This research aims to improve the understanding of the GAB groundwater flow in the Pilliga region through integration of existing information from models, hydrochemical data and environmental tracers.

The outcome of this project is an assessment of potential changes in GAB groundwater flux (flow volumes) as a result of CSG development using state of the art uncertainty analysis and modelling.

Reports and papers

Uncertainty analysis of CSG- induced GAB flux and water balance changes in the Narrabri Gas Project area – Final report PDF 5 MB

Uncertainty analysis of CSG-induced GAB flux and water balance changes in the Narrabri Gas Project area – Final report quantifies potential groundwater flux and water balance changes in the Great Artesian Basin (GAB) aquifer (Pilliga Sandstone) under CSG development scenarios in the Gunnedah Basin, NSW.

It provides an independent probabilistic estimation of potential regional scale coal seam gas (CSG)-induced impacts on the groundwater resource in this GAB aquifer arising from generic depressurisation of Gunnedah Basin coal seams.

Final Report, August 2018.

Probabilistic modelling and uncertainty analysis of flux and water balance changes in a regional aquifer system due to coal seam gas development

This paper explores the impact of coal seam gas on groundwater resources through modelling and uncertainty analysis.

 

Science of The Total Environment, April 2018.

Uncertainty analysis of CSG- induced GAB flux and water balance changes in the Narrabri Gas Project area PDF 2 MB

This report, Uncertainty analysis of CSG-induced GAB flux and water balance changes in the Narrabri Gas Project area, quantifies potential groundwater flux and water balance changes in the Great Artesian Basin (GAB) aquifer (Pilliga Sandstone) under CSG development scenarios in the Gunnedah Basin, NSW. It provides an independent probabilistic estimation of potential regional scale coal seam gas (CSG)-induced impacts on the groundwater resource in this GAB aquifer arising from generic depressurisation of Gunnedah Basin coal seams.

 

  • The interim report demonstrates that CSG development will result in some changes to the groundwater flow and water balance of the Pilliga Sandstone aquifer in this recharge area of the GAB.
  • Based on 500 simulations constrained with observations, preliminary results of the groundwater modelling showed an expected maximum water loss from this GAB aquifer due to CSG development of around 85 megalitres per year, equivalent to about 0.3% of the Long Term Annual Average Extraction Limit from this aquifer.
  • Water for CSG development is not taken from the GAB aquifer, but from the coal seams which are part of the Gunnedah Basin that underlie this GAB formation resulting in a reduction in pressure in the coal seams.
  • The expected value of induced change in flow from the near-surface aquifer, called the Namoi Alluvium, into the Pilliga Sandstone was estimated at 0.89 megalitres a year or nearly 0.001 % of the average annual extractions from the alluvium.  The groundwater of the Namoi Alluvium is a major agricultural resource for the region.
  • This modelling study has provided an independent estimate of the range in potential maximum impacts on water volumes of the Pilliga Sandstone GAB aquifer under a broad range of scenarios.

Ongoing studies should improve the understanding of recharge and aquifer connectivity and refine the model predictions of water impacts to water resources in the Namoi region.

Interim report, October 2017.

Extras

Potential water impacts of coal seam gas in the Pilliga Sandstone PDF 310 KB

This factsheet highlights outcomes of a regional-scale groundwater modelling project which quantifies potential changes in groundwater flows to, and water balance of, the Pilliga Sandstone arising from coal seam gas production in the Narrabri region of New South Wales.

Factsheet, August 2018.

Impacts of CSG depressurization on Great Artesian Basin flux PDF 4 MB

The outcomes of the project were presented at a knowledge transfer session held in August 2018.

Presentation, August 2018.

Project Progress

This project is approximately 80% complete.

Project proposal PDF 259 KB

A detailed description of the project, budget and research milestones.

Project order, July 2016.

Progress report PDF 583 KB

The project outline, any variations and research progress.

Progress report, August 2018.

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