1.1.6 Surface water – groundwater interactions

From existing literature, information on groundwater – surface water interactions for the Galilee subregion appears to be largely derived from regional scale desktop studies. Significant data compilations exist for features such as springs and wetlands across the Galilee subregion (e.g. Queensland Government, 2013). However, the focus here seems to be towards characterisation of the features’ hydrology and ecology, with less on hydrogeological issues.

Numerous spring complexes exist in the Galilee subregion (Figure 50). Miles et al. (2012) noted 55 spring complexes in the Barcaldine spring supergroup alone although this work is largely restricted to springs within the Great Artesian Basin (GAB). Further information on wetlands and groundwater dependent ecosystems in the Galilee subregion can be found in Section 1.1.7.

The report by the Queensland Department of Natural Resources (QDNR, 2005) includes a summary of water features for which there is potential for baseflow contribution from Great Artesian Basin aquifers. Maps showings specific stream reaches with potential for baseflow contribution are included in Appendix 1 of QDNR (2005). Aquifers identified by QDNR (2005) with potential to contribute to river baseflow include the Hooray Sandstone and its equivalents, the Ronlow beds and the Clematis Group. QDNR (2005) also identified some river reaches that could provide recharge to aquifer systems. The streams identified in the QDNR (2005) desktop study which could potentially receive baseflow from the aforementioned aquifers were P R Creek (Lake Buchanan outflow), Dyllingo Creek (a tributary of the Carmichael River), Lake Galilee outflow, Reedy Creek (south of Lake Galilee), Alice River and Patrick Creek (a tributary of the Alice River). For all of these streams with the exception of Dyllingo Creek, the source aquifers were identified as GAB (Hooray Sandstone or Ronlow beds) by QDNR (2005). For Dyllingo Creek, the baseflow was assessed as being sourced from the Clematis Group. QDNR (2005) also noted the presence of two high conservation value springs in the vicinity of Dyllingo Creek. It should be noted that QDNR (2005) did not investigate areas where there are outcropping Late Carboniferous to Permian Galilee Basin sediments, along the eastern margin of the Galilee subregion.

Estimates of baseflow will be considered as part of surface water modelling projects for major catchments in the Galilee subregion. This information will be reviewed and assessed as part of later components of the Galilee bioregional assessment.

Preliminary potentiometric surface maps produced as part of the bioregional assessment suggest there is potential for the east flowing Carmichael and Belyando rivers to act as groundwater drains for the Warang Sandstone, Dunda beds and Clematis Group aquifers. Their potential for connectivity is likely to be higher where these Galilee Basin aquifers outcrop near major waterways. The pressure surface for the Clematis Group aquifer is shown in Figure 32 of Section 1.1.4 (this report). The potentiometry shows a groundwater sink at less than or equal to 300 mAHD centred about the Carmichael River/Dunda Creek area. Since the channels of both of these streams are significantly lower than this, there is the potential for baseflow from the Clematis Group to these streams and the Belyando River, provided a pathway exists. This will be more fully investigated in future components of the Galilee bioregional assessment.

Ransley and Smerdon (2012) found evidence that suggested that the shallow watertable may be interacting with surface water along significant reaches of the Diamantina River and Cooper Creek. They suggested that some reaches of these drainage systems may be receiving baseflow from shallow aquifer systems, that is, there is potential for the shallow groundwater system to discharge to surface drainage. This is evident along significant reaches of the Diamantina River and Cooper Creek, within the Galilee subregion.

Using remote sensing techniques, Ransley and Smerdon (2012, Figure 6.25) identified reaches along Cooper Creek and the Diamantina River where riparian vegetation was likely to be drawing from shallow groundwater systems. Again, this was evident along the major channel ways of the Diamantina River and Cooper Creek within the Galilee subregion.

Existing studies in the Galilee subregion are largely focused on the potential for surface water – groundwater interactions to occur between surface water bodies and Great Artesian Basin (Eromanga Basin) aquifers. Knowledge of surface water – groundwater interactions involving aquifers in Cenozoic sequences is limited. There also appears to be limited information on surface water – groundwater interactions in areas where Galilee Basin sediments outcrop, along the eastern margin of the Galilee subregion. Understanding surface water – groundwater interactions along the eastern margin of the Galilee subregion is important as there are proposals to develop a number of large coal mines.

Figure 50 Major spring complexes in the Great Artesian Basin, located within the Galilee subregion

Source data: spring complexes after Figure 1.5, Smerdon et al. (2012).