This bioregional assessment helps us understand how coal seam gas and coal mining development could affect water resources and water-dependent assets in the Pedirka subregion. It identifies where potential impacts might occur, as well as the areas that are unlikely to be affected. The assessment was undertaken in collaboration with the South Australian Government.
About this subregion
The Pedirka subregion is part of the Lake Eyre Basin bioregion and falls within both the Northern Territory and South Australia. This is one of the driest areas in Australia. The subregion has a largely flat landscape covered with sandy deserts, gravelly ‘gibber’ plains and vegetation adapted to arid conditions. Finke (Aputula) is the largest settlement in the sparsely populated subregion. The primary land use in the Pedirka subregion is beef-cattle production.
The Pedirka subregion contains arid-zone river systems that are seasonal and semi-permanent. It has a number of nationally important wetlands including the swamps, interdunal lakes and extensive woodlands in the area known as the Finke Floodout. These wetlands support a diverse range of plants and animals, many of which are listed as rare or threatened under Commonwealth and state government legislation. The lack of surface water resources means that groundwater is the main water supply for the subregion, mostly sourced from the Great Artesian Basin.
Coal mining and coal seam gas operations
The Pedirka subregion is underlain by rocks of different ages that belong to five geological basins: the Pedirka, Eromanga, Simpson, Amadeus and Warburton basins. Although coal is present in the Pedirka Basin, as at July 2015 there were no coal mines and no coal seam gas production in this subregion. Preliminary evaluation has shown that coal in the eastern Pedirka basin is located too deep below the surface for coal mining and coal seam gas extraction using existing technologies. The coal in the western basin is not as deep, but is too immature to have generated coal seam gas. It is considered that the scarcity of knowledge, remoteness and depths of coal resources within the Pedirka Basin would rule out economically viable production in the near term.
About the bioregional assessment
The bioregional assessment for the Pedirka subregion includes compilation of background information, a water-dependent asset register and a data register. Results from this work have shown there is very low potential for coal or coal seam gas development in this subregion. It is for this reason that the bioregional assessment will not include further analysis such as model-data, impact and risk analyses. The information collected for the Pedirka subregion may be used for future assessments or environmental studies.
- Area: 75,760 square kilometres
- Population: 2,975
- Climate: arid
- Annual rainfall: 140 to 260 millimetres
- Lake Eyre Basin bioregion
- Northern Inland Catchments bioregion
- Clarence-Moreton bioregion
- Northern Sydney Basin bioregion
- Sydney Basin bioregion
- Gippsland Basin bioregion