3.3.1 Defining the zone of potential hydrological change

The zone of potential hydrological change is the area within the subregion where changes in hydrology due to additional coal resource development exceed defined thresholds for groundwater and surface water changes. The zone is represented at the surface, or in the relevant geological layer from which landscapes or assets source water.

The impact and risk analysis presented in the remainder of this product focuses on landscape classes and assets that intersect this zone. Any landscape class or asset wholly outside the zone of potential hydrological change is considered very unlikely (less than 5% chance) to be impacted by hydrological changes due to additional coal resource development, and thus is ‘ruled out’ from any further analysis as part of this bioregional assessment (BA).

As surface water modelling was not undertaken in the Maranoa-Balonne-Condamine subregion, groundwater hydrological changes alone are used to define the zone.