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Water in Mining Guideline – Western Australia

August 5, 2013

Duncan

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Western Australia’s Water in Mining Guideline

The Western Australian Department of Water recently published a new guide outlining the approval process related to water management for mining projects in Western Australia – Western Australian water in mining guideline, May 2013.

The guide applies statewide and outlines how the Department of Water (DoW) will regulate the management of water resources for a mining project (principally by the Rights in Water and Irrigation Act 1914).

DoW advocates a consultative approach and encourages preliminary discussions with the proponent very early in the mining project.  The guide also provides advice on the key issues and information related to water that maybe required as part of the approval process.  These include water supply and dewatering requirements, mine water balance and management plans for any excess water and key water-dependent environmental receptors that may be affected by the proposed mine.  DoW advocates flexibility in determining the important water management issues for each specific mining project.

The overall process is summarized below and detail can be obtained from the guideline itself which can be downloaded from the DoW website.  There are six stages in the approval process.

  • Stages A and B (Consultation and Scoping) – encompass the introduction of the project to DoW and scoping: of important water issues; and of the later investigations that will be undertaken to address these issues.  Any licenses that are required to undertake investigations will be obtained during this stage (for example 26D groundwater License to drill and construct bores).
  • Stage C (Regulatory Assessment) – implementation of investigations determined above along with detailed analysis, modeling and design and the submission of reports in support of environmental approval and water operating licenses (for example 5C Groundwater License to abstract water).
  • Stage D (Operating Strategy) – is primarily aimed at developing operational plans and monitoring regimes.  This stage may also include any infill investigations that arise from the work (or from regulator review of the work) undertaken during Stage C.  If additional licenses were required prior to construction, they would typically be obtained at this stage (for example 26D Groundwater Licenses to construct additional bores if any are required for water supply or dewatering).
  • Stage E (Construction and Mining) – from a regulatory perspective, the focus moves to monitoring, reviewing and reporting and the implementation of adaptive management strategies as required.  Key reports are the Annual Wellfield Assessment, the Triennial Aquifer Review and the Annual Environmental Report.  Mine closure plans will have been considered during the initial approval process.  However, closure plans will likely be refined during operations  – for example, how a pit is backfilled above the water table on closure is likely to evolve as mine plans evolve.
  • Stage F (Closure) – the mine closure plan is implemented and any post-mining monitoring and reporting is implemented.

Mining Project Development Cycle

 

Hydrogeology and hydrology investigations are required as part of a project’s feasibility studies – to address technical issues and to confirm the quantum and costs of mine water supply and mine dewatering.  A well-designed field programme should aim to address both environmental and technical feasibility.  Dedicated groundwater investigations are usually required later in pre-feasibility or feasibility reporting.  However, early in the project, relevant information can often be gleaned from mineral drilling and geotechnical drilling campaigns.

The summary figure also included the link between water-investigations and various stages of environmental approval and technical assessment for a mining project.

The early discussions with DoW are clearly important in framing the water management task.  There is then scope for efficiencies in both time and cost with appropriately designed hydrogeology field programmes that target multiple objectives and use information from parallel mineral and geotechnical programmes where relevant.  The team at AQ2 have helped steer some of the most challenging mining projects developed in Western Australia through this process.

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