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Summary of the Great Artesian Basin Research Priorities Workshop27-28 April 2016, Canberra

GEOSCIENCE AUSTRALIARECORD 2016/23

É.C.S. Lai1, B. Sundaram1, R. Evans2, T.R. Ransley1 and T.J. Evans1

1. Geoscience Australia2. Salient Solutions Australia Pty Ltd

Department of Industry, Innovation and ScienceMinister for Resources and Northern Australia: Senator the Hon Matthew CanavanAssistant Minister for Industry, Innovation and Science: The Hon Craig Laundy MPSecretary: Ms Glenys Beauchamp PSM

Geoscience AustraliaChief Executive Officer: Dr Chris PigramThis paper is published with the permission of the CEO, Geoscience Australia

© Commonwealth of Australia (Geoscience Australia) 2016

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ISSN 2201-702X (PDF)ISBN 978-1-925297-22-5 (PDF)eCat 101440

Bibliographic reference: Lai, É. C. S., Sundaram, B., Evans, R., Ransley, T. R., and Evans, T.J. 2016. Summary of the Great Artesian Basin Research Priorities Workshop: 27-28 April 2016, Canberra. Record 2016/23. Geoscience Australia, Canberra. http://dx.doi.org/10.11636/Record.2016.023

http://dx.doi.org/10.11636/Record.2016.023

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Executive Summary

The Great Artesian Basin (GAB) is the largest groundwater basin in Australia, underlying parts of Queensland, New South Wales, South Australia and the Northern Territory. The GAB contains a vast volume of underground water and it is a vital resource for pastoral, agricultural, and extractive industries as well as for town water supplies. Properly managing these groundwater resources, often with competing interests, requires sound understanding of the whole groundwater system.

The outcomes from past projects have identified numerous knowledge gaps, and have clearly shown that the GAB is a complex groundwater basin with a large component of vertical flow through geological structures and hydraulic connections in some areas to basins above, below and within the GAB. Understanding of the nature of groundwater occurrence and flow in the GAB is continually improving, and will need to continue to do so into the future. New information is required as new challenges arise; this knowledge evolution leads to a recognition that current key science issues exist that need to be explored. It is essential to share information about GAB water policy, management and research activities with relevant stakeholders and decision makers and work collaboratively to develop future science priorities.

The Great Artesian Basin Research Priorities Workshop, organised by Geoscience Australia (GA), was held in Canberra on 27 and 28 April 2016. Workshop attendees represented a spectrum of stakeholders including government, policy, management, scientific and technical representatives interested in GAB-related water management. This workshop was aimed at identifying and documenting key science issues and strategies to fill hydrogeological knowledge gaps that will assist federal and state/territory governments in addressing groundwater management issues within the GAB. The workshop was timely as the current GAB Strategic Management Plan (SMP) expired in 2015 and a new GAB SMP is being developed by the Australian and state/territory governments.

The workshop began with short presentations highlighting the current status of policy, management and science issues in the GAB, which provided initial ideas for the most pressing knowledge gaps in need of research. After the initial presentations, the groups of participants discussed and listed key knowledge gaps and management issues. When these ideas were collated, a number of concepts repeated across several discussion tables. This highlighted a number of key science issues for targeting future research.

Key science issues and recommendations for future research

Seven key science issues were identified from discussions in the workshop:

Water Balance and Scale

Recharge Estimation and Conceptualisation

Connectivity Above, Below and Within the GAB

Structural Geology, Tectonics and Sub-basins, and their Influences on the GAB

Springs and Other Groundwater-Dependent Ecosystems

Hydrochemistry and Groundwater Flow

Climate Change and Variability

The workshop sessions then focussed on listing objectives, deliverables, linkages to existing programmes, and formulating possible methods to address the key science issues.

Summary of the Great Artesian Basin Research Priorities Workshop: 27-28 April 2016, Canberra. iii

The seven key science issues were dealt with separately, but are inter-linked. As such, no single issue should be researched in isolation. Furthermore, each of these seven science issues has multiple components. The development of strategies to address the key science issues should include components aimed at aligning with policy timeframes.

Future directions

This workshop report records stakeholders’ views on emerging groundwater management issues, key knowledge gaps and future research priorities for the GAB. It is anticipated that this report will inform the development of the next GAB SMP. The development of the GAB SMP is of high priority, at the Commonwealth level, as it will guide management directions and investment in the GAB for the next 15 years.

A pressing need for science, policy and management to collaborate and communicate effectively was acknowledged by all participants. Policy requires information over short timeframes (the next 5, 10 and 15 years), so prioritising issues accordingly is essential. Also, past efforts dealing with the GAB in its entirety have found many shortcomings – the concept of “hotspots” (or areas of high priority for focused investigation) was advocated for immediate future research. These hotspots are prioritised study areas within the GAB, enabling rigorous analysis around a chosen feature to address issues of community concern, rather than treating all regions with equal importance.

Consensus was that future work should be collaboratively undertaken. Overall, the workshop identified significant knowledge gaps in our current understanding of the hydrogeology of the GAB – impacting management of groundwater resources within the basin.

iv Summary of the Great Artesian Basin Research Priorities Workshop: 27-28 April 2016, Canberra.

Contents

Executive Summary............................................................................................................................... iii

1 Introduction and overview.................................................................................................................... 1

2 Workshop discussions......................................................................................................................... 32.1 Welcome and introduction..............................................................................................................32.2 Group breakout and discussion session: identification of key knowledge gaps and management issues............................................................................................................................. 52.3 Group breakout and discussion sessions: priorities for future research.........................................7

2.3.1 Water Balance and Scale.........................................................................................................72.3.2 Recharge Estimation and Conceptualisation............................................................................92.3.3 Connectivity Above, Below and Within the GAB.....................................................................112.3.4 Structural Geology, Tectonics and Sub-basins, and their Influences on the GAB..................122.3.5 Springs and Other Groundwater-Dependent Ecosystems......................................................142.3.6 Hydrochemistry and Groundwater Flow..................................................................................162.3.7 Climate Change and Variability...............................................................................................172.3.8 Predictive Capability and Transience......................................................................................18

3 Summary and Future Directions........................................................................................................203.1 Summary...................................................................................................................................... 203.2 Future Directions.......................................................................................................................... 20

4 Acknowledgements............................................................................................................................ 234.1 Contributors to the Workshop.......................................................................................................234.2 Other Acknowledgements............................................................................................................24

Appendices........................................................................................................................................... 25

Appendix A Workshop invitation and program......................................................................................26

Appendix B GAB water management issues, knowledge gaps and priorities for future research preliminarily identified by workshop participants...................................................................................30

B.1 Responses to Q1 (issues)............................................................................................................30B.2 Responses to Q2 (gaps)..............................................................................................................33B.3 Responses to Q3 (priorities)........................................................................................................36B.4 Responses to Q4 (atlas)..............................................................................................................39

Summary of the Great Artesian Basin Research Priorities Workshop: 27-28 April 2016, Canberra. v

vi Summary of the Great Artesian Basin Research Priorities Workshop: 27-28 April 2016, Canberra.

1 Introduction and overview

The Great Artesian Basin (GAB) is the largest groundwater basin in Australia, underlying parts of Queensland (Qld), New South Wales (NSW), South Australia (SA) and the Northern Territory (NT). Groundwater resources in the GAB are used to support the pastoral, agricultural, and resource sectors as well as supplying water to inland communities – and demand for these resources is increasing. Effective and responsible management of these groundwater resources, often for competing interests, requires sound understanding of how the GAB groundwater systems operate. It is essential to communicate GAB water policy, management and research activities to relevant stakeholders and decision makers and use them to inform future research priorities.

Various government agencies and research organisations have been involved in studies to improve the understanding of GAB groundwater systems. Contemporary research demonstrates that the GAB is an extensive and complex groundwater basin, rather than the former concept of a simple, laterally-continuous aquifer system. The recent work undertaken by Geoscience Australia (GA) in the Great Artesian Basin Water Resource Assessment project and the former Carbon Capture and Storage Groundwater Project, as well as work by other agencies (such as the Allocating Water and Maintaining Springs in the Great Artesian Basin project and ongoing investigations associated with the Bioregional Assessments Programme), has led to revising some of the historical conceptual understandings and interpretations of the GAB structure. Some of these findings are described in GA’s 2015 publication, the “Hydrogeological Atlas of the Great Artesian Basin” (GAB Atlas).

Recent projects have highlighted areas of uncertainty and identified limitations in the existing knowledge of the GAB. Acknowledging these knowledge gaps encouraged GA to hold a workshop to identify research priorities and invite discussion from a variety of federal and state/territory perspectives. The Great Artesian Basin Research Priorities Workshop, organised by Geoscience Australia, was held in Canberra on the 27th and 28th of April 2016. Workshop attendees represented a wide spectrum of stakeholders with an interest in GAB-related water management, research and policy activities and included government, policy, management, scientific, and technical representatives. There were representatives from the Australian Government, and the governments of the four state/territory governments (“jurisdictions”) that include parts of the GAB (see list of attendees in Section 4.1).

The workshop began with a few short presentations highlighting the current status of policy, management and science issues in the GAB (Section 2.1). These provided initial ideas for the most pressing knowledge gaps in need of research. After the initial presentations, the groups of participants discussed and listed key knowledge gaps and management issues (Section 2.2). The ideas were collated, as a number of concepts repeated across several discussion tables. Seven prominent but interlinking key science issues were identified, and participants were divided amongst these based on their areas of expertise (Section 2.3). These groups first discussed listing objectives, deliverables and linkages to existing programmes relating to their key science issue; the final session focused on developing strategies to address the key science issues, primarily by formulating possible methods to progress the research. The workshop program is provided in Appendix A.

The workshop identified key hydrogeological knowledge gaps, as well as current and emerging groundwater management issues in the GAB. Some time was also spent formulating collaborative and deliverable projects that could fill the key knowledge gaps, and provide new scientific understandings to underpin the future management of the GAB.

The Great Artesian Basin Research Priorities Workshop, Canberra, April 2016 1

The main purposes of the workshop were to:

provide an opportunity to better understand the policy, management and science activities of the GAB, from both Commonwealth and jurisdictional perspectives

provide a forum to discuss priorities for future work to address gaps and shortcomings in the current knowledge related to sustainable management of groundwater resources within the GAB

explore opportunities for organisations to collaborate on future research

This report will form the basis of advice to the Australian Government on priorities for future GAB groundwater management and research.

2 The Great Artesian Basin Research Priorities Workshop, Canberra, April 2016

2 Workshop discussions

2.1 Welcome and introduction

Dr Stuart Minchin, Chief of the Environmental Geoscience Division of GA delivered the welcome address and briefly outlined the purpose of the workshop. Ray Evans, facilitator of the workshop, followed on, discussing the Great Artesian Basin (GAB) workshop context and provided a brief overview of the workshop program.

After this introduction, the workshop began with some short presentations from key stakeholders from both State and Commonwealth agencies. These talks outlined the current status of policy, management and science issues in the GAB from an agency perspective. This was aimed at providing some initial ideas of the most pressing knowledge gaps that future research should focus on, for consideration during the workshop. The list of presenters was brief and therefore the views were not presented as being comprehensive.

The following provides the key summary of some of the major points these presentations:

The Commonwealth Department of Agriculture and Water Resources (DAWR) is in the process of developing new policy initiatives for the GAB. While the Commonwealth does not have an operational role in GAB management, it does have a coordination and funding role. The new policy initiatives are being developed within the context of lessons learnt from the Great Artesian Basin Sustainability Initiative (GABSI) program, and the lead-up work for the development of the next GAB Strategic Management Plan.

The GABSI program has been a very substantial investment in environmental outcomes when viewed against similar national programs. The questions being asked, as GABSI moves into any new phase, concentrate on what has been achieved thus far from the investment. This provides direction for any new GAB investment, in that a clear return on future investment will be required.

The current GAB Strategic Management Plan (SMP) expired in 2015 and a new SMP is being developed. The workshop was considered to be timely assessment and review point for what new science could potentially provide input to the SMP. The new SMP is likely to focus on managing the resource, rather than funding programs. The Commonwealth is looking to bring GAB management in line with National Water Initiative principles. For instance, how far can management be moved to a Cap on Allocations across the Basin.

In addition, DAWR intend to explore the possibility of merging the current ministerial advisory arrangements in place for the Lake Eyre Basin and the GAB (namely the Great Artesian Basin Coordinating Committee and its subcommittees, as well as the Lake Eyre Basin Community Advisory Committee and the Lake Eyre Basin Scientific Advisory Panel). DAWR indicated a desire to consider managing the resources of the GAB integrated with the Lake Eyre Basin at the institutional level in some form. This merged management approach was raised in this presentation, but not discussed in further detail during the workshop.

From a Commonwealth perspective, it is recognised that more research is required. However, any funding would be contingent on a sound scientific justification.

The development of Coal Seam Gas within the Surat Basin (part of the GAB) has produced some challenges for water management. The Queensland Office of Groundwater Impact Assessment (OGIA) is currently developing a suite of products to inform the management of water take in the Surat. These works include a new geological model and the development of a revised groundwater


numerical model. OGIA has also undertaken work on estimating Stock and Domestic bore use, spring typology and the nature of the contact between the Surat and Bowen Basins.

Under current Queensland legislation it is difficult to apply the National Water Initiative (NWI) sustainable take principles, including caps on allocation and groundwater trading. This is a particular issue for the Walloon Coal Measures, as co-produced groundwater from CSG production is not managed under the Water Act 2000 (Qld) but comes under the Queensland Petroleum and Gas Act 2004 (Qld).

Recent work undertaken by the Gas Industry Social & Environmental Research Alliance (GISERA) has identified that the Hutton Sandstone in the Surat Basin acts as a dual porosity aquifer and is receiving far less recharge than previously estimated. This demonstrates that an improved understanding of recharge processes is warranted.

An emerging issue is the condition of artesian bores (including the bores capped under GABSI), with the condition of historic bores creating artificial conduits causing a problem by enhancing inter-aquifer flows.

A large proportion of bores in the Queensland section of the Eromanga Basin in the GAB are naturally subartesian. Although past trends have seen increasing proportions of artesian bores becoming subartesian, in recent decades it appears that groundwater pressures are stabilising and even rising in the Cadna-owie–Hooray Aquifer in some parts of the basin. This may in part be due to intercepted groundwater flow that would otherwise have discharged to the Winton-Mackunda Aquifer, and in part because of bore capping and piping especially under GABSI. Groundwater extraction (in the Eromanga Basin) is the lowest it has been in the last 100 years.

A general lack of information precludes the development of a reliable water balance in the Eromanga Basin. More accurate estimates of discharge generally (not just from spring complexes) are needed.

The South Australian portion of the GAB is managed through the Water Allocation Plan (WAP) for the Far North Prescribed Wells Area (2009). The plan provides a framework for groundwater allocations for various users and uses. However, over the past 4 to 5 years, new studies have produced a revised understanding of the GAB flow processes in the region. These processes include the role of recharge from ephemeral rivers, more permeable layers within the Rolling Downs Group, faults and their influence on groundwater flow, hydraulic connectivity between hydrogeological units (particularly in relation to which layer is connected to each spring complex), and better understandings of groundwater discharge via remote sensing applications.

Planning in SA is now considering whether to manage the resource as one entity or to subdivide it into management compartments (zones).

Major priorities for SA are to understand: connectivity, how to upscale (regionalise) information taken at specific sites, non-artesian (subartesian) water security, improving understanding about springs and their source aquifers, enhancing monitoring of springs with risk assessments addressing concerns such as acid sulphate soils, augmenting knowledge of the overall Basin architecture and its influence on hydraulic connections between the GAB and underlying or overlying units, and the hydraulic connectivity between the GAB and Lake Eyre Basin.

The South Australian Government indicated numerous other priorities, particularly in terms of risks and risk assessment. Examples included: mechanisms controlling increases in salinity, acid sulphate soils, and bore capping and rehabilitation were stated. Combining a range of tools including remote sensing, down-hole geophysics, groundwater age dating, and transient groundwater models could resolve uncertainty and inform risk assessments. These tools need to be reviewed and methods validated against each other.


Groundwater management planning in New South Wales imposes extraction limits across the NSW portion of the GAB, and subdivides the basin into a number of separate groundwater sources. Extraction limits are set considering the internal connections within the GAB and the connectivity to overlying and underlying groundwater systems.

Priorities for NSW (in terms of information gaps) are: the lack of up-to-date information on bore status; the existence of culturally significant sites and any water requirements in allocation plans; problems with bore construction information and how that is interpreted, as extraction bores are generally screened across multiple aquifers, so pressure readings from these bores are composite measurements; the nature of faults; quantifying the vertical connectivity in the GAB; and how much more capping and piping is required.

Geoscience Australia (GA) outlined the results of the GAB Water Resource Assessment (GABWRA) project, a brief overview of the Hydrogeological Atlas of the GAB and also gave an update on the Bioregional Assessment work in the Galilee Basin. These projects indicated several knowledge gaps remain, and resolving these will clarify how best to manage the GAB.

GA also provided information on emerging issues related to the structure of the GAB.

GA indicated its view on key emerging priorities. These were:

that existing water balance estimates are currently too uncertain to be useful and therefore need updating in the light of new conceptual understandings;

there is a need to understand the long-term impacts of GABSI, which requires ongoing, and possibly specifically-aimed, monitoring;

the role of volumetric management should be scrutinised, as the GAB is a system that is mainly managed for pressure;

further research into how sub-basins interact within the GAB is essential; and

the places where climate change issues may be relevant need to be identified. Some examples where this may be an issue include: changes to recharge, spring complexes, changing land use and land use practices due to changing climate.

2.2 Group breakout and discussion session: identification of key knowledge gaps and management issuesWorkshop participants were divided into seven groups for the first breakout session on Day 1. The groups were asked to identify the key issues relevant to GAB groundwater management, based on the participants’ own views and based on the ideas presented during the previous session. Prior to the workshop, a questionnaire was sent to participants with the aim of facilitating focussed discussion in this first breakout discussion session. In this questionnaire, attendees were asked to provide input on their perceptions of (see the third page of Appendix A):

1. What are the key groundwater management, current and emerging, issues in the GAB?

2. What important knowledge and information gaps do you perceive to exist in GAB groundwater management?

3. What are the priorities for future research to inform groundwater management in the GAB?

4. What further improvements should be included in a second edition of the Hydrogeological Atlas of the Great Artesian Basin? (http://www.ga.gov.au/metadata-gateway/metadata/record/gcat_79790). Note: the second edition is likely to be an online interactive map service.

The responses (see Appendix B) were compiled and grouped into preliminary themes to form the basis of discussion.


http://www.ga.gov.au/metadata-gateway/metadata/record/gcat_79790

A number of common issues were apparent from the discussion of several groups have been summarised below:

Asset management and bore integrity

Structural geology, sub-basins and influence on GAB groundwater flow, and understanding the size of groundwater flow systems

Water Balance, with differences at various scales, and possibly considering pressure management rather than volumetric overall management

Appropriate scales of analysis

Choosing study areas within the GAB, such as prioritising analysis around chosen features addressing issues of community concern such as springs, or zones of development (e.g. around existing and potential unconventional gas operations) – this lead to the concept of “hotspot” studies that focus on a high priority area for investigation

Recharge estimation – understanding rates and processes

Connectivity between the GAB and other basins or aquifers, both overlying and underlying

Groundwater connection with surface water systems, such as the Murray-Darling Basin and Lake Eyre Basin

Inter-aquifer connectivity between components within the GAB

Springs and Other Groundwater Dependent Ecosystems (GDEs)

The effects of climate change and climate variability on the GAB, including changes in water use or demand

Dealing with timescales and temporal lags, and considering whether to use steady state or transient approaches

Creating predictive capability, and the need to have sufficient benchmarking and monitoring to achieve this

Improving baseline data, including hydrochemistry, for understanding groundwater flows and water quality

Upscaling from local studies to a whole-of-system understanding

Valuation of the water resource, and considering resources (water and otherwise), bearing in mind that bores present opportunities for data-acquisition locations

The effects of development (particularly emerging and future uses, such as unconventional gas) and the differences between using historic and current data baselines to compare future values against

Stratigraphy and hydraulic properties

Communicating the science, with differences for scientists (e.g. peer-reviewed work with integrity), multidisciplinary teams (linking conceptual models together), laypeople (making relevance and not overcomplicating issues), and policy makers (needing to be clear with terminology)

Relating policy and science together

Furthermore, a number of Policy Issues were raised during discussion, including:

Is there equity among water users, and if not how could it be achieved?

When does Stock and Domestic take become a commercial enterprise?

What are the knowledge gaps that prevent or hamper management of third party impacts?

What is sustainability, and is the concept relevant for the GAB?

What aspects of the National Water Initiative framework could be applied to the GAB?


What effects do state boundaries and other local management boundaries have, when these may not be physical barriers compartmentalising the GAB?

2.3 Group breakout and discussion sessions: priorities for future researchRecurring issues were grouped together following the first break-out session. As a result of the discussion, seven Key Science Issues were identified (through general consensus rather than an exhaustive assessment approach) as a framework for the remaining break-out sessions to discuss in greater detail. These seven key science issues were:







Predictive Capability and Transience

During discussion, it was decided that the issue of “Predictive Capability and Transience” was not easily dealt with during the workshop. The issue of “Hydrochemistry and Groundwater Flow” was considered during later sessions. The former issue is still relevant but requires further thought as to what it means and how one would approach it.

Participants were divided into seven groups aiming to match expertise to these seven key science issues. These groups were different to the previous groups and they focussed on discussion of three components:

Developing one or more objective(s)

Identifying deliverables

Detailing linkages to existing programmes

The same groups then continued their discussions with the aim of achieving a strategy that would address the key science issues, primarily by developing possible research method(s) that could be used to undertake the required task.

It was identified that issues had different time horizons – distinguishing 5-year, 10-year and 15-year issues would assist in meeting policy objectives. Each key science issue could contain several topics over one or more of these horizons. For each of the key science issues discussed at the workshop, a high-level summary is provided below.

2.3.1 Water Balance and Scale

Robust estimates of water balance components are important inputs for achieving sustainable groundwater use. A typical water balance involves identifying and quantifying inputs (such as rainfall, river leakage, irrigation accessions and recharge) and outputs (such as extraction, spring discharge, evapotranspiration, river baseflow and diffuse discharge), transfers (inter-aquifer) as well as the changes in storage volume. Some GAB jurisdictions manage to water volume, whereas others manage to pressure, in part using impact offset or make-good arrangements.


As an example, environmental asset management (springs) has best been achieved by understanding local scale water balances within the context of ameliorating the impacts of groundwater extraction. Work should be undertaken to better understand when and at what scale water balances are important and appropriate.

2.3.1.1 Objectives

To achieve improved water balance calculations, three objectives were identified:

Identify the scale(s) at which water balances are most appropriately derived and reported, to inform water and asset management in the GAB. This would include understanding how different spatial domains relate to each other (e.g. hotspot, catchment, basin compartment). This also includes understanding appropriate timeframes for reporting a water balance, considering the broad range of times scales in the dynamics of GAB processes (from daily to millennial). The concept of ‘hotspots’, or areas of high priority for investigation, gathered significant attention during the workshop.

Define appropriate water accounting terminology and frameworks for the GAB, which will enable better definition of indicators appropriate for GAB management issues.

Identify and prioritise key data gaps in determining quantitative water balances, which can be used in water allocation planning and impact assessment. Furthermore, in producing a water balance, it is vital that appropriate tools and methods are identified for each component of the water balance.

2.3.1.2 Deliverables

This would entail generating the following:

An initial report advising the most appropriate spatial and temporal scale(s) for determining water balances as an input to GAB management.

Prioritisation of water balance components with the greatest need for improved quantification

Development of tools for quantifying water balance components, especially the high-priority components.

A case-study approach implementing the suggested framework and tools in exemplar hotspot domains in the GAB.

2.3.1.3 Linkages

Links to existing water balance approaches used by each jurisdiction could be made, as well as with broader assessments made in GABWRA and other initiatives. The Bureau of Meteorology is custodian to national hydrological data, and is also constructing water balances for several regions in Australia (including both surface-water and groundwater), notably in the Murray-Darling Basin.

2.3.1.4 Methods

Many previous investigations have focused on the GAB either as a whole or as large sub-basins, and these have identified significant information gaps. It is proposed that a hotspot case study approach would likely be the initial scale of analysis. However, initial scoping would need to confirm this approach.

Methods for two parts were developed: (i) project development and overview, describing the general process; and (ii) more detail in how a more detailed hotspot water balance case study would be handled.


The project development and overview would consist of four stages:

1. Defining the appropriate water accounting framework for the GAB, considering the most beneficial spatial and temporal scales of analysis, and preferred broad areas for case studies;

2. Defining the appropriate indicators to be reported for management issues, including the level of scrutiny in determining their uncertainties. This is assisted with acknowledging the most critical components of water balances;

3. Nominating the hotspots and suggested case studies, including defining the spatial boundaries and the locally critical components of the water balance for each hotspot;

4. Conducting the water balance in these case studies, while developing tools for components, and testing the methods for accounting, consistency and for upscaling.

A hotspot water balance case study would consist of five stages:

1. Developing a conceptual model and hydrogeological framework for the groundwater system;

2. Applying the appropriate tools for estimating the significant water balance components, which would allow for sensitivity analysis, confidence intervals, and be dependent on data availability;

3. Identifying information gaps, and recommending future data acquisition approaches and priorities;

4. Quantifying and reporting the water balance for the hotspot;

5. Assessing the approach for repeatability, consistency and scalability.

Water Balance and Scale would be an overarching program, taking other projects as inputs and having a coordination role for the work across different key science issues. In particular springs (Section 2.3.5), hydrochemistry (Section 2.3.6) and recharge (Section 2.3.2) science issues are considered to have a strong connection to the Water Balance and Scale investigations; close connections to connectivity (Section 2.3.3) and sub-basins (Section 2.3.4) were also acknowledged.

2.3.2 Recharge Estimation and Conceptualisation

Until recently, our understanding of groundwater recharge to the GAB has been based on conceptualisations developed decades ago. However, new data (particularly in the Surat Basin and the south-western recharge area of the Eromanga Basin) has led to a revised understanding of recharge processes. As a result, the relatively simple conceptualisation of recharge processes is probably not valid in some areas of the basin. Instead, conceptual models of recharge need to be more localised in scale and deal with the specifics of each setting. For example, local conditions may include: the impact of extraction on hydraulic heads/pressures in the recharge zone and how this affects recharge, the difference between recent natural recharge and anthropogenic activities that may be occurring, understanding the difference between diffuse and localised recharge mechanisms (for instance, ephemeral river flow recharge in the west).

A useful approach would be to build on the learnings from recent recharge studies and understandings – such as work in the Surat Basin (GISERA) and South Australia (Allocating Water and Maintaining Springs in the Great Artesian Basin) along with any other studies in parts of Queensland, New South Wales and South Australia – and test these methods in other places.

2.3.2.1 Objectives

The objective of further investigation into this issue is to critically re-assess current models of recharge within the context of new knowledge of recharge processes, specifically at the local scale. This may include, not only better approaches for quantifying the recharge, but also understanding the


mechanisms including the effects of anthropogenic changes as well as upscaling. The first step would be a scoping study to determine which areas may provide the greatest return (in terms of useful knowledge) for groundwater management.


A summary report identifying the areas in greatest need of reassessing recharge is essential. This report would review the findings from recent work and identify which aquifers and areas are to be prioritised for new recharge studies. This would enable targeted local studies to occur.

2.3.2.3 Linkages

Research and data from the following projects may be pertinent for improving regional understanding and quantification of recharge processes:

University of Queensland’s Centre for Coal Seam Gas, with their work in the Surat Basin

the Gas Industry Social & Environmental Research Alliance (GISERA) research, especially in the Namoi area of New South Wales and the Queensland component of the Surat Basin

Studies into connectivity between the Murray-Darling Basin and the Great Artesian Basin, which are known to have occurred in New South Wales

Bioregional Assessments work, especially in the Galilee, Perdirka and Arckaringa subregions

the Border Rivers Model

South Australian springs studies and work by Andy Love at Flinders University

2.3.2.4 Methods

The discussions highlighted that any future study should not begin with a regional GAB-wide recharge assessment. Instead, the first steps of future recharge studies should be:

1. Identification of areas and aquifers that are important for GAB recharge. This can, for example, be achieved through assessment of basic hydraulic or hydrochemical data.

2. Identification of areas where an improved understanding of groundwater recharge is of particular importance due to specific management issues.

One potential priority area identified during the discussions was the eastern part of the GAB, in NSW. During discussions, it was highlighted by NSW’s Department of Primary Industries – Water (DPI Water) that there is a requirement in NSW to re-assess recharge to the sedimentary bedrock in NSW by 2018. Currently, the recharge assessment in NSW is based on a fixed percentage of rain, and recharge mechanisms such as recharge from surface water drainage systems are not taken into account.

The discussion on recharge assessment during the GAB workshop also suggested that prior to selecting any particular technique for recharge estimation, there needs to be an improved hydrogeological conceptualisation to better comprehend recharge processes in order to obtain meaningful estimates. Therefore, no specific methods were discussed, although there was agreement that a multi-disciplinary approach which uses existing hydraulic data (hydrograph interpretation from existing bores), hydrochemical data and newly collected environmental tracer data (isotopes) is necessary for an adequate assessment.


2.3.3 Connectivity Above, Below and Within the GAB

The GAB is a complex arrangement of hydrostratigraphic layers lying adjacent to, above, and beneath other sedimentary basins. Much work to date has focused on the major artesian Jurassic-Cretaceous aquifers, with the subartesian Cretaceous Aquifers less well studied and understood. The degree of inter-connectivity between deeper artesian and shallower subartesian aquifers is also poorly understood.

Connections between the GAB and underlying basins are equally important and are relevant for understanding the impacts of resource extraction from deeper basins. In addition, the upward connectivity of the GAB with overlying Cenozoic basins and sediments requires more investigation to be able to quantify groundwater fluxes (for instance connections between the GAB and the Lake Eyre Basin and the Cenozoic aquifers of the inland rivers of NSW). Such information about the degree of connectivity could be used to better inform a basin-wide definition of management zones (groundwater flow compartmentalisation), local predictions of impact zones of future development and to understand of the hydrogeological settings of Springs/GDEs. Through better understanding the hydraulic relationship between aquifers (within and beneath the GAB) and overlying cover, more accurate system conceptualisations can be conceived, with a future goal of quantifying hydraulic linkages.

2.3.3.1 Objectives

This key science issue aims to improve conceptual knowledge of connectivity of aquifers through their geometry and properties, and ultimately to quantify the groundwater flux and input into water balances.


Five deliverables were identified by the group:

Development of three dimensional model(s) of the groundwater fluxes between different elements of the GAB and its wider setting that could then be aggregated to give a whole-of-basin view.

Fluxes that could be used in the quantification of local scale water balances

Maps of areas of potential high connectivity that would assist in determining areas of focus for future studies

Improved data – lithology, hydrostratigraphy, aquifer parameters for study areas

Improved understanding of aquifer and basin connections

2.3.3.3 Linkages

Several existing studies have investigated different aspects of connectivity, including:

Queensland: several investigations into hydraulic connection between Surat & Bowen basins, Surat Basin & Condamine Alluvium, and Eromanga & Galilee basins (e.g. Galilee subregion work in the Bioregional Assessments Programme)

SA (Arckaringa) and SA-NT (Pedirka) studies on interconnectivity with the GAB and the Cooper, Arckaringa and Pedirka bioregional assessments

NSW: an investigation between Gunnedah Basin & overlying aquifers

NSW-NT: between the alluvial systems and the GAB aquifers

A basin-wide conceptual approach into several aspects of connectivity was included in the Hydrogeological Atlas of the Great Artesian Basin (Geoscience Australia)


2.3.3.4 Methods

The “Connectivity” key science issue consists of three component projects that would need to be undertaken separately by using varying research approaches:

Project A: Underlying Basin Connectivity to GAB

Project B: Connectivity of GAB aquifers with overlying Cenozoic Basins

Project C: Inter-aquifer connectivity

Each project was considered to have three phases to gradually refine interpretation and estimates of groundwater fluxes. The first phase would assimilate existing data or published sources to produce conceptual models, primarily of known geometries. The second phase would further refine concepts and produce a more regional analysis with targeted acquisition of additional data such as geophysics, hydrochemistry, and/or hydraulic heads. The third phase, if required, would address hotspot issues arising from resource development. This would be in concert with state authorities and industry; however, synthesising models across state borders may be best facilitated by federal coordination.

2.3.4 Structural Geology, Tectonics and Sub-basins, and their Influences on the GAB

The GAB groundwater systems occur in a complex series of sedimentary basins (primarily the Surat, Eromanga and Carpentaria basins) that have been subject to tectonic activity since their formation. In particular, morphotectonics and recent tectonic activity has the potential to influence local hydrogeological properties and hence groundwater flow. This hypothesis has been supported by local scale investigations and numerical simulation of different structural scenarios.

Broader basin structure, and topography, can influence or direct groundwater flow. This is not thought to involve discrete aquifer segments (compartments) with no connection with adjacent blocks, but rather a series of segments that may not be well-connected across the basin. This challenges the simple conceptual model of one set of well-connected aquifers at the basin scale. The dimensions of a groundwater system (e.g. local, intermediate or regional) that can develop are dependent on a number of factors including: aquifer/aquitard configuration, hydraulic properties, geological architecture, structure and topography.

The degree of segmentation and connectivity between different parts of an aquifer will influence how an aquifer should be managed. For instance, on a local intermediate scale, volumetric sustainability and pressure maintenance are important considerations in managing key assets such as springs/GDEs or to manage groundwater extraction impacts. However, volumetric water budget analysis is difficult to apply at the basin scale: given the basin size, complexity and associated uncertainty in hydrogeological properties.

2.3.4.1 Objectives

The key objectives discussed are:

Identify how geological structuring and sub-basins influence groundwater flow and pressure propagation both laterally and vertically.

Identify how this information can be used to better comprehend a meaningful method to discretise the GAB, so that more local areas of “common” groundwater flow that could be considered when addressing local volumetric sustainability issues.

Determine the most appropriate scale(s) of analysis to assist research in other key science issues.



Successful completion would provide the means to better identify the locations, types, characterisation, and representation of structural and architectural features, such as folds, faults (linear and polygonal), stratigraphic changes, geological sub-basins, and changes in permeability. These features also influence groundwater flows and pressure propagation, so research understanding these influences needs to be documented. Furthermore, methods to represent these features for numerical simulations need to be developed. Beyond reporting, outputs to be delivered include the provision of maps, cross-sections and conceptual models to better communicate the complexity of these structural features and their potential to influence groundwater flow.

2.3.4.3 Linkages

Strong links were identified with a few specific projects:

The Hutton/Precipice project within Gas Industry Social & Environmental Research Alliance (GISERA), conducted by CSIRO

The Faults, Aquitards & Models (FAM) project between the Office of Water Science (OWS) and CSIRO.

The Arckaringa and Pedirka Groundwater Assessment and associated architectural mapping of the GAB, Arckaringa Basin and Pedirka Basin, conducted by the South Australian Department of Environment, Water and Natural Resources (DEWNR) across parts of SA and NT

The current GAB Atlas, and likely development of a GAB Atlas version 2, produced by Geoscience Australia

Galilee, Cooper, Arckaringa and Pedirka subregions in the Bioregional Assessments Programme

Furthermore, a range of broad structural mapping programs and capabilities, such as with Gravity Recovery and Climate Experiment (GRACE) satellite data, would connect with this research.

2.3.4.4 Methods

Major faults/folds and stratigraphic pinch-outs can have a strong influence on groundwater flow and connectivity within an aquifer. Given the size of the GAB, it is not feasible to characterise every structure, so a broad overview and a pragmatic methods are required to determine how basin architecture and structures may influence groundwater flow. Large-scale structural geology features can be used to compartmentalise basin models, and can have a strong influence on how drawdowns propagate laterally. These features could potentially also be used to delineate groundwater management boundaries.

To achieve the aims set out above, a four-stage investigation was proposed:

1. Utilising results from recent studies such as those outlined in Section 2.3.4.3, review the basin conceptualisation, architecture and structural setting. The review phase could include some desktop studies, such as production of potentiometric surfaces for confined aquifers, that take into account the potential influence of basin structure and morphology.

2. Identify a pilot sub-area to test new conceptualisations that result from the basin wide review, and as required obtain new data. Testing of scenarios (including flow barrier properties), possibly through numerical modelling, would be done at this stage. The sub-area must be chosen with consideration to groundwater demand, potential impacts and subsequent management requirements.

3. A second test area will be used for validation of this pilot case study.


4. Following validation, the next stage is to upscale, with the aim of eventually covering the entire GAB. This does not have to be immediate – an intermediate scale could also be used.

2.3.5 Springs and Other Groundwater-Dependent Ecosystems

The GAB supports a range of groundwater dependent ecosystems (GDEs) including surface expression (springs), terrestrial and subterranean ecosystems. Further investment in understanding the role and function of springs in the GAB is still required, even though a great deal of work has already been undertaken in Queensland and South Australia. Recent work aimed at mapping spring complexes that had not been previously studied, showed that new typologies and species still are being found.

There is also a range of work currently being undertaken, predominantly in South Australia and Queensland. Examples include ongoing source aquifer assessments by the South Australian Department of Environment, Water and Natural Resources (DEWNR) for the Dalhousie supergroup; and by Queensland’s Department of Science, Information Technology and Innovation (DSITI) for the Barcaldine supergroup; along with the recent Allocating Water and Maintaining Springs in the Great Artesian Basin project. Any new work will need to coordinate with current studies. Alternatively, there are greenfield spring mapping opportunities that could be undertaken in New South Wales in conjunction with the New South Wales’ Government priorities.

Work should be aimed at understanding the source aquifer for each spring complex, spring resilience studies of changes in flow and/or chemical make-up, diffuse discharge studies aimed at terrestrial GDEs and routine mapping of spring/terrestrial GDE locations.

Some GAB jurisdictions are managing impacts on springs via specifying adjacent pressure-reduction triggers/limits. This is similar in concept to Resource Condition Limits specified under the Murray Darling Basin Plan. This approach assumes that the pressure specified adjacent to the spring is linked to its longevity – further work is required to understand the relationship between head/pressure at the spring and spring resilience.

2.3.5.1 Objectives

The key objectives identified are:

Develop a standard assessment method for all springs in the GAB to update prioritisation levels. This prioritisation would be based on relevant state agency lists such as from South Australia’s Water Allocation Planning process; but the prioritisation may need to be updated.

Define the connection of springs to source aquifers for the high priority springs of the GAB.

Understand the resilience of springs to external change.

Map all high-priority spring complexes in the GAB (including NSW). More details may be required for some areas, such as in NSW.

Develop decision tools for management of springs.


The main deliverable would be a standard assessment method for all GAB springs that could be used by all agencies involved in spring management in the GAB, rather than disjointed efforts. This would be supported by reports and articles, and peer-reviewed journal papers, to provide details for the various objectives.


2.3.5.3 Linkages

There have been several recent studies to identify spring source aquifers and risks to springs. It is through this research that the needs of this key science issue were highlighted. Several spring supergroups, such as the Barcaldine and Springsure supergroups (Queensland) and Dalhousie supergroup (South Australia), are actively being studied by their respective state agencies. There is also an existing relationship between some springs’ researchers from state governments in these two jurisdictions, aiming to coordinate their classifications and approaches. There are opportunities to link with OGIA’s proposed spring pilot monitoring study.

2.3.5.4 Methods

Methods are described below by type of GDE.

Surface expression GDEs (springs)

A risk management approach is proposed, based on the existing DEWNR work to account for the effect of altered flows and water quality on ecosystems, so research needs to focus on likelihood and consequence aspects, as well as developing frameworks suitable for management such as spring typology. Mapping and source aquifer assessments focus on likelihood; consequence aspects are targeted by comprehending the resilience of spring ecology; while building conceptual models and monitoring tools steers management frameworks.

Priority sites for source aquifer assessments include springs in the Doongmabulla (Queensland), Callabonna and Dalhousie (South Australia) supergroups. These are priority areas where there is: (a) uncertainty with source aquifer and emerging water demand; or (b) where there is uncertainty with source aquifer and known high ecological values. A classical hydrogeological assessment and ecological characterisation (inventory) is required to determine source aquifer and to provide a local scale ecohydrological understanding.

Improving the understanding of the resilience of spring ecology to change can be achieved through building on existing investigations. The Queensland spring monitoring pilot should be expanded to include ecological aspects, not just flow rates, which will provide the necessary dataset to understand species habitat preferences and likely resilience. In addition, sites in other jurisdictions (e.g. NSW and SA) should be incorporated to apply this Queensland-derived approach at different spring types. One site in South Australia (Freeling Springs) would be potentially suitable for incorporation: this site is close to an existing uncontrolled bore which could be controlled to assess the change in the ecosystem in response to pressure recovery.

Within each of the jurisdictions, spring conceptual models have been developed. It is recommended that a component project be undertaken to consolidate the existing models into a single set of models for the GAB. This, along with appropriate monitoring, will provide a tool for the consistent assessment of risk and management of springs across the GAB. In addition to the typology a national repository for information on GDEs should be established and maintained.

Terrestrial GDEs

Desktop assessments to identify likely terrestrial GDEs have been completed in South Australia and Queensland. Field validation of these datasets is required. A component project is required to develop remote-sensing tools to validate the existing dataset and to inform further desktop GDE assessments in other areas. A remote sensing toolbox which describes the options, their advantages/disadvantages and preferred scales, as well as case studies of their use, should be developed. Outputs need to be validated, so they can inform the identification of surface-water/groundwater zones of interaction.


2.3.6 Hydrochemistry and Groundwater Flow

There are two aspects of basin hydrochemistry that are worthy of further work. Firstly, there is little information on the baseline water quality of many aquifers within the Basin. Appropriate data needs to be collected (if this does not already exist) and compiled for this purpose. This would seem to be an operational/water management activity suited to jurisdictional water agencies.

Secondly, groundwater chemistry (both inorganic and isotopic) can provide independent information about groundwater flow. Tracer and paleo-environmental studies can be used to build stronger conceptual models of groundwater flow for use in simple water balance assessments, and to constrain complex groundwater numerical models. Groundwater hydrochemistry including state-of-the-art tracers can significantly improve understanding of processes controlling groundwater movement, recharge processes, the age of groundwater, inter-aquifer connectivity and the likely chemical compositions of aquifer materials.

2.3.6.1 Objectives

The aim is to provide an independent assessment of groundwater flow for use in the development of conceptual models of the basin’s hydrogeology. This will enable understanding palaeo-environmental/hydrological conditions as a tool to interpret other studies (most notably water balances, recharge and aquifer connectivity). In addition, targeted sampling should be conducted to provide baseline hydrochemical characterisation of aquifers prior to large-scale development (e.g. shale gas).


A range of new data sets (including state-of-the-art tracer analyses) are to be collected and analysed – these would be interpreted and used to develop a revised hydrodynamic model of the GAB. The hydrodynamic model would be used update the conceptual model of the basin. Data produced could also be used to constrain, improve and validate numerical models.

2.3.6.3 Linkages

Some water quality mapping is found in the GAB Atlas, and also a Queensland hydrochemical database is known to exist. Work in GABWRA incorporated hydrochemistry to improve understanding of flow systems at the basin scale.

2.3.6.4 Methods

A range of hydrochemical parameters can be considered. Mining of existing data, along with new sampling along key transects will provide the majority of the inputs to constrain the work. In particular, isotopes such as 81Kr, 39Ar, 36Cl, and 14C are identified, along with noble gases and field gas extraction. Development of an improved understanding of the hydrostratigraphy and a better conceptual model will enable an enhanced development of analytical and numerical models – this should be coordinated with conceptual models across the key science issues.

The hydrochemistry data will be analysed using a variety of methods to characterise the groundwater chemistry in each study area. The proposed methods included spatial mapping of groundwater chemistry variations, determining major hydrochemical water types (e.g. through Piper diagrams) and statistical data analyses (such as Principal Component Analysis).


2.3.7 Climate Change and Variability

Work would seek to understand what impacts climate change will have on the water budget of the GAB. This could include understanding the impact of climate variability on: recharge to the groundwater system; farm water demand; and spring condition (e.g. wetted area and evaporative loss). This would not be a study of climate change effect on water resources per se, but rather a study of the impact of changes in rainfall and temperature on land use and hence water demands. However at certain scales, the study of groundwater recharge sensitivity to climate variability and change are also important. In addition the effect of rising temperature is likely to be important to ecological conditions of the GAB springs. Hence the scale of the study will be important.

2.3.7.1 Objectives

The objective is to define the likely impacts of climate change and climate variability on the water budget of the GAB. These impacts will fall into three categories:

1. Impacts on changes in human demands such as extraction rates and land use patterns

Change in water demand is likely to be one of the greater manifestations of climate change on GAB water resources. Therefore, investigations will focus on assessing alterations in the composition of industries and their footprint in the GAB, as well as their water demands due to changes in temperature and rainfall, and global drivers.

2. Impacts on changes to recharge

Understanding of climate change effects on groundwater recharge will be critical in some sub-regions (e.g. eastern NSW and eastern Queensland). This objective will be linked with “Recharge estimation” key science issue discussed in Section 2.3.2.

3. Impacts on changes to springs (discharge zones)

It is likely that changes in temperature can affect ecological conditions in springs. This objective will be linked with the “Springs and Other GDEs” key science issue discussed in Section 2.3.5.

Therefore, the main research question is: if climate change occurs, as per a given input scenario of how climate change occurs, how will it affect receptors?


The main deliverable would be an understanding of the drivers for changes to the water resource and patterns of consumption. All work would be in the context of the socio-economic aspects of the regional sustainable development, as well as environmental implications. To achieve this understanding would require:

a clear definition of current water/land use and other receptors in the GAB

delineation of the areas with various types of climate-change risks (e.g. projected rainfall, temperature, land cover and associated receptors, water demands, recharge, springs etc.)

liaison with state planning agencies to define the future regional development in context of the global drivers (e.g. increase in renewable energy use)

Each aspect will be charactered in terms of the thresholds of change and definition of resilience to climate variability change for current industries, recharge or ecosystems.

The deliverable could take the form of interactive maps, supporting the stakeholders’ participation and advice to policy makers, as well as specific initiatives related to adaptation to change. In addition a series of reports and conceptualisations, as well as peer-reviewed papers and articles, are also to be delivered.


2.3.7.3 Linkages

No linkages were identified at this stage, but any work would need to understand what other activities are occurring and work within that context. Obviously, the chosen climate change scenarios would need to be inputs. Climate change predictions from the CSIRO are one option for these input scenarios.

2.3.7.4 Methods

The method would consider links to research in the other key science issues as inputs – particularly in recharge (Section 2.3.2), springs (Section 2.3.5), and water balance (Section 2.3.1) components; additionally scale definition for extraction and use would be assisted from structural geology (Section 2.3.4) work. To create a realistic outcome, a baseline assessment must be the first step, identifying the current condition.

The climate change scenarios are expected to fall within three categories (high, medium and low impact scenarios). Rather than high/medium/low overall impact versions, the impacts of several aspects (such as the intensity of climate change, land use alteration and regional or global policies), could be considered separately with their own high/medium/low forms, thus producing numerous combinations. These will require multidisciplinary teams, defining the scenarios. These scenarios become inputs which allow calculating predicted changes to groundwater flow variables, such as various natural and anthropogenic components of recharge and discharge.

Modern technologies will be adapted in developing:

interactive mapping that assists stakeholder communication

platforms for data collection

decision support systems to support sustainable regional development

Such an approach will facilitate stakeholders’ engagement (e.g. science, policy makers, industry, Natural Resources Management organisations) in identification of local scale impacts to people on the ground and adaptation to climate change. Successful completion of the work would allow development of end use adaptation strategies.

2.3.8 Predictive Capability and Transience

This issue was identified as important during general discussion. In particular, groundwater models were identified as often-desired management tools, but transience is generally necessary for providing trustworthy results (especially in large-scale systems). That being said, the nature of transience produces complexity that could easily produce less valid answers than steady state modelling if poor assumptions are used. Furthermore, any model will require baseline observational data to calibrate – this baseline depends on what question is being addressed.

However, it proved difficult to identify the researchable component of the issue when considered within the context of developing a work program. The main difficulty was related to the scope of any proposed work. At one level, the original issue was driven by the use of numerical groundwater models in groundwater management. There is a simple model for the Basin of the main Jurassic aquifer, and discussion occurred whether it was warranted and indeed possible to extend this model to other basin-wide aquifers. At the same time, it was also seen as relevant that OGIA had developed a groundwater model for the Surat Basin Cumulative Impacts Area. Whilst it was also acknowledged that this Cumulative Impacts Model was extremely complex, and upscaling such a model to a more regional context would be difficult, discussion centred on how realistic quantitative predictions of


impact due to extraction could be generated. This was driven by the premise that policy should be formulated in an evidence-based framework.

Given the difficulties in (and probable undesirability of) developing a complex whole-of-basin model, discussion turned to the issue of how one could generate a predictive capability. The issue was also raised that the current, whole-of-basin modelling was based on steady-state analysis, whereas any future analysis had to be cognisant of transient conditions.

A tentative objective statement was formulated: “Generate a set of tools (physical, chemical, biological, geophysical) to support and underpin best management practices in the GAB”. However, providing further information about a possible work program proved difficult. In the light of this, no further analysis occurred at the workshop, and the issue was removed from the list of those considered. This should not preclude others from exploring work programs associated with this issue, as it was still seen as important and a high priority.


3 Summary and Future Directions

3.1 Summary

A number of Key Science Issues were raised and considered in detail over the course of the GAB Research Priorities Workshop, including:






Hydrochemistry and Groundwater Flow


The workshop participants discussed these issues in detail. An initial session focused on listing objectives, deliverables and linkages to existing programmes; while the final session aimed at crafting a strategy by formulating possible research methods aimed at addressing the key science issues.

Commonly, groundwater system managers use volumetric measures for sustainably managing the water resource; however, in the GAB, pressure management is seen by some as of greater importance. As such, there is debate as to what GAB-wide sustainability actually means. There may be local-scale issues related to sustainable use of groundwater, so identifying appropriate scale(s) is a vital consideration for effective management of the GAB. Therefore, there is a need to discretise the GAB into appropriate units or management zones at the inter-jurisdictional level. Although present management zonation is used for some aspects, these may not be perfectly suitable physical boundaries.

Defining sub-basins is one approach – this would typically divide the GAB into management regions. However, to protect assets of interest and prioritise work, the discretisation can go further. In a “hotspot” approach, local areas are focused on, and areas distant from hotspots are not scrutinised as heavily. Hotspots are chosen by prioritising issues – this could be done by each jurisdiction nominating their most important sites to be managed, which may include some level of community priority or interest from the broader stakeholder group. Locations subject to development may receive substantial interest in this regard. As such, there may be a difference between existing issues and areas and those identified during future assessment.

3.2 Future Directions‘What are the key science issues for the GAB?’ was the theme for the workshop. This was seen as important within the context of developing a new GAB Strategic Management Plan (SMP). It was acknowledged that key science issues needed to be addressed within specific timeframes related to feed into management and policy decisions. For example, ‘what is the highest priority issue for the next 5 years, the next 10 years and the next 15 years?’.


A key question was whether the science issues that were developed at the workshop were in fact the same as the key issues for consideration in framing the new SMP. If they were, could these be placed into the timeframes posed?

An attempt to generate discussion at the workshop around this task could not provide clarity to the issue. The main problem was that each of the seven key science issues meant different things to each participant, and some objective description of what each of the seven key science issues meant was required.

Each key science issue required some context about what its objective was, where it applied spatially, and how it related to the other key science issues.

For instance, take the issue of water balances. Understanding the spatial extent the water balance is applied over, and the purpose of conducting the water balance, are both necessary before determining the appropriate policy timeframe the research aligns with. Each jurisdiction would have a different view on this question (and may have more than one view institutionally within a jurisdiction).

A task flowing from this workshop would be to:

1. Provide a higher level of detail around the seven key science issues. This would include the objectives of any potential project, but also a discussion of why the issue is of strategic importance. This would provide detail of where and at what scale (spatial and temporal) it can be undertaken.

2. Canvas the views of each jurisdiction (and potentially within jurisdictions where more than one institution is involved), and non-jurisdictional science providers, as to how important the issue is to them;

3. Compile the various views and synthesise into advice that can be used in the formulation of the next SMP.

Future direction and collaboration

The identification of the key science issues at the workshop provides a good platform to pursue these ideas further, even if they are in a preliminary state. The intention of the organisers was to develop a series of initial concepts as a basis for further development, either by the organisers or collaboratively between other interested agencies. That task is now complete.

The next step will be to use the workshop outputs as a basis for further development of the issues. Researchers should propose collaborative projects aligning with the workshop outcomes, and funding agencies should favour opportunities meeting the needs determined in the workshop. These key science issues can be further explored via the development of detailed work plans in association with potential collaborators and key stakeholders. This is particularly important as the new SMP is currently being developed and additional information related to some or all of these issues would add value to the Plan. However, the key science issues can also be viewed as important outside of the SMP development.

The key science issues identified at the workshop could provide the basis for forming several smaller working groups, each tasked with progressing collaborative research in focused aspects for the GAB. Geoscience Australia (GA) perceives it may be well placed to take a coordinating role and provide input into a whole-of-basin synthesis, drawing together the outputs produced to address the key science issues identified. GA has skills relating to research in several facets including: recharge conceptualisation; non-spring discharge; sub-basin characterisation; intra-GAB connectivity; using hydrochemical and isotopic data to better comprehend how structural geological features influence groundwater flows; and connectivity between the GAB and other geological provinces. As such, GA


has the ability to substantially contribute in several of the key science issues identified at the workshop. GA recognises that all of the key science issues require multiple perspectives that only a collaborative approach could successfully deliver.

At a Commonwealth level, the development of the GAB SMP is of high priority as it will guide management directions and investment in the GAB for the next 15 years.

Further scientific research is essential to determine the most appropriate management methods. From the workshop it became clear that work needs to be collaboratively undertaken. Participants in the workshop showed goodwill and an eagerness to collaborate, and ambitions for mutually-beneficial arrangements are viable.

Participants viewed the two-day meeting as a very useful exchange of ideas and an opportunity to exchange information about where work programs were headed across jurisdictions. There was support for future meetings to provide information on the progress of research and further exchange ideas, perhaps repeating on a regular basis.


4 Acknowledgements

4.1 Contributors to the Workshop

The following people attended the GAB Research Priorities Workshop and their input and contributions are gratefully acknowledged:

Name Organisation

Ian Prosser Bureau of Meteorology

Olga Barron Commonwealth Scientific and Industrial Research Organisation

Mattias Raiber Commonwealth Scientific and Industrial Research Organisation

Paul Shand Commonwealth Scientific and Industrial Research Organisation / Flinders University

Chris Turnadge Commonwealth Scientific and Industrial Research Organisation

Chris Biesaga Department of Agriculture and Water Resources (Cwlth)

Richard McLoughlan Department of Agriculture and Water Resources (Cwlth)

James Hill Department of the Environment (Cwlth)

Scott Lawson Department of the Environment (Cwlth)

Moya Tomlinson Department of the Environment (Cwlth)

Ross Brodie Geoscience Australia

Hash Carey Geoscience Australia

Jane Coram Geoscience Australia

Tim Evans Geoscience Australia

Andrew Feitz Geoscience Australia

Kriton Glenn Geoscience Australia

Eamon Lai Geoscience Australia

Ken Lawrie Geoscience Australia

Lucy Lytton Geoscience Australia

Stuart Minchin Geoscience Australia

Narelle Neumann Geoscience Australia

Jess Northey Geoscience Australia

Tim Ransley Geoscience Australia

Baskaran Sundaram Geoscience Australia

Luke Wallace Geoscience Australia

Tariq Rana Murray-Darling Basin Authority

Anna Bailey Department of Primary Industries – Water (NSW)

Sue Hamilton Department of Primary Industries – Water (NSW)

Hari Haridharan Department of Primary Industries – Water (NSW)

Madhwan Keshwan Department of Primary Industries – Water (NSW)

John Wischusen Department of Land Resource Management (NT)


Name Organisation

Michael Jamieson Department of Natural Resources and Mines (QLD)

Adrian McKay Department of Natural Resources and Mines (QLD)

Rod Fensham Department of Science, Information Technology and Innovation (QLD) / University of Queensland

Leon Leach Department of Science, Information Technology and Innovation (QLD)

Randall Cox Office of Groundwater Impact Assessment (DNRM-QLD)

Steve Flook Office of Groundwater Impact Assessment (DNRM-QLD)

Linda Foster Office of Groundwater Impact Assessment (DNRM-QLD)

Keith Phillipson Office of Groundwater Impact Assessment (DNRM-QLD)

Tom Carrangis Department of Environment, Water and Natural Resources (SA)

Travis Gotch Department of Environment, Water and Natural Resources (SA)

Mark Keppel Department of Environment, Water and Natural Resources (SA)

Daniel Wohling Department of Environment, Water and Natural Resources (SA)

Andrew Love Flinders University

Bruce Radke B.M.R. Consultants

Patrick McKelvey QGC

Ryan Morris Origin Energy

Andrew Moser Origin Energy

The organisers would like to thank Ray Evans for facilitating the workshop.

4.2 Other AcknowledgementsThe authors gratefully acknowledge those workshop attendees who provided contributions and feedback that aided writing and editing this report. The authors would also like to thank Emily Slatter and John Magee, both from Geoscience Australia, for providing valuable comments and suggestions in the review process.


Appendices

Appendix A: Workshop invitation and program

A copy of the invitation flyer sent to prospective participants, and a copy of the workshop program/agenda and pre-workshop questionnaire sent to participants prior to attending

Appendix B: GAB water management issues, knowledge gaps and priorities for future research preliminarily identified by workshop participants

Responses to the pre-workshop questionnaire


Appendix A Workshop invitation and program





Appendix B GAB water management issues, knowledge gaps and priorities for future research preliminarily identified by workshop participants

Prior to the workshop, Geoscience Australia asked participants for their perspectives on GAB research with four questions. These were intended to allow participants to think about topics before arrival, and also to allow feedback to be collected. Ten responses were collected.

The questions sent (Appendix A) were:

1. What are the key groundwater management, current and emerging, issues in the GAB?

2. What important knowledge and information gaps do you perceive to exist in GAB groundwater management?

3. What are the priorities for future research to inform groundwater management in the GAB?

4. What further improvements should be included in a second edition of the Hydrogeological Atlas of the Great Artesian Basin? (http://www.ga.gov.au/metadata-gateway/metadata/record/gcat_79790). Note: the second edition is likely to be an online interactive map service.

This appendix provides the responses received by email to the questionnaire. For each question, a summary table shows the information collated and synthesised. This is followed by the verbatim responses received (with the names of respondents removed).

B.1 Responses to Q1 (issues)

Category Topics

Recharge Estimating recharge valuesRecharge from overlying aquifers & losing streams

Users / Development Many users, not just grazingMining/coal/petroleum, incl. unconventionalEnvironment, cultural use, geothermal, CO2 storage↑ industrial agricultureGW mining; Injection/MAR; water storage & disposal

Discharge Springs: ↓ spring flows & Water quality/acidificationImpacts of anthropogenic effects on dischargeUpward leakage

Components Too complicated to be a single basinSemi-connected sub-basinsInter-aquifer leakage, e.g. through water bores

Governance / State borders Impact of extractions on neighbour states & Interstate trade?Legislation: Joint responsibility? (spring discharge)


http://www.ga.gov.au/metadata-gateway/metadata/record/gcat_79790

A

1a. Aquifers:

Impacts of groundwater abstraction in the unconventional gas industry on water levels and water quality

Groundwater mining of palaeowaters (sustainability)

Calculating water-balance (past vs. present)

1b. Discharge zones (springs):

Decreasing spring flows due to over-abstraction superimposed on long-term decrease due to natural climate change

Impacts of anthropically-induced effects on recharge areas (point source and diffuse) and seasonality

Extreme acidification of soils (acid sulfate soils) and water in areas where flows are decreasing (SA and QLD)

B

over estimation of recharge and associated over allocation, increased development through resource (mineral/petroleum) but also industrialised agriculture, positive pressure changes from MAR/injection

C

That the basin is probably too complicated to be treated as a single entity and that treatment as a number of semi-connected sub basins may be more appropriate

D

I. Impact of CSG extraction from Gunnedah Basin and in future from Southern part of Bowen Basin on overlying NSW GAB aquifers.

II. Impact of extraction from other states on the NSW GAB.

III. Impact of potential interstate trade on the NSW GAB.

IV. Impact of upward leakage from NSW GAB aquifers to overlying water sources and recharge from overlying/adjacent water sources to NSW GAB aquifers.

V. Reliable recharge estimates for the intake recharge areas of NSW GAB.

E

Access continues to be demanded to the Basin for more than just water supply for the grazing industry. The issue is how to balance multiple demands for access to water and other commodities such as coal and gas, as well as the environment and cultural use. Non water commodities include mining/petroleum/geothermal/carbon storage. Also water disposal/storage.

Legacy issues from the grazing industry are yet to be fully resolved, although significant progress has been made on capping and piping. A hidden issue is inter-aquifer leakage through water bores.

F


MDBA is not legislatively required to manage GAB resources under the Water Act or Basin Plan, but has joint responsibility with the States to manage environmental assets of national significance such as GAB discharge springs.

Section 10.14 of the Basin Plan says WRPs must identify the effects or potential effects of taking non-MDB groundwater( e.g. GAB) from a groundwater SDL resource unit due to hydrological connections. This includes monitoring and actions to be taken.

The MDBA acknowledges the connectivity and interaction between the MDB and the GAB resources, and the potential impact management of either resource may have on the other. Known natural exchange of water via connectivity of MDB and GAB water resources include:

GAB discharge to MDB via springs

GAB discharge to MDB as baseflow to streams and rivers

MDB discharge to GAB via losing streams

The full extent of connectivity between the MDB and the GAB water resources is unknown and unquantified. Improving the current lack of knowledge base would be an appropriate first step to manage these two resources effectively.

G

A1.a Consistent management plans for GAB shared water in SA, Queensland and NSW

A1.b Adoption of zonal boundaries which are consistent across the whole Basin

A1.c Identification of potentially conflicting objectives in water management such as trade-offs between recovery of pressure and allocation of water for new users for example GSG

H

Adequate management of emerging groundwater demand from industries such as agriculture, P&G and mining.

Groundwater pressure monitoring – adequacy of the existing network and operational needs to undertake monitoring (change in storage).

Improving estimation of water balance components:

recharge and storage.

current and future GAB groundwater demand.

uncontrolled bores – ongoing management of this issue – including old petroleum wells and deterioration water bores providing conduits for flow between formations. Will growth over time.

I

Implications of groundwater extraction for aquifer interconnectivity and groundwater dependent ecosystems

Improved volumetric estimation of GAB extraction (ag, industry, stock and domestic) and discharge (interaquifer, stream, spring) to contribute to improved water balance modelling

J

I see the key groundwater management issues are the new extractive industries namely CSG and deep gas. These are currently not being addressed in management plans in terms of water security for existing water entitlements. Current water bore extraction in the Walloon Coal Measures in the Surat Basin is in the order of 50,000 ML. The CSG industry are predicting up to 70,000ML extraction for the next 30 years. In 2004 when the P& G legislation was introduced to


accommodate CSG landholders where assured that they would be allowed to access alternate aquifers if there bores where impacted by CSG activities. We have CSG monitoring bores drilled prior to any CSG activity indicating up to 3m yearly declines in the Hutton Sandstone south of Chinchilla. Clearly a system under stress from existing agricultural take. Feedlots. This was pointed out to Water planners prior to the first Gab water release. As the water planners had zero pressure monitoring data. They ignored our advice and allocated more water in an already stressed system. Actually the water planners in Qld have no pressure monitoring in the GAB WRP. Very surprising. They held a workshop to decide how to report on GAB WRP aquifer pressure outcomes without having to measure water pressures. quite remarkable.

B.2 Responses to Q2 (gaps)

Category Topics

Flow paths Locations of & Quantity of cross-formational flowHydrodynamics: Long flow paths & in deeper formationsConsistency in head (long-term) monitoring sitesMore bores = more data generally by development

Recharge Quantifying rechargeEstimates from long flow paths

Discharge Diffuse discharge & small-scale preferential pathwaysSprings and their source aquifers

Chemistry Contaminants (acidity/metals/metalloids) in discharge zonesVertical and time-series water quality dataSpatial gaps for isotope studies

Extraction Historical and current water extractions

Large system Time lagsUnderstanding of sub-basins with unique characteristicsHow to split up the GAB?

A

Understanding the locations and quantity of cross formational flow

Quantification of recharge

Quantification of diffuse discharge

Geogenic contaminants (acidity/metals/metalloids) in discharge zones

B

historical and current water extraction, steady state hydrodynamics in the deeper Surat formations, net long flow path recharge estimates

C

The above. If a sub basin region with it’s own unique recharge, discharge, flow system characteristics and inter-aquifer relationships is identified, there is an argument that it should be managed somewhat separately to other parts of the basin that may have differing characteristics. A “one size fits all” or even a “few sizes based on state boundaries and /or major, continental scale structures” may not be the best way moving forward for all stakeholders involved. That being said, some appreciation that we are dealing with “sub-basins” should be kept in mind, ie. I anticipate that no sub-basin exists in complete hydraulic isolation.


D

I. Water quality information on vertical profile of GAB aquifers is not available across NSW GAB over a period of time to identify the change in water quality, source of inter aquifer leakage and the source water for GAB springs.

II. Long term monitoring of hydraulic head on vertical profile of NSW GAB aquifers is not consistent and the distribution of monitoring sites is not uniform across NSW GAB. The information will help to identify inter aquifer leakage, pressure recovery across NSW GAB.

III. No isotope studies existed in the western part (Warrego & Central groundwater sources) of NSW GAB and therefore the flow path information in that area are inferred from other studies.

IV. Springs in NSW GAB were identified in a few studies. However, the source aquifer of individual GAB spring is not clearly identified. If identified, management actions could be taken confidently to address the impact issues. A few GAB springs are identified outside the boundary of NSW GAB and need further investigation.

E

The GAB is a data poor system that needs development before data can be created (i.e. bores are needed to learn about the system. Bores are expensive so will usually only be put down by those wanting to use the GAB to support a business. But this in turn puts stress on the resource). There are time lags between impacts and development; recharge and discharge; that are hard to deal with using water management approaches appropriate to other groundwater systems. The scale of the system is large (approx. 75% of Qld), and funding for management comparatively small. A risk assessment approach is the best way to identify the issues most in need of research. Such an approach, combined with stakeholder consultation, has contributed to the following list of priorities from a Qld GAB water planning perspective. Some high priority issues have not been listed, including the need to audit current water extractions from water bores, as this has not been viewed as a research issue.

F

Gain information on the nature of any GAB-MDB connections where possible, especially in areas of high environmental significance and/or groundwater extraction. Identify gaps and create a strategy to address shortfall.

Improve baseline information and ongoing monitoring and reporting on GDEs such as GAB springs, including ecological water requirements.

G

A2.a Assessment of stock and domestic use (this can be included in NGIS)

A2.b comprehensive reporting of annual groundwater extraction including mining extractions, use (this can be included in Insight and WIA)

A2.c establish a consistent Basin – wide reference bore monitoring network (this can be included in NGIS)

A2.d Identification of all springs and other groundwater dependent ecosystem and their inclusion in GDE Atlas


H

Groundwater flow directions and preferential recharge zones for the main hydrostratigraphic units.

Improved estimates of aquifer recharge and aquifer storage.

Influence of geological features (fault hydrology) and basin contact zones on groundwater flow

Location and aquifer attribution for all bores

Local hydrology of springs and source aquifer.

Extent of artesian conditions for the main hydrostratigraphic units.

I

Better understanding is needed at local and regional scales of hydrogeological characteristics including values of storage properties and vertical hydraulic conductivity for key aquifers and aquitards

Improved understanding of faults and their potential hydraulic properties

Improved understanding of the magnitude of discharge potentially associated with polygonal faulting across the Rolling downs group (for input into water balance modelling)

Improved understanding of the likelihood and consequence of interaquifer transfer associated with the failure of water and petroleum bores

J

Obviously from the above the biggest knowledge gap is the lack of pressure data across the GAB. Luckily for water planners the CSG industry in the Surat and southern Bowen basin is providing pressure data for that part of the GAB in Qld. Virtually no data for the remainder of Qld GAB.

Another major knowledge gap is the impact of free gas being mobilised by CSG depressurisation moving off site from CSG development fields. This is happening and we are seeing free gas moving up dip from gas fields. This gas migrates through geological pathways and often enters water bores creating pumping issues for landholders. This impact is not covered in Legislation as a potential impact on water bores so landholders have no access to compensation from CSG companies.

Further research is required to better understand the process of gas migration away from Active CSG fields and the potential impacts on landholder bores and fugitive pathways. We have data from one CSG company that is monitoring rising water levels in neighbouring water bores. Of 16 water bores being measured with rising water levels some have risen up to 30m in the last 3 years.. The company is monitoring to decide which landholders to treat as a priority in terms of decommissioning the bores before they start expelling water. They see bores blowing out as a bad optic for the industry that was never going to impact on water bores. Ha Ha.


B.3 Responses to Q3 (priorities)

Category Topics

Whole GAB Discretisation / determining sub-basins (several levels)Connectivity between GAB and underlying/overlyingInter-aquifer leakage / connectivity within GABSteady state hydrodynamics in deeper formations

Springs Acidification and contaminant hazards springsCensus of springs & identifying source aquifers for eachMethods for monitoring springs

Extraction Document historical & current extractionsImpacts: of CSG extraction & of remaining uncapped boresEconomic assessment of capping & piping

Recharge Refining recharge estimates – e.g. net long flow path est.

Chemistry Water quality monitoring methods & profiling

Non-economic assets Links between springs, aquifers & environmentCultural and ecological assets reliant on bore drainsBaseflow contributions / GW-SW interactions

A

Discretisation of GAB at different scales

Assessing connectivity across the GAB

Assessing connectivity between GAB and underlying and overlying basins

Quantifying acidification and contaminant hazards and risks in spring discharge zones

B

as above

C

Determining what these sub-basinal areas are with respect to the geology and hydrogeology characteristics. I realise that this may have been an intention in the GABWRA work, in that portions of the basin were reported separately, but for technical and management necessities, particularly at a state level, I still think this was too broad.

D

I. Impact of CSG extraction from underling basins on the NSW GAB.

II. Refinement of recharge estimates in WRA for NSW GAB recharge areas.

III. Census of NSW GAB Springs and the identification of source aquifer for each spring.

IV. Impact of extraction from the remaining unrestricted flowing bores in GAB on the springs, aquifers and environment (greenhouse gas contribution and salinity contribution to Murray Darling Basin).


E

High priority

Springs monitoring: Research on optimal springs monitoring methods. This could build on OGIA research outputs and could require a stand-alone workshop.

Source aquifer for GAB springs: Determine source aquifers for priority springs. Need to work out which, where, Build on DNRM/PB 2011 Manual and link to OGIA research in the Surat.

Pressure monitoring: investigate new technologies and alternative approaches to monitoring that are potentially more cost effective than current methods. This should include community based monitoring approaches such as CSG Net as well as the relevant technology available for measuring pressure, flow, temperature, and salinity of groundwater at the bore head, or within the bore, for the range of GAB temp/pressure/salinity conditions, including controlled artesian bores, uncontrolled artesian bores, and subartesian bores; and appropriate loggers, and telemetry systems and near real time web based access for the public to monitoring data. One aspect of this is the need to rely less on DNRM staff resources to do the pressure monitoring, analysis to calculate static head, and provide data to the public. The review should cover trials of technologies and limits of current methods.

Inter-aquifer leakage: Methods for estimating/measuring the volume of water being transferred within a water bore between aquifers, that identifies the losing and receiving aquifers, as well as the rates of movement (ML/yr) and water quality of the respective aquifers. Output could be fact sheets/guidelines for bore owners about how to apply the methods to identify inter-aquifer leakage and basic options for preventing the inter-aquifer leakage - decommissioning and replacement, or rehabilitation. Many bores won’t be suited to rehab, but will need decommissioning.

Identify cultural and ecological assets reliant on bore drains: Survey landholders to determine any environmental and cultural assets that require maintained water flows from drains. Some bore drains may have local or international environmental significance, how do we assess which are worth keeping, both from a cultural value and ecological value perspective.

Medium level priority

Monitoring groundwater storage: investigate the usefulness of satellite data such as GRACE for monitoring changes in groundwater storage in the Qld GAB, at scales useful for the water plan.

Capping and piping: Update economic assessment of value of carrying out capping and piping works. Possible case study approach with landholders who carried out works covered in earlier studies.

Baseflow streams: Improve the identification of watercourse reaches that are receiving baseflow contributions from GAB aquifers

Lower priority

Water quality monitoring: review the most cost effective and appropriate way of monitoring water quality. Need to identify reasons for water quality monitoring, risks to water quality, then suitable methods, including who should do it.

Cooper Basin – water quality profile for aquifers in the region: data collection and compilation from resource company surveys, to produce a Cooper Basin water atlas.

Long term goal - Hydrogeological models for all aquifers in the whole Basin: However these should be prepared only in response to specific management problems. Models achieve nothing in themselves.


F

N/A

G

A3.a Improved modelling of water availability to plan for allocation of groundwater including CSG, applying for example QWC model to the whole of GAB

For example:

The Queensland Water Commission (QWC) developed a regional groundwater flow model to predict the impacts of groundwater extraction by the petroleum and gas activities. The groundwater flow model is large and complex, containing 19 layers and more than three million individual cells.

https://www.dnrm.qld.gov.au/__data/assets/pdf_file/0016/31327/underground-water-impact-report.pdf

It is conceptually feasible that impacts on the Cretaceous aquifers, as simulated by the QWC model, could be translated to the GABtran model as a means for ensuring consistency between them. The potential impacts from CSG developments cannot be simulated directly by the GABtran model because it does not include the Jurassic, Triassic and deeper basin sediments that contain the target coal beds. (Review of groundwater models and modelling methodologies for the Great Artesian Basin A technical report to the Australian Government from the CSIRO Great Artesian Basin Water Resource Assessment Smith AJ and Welsh WD)

http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.455.4597&rep=rep1&type=pdf

A3.b Test with the above model the impacts of water allocation on springs, potentiometric heads and interaquifer leakage etc etc.

H

The above.

I

A review of methods to link groundwater models of different scales would assist in analysing potential cumulative impacts of multiple developments.

Better linking of hydrogeological, hydrological and ecological conceptual models to assist prediction of impacts of groundwater extraction

Improvements are needed to groundwater modelling to better represent faults and geomechanical effects

J

Future management priorities need to directed at where alternate water supplies will be available to landholder bores that have been impacted by CSG activities. Even though OGIA publicly state the Walloon Coal Measures are an aquitard they are called up in the qld GAB WRP as an groundwater management unit. Therefore recognised in the plan as an aquifer. Actually in the Surat they have the second highest number of bores and the second highest entitlement of all GAB aquifers.

In 2004 the Qld govt advised all landholders impacted by CSG activities that they would be allowed to access deeper GAB aquifers by way of compensation. Since then the water planners have had two releases of additional allocation from the deeper aquifers rendering them fully allocated. The Huttons are clearly under stress but the water planners don't measure heads so they are totally


http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.455.4597&rep=rep1&type=pdf



unaware of the existing system stress. In the next 2 years CSG make good arrangements will kick in and the water planners will say "there is no allocation left sorry" for relocation of impacted bores into deeper aquifers. A case of right hand not knowing what the right hand is doing .

B.4 Responses to Q4 (atlas)

Category Topics

Chemistry Acidification hazard of spring groupsWater quality mapping

Usability Digital formatDownload database & ease of accessing databaseExplaining abbreviations, superscripts, etc.Explaining data collection, e.g. types of isotopic studiesIntention of information non-technical audiencesAlign style to resource managers/bore owners

Detailed areas Smaller areas for more detail sub-basinsSmaller-scale maps in data-dense areas

Continuation Incremental improvements to evolve atlas

Uncertainty Checking predicted error maps

Water depths “aquifer depth from surface” rather than “water table”

A

Acidification hazard of spring groups

Water quality

B

I support digital format, provide access to the database

C

I think incremental improvements as we obtain new levels of detail will come organically. As above, there has been some effort to look at particular parts of the basin in more detail but I feel this is still too broad. I think the appropriate level of detail will come out once we understand where the sub-basins are.

D

I. The atlas in the current form is an excellent product with so much of valuable information in it. However, if a second edition is planned, recommend that we provide an explanation of abbreviation used and also the meaning of superscript numbers used in the current atlas.

II. If some explanation of the type of isotopic study and what information it intends to provide would be ideal for users of non-technical background. There is some information available on the current atlas, but a bit of expansion is ideal.

III. A map shows low error area in the inset map (predicted error map), but on the map there is no monitoring point is shown. Example Map No 45 – see western part of NSW.


E

The current Atlas is very useful for helping people understand what the GAB is. However it is less useful for managing the resource or helping bore owners. A possible improved second edition might identify areas (eg the Flinders area/ Darling Downs) that have enough data to allow smaller scale maps to be developed for “aquifer depth from surface”, and replace the imaginary “water table” map with aquifer specific piezometric surfaces.

F

N/A

G

Q4. Bore data released together with already available maps including: bore ID with location screen interval, screened aquifer, time series data of TDS and levels all to be included in NGIS

H

Potentiometric surfaces for key hydrostratigraphic units

Surface-water and groundwater interaction chapter (inclusive of springs)

I

No response

J

Sorry I haven't looked at the atlas so can't offer a suggestion for improvement at this stage.,

In terms of future research needs I see the highest priority being the areas of quantifying take in the absence of metered use..OGIA have totally changed the S&D take from each GAB management unit by simply coming up with a new methodology for determining same. Interesting but just juggling numbers until actually measured. The next priority would be the issue of gas migration once depressurisation has released free gas and buoyancy controls the movement of gas on the edges of gas fields away from the gas wells.

Happy to discuss further or clarify comments written after a few seconds reds.


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