The model is designed to estimate drawdowns caused by the coal resource developments in the modelled CRDP at specified locations in the upper Permian coal measures, the Clematis Group and the Cenozoic and Quaternary cover sediments. These model nodes are presented in Figure 4 and Table 4 in Section 2.6.2.1 . Table 14 conveys the same information, together with a short description of each model node, its water source and the model layer the model node is assigned to.
As outlined in Table 14, the water source for two model nodes is interpreted to be the Ronlow beds (part of the GAB). Conceptually, it is unlikely there could be measureable drawdown impacts to aquifers in the Ronlow beds due to its distance from coal resource development areas and the presence of a thick aquitard (the Moolayember Formation) between the Ronlow beds and the underlying Clematis Group. To test this hypothesis, some model nodes, for which the water source is the Ronlow beds, are incorporated into the model. For the sake of model simplicity and for minimising model runtimes, the decision was taken to attribute these model nodes to the Clematis Group. The reasoning being that, the probability of a measurable impact in the Ronlow beds will always be less than the probability of measurable impact in the underlying Clematis Group at these particular model nodes. A similar approach was also taken for model nodes associated with wetlands and streams underlain by the Moolayember Formation (e.g. Lake Galilee).
For one of the model nodes listed in Table 14, it is not deemed justified to estimate drawdown with the analytic element model. This is model node GAL_041, the Alpha town water supply. The town water supply sources water from the Belyando alluvium, which is only connected to the Galilee Basin via the Joe Joe Group. This part of the alluvium and the connection is not well represented in the analytic element model and drawdown at the Alpha town water supply is therefore not simulated.
In addition to the model nodes listed in Table 14 and Figure 4, drawdown is also calculated for each model layer at the model nodes indicated in Figure 10. These model nodes are distributed throughout the model domain with a higher density around areas of high potential hydraulic gradients (i.e. the coal mines and no-flow boundary).
Table 14 Model nodes for which drawdown due to coal resource development in the Galilee subregion was calculated with the groundwater analytic element model
ID |
Easting |
Northing |
Description |
Water source |
Model layer |
---|---|---|---|---|---|
GAL_001 |
453657.9 |
7471715 |
Sandy Creek Belyando confluence / Sandy Creek GDE |
Alluvium |
0 |
GAL_002 |
467416.3 |
7391929 |
Native Companion Creek / Alpha Creek confluence, Native Companion Creek GDE |
Alluvium |
0 |
GAL_003 |
453168.4 |
7366093 |
Alpha Creek upstream of Alpha, Alpha Creek GDE |
Alluvium |
0 |
GAL_004 |
465511.3 |
7448484 |
Native Companion Creek GDE |
Alluvium |
0 |
GAL_005 |
449398.1 |
7451778 |
Sandy Creek GDE |
Alluvium |
0 |
GAL_006 |
443960.9 |
7409432 |
Sandy Creek |
Alluvium |
0 |
GAL_007 |
451739.7 |
7498689 |
Belyando River GDE just upstream of Fiery Creek anabranch |
Alluvium |
0 |
GAL_008 |
451700 |
7510913 |
Fiery Creek GDE anabranch |
Alluvium |
0 |
GAL_009 |
455986.2 |
7511072 |
Belyando River GDE |
Alluvium |
0 |
GAL_010 |
453565.3 |
7524605 |
Dunda Creek GDE / Fiery Creek GDE confluence |
Alluvium |
0 |
GAL_011 |
454795.6 |
7534884 |
Belyando River GDE |
Alluvium |
0 |
GAL_012 |
443564 |
7514485 |
Dunda Creek GDE |
Alluvium |
0 |
GAL_013 |
430030.6 |
7512183 |
Dunda GDE overlying Clematis Group |
Alluvium |
0 |
GAL_014 |
437055.3 |
7509603 |
Dunda GDE overlying Rewan Group |
Alluvium |
0 |
GAL_015 |
452414.4 |
7541155 |
Belyando GDE |
Alluvium |
0 |
GAL_016 |
449040.9 |
7538496 |
Belyando GDE anabranch |
Alluvium |
0 |
GAL_017 |
443802.2 |
7533932 |
Belyando tributary drainage line |
Alluvium |
0 |
GAL_018 |
453564.2 |
7556466 |
Carmichael – Belyando GDE confluence |
Alluvium |
0 |
GAL_019 |
437371.7 |
7555196 |
Carmichael GDE at confluence of two anabranches |
Alluvium |
0 |
GAL_020 |
430942.3 |
7554878 |
Carmichael GDE overlying Dunda beds subcrop |
Alluvium |
0 |
GAL_021 |
425756.4 |
7556783 |
Carmichael GDE overlying Clematis Group |
Alluvium |
0 |
GAL_022 |
421999.3 |
7558212 |
Dyllingo Creek near Moolayember Formation subcrop |
Clematis Group |
1 |
GAL_023 |
443060.2 |
7557895 |
Carmichael River GDE at subregion boundary |
Alluvium |
0 |
GAL_024 |
459411.5 |
7562340 |
Belyando River GDE |
Alluvium |
0 |
GAL_025 |
402631.8 |
7562670 |
Dyllingo Creek GDE near Clematis Group subcrop |
Alluvium |
0 |
GAL_026 |
388212 |
7563993 |
Dyllingo Creek GDE near Clematis Group / Moolayember Formation subcrop |
Alluvium |
0 |
GAL_027 |
382060.4 |
7565978 |
Dyllingo Creek GDE near Ronlow beds subcrop |
Alluvium |
0 |
GAL_028 |
413175.5 |
7591908 |
China Stone near Clematis Group outcrop |
Clematis Group |
1 |
GAL_029 |
389025 |
7518959 |
Lake Galilee wetlands (underlain by Moolayember Formation) |
Clematis Group |
1 |
GAL_030 |
388892.6 |
7534713 |
Lake Galilee wetlands (underlain by Moolayember Formation) |
Clematis Group |
1 |
GAL_031 |
441970.2 |
7513781 |
Cluster of groundwater licences in Betts Creek beds |
Upper Permian coal measures |
2 |
GAL_032 |
449673.4 |
7521390 |
Cluster of groundwater licences in Betts Creek beds |
Upper Permian coal measures |
2 |
GAL_033 |
427963.3 |
7508796 |
Cluster of groundwater licences in Clematis Group |
Clematis Group |
1 |
GAL_034 |
428043.8 |
7383876 |
Cluster of groundwater licences in Clematis Group / Dunda beds |
Clematis Group |
1 |
GAL_035 |
419180.2 |
7454256 |
Cluster of groundwater licences in Clematis Group / Dunda beds |
Clematis Group |
1 |
GAL_036 |
369975.8 |
7549910 |
Springnv38_Desert – source possibly Ronlow beds |
Clematis Group |
1 |
GAL_037 |
421384.5 |
7557193 |
Doongmabulla springs |
Clematis Group |
1 |
GAL_038 |
424294.9 |
7556829 |
Doongmabulla springs |
Clematis Group |
1 |
GAL_039 |
363390.3 |
7498810 |
Spring107A. Ronlow beds source |
Ronlow beds |
1 |
GAL_040 |
373047.6 |
7427372 |
Spring114. Ronlow beds source |
Ronlow beds |
1 |
GAL_041 |
463268.9 |
7384570 |
ALPHA TWS environs |
Alluvium |
NA |
GAL_042 |
410776.3 |
7389482 |
JERICHO TWS environs |
Clematis Group |
1 |
GAL_043 |
446766.4 |
7532055 |
Mellaluka springs |
Upper Permian coal measures |
2 |
GAL_044 |
421085.9 |
7559288 |
Doongma spring_Burdekin_51 |
Clematis Group |
1 |
GAL_045 |
438099 |
7484976 |
Hector spring_Burdekin_84 |
Upper Permian coal measures |
2 |
GAL_046 |
443606.8 |
7494960 |
Albro springs_Burdekin_85 |
Upper Permian coal measures |
2 |
GAL_047 |
423823.8 |
7557007 |
H202 Clematis Group monitoring bore |
Clematis Group |
1 |
GDE = groundwater-dependent ecosystem; TWS = town water supply; the topmost layer in the groundwater model is assigned ‘0’; NA indicates drawdown at model node could not be simulated. Potential hydrological change at this location will be discussed qualitatively in companion product 3-4 (impact and risk analysis) for the Galilee subregion.
Data: Bioregional Assessment Programme (Dataset 1); Bioregional Assessment Programme (Dataset 2)
The GW AEM calculates a time series of the change in groundwater level due to coal resource development. As initial conditions in each model layer are set equal to zero metres, this change in groundwater level corresponds to the drawdown. Figure 11 shows an example of these time series. For each model node, only the drawdown (dmax; the maximum difference in drawdown between the CRDP and baseline, due to additional coal resource development) and year of maximum change (tmax) are recorded and stored. Figure 11 illustrates how these values are calculated.
dmax = maximum difference in drawdown between the coal resource development pathway (CRDP) and baseline, due to additional coal resource development
CRDP = baseline + additional coal resource development
Data: Bioregional Assessment Programme (Dataset 1)
The graphs in Figure 11 show the results of parameter combination number 1980 of the 10,000 parameter combinations of the groundwater model that have been evaluated for the uncertainty analysis (Section 2.6.2.8). For this parameter combination, the drawdown is only realised within the simulation period in the upper Permian coal measures.
In the remaining sections of this product, the results of the modelling will always be presented as summary statistics of the resulting predictive distributions, such as the median dmax value or the probability that dmax exceeds a pre-specified threshold.

Product Finalisation date
- Methods
- Review of existing models
- Model development
- Boundary and initial conditions
- Implementation of the coal resource development pathway
- Parameterisation
- Observations and predictions
- Uncertainty analysis
- Limitations and conclusions
- Citation
- Acknowledgements
- Currency of scientific results
- Contributors to the Technical Programme
- About this technical product