The Galilee Basin mine proposals are located within the Central Queensland Desert Uplands bioregion which is characterised by sandstone ranges and sand plains, acacia woodlands and eucalypt woodlands and spinifex understorey. The climate is semi-arid with variable rainfall.
The bioregion provides habitat for many threatened species of plants, mammals, birds, reptiles, and fish. It contains 77 mapped regional ecosystems, with two listed as ‘endangered’ and 26 defined as ‘of concern’1. This unique landscape contains two major catchments, the Burdekin and Lake Eyre Basin.
Mining is proposed both on the surface (open-cut) and underground. Both extraction methods have a number of associated environmental impacts.
Both underground and open-cut coal mining can significantly impact the integrity of aquifers and groundwater-dependent ecosystems through dewatering, subsidence and contamination. In a semi-arid climate like the Desert Uplands, plants and animals depend on the availability of water and the ability to utilise water sources in order to survive and reproduce. Contaminated water and waste material from coal mines pose a threat to the surrounding terrestrial and aquatic habitats, as can loss of water. Read more about water here.
All stages of coal production — mining, washing, transportation, burning, disposal — release dust into the air and water, adversely impacting on ecosystems and human health.
Coal dust particles are generally small enough to be raised and carried by wind. Coal dust may contain metals, such as lead or selenium, which are directly hazardous air pollutants. Read more.
Ecological communities and species
The key threats to Australia’s biodiversity are habitat loss and fragmentation due to land clearing, climate change, land use, invasive species and pathogens, grazing pressure, altered fire regimes, and changed hydrology.
The Black Throated Finch is of particular concern in the Galilee Basin. It is an Endangered species under state and federal environmental law, with the largest known population of the Southern Black Throated Finch at Moray Downs, where the Carmichael mine is proposed. Habitat loss associated with mining and infrastructure is a significant threat to the survival of the species.
Open-cut mining involves the complete removal of vegetation and topsoil layer, removing habitat that sustains ecological communities. This can also cause soil erosion and degradation of adjacent land, as well as sedimentation and contamination of nearby water bodies.
All of the proposed coal mining projects in the Galilee Basin involve either open-cut or a combination of open-cut and underground mining. The following impacts on the environment can result:
- Habitat loss due to land clearing resulting in the complete removal of vegetation. Associated animal species might be affected through direct mortality during clearing operations, or losing their nesting/roosting/foraging habitat.
- Habitat fragmentation and loss of connectivity due to construction of roadways, railways, and other mine infrastructure, increasing edge and barrier effects.
- Increase in noise, vibration, dust, and artificial lighting affecting many species’ breeding and foraging behaviour.
- Introduction and spread of invasive weeds and other pest species.
- Increase in fire frequency, disrupting the life cycle of many plant species, potentially aiding the spread of weeds and causing direct mortality of many animal species.
- Surface cracking and areas of heave and/or collapse due to subsidence may result in tree fall, ponding, and significant changes to the local vegetation structure.
- Loss of many plant and animal species and entire communities of high state, national and sometimes international biodiversity status.
Proponents of mining projects must complete an Environmental Impact Statement to outline their plan to manage these impacts during the planning and approvals process. The state government must sign off on this document before a mine is able to be developed.
References and reading:
- Desert Uplands: Information about the region that covers 75,000 square kilometres of outback Queensland.
- Desert Uplands bioregion: Mapping and information about biodiversity, water and land use in the Central Queensland region.
- Mining and the environment: A briefing paper from the NSW Parliamentary Library Research Service.
- Probable causes of adverse effects of chronic coal dust exposure on human and environmental health: A briefing paper.
- Threats to Australian biodiversity: Federal government’s 2008 assessment of Australia’s Terrestrial Biodiversity.