Galilee Basin Hydrogeological Flow Model

Brief description

The Galilee Basin Hydrogeological Model is a numerical groundwater flow model of the Galilee subregion in Queensland, an area of approximately 300,000 square kilometres. The model encompasses the entire geological Galilee Basin as well as parts of the overlying Eromanga Basin and surficial Cenozoic sediments. The model includes aquifers that form part of the Great Artesian Basin (specifically those aquifers in the Eromanga Basin), a hydrogeological system of national significance (see Evans et al 2018). The development of the Galilee Basin Hydrogeological Model represented an ambitious, first-pass attempt to better understand potential regional-scale cumulative groundwater impacts of seven proposed coal mines in the Galilee Basin (as known circa 2014, see Lewis et al. 2014 for details). This work was commissioned as part of the bioregional assessment for the Galilee subregion (https://www.bioregionalassessments.gov.au/assessments/galilee-subregion). Geoscience Australia has made the flow model and associated datasets available to support further academic or research investigations within the region. Importantly though, due to a number of limitations and assumptions (outlined in the final model report, Turvey et al., 2015), the model is not suitable for decision-making in relation to water resource planning or management. Further, the model was not developed to predict potential groundwater impacts of any individual mining operations, but provides a regional cumulative development perspective. The groundwater model and associated report were produced by HydroSimulations under short-term contract to Geoscience Australia in 2015. The report is referenced in several products released as part of the bioregional assessment (BA) for the Galilee subregion. However, due to the size, complexity and limitations of this model, this model was not used as the primary groundwater modelling input for the Galilee BA. Further detail about the key modelling limitations and why it was unsuitable for use in the Galilee BA are outlined in the BA Groundwater modelling report (Peeters et al., 2018). References Evans T, Kellett J, Ransley T, Harris-Pascal C, Radke B, Cassel R, Karim F, Hostetler S, Galinec V, Dehelean A, Caruana L and Kilgour P (2018) Observations analysis, statistical analysis and interpolation for the Galilee subregion. Product 2.1-2.2 for the Galilee subregion from the Lake Eyre Basin Bioregional Assessment. Department of the Environment and Energy, Bureau of Meteorology, CSIRO and Geoscience Australia, Australia. http://data.bioregionalassessments.gov.au/product/LEB/GAL/2.1-2.2. Lewis S, Cassel R and Galinec V (2014) Coal and coal seam gas resource assessment for the Galilee subregion. Product 1.2 for the Galilee subregion from the Lake Eyre Basin Bioregional Assessment. Department of the Environment, Bureau of Meteorology, CSIRO and Geoscience Australia, Australia. https://www.bioregionalassessments.gov.au/assessments/12-resource-assessment-galilee-subregion. Peeters L, Ransley T, Turnadge C, Kellett J, Harris-Pascal C, Kilgour P and Evans T (2018) Groundwater numerical modelling for the Galilee subregion. Product 2.6.2 for the Galilee subregion from the Lake Eyre Basin Bioregional Assessment. Department of the Environment and Energy, Bureau of Meteorology, CSIRO and Geoscience Australia, Australia. http://data.bioregionalassessments.gov.au/product/LEB/GAL/2.6.2. Turvey C, Skorulis A, Minchin W, Merrick NP and Merrick DP (2015) Galilee Basin hydrogeological model Milestone 3 report for Geoscience Australia. Prepared by Heritage Computing Pty Ltd trading as Hydrosimulations. Document dated 16 November 2015. http://www.bioregionalassessments.gov.au/sites/default/files/galilee-basin-hydrological-model-pdf.pdf. The model is available on request from clientservices@ga.gov.au - Quote eCat# 146155

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Maintenance and Update Frequency: notPlanned

Statement: As part of the Bioregional Assessment Program, Geoscience Australia contracted HydroSimulations in 2015 to develop a numerical groundwater flow model of the Galilee Basin in Queensland. The 13 layer model was run in both steady-state and transient mode using the finite volume code MODFLOW-USG using an unstructured Voronoi mesh created with the Algomesh software package. The model was designed to support the bioregional assessment of the Galilee subregion, part of the larger Lake Eyre Basin bioregion.

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Purpose
The Galilee Basin Hydrogeological Model was undertaken as a supporting knowledge initiative for the bioregional assessment of the Galilee subregion in central Queensland. It was originally developed as an initial attempt to improve understanding of potential regional cumulative groundwater impacts due to the combined effects of seven large coal mining operations in the Galilee Basin. However, the potential impacts of individual mining operations were not assessed with the model, consistent with the objectives of the bioregional assessment. Furthermore: 1. the Galilee model was not directly developed by Geoscience Australia or the Queensland Government (or their entities) and any follow-up research or publication should clearly reflect this; and 2. Any publication relating to use of the model within a Queensland water resource management context should seek endorsement from the Queensland Government.