Historically water management at mines that are no longer producing, has often resulted in long-term ongoing costs and/or environmental legacy issues. This has made it very difficult for proper mine closure and lease relinquishment. This is especially true for open pit mines that have been dewatered for mine operation.
Yet, pit lake water could provide a valuable resource rather than constitute a liability for regional environments, their communities and economic development in a post mining environment. Realising the potential for this water resource would support orderly transition to relinquishment and facilitate successful transition to sustainable post-mining regional communities and economies.
Successful management strategies for pit lakes have to establish the resource capacity and quality under the local climatic and hydro(geo)logical conditions of the mine site. This forms the basis for considering post-mining land-use strategies, such as tourism Aquaculture and agriculture, while safeguarding water requirements for ecosystem protection and revegetation at the local and regional scale.
This project will examine the potential to optimise water management and water use for environmental restoration and examine the potential opportunities and value of other beneficial water uses. It will identify challenges and opportunities and the key research needed to enable water management to achieve environmental, cultural and economic goals. The work is only possible by bringing together a team with expertise in groundwater and surface water flow, water chemistry and water quality and an understanding of mine operational requirements.
Project Aim, Objectives & Outcomes
This project seeks to develop a conceptual model of water options at mine closure and beyond. Some of the questions that will be answered include:
- What is the magnitude of the water management problem for closure of open pit mines?
- What is the range of factors that must be considered (environmental, cultural, economic, climatic)?
- What is the timescale for groundwater recovery after mine closure, and what are the factors that control this?
- How do mine operations impact on mine closure options?
- How do other mine closure options (e.g. revegetation, backfilling) impact on post-closure water balance and therefore availability of water post mining?
- How do mine pits interact with surface drainage post-closure, and how does this affect the water quantity and quality?
- What are the different potential uses of mine voids and pit lakes in different environments, and what are the impediments and constraints on these different
- What information exists already (guidelines, practice, reports) from any forum?
- What are the challenges and opportunities?
- What research is needed to transform this space?
The project will identify knowledge gaps that constrain water management during mine life and after mine closure that prevent optimal water management. The objective is to provide a roadmap to guide mine closure to best satisfy environmental goals and constraints and deliver value from water in the post-mining environment.
BHP Group Operations Pty Ltd, Rio Tinto Services Limited, Newmont Mining Services, Fortescue Metals Group Ltd, Department of Water and Environmental Regulation, Golder Associates Pty Ltd, South 2 Group Operations Pty Ltd, Flinders University, The University of Queensland, ChemCentre, University of Western Australia.
Visit the CRC TiME website.
Helping to drive transition to a sustainable post-mine future
Mine Pit Lakes Study will bring certainty