2.6.2.3.1 Objectives

As stated in Section 2.6.2.1, the objective of the numerical modelling undertaken as part of a BA is to probabilistically assess hydrological changes arising from coal resource development at water-related assets. The main objectives of the groundwater model therefore are (i) to provide the drawdown due to additional coal resource development (additional drawdown) at the model nodes (Section 2.6.2.1, Figure 4 and Table 4), and (ii) to estimate the change in surface water – groundwater flux to propagate to the surface water models (companion product 2.6.1 for the Galilee subregion (Karim et al., 2018a)).

In addition to the additional drawdown at the model nodes, probabilistic maps of the drawdown under the baseline coal resource development (baseline), the coal resource development pathway (CRDP) and the difference between the two will be provided.

There is no model node for which changes in water balance are considered to be the hydrological response variable. Therefore, while changes in water balance are not an objective of the modelling, probabilistic estimates of changes in the surface water – groundwater flux are discussed. A more comprehensive discussion on the water balance of the Galilee subregion is presented in companion product 2.5 (Karim et al., 2018b).