2.6.1.3.5 Estimation of additional coal resource development impacts on streamflow

The ACRD impacts on daily streamflow at each model node are estimated as the total of two impacts: direct open-cut mine footprints and baseflow impact. Section 2.6.1.3.4 describes how the open-cut mine footprints are obtained. Their direct impact is the streamflow detained in the mine footprint areas, simulated from the Australian Water Resource Assessment Landscape model (AWRA-L) daily streamflow multiplied by the ratio of the ACRD area to each node’s contribution area. This means that there will be no impact on streamflow if there is no ACRD, and the reduction in streamflow will be 100% if the ACRD area covers 100% of the node’s contribution area.

The hydrological changes to baseflow are estimated using the MODFLOW groundwater model, which is described in detail in Section 2.6.2.3 of companion product 2.6.2 for the Gloucester subregion (Peeters et al., 2018). The MODFLOW model estimates monthly baseflow for each model node under the baseline and CRDP. The difference between CRDP and baseline simulations is taken as the monthly hydrological change in baseflow, which is then equally partitioned to obtain the daily changes.

Last updated:
31 October 2018
Thumbnail of the Gloucester subregion

Product Finalisation date

2018