Impacts of coal seam gas extraction on water resources in Australia David Post CSIRO, Canberra, Australia Impacts of coal seam gas extraction on water resources in Australia Extraction of coal seam gas may impact on ecosystems and water related assets through changes in the quantity and quality of groundwater and surface water. A 4-year, AU$60 m program of research titled Bioregional Assessments is currently underway to examine the impacts of coal resource development in Australia. Approach The overall steps in a bioregional assessment are: Derive the most likely coal resource development pathway and determine the hazards associated with it. Build conceptual and numerical models of the system, including groundwater, surface water and ecological response models. Run these models into the future for both a baseline and coal resource development pathway, explicitly taking uncertainty in the predictions into account. Use the outputs of these models to determine the potential hydrological and ecological impacts of coal seam gas extraction and coal mining on ecosystems and water-dependent assets. 1. What are the hazards? 2. How is the system connected? 3. Is surface water or groundwater changed? 4. Which ecosystems may be impacted and how? 5. Which assets may be impacted and how? Figure 3: The focus of a Bioregional Assessment is on the cumulative impacts of the coal resource development pathway (CRDP) on top of those already seen due to ‘baseline’ developments in a region. Figure 2: Conceptual model of the Gloucester subregion. Progress to date The Bioregional Assessment Programme commenced in July 2013. Work to date has focused on: Creating water-dependent asset registers containing important ecological, economic and social assets for all regions. Determining which regions are more likely to see coal resource development in order to prioritise work there. Developing conceptual and numerical models for these priority regions. Models have now been developed for the Gloucester, Clarence- Moreton, Galilee and Maranoa-Balonne-Condamine regions, while work is still underway in the Hunter and Namoi regions. Next steps The programme of work is now delivering, and it is anticipated that it will be complete by April 2017. Work from here on will focus on determining the impacts of coal seam gas extraction and coal mining on ecosystems and water-dependent assets in the priority regions. An important aspect of the work lies in not just reporting impacts, but also the associated uncertainties and risks associated with these impacts. This is done through a comprehensive uncertainty and risk analysis. Figure 1: Location of the bioregions being assessed FURTHER INFORMATION David Post Senior Principal Research Scientist, CSIRO e david.post@csiro.au p +61 2 6246 5751