top-up.
Recent coverage of Greatland Resources in Western Australia shows a rapid progression from feasibility (December 2025) through environmental approvals (May 2026) to final investment decision (June 2026), suggesting the Telfer–Havieron complex is being advanced on one of the faster timelines among gold–copper projects in our 1200 Mining stories database.
The addition of large-scale mobile equipment at Telfer earlier in 2026, combined with a 5 Moz reserve base across Telfer–Havieron, implies Greatland is positioning the Paterson Province complex as a long-term hub operation, which could support further satellite gold–copper discoveries in this part of Western Australia without standalone processing plants.
Prepared by collating external sources, AI-assisted tools, and Geomechanics.io’s proprietary mining database, then reviewed for technical accuracy & edited by our geotechnical team.
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