Overall, additional coal resource development in the Gloucester subregion is predicted to lead to changes in groundwater drawdown and streamflow that are small in both magnitude and area. While there is large uncertainty in future ecological trends, the changes in hydrology due to additional coal resource development are generally so small that adverse ecological impacts are unlikely. There are some stream reaches in the vicinity of the Rocky Hill, Stratford and Duralie mines where hydrological changes were not able to be quantified. The possibility of significant ecological impacts in these streams cannot be ruled out.
These regional-scale results do not replace the need for detailed site or project specific studies, nor should they be used to pre-empt the results of detailed studies that may be required under NSW legislation. Where potentially significant impacts are identified from the regional scale analysis, local scale information should be used to better define the risk.
There is much more confidence around the areas and assets that are very unlikely to be impacted (those outside the zone of potential hydrological change). Within the zone, any further monitoring to determine potential impacts of additional coal resource development 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.
To increase confidence in groundwater, surface water and receptor impact modelling, the focus should be on better characterisation of hydraulic properties; improving understanding of the role of faults in conducting or retarding groundwater flows; mapping depth to groundwater; and improving the mapping, identification and characterisation of groundwater-dependent ecosystems in the subregion.
Future cumulative impact assessments should also explicitly assess the cumulative impacts of baseline coal mines, as well as changes in other land uses and include climate variability and change.
Product Finalisation date
- 3.1 Overview
- 3.2 Methods
- 3.3 Potential hydrological changes
- 3.4 Impacts on and risks to landscape classes
- 3.5 Impacts on and risks to water-dependent assets
- 3.6 Commentary for coal resource developments that were not modelled
- 3.7 Conclusion
- Contributors to the Technical Programme
- About this technical product