The Cloudbreak Iron Ore Mine: One of the World’s Largest and Most Advanced Mining MAR Schemes

Authors: B. Willis-Jones, J. Youngs, I. Brandes de Roos and D. Brown.
 
Abstract:
The Cloudbreak iron ore mine in Western Australia’s Pilbara region is hosted by the Marra Mamba Formation aquifer, which contains a lens of fresh to brackish groundwater underlain by a saline to hypersaline groundwater system. This groundwater system extends beneath the Fortescue Marshes – an internally-draining wetland of national significance.

The open-pit mining operations are predominantly below-watertable, and pit dewatering volumes exceed the ore-processing water requirements. Since mining operations commenced in 2008, Managed Aquifer Recharge (MAR) has been employed to preserve the finite fresh-to-brackish groundwater resource for future ore processing needs.

The long-term benefits of the Cloudbreak MAR scheme are presented. In contrast to other non-mining MAR applications, mining operations are typically of a finite timescale; however, post-mining benefits are highlighted, whereby the environmental benefit from the water management scheme extend beyond the mine’s operational life.

The scale and complexity of the Cloudbreak MAR scheme are such that there are unique operational requirements, including: an extensive trigger level system for ensuring that ecological values are maintained; requirements for separate water conveyance systems for separate water types; and long-term design features that facilitate future intra- and inter- mine water conveyance. As one of the world’s largest and most advanced mining MAR projects, the Cloudbreak water management scheme is showcased