South East Queensland
18.1 Groundwater outflow to outside region

Supporting information

a. Overall

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.

b. Great Artesian Basin summary

The Great Artesian Basin (GAB) underlies a large portion of Queensland. The groundwater resources in the GAB in Queensland are managed under the Water Resource (Great Artesian Basin) Plan 2006  (Queensland Government 2013b) and the Great Artesian Basin Resource Operations Plan (Department of Natural Resources and Mines 2013a) . This divides the Queensland component of the GAB into 25 management areas. One of these areas, the Clarence-Moreton management area, is located partially within the SEQ region and is made up of Walloon Coal Measures, Marburg Sandstone, and Helidon Sandstone. The Clarence-Moreton management area is 400 km in length and 125 km wide, and extends from Toowoomba in the west to Darr Creek in the northwest, Esk in the north, Ipswich in the east, and Rathdowney in the south (Department of Natural Resources and Mines 2013a). It underlies the Lockyer Valley, Bremer River Valley, and Teviot Brook catchment.

c. Great Artesian Basin flows

This process occurs in the SEQ region, but the volume could not be quantified due to the lack of both data and a suitable quantification approach.

The Clarence-Moreton management area of the Great Artesian Basin (GAB) is connected in the west to the neighbouring Eastern Downs management area. The Eastern Downs management area which is located outside the SEQ region. Surface water catchments within the Clarence-Moreton recharge the Clarence-Moreton management area aquifers. Some of this groundwater then flows out of the SEQ region and into the Eastern Downs. As the northwest part of the Clarence-Moreton management area is not located within the SEQ region, groundwater flows both into and out of the SEQ region will occur. These flows could not be quantified, but it would be expected that the outflow from the SEQ region would be greater than the inflow because the Clarence-Moreton management area acts as a recharge area for the GAB.

These inflows and outflows are important flows within the region. Individually, these flows would be considered material to the water balance of the groundwater store. Further information may be found in the Groundwater note.