Executive summary
This product presents estimates of net changes in surface water flow and groundwater as a result of seven proposed new coal mines in the Galilee subregion (South Galilee, China First, Kevin’s Corner, Alpha, Carmichael, China Stone and Hyde Park). Changes in surface water flow are presented for three time periods (2013 to 2042, 2043 to 2072 and 2073 to 2102) and changes in groundwater as the difference between a conceptual groundwater balance at 2012 (pre-development) and 30 years in the future (when proposed mines are assumed to be in production).
There are no existing coal resource developments in Galilee subregion. This bioregional assessment identified 17 proposed coal seam gas and coal projects in the subregion but only the seven new coal projects mentioned above had enough information to be included in the water balances.
Water balances for the Galilee subregion
The Burdekin river basin was chosen as the model area for both surface water and groundwater balances as all seven coal mining projects included in the modelled coal resource development pathway are situated within this basin.
The surface water balance was modelled at a specific location on the Belyando River, as this area shows the largest combined changes in streamflow as a result of the seven modelled coal mining projects in the Galilee subregion. The model predicts a less than 1% change to annual surface water outflow due to the additional coal resource developments. The interception of surface runoff on the mine sites is the main cause of change in modelled streamflow.
The groundwater results are presented for the entire modelling area. The conceptual groundwater balance, 30 years into the future, indicates that mine groundwater use will be equivalent to up to 66% of groundwater recharge. This is primarily due to mine dewatering. Most of this groundwater is proposed to be used within the coal projects as part of the mine water management system.
Relationship to other products
This analysis is part of a series of model-data analysis products, which describe the hydrological relationships between coal resource development and potentially impacted water resources and water-dependent assets in the subregion. This product informs the impact and risk analysis products, which examine the risk to, and potential impacts on water resources and water-dependent assets, such as bores and habitats.
