Building on this assessment

Bioregional assessments have been developed with the ability to be updated, for example, incorporating new coal resource developments in the groundwater or surface water modelling. Components such as the water-dependent asset register (Bioregional Assessment Programme, 2017; Dataset 3) will remain relevant for future assessments. If new coal resource developments emerge in the future, the data, information, analytical results and models from this assessment provide a comprehensive basis for bioregion-scale re-assessment of potential impacts under an updated CRDP. It may also be applicable for other types of resource development, such as agriculture or shale gas.

The Galilee Basin hydrogeological (GBH) model is a regional-scale numerical groundwater flow model developed utilising data and interpretations compiled to support the bioregional assessment of the Galilee subregion (Turvey et al., 2015). The GBH model provides a more sophisticated representation of the hydrogeology of the Galilee and Eromanga basins and mine developments, and could provide the basis for future cumulative impact assessments, building upon the initial work undertaken for this assessment. Peeters et al. (2018) provided an overview of the GBH model as well as a summary of its strengths and current limitations.

The assessment provides information about potential cumulative impacts of coal mining and CSG developments on water resources and water-dependent assets. It did not assess potential impacts from rail development or coal handling and processing facilities at coal terminals or ports.

Non-modelled coal resource developments

The main focus of the impact and risk analysis for the Galilee subregion is in the central-east, where the initial seven proposed coal mines are most likely to begin operations. However, a further seven potential coal mine projects and three CSG projects were included in the CRDP for this assessment, though these were not modelled.

Most of these later-stage coal resource developments will occur in parts of the subregion away from the area where the modelling analysis was undertaken for this assessment. This includes a suite of five potential coal mines near the northern edge of the Galilee Basin, and a stand-alone operation in the southern part of the subregion (near Blackall) targeting geologically younger coal from the Eromanga Basin. The seven non-modelled coal mine projects in the CRDP are (from north to south) Clyde Park, Hughenden, Pentland, West Pentland, Milray, Alpha West and Blackall (Figure 2).

The most likely area for future CSG development spans the central part of the basin, from the Glenaras Gas Project in the west, across to the Gunn Project in the east. All of the subregion’s CSG projects remain at exploration and early appraisal stages, with no clear understanding yet as to the timing, scale and longevity of any CSG production fields. The areas of most interest for CSG development in the Galilee subregion all occur within the Cooper Creek – Bulloo river basin.

More information on the non-modelled coal resource developments is available in Section 3.6 of Lewis et al. (2018), which describes:

  • the most likely areas for subsequent phases of coal resource development
  • information about non-modelled coal mine and CSG projects, to assist any future assessment of cumulative impacts across the wider Galilee Basin
  • qualitative analyses of the potential for impacts on the water-dependent landscape groups and assets that are near these sites, including any overlap with hydrological changes caused by the seven coal mines that were modelled for this assessment.

This information will assist users of the assessment to understand where subsequent stages of coal resource development may potentially occur in different areas of the Galilee Basin, as well as a flag for the key ecosystems and assets that are near these later-stage developments. This information may assist future planning and management of potential water-related impacts and risks in the Galilee subregion.

Future opportunities

Section 3.7.4 in Lewis et al. (2018) details data gaps and future opportunities to build upon the work of this assessment and further improve knowledge in key areas such as geology and hydrogeology, hydrological modelling, assessing impacts on ecosystems, water quality considerations and incorporating other climate change and land use impacts.

Geology and hydrogeology

An opportunity exists to improve the surface geological and structural mapping along the central-eastern margin of the Galilee Basin, which would address some notable discrepancies in the current mapping (across different scales). New mapping efforts should ideally incorporate as much information as possible from recent geophysical surveys as well as any available finer-scale mapping or geological modelling that may have been completed (e.g. to aid coal exploration or resource evaluation activities). Information such as this could then be used to refine knowledge of the three-dimensional geological architecture within this area of interest, potentially leading to more robust and reliable hydrogeological conceptualisations to underpin subsequent local-scale modelling.

Hydrogeological interpretation of spring source aquifers within the zone of potential hydrological change (a noted point of current scientific debate as outlined in Section 3.4 of Lewis et al. (2018) and references therein) would benefit from additional field-based measurements and data collection, for example, using suitable environmental tracers, geophysical data and application of local-scale geological mapping and groundwater modelling. Also, determining the source aquifer for bores in the zone with missing screen depths will improve estimates of water take from different aquifers, decreasing uncertainty around potential impacts of groundwater drawdown on these bores.

Hydrological modelling

Future iterations of surface water and groundwater modelling to support management or planning decisions in the Galilee subregion should revisit the choice of individual coal resource developments in the CRDP, and their proposed operational characteristics, and assess if any updates or changes are required. This could be done on a regular basis, such as every 3 to 5 years, to ensure that the CRDP is aligned with any possible changes to the number of likely developments and their proposed timing.

Consideration could also be given to evaluating multiple potential development scenarios for the Galilee subregion within the hydrological models. Additionally, future modelling iterations could evaluate the potential for hydrological interaction between coal mining operations and CSG development in the basin’s most prospective central area.

The distribution of surface water model nodes in this assessment did not enable a comprehensive extrapolation to all network reaches, and resulted in identification of some ‘potentially impacted’ stream reaches where hydrological changes could not be quantified. A higher density of surface water modelling nodes and gauging information, located immediately upstream of major stream confluences as well as upstream and downstream of mining operations, would allow the point-scale information to be interpolated to a larger proportion of the stream network. More extensive quantification of hydrological changes along the stream network would enable better spatial coverage of the results of the receptor impact modelling.

A more detailed understanding of all water balance components, including recharge, evapotranspiration, inter-aquifer leakage and groundwater fluxes between the Galilee and Eromanga basins would decrease uncertainty and improve future updates to this assessment. This work would build upon the higher-level water balance reporting presented for this bioregional assessment (Karim et al., 2018b), and include revised estimates of mine water extraction, on-site use and any potential stream releases (if appropriate). Improved understanding of the dynamic interaction between components of the water balance for key assets such as the Doongmabulla Springs complex could be gained through analysis of baseline time-series remote sensing datasets.

As mentioned above, further investments to improve the structure and robustness of the GBH numerical groundwater model (Turvey et al., 2015) would provide a strong foundation for assessing cumulative impacts of coal resource development on groundwater systems into the future.

Assessing impacts on ecosystems

Extending this bioregional assessment should focus on improving confidence in assessing impacts in the landscape through more mapping of groundwater depths, vegetation communities and their water requirements, and identification of GDEs.

Improved knowledge of surface water – groundwater interactions would provide a better understanding of the separation between groundwater-dependent and surface water-dependent wetlands for future assessments. In particular, the impact assessment would benefit from better characterisation of surface water – groundwater interactions along the Belyando and Carmichael rivers (and their tributaries) with adjacent Cenozoic aquifers, and an improved understanding of potential for connectivity between aquifers in Cenozoic sediments and deeper aquifers in the Galilee Basin.

The remote sensing techniques applied for this assessment (see Section 3.5.2 in Lewis et al. (2018) for further details) demonstrate the potential for multi-decadal earth observation data to provide insight and baseline information for assessing dynamics of vegetation and wetlands. However, further quantitative analysis could be undertaken to determine the relative contributions of rainfall, streamflow and groundwater to water-dependent features. Better understanding of the hydrological contributions from different sources will assist with management and improve understanding around potential impact pathways from future development.

There is also a major data gap in the understanding of water thresholds for ecosystems associated with springs and other key water assets. In part, this results from the lack of bores available to provide meaningful time-series groundwater level data. Some examples of these data gaps appear in the discussion of the functioning of springs in the Doongmabulla Springs complex (see Lewis et al. (2018) for further details).

Subsurface GDEs have not been adequately surveyed within the ssessment extent and are not well represented in this landscape classification. A consequence of this gap is uncertainty in the understanding of the water dependency of these GDEs, although most would be expected to have a high degree of reliance on groundwater for their survival.

Water quality

The potential large yearly variations in streamflow in the Belyando river basin mean that hydrological changes due to modelled additional coal resource development may not lead to substantial changes in water quality parameters such as salinity at the regional (or basin) scale, at least beyond the natural annual variability that these streams may already experience. However, there are scant baseline water quality data available, and hence there are opportunities to better characterise the natural range of water quality parameters, to develop an improved regional baseline. This would assist in better understanding potential water quality changes that could occur due to coal resource development, for example, due to variations in the relative contributions of surface runoff and (groundwater) baseflow to streams. Likewise, available groundwater quality data are also sparse within the zone of potential hydrological change, and additional knowledge of groundwater quality parameters would greatly assist in characterising the regional baseline for key aquifers. There is also a future opportunity to integrate any updated understanding of regional water quality in the zone with the quantitative outputs derived from the surface water and groundwater modelling developed for this assessment.

Climate change and land use

In comparing results under two different futures in this assessment, factors such as climate change, land use and other types of water extraction and usage are held constant. Future assessment iterations could include these and other stressors to more fully predict cumulative impacts at a landscape scale.

Future monitoring

Future monitoring to confirm predictions made in this assessment should focus on the discrete drawdown zones identified in the hydrological modelling. These include monitoring bores installed to target: the confined parts of the Clematis Group aquifer and Dunda beds, up-hydraulic gradient (west and south) of the Doongmabulla Springs complex; the unconfined Cenozoic aquifers in key areas of the Belyando River floodplain to assist in determining the degree of near-surface drawdown and potential connectivity with deeper aquifers; and Cenozoic aquifers associated with the Alpha town water supply.

Future surface water monitoring efforts would be best targeted along suitable reaches of Native Companion, North, Sandy, Alpha and Tallarenha creeks, and the Belyando and Carmichael rivers, where the bioregional assessment modelling results indicate the most substantial changes across the spectrum of low-flow, high-flow and annual flow regimes.

Besides future targeted monitoring points, there are a number of data-sparse areas that would benefit from consistent and regular data collection, which would improve risk quantification for this assessment. This includes surface water and ecological baseline data collection to improve the understanding of relevant environmental conditions and parameters, including those related to surface water and groundwater quality. Future monitoring efforts could also be directed towards testing some of the key hypotheses developed through the receptor impact modelling undertaken for this assessment.

The availability of ecological monitoring data for benchmarking, including identifying current conditions, and comparing and identifying changes in ecosystems and ecosystem indicators, is very limited, especially for dealing with regional-level changes. There is a lack of ecohydrological understanding around the water requirements for the many water-dependent vegetation communities and how these relate to specific hydrological response variables – a crucial requirement for assessing impacts related to hydrological changes. Consequently, future investigations and coordinated monitoring to address such knowledge shortcomings would strengthen any further assessment of cumulative impacts due to coal resource development in the Galilee Basin.


See ‘Knowledge gaps’ sections in:

Description of water-dependent asset register, product 1.3 (Sparrow et al., 2015)

Current water accounts and water quality, product 1.5 (Evans et al., 2015)

Observations analysis, statistical analysis and interpolation, product 2.1-2.2 (Evans et al., 2018a)

Conceptual modelling, product 2.3 (Evans et al., 2018b)

Water balance assessment, product 2.5 (Karim et al., 2018b)

Surface water numerical modelling, product 2.6.1 (Karim et al., 2018a)

Groundwater numerical modelling, product 2.6.2 (Peeters et al., 2018)

Receptor impact modelling, product 2.7 (Ickowicz et al., 2018)

Impact and risk analysis, product 3-4 (Lewis et al., 2018)

See for links to information about all datasets used or created, most of which can be downloaded from

Last updated:
6 December 2018