The Rocky Hill Coal Project is a proposed open-cut coal mine located approximately 100 km north of Newcastle, New South Wales. The project occurs within the Gloucester Basin and targets the Gloucester Coal Measures. AGE were engaged by R.W Corkery & Co Pty Ltd., on behalf of Gloucester Resources Ltd., to complete a groundwater impact assessment as part of the project’s Environmental Impact Statement.
The groundwater impact assessment involved review of historic data and field studies in order to gain an in-depth understanding of the hydrogeological regime for development of the conceptual groundwater model.
A key consideration of the project was to quantify the potential for the project to impact upon the Avon River and Waukivory Creek occurring immediately to the west and south of the mine area. The potential for cumulative impacts from planned coal seam gas and active coal mining within the region also required quantification.
To address these issues, a numerical groundwater model was developed in MODHMS to simulate natural groundwater processes and system stresses from mining and in order to predict potential changes due to the project. The model also simulated groundwater/surface water interactions using the various capabilities of MODHMS.
The outcomes included:
- quantification of groundwater take from the Avon River and Gloucester Basin water sources, for licensing purposes;
- predicted changes in water levels and quality in the various aquifers, as well as the Avon River and Waukivory Creek; and
- assessment of impacts on key receptors, including private landholder bores and groundwater dependent ecosystems.
AGE has enjoyed a continued involvement with the project and in mid-2016, updated the original 2013 groundwater impact assessment to represent amendments to the project.