This bioregional assessment helps us understand how coal seam gas and coal mining development could affect water resources and water-dependent assets in the Gwydir subregion, which is part of the Northern Inland Catchments bioregion. It identifies where potential impacts could occur, as well as the areas that are unlikely to be affected.
About the subregion
The Gwydir subregion includes parts of the northern Murray–Darling Basin in northern New South Wales and southern Queensland. The main rivers draining the subregion are the Gwydir and Macintyre-Barwon rivers. The subregion extends westward from the lower slopes of the New England Tablelands onto the low-lying riverine plains of the Barwon-Darling river system. Moree is the largest town in the subregion. Most of the land in the subregion is used for grazing and cropping. Groundwater is heavily used for irrigation of summer crops such as cotton.
The subregion contains seasonal, semi-permanent and permanent wetlands and lagoons. This includes the Gwydir Wetlands, which is an internationally recognised and protected wetland. The subregion is home to a number of endangered water-dependent ecological communities, animals and plants which are protected under Commonwealth and New South Wales legislation.
Coal mining and coal seam gas operations
Rocks of different ages from the Bowen, Gunnedah and Surat basins underlie the Gwydir subregion. There has been little coal exploration in the subregion. Although coal is mined extensively from other areas of the Bowen and Surat basins, there are no coal mines and no coal seam gas production within this subregion. It is also unlikely that there will be commercial production of coal seam gas from coal-bearing rocks in this subregion. This is due to the high levels of carbon dioxide gas in the coal and the limited ability for the gas to move through the coal, which makes production uneconomic. As of October 2014, there were no coal or coal seam gas developments planned or proposed in the Gwydir subregion.
About the bioregional assessment
The bioregional assessment for the Gwydir subregion includes compiling background information, a water-dependent asset register and a data register. Results from this work have shown that there is unlikely to be coal and coal seam gas development in the Gwydir subregion. For this reason, the bioregional assessment will not include further analysis such as model-data, impact and risk analyses. Instead further work will be done in other subregions in the Northern Inland Catchments bioregion where a greater level of coal and coal seam gas development is expected. The information collected for the Gwydir subregion may be used for future assessments or environmental studies.
- Area: 28,109 square kilometres
- Population: about 16,500
- Climate: varies from hot and dry (west) to sub-tropical (east)
- Annual rainfall: ranges from 500 millimetres (west) to 950 millimetres (east)
- Lake Eyre Basin bioregion
- Northern Inland Catchments bioregion
- Clarence-Moreton bioregion
- Northern Sydney Basin bioregion
- Sydney Basin bioregion
- Gippsland Basin bioregion