Building on this assessment

If new coal resource developments emerge in the future, the data, information, analytical results and models from this assessment would provide a comprehensive basis for bioregion-scale re-assessment of potential impacts under an updated coal resource development pathway. For example, new coal resource developments could be incorporated in the groundwater model. Components such as the water-dependent asset register (Bioregional Assessment Programme, 2017; Dataset 19) remain relevant for future assessments. The information and approach may also be applicable for assessing other types of resource development.

Assessing impacts on ecosystems

Assessment of impacts on water-dependent assets would be improved by additional vegetation mapping and ongoing research to identify groundwater-dependent ecosystems in the subregion. This will improve understanding of the interactions between changes in groundwater availability and the health of terrestrial vegetation that relies on groundwater.

As actual water requirements of different plant communities is only approximately known, future assessments would be assisted by more work to identify suitable indicators of ecosystem condition, or alternative methods of assessing the condition of water-dependent ecosystems.

Groundwater data and mapping

Groundwater data available from state databases include primarily monitoring data for shallow groundwater systems and aquifers used for irrigation, stock and domestic purposes. These data are usually in the form of water level measurements and major ion analyses, which support understanding of groundwater recharge processes and interactions between rivers and groundwater. However, they provide limited understanding of the deeper groundwater systems that are relevant for coal and coal seam gas development. This has been factored into the assessment’s uncertainty analysis and modelling. Future assessments would be assisted by improved information on deeper groundwater systems.

Future investigations of the mapping of depth to groundwater would improve confidence in assessment predictions. Interactions between changes in groundwater availability and the health and persistence of terrestrial groundwater-dependent vegetation remain uncertain due, in part, to sparse mapping of groundwater depths outside of alluvial layers.

Drawdown predictions are very sensitive to hydraulic properties of the deeper sedimentary basin, especially predictions of the surface weathered and fractured rock layer. Improved knowledge of the hydraulic properties of the surface weathered and fractured rock layer and storage is needed to better understand changes at different depths.


Groundwater modelling conducted in this assessment demonstrates that it is unlikely that faults connect shallow groundwater systems with groundwater systems associated with coal measures. However, there remains a knowledge gap in the geological understanding of the Gloucester Basin regarding the number of faults present, their orientation and other characteristics.

The modelling highlighted that the predictive uncertainty would reduce with improved characterisation of hydraulic properties of the surface weathered and fractured rock layer and more detailed information of local geology around developments.

Climate change and land use

In comparing results under two different futures in this assessment, factors such as climate change and land use were held constant. Future assessments could include these and other stressors to more fully predict cumulative impacts at a regional scale.

Future monitoring

Future monitoring to confirm predictions made in this assessment should focus on the northern part of the subregion, specifically the area north-east of Stratford and including Avondale Creek, Dog Trap Creek, Waukivory Creek, Oaky Creek and the Avon River.


See sections titled ‘Gaps’ in:

Description of water-dependent asset register, product 1.3 (McVicar et al., 2015)

Current water accounts and water quality product 1.5 (Rachakonda et al., 2015)

Conceptual modelling, product 2.3 (Dawes et al., 2018)

Groundwater numerical modelling, product 2.6.2 (Peeters et al., 2018)

Impact and risk analysis, product 3-4 (Post et al., 2018)

See for links to information about all datasets used or created, most of which can be downloaded from

Last updated:
8 November 2018