3.1 Overview

Summary

The Maranoa-Balonne-Condamine subregion has an area of 144,890 km² and includes the headwaters of the Condamine River and the Maranoa River, as well as the floodplains of the Upper Darling Plains. The main cities and towns are Chinchilla, Dalby, Goondiwindi, Roma, St George, Toowoomba and Warwick. The subregion contains seasonal, semi-permanent and permanent wetlands and lagoons, including some nationally significant wetlands.

Bioregional assessments (BAs) are independent scientific assessments of the potential cumulative impacts of coal seam gas (CSG) and coal mining developments on water resources and water-dependent assets such as rivers, wetlands and groundwater systems. The assessments identify areas where water resources and water-dependent assets are very unlikely to be impacted (less than 5% chance), or are potentially impacted. This will allow governments, industry and the community to focus on areas that are potentially impacted when making regulatory, water management and planning decisions.

The impact and risk analysis considers hydrological changes under two potential futures: the baseline and the coal resource development pathway (CRDP). Baseline drawdown is the maximum difference in groundwater drawdown (dmax) in metres under the baseline relative to no coal resource development. Additional drawdown is the maximum difference in drawdown (dmax) between the CRDP and baseline, due to the two additional coal resource developments: New Acland Coal Mine Stage 3 and The Range coal mine. The groundwater model’s limited capabilities with respect to simulating surface water – groundwater interactions mean that surface water modelling was not undertaken for this subregion.