The Geological and Bioregional Assessment (GBA) Program developed a robust methodology using causal networks to assess the regional-scale risks of unconventional gas resource development on water and the environment. The methodology allows consistent analysis of risks at each step in a chain of events – called pathways – from unconventional gas resource development activities to protected environmental and water-related values. The methodology can be applied to other regional-scale assessments in the future.
The GBA Program has developed a publicly accessible online tool (the GBA Explorer), which allows anybody to interact with the complex causal network supporting the assessment. The tool lets users focus on the matters of relevance to them and examine the underlying scientific evidence in more detail. The Program worked closely with people living and working in the region. The experience and insights given by the local community and stakeholders directly informed what was investigated in detail by Program scientists and then assessed through the GBA Program.
| Key finding: The GBA Program assessed 2,078 pathways for potential impact in the Beetaloo GBA region. The assessment found, with high confidence, that the majority of pathways have low to very low potential for impact. Potential impacts from other pathways can be mitigated through ongoing compliance with existing regulatory and management controls. | |
| Assessment: the Beetaloo GBA region covers an area of about 28,000 km2 in the Northern Territory (Figure 1). A resource development scenario of 1,000 tera joules per day was used for this assessment. It included direct disturbance of between 8 and 35 km 2 for infrastructure such as access roads and well pads, within a total project area of between 430 and 7,700 km2 or 1.5 to 28% of the Beetaloo GBA region. Most potential impacts that could occur are at the surface and can be mitigated by existing controls. | FIGURE 1 The Beetaloo GBA region
Element: GBA-BEE-3-581 |
| Surface water: Where activities are conducted in the vicinity of waterways, a small number of pathways have potential for impact. There is high confidence that existing mitigation strategies will avert these impacts. | Groundwater: Groundwater is the most probable source of water for unconventional gas resource development. The assessment has found that aquifers in the region, such as the Cambrian Limestone Aquifer, can supply this water without adverse regional impacts. |
| Environment: Invasive plants and broadscale landscape changes due to vegetation removal and vehicle movement have the strongest influence on threatened species and protected areas in the Beetaloo GBA region. There is high confidence that existing management controls can avoid and mitigate these potential impacts. | Protected fauna and flora: The assessment prioritised 6 protected animals based on the importance of the Beetaloo GBA region to each species. Potential impacts involve activities at the surface leading to increased invasive plants and animals, and vegetation removal. There is high confidence that existing management controls can avoid and mitigate these impacts. |
