South East Queensland
18.2 Groundwater outflow to outside region at coast

Supporting Information

This process occurs in the South East Queensland (SEQ) region, but the volume could not be quantified in a way that is complete, neutral and free from material error due to the lack of both data and a suitable quantification approach.

Given the underlying geology of the SEQ region (line item 2.2 Underlying aquifers), a large-scale flux of groundwater is not the major outflow of water at the coast. Surface water outflow described in line item 17.2 River outflow to outside region would be more significant in terms of volume.

Onshore coastal sand aquifers do occur in the SEQ region, with main deposits located near Beachmere, Donnybrook, Toorbul, Jumpinpin Bar, Jacobs Well and Hollywell (Queensland Department of Natural Resources, Mines & Water 2006c). In these aquifers there is generally a long-term balance between recharge and groundwater outflow at the coast. Given the 2010–11 year had considerable precipitation, it can be expected that the coastal outflow from these onshore coastal sand aquifers would have been greater than in a typical year; however, the volume associated with this outflow could not be quantified.

This flow is not a significant proportion of the groundwater store outflows and would not be considered material to the water balance for the groundwater store. Further information may be found in the Groundwater note.