_g Projections of Groundwater Extraction Rates and Implications for Future Demand and Competition for Surface Water Surface for Competition and Demand Future for Implications and Rates Extraction Groundwater of Projections

KNOWLEDGE Landscapes & Industries Competition forSurfaceWater for Future Demand and Extraction Rates andImplications Projections ofGroundwater 57548_Book 17/6/03 2:13 AM Page tit1

Projections of Groundwater Extraction Rates and Implications for Future Demand and Competition for Surface Water 57548_Book 17/6/03 2:13 AM Page tit2

Author: Sinclair Knight Merz

Published by: Murray-Darling Basin Commission and CSIRO

Level 5, 15 Moore Street Canberra ACT 2600

Telephone: (02) 6279 0100 from overseas + 61 2 6279 0100 Facsimile: (02) 6248 8053 from overseas + 61 2 6248 8053 Email: [email protected] Internet: http://www.mdbc.gov.au

ISBN: 1 876830 37 9

Cover photo: Arthur Mostead

© 2003 Murray-Darling Basin Commission

This work is copyright. Graphical and textual information in the work (with the exception of photographs and the MDBC logo) may be stored, retrieved and reproduced in whole or in part, provided the information is not sold or used for commercial benefit and its source (Murray-Darling Basin Commission, Landscapes & Industries Program, Projections of Groundwater Extraction Rates and Implications for Future Demand and Competition for Surface Water) is acknowledged. Such reproduction includes fair dealing for the purpose of private study, research, criticism or review as permitted under the Copyright Act 1968. Reproduction for other purposes is prohibited without prior permission of the Murray-Darling Basin Commission or the individual photographers and artists with whom copyright applies.

To the extent permitted by law, the copyright holders (including its employees and consultants) exclude all liability to any person for any consequences, including but not limited to all losses, damages, costs, expenses and any other compensation, arising directly or indirectly from using this report (in part or in whole) and any information or material contained in it.

The contents of this publication do not purport to represent the position of the Murray-Darling Basin Commission. They are presented to inform discussion for improved management of the Basin's natural resources.

MDBC Publication 04/03. 57548_Book 17/6/03 2:13 AM Page i

Foreword

Groundwater is an important component of •provide an estimate of the economic cost the water resources of the Murray-Darling of potential loss to industry due to limited Basin. A Cap on diversion of surface water access to groundwater resources (within from the Murray-Darling Basin was agreed by context of the Cap); the Murray-Darling Basin Ministerial Council • outline potential progression implications in June 1995. The Cap was seen as an of tension resulting from any increased essential first step in establishing demand on surface water due to loss of management systems to achieve healthy groundwater resources; and rivers and sustainable consumptive uses. •define in qualitative terms the degree of Based on the findings from the Review of the connection between stream and aquifer Operation of the Cap, the Ministerial Council for given river reaches. in August 2000 agreed to the following The project has essentially collected, collated recommendations related to groundwater: and analysed the existing data rather than • Groundwater be managed on an integrated carrying out new investigations to generate basis with surface water within the spirit of new data. the Cap (Recommendation 20); and The recommendations contained in the • A Murray-Darling Basin Groundwater report are very valuable in that the majority of Management Strategy be developed by them are directed at investigating and the Groundwater Technical Reference quantifying the groundwater resources of the Group (GTRG) that is based on Basin and supporting their sustainable use. jurisdictional management of groundwater It is noted with great satisfaction that all State through sustainable yields and include and Territory Governments are already taking investigations clarifying how groundwater measures to implement them. management practices may impact upon the integrity of the Cap in the future Given the state of knowledge of groundwater (Recommendation 21). in the Basin and especially the limited availability of data, the project has delivered The GTRG is currently directing a number of a most insightful report. I commend this projects aimed at implementing the above document to the partner Governments and recommendations. This report Projections of the broader Basin community as an Groundwater Extraction Rates and important contribution to integrated resource Implications for Future Demand and management. Competition for Surface Water was specifically commissioned to:

•project future groundwater extraction rates over the next five, ten, 20 and 50 years; • identify extraction and quality thresholds Dr Roy Green for groundwater resources of the Basin President beyond which current usage becomes Murray-Darling Basin Commission void; •predict the rate at which groundwater resources will be exhausted due to extraction or deterioration of resource quality; •predict trends for any subsequent displacement of demand for water to surface water;

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Acknowledgments

The authors would like to thank the following people for contributing their time and energy to this project, without which, it could not have been undertaken.

1. Murray-Darling Basin Commission—Scott Keyworth, Imogen Fullagar, Heather Sedgemen 2. Department of Natural Resources and Mines, Queensland—David Free 3. Department of Land and Water Conservation, —George Gates, Mike Williams 4. Department of Natural Resources and Environment, Victoria—Gordon Walker 5. Department for Water Resources, South Australia—Steve Barnett

ii Projections of Groundwater Extraction Rates and Implications for Future Demand and Competition for Surface Water 57548_Book 17/6/03 2:14 AM Page iii

Executive Summary

The Cap on diversions in the increased risk that the environmental Murray-Darling Basin (MDB) degradation of the river system of the Murray-Darling Basin would have been In June 1995, in response to declining river worse. However, the MDBC recognises that health coupled with an incremental erosion of there is no certainty that the Cap on the security of supply to existing irrigators, diversions at its current level represents a the Murray-Darling Basin Ministerial Council sustainable level of diversions’ (MDBC decided to introduce a Cap on the diversion 2000). of water from the Basin’s river system. In fact, in its contribution to the review, the The introduction of the Cap was seen as an Cooperative Research Centre for Freshwater essential first step in establishing Ecology (CRCFE) (2000) stated that: management systems to achieve healthy ‘The Cap is set at a level of diversions rivers and sustainable consumptive uses. that contributed to the current In other words, to develop a balance between degradation of the riverine environment, the significant economic and social benefits and while the Cap is an essential step in that had been obtained from the development slowing ongoing decline, there should be of the Basin’s surface water resources on the no expectation that the Cap, at its current one hand, and the environmental uses of the level, will improve the riverine water in the rivers on the other. environment. However, without the Cap it The Cap is a key policy decision to support is most probable that the health of the the goal of the Murray-Darling Basin Initiative: Basin’s river system would be significantly ‘to promote and coordinate effective poorer as extractions approached the full planning and management for the development scenario level.’ equitable, efficient and sustainable use of From an economic and social perspective, the water, land and other environmental the MDBC considers that the overall benefit resources of the Murray-Darling Basin.’ of the Cap, especially in ensuring security of However, to date, groundwater resources supply at a valley level and providing an have not been included in the assessment of environment within which water trading and the Cap, which is why this study was initiated related reforms could be developed, has to determine the impact of groundwater use been a positive one and that the net benefit on its integrity. will increase over time. As such, the Cap is not an end in itself, but The results of research conducted for the rather a first step towards achieving the review make it clear that, in the absence of the longer-term objective of the Initiative. Striking Cap, the erosion of security of supply for the right natural resources management irrigators and other users would have been balance in the Murray-Darling Basin is, and significant. Without the Cap there would have will continue to be, an ongoing process. been continued development and activation of surface water entitlements that had not been The 2000 review of the fully used without a method of overall control. operation of the Cap Through guaranteeing security, the MDBC views the Cap as having provided a more As part of the Murray-Darling Basin certain climate for long-term investment and Ministerial Council’s decision to introduce the development, particularly in high value Cap, a major review of its operation was agriculture and value adding processing, as scheduled for 2000, which marked five years well as providing benefits to the environment. of Cap implementation. From an ecological perspective, the Murray- The groundwater situation Darling Basin Commission (MDBC) Parallel to the development of the surface concluded that: water resources in the Murray-Darling Basin, ‘The Cap has been an essential first step in the groundwater resources too have been providing for the environmental sustainability extensively developed and are now of the river system of the Basin. Without the approaching the upper limit of sustainable Cap there would have been significantly development. Groundwater and surface water

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resources are fundamentally interconnected issue of additional surface water licences on the and, in fact, it is often difficult to separate the major regulated rivers in New South Wales, has two because they ‘feed’ each other. coincided with a period of rapid expansion in total irrigated agriculture production. In the In terms of total water allocation in the Basin, 13 seasons 1983–84 to 1996–97, cotton groundwater allocations account for 3,471 production grew by over 300%, rice production GL/yr, and surface water some 11,246 GL/yr. by 150%, milk production by 54%, and grape Irrigated agriculture accounts for 2,879 GL/yr production by 37% (ABARE 2000). (or 82%) of the groundwater allocations, and stock and domestic use 427 GL/yr (12%). However, it is important to note that over The remaining 6% is accounted for by urban, 67% of the sustainable yield volume in the industrial and commercial use. Murray-Darling Basin lies within the UAs. These are the areas in which there historically To illustrate the current level of development has been little demand for groundwater, most of groundwater resources in the Murray- likely due to the fact that 46% of the UA Darling Basin even further, the following key resource is more saline (greater than 3,000 statistics are provided: mg/L total dissolved solids). GMU—groundwater modelling unit From social/community and environmental GAB—Great Artesian Basin perspectives the problems caused by this UA—unincorporated areas degree of over-commitment are likely to • There are 88 GMUs, 10 GAB GMUs and manifest themselves in: 16 UAs in the Murray-Darling Basin. • increasing tension between groundwater • 35 GMUs and 10 GAB GMUs are and surface water users (where there is overallocated in the Murray-Darling Basin. an obvious physical connection between These 35 GMUs contain 54% of the surface and groundwater). Groundwater groundwater GMU resources. This also extractions are currently estimated as represents 80% of the total allocations in reducing stream flow since 1993–94 by GMUs. In the GAB allocations exceed 186 GL/yr sustainable yield estimates by 111 GL/yr. • increasing tension between groundwater • 12 GMUs, 10 GAB GMUs and 1 UA and surface water users and proponents (Yarraman UA) are overused in the of environmental flows Murray-Darling Basin. The 12 overused • the unwelcome prospect, and in some GMUs represent 15% of groundwater cases the existence, of groundwater GMU resources and 24% of groundwater salinisation by aquifer depletion use in GMUs. consequently drawing in more saline • There is 2,121 GL/yr of estimated groundwater from adjacent sources. This sustainable yield within the GMUs may result in a reduction of higher quality (excluding the GAB), of which 59% is used, groundwater resource by up to 175 GL/yr. and 134% is allocated. •Groundwater allocations in the Murray- Significant tensions already exist because of Darling Basin currently total 3,471 GL/yr. the Cap on surface water diversions from the •Groundwater use in the Murray-Darling cessation of new allocations, the need to Basin currently totals 1,927 GL/yr. provide environmental flows, and in some cases the need to reduce usage. These Groundwater development lies primarily in the tensions are expected to increase as dryland GMUs, including the GAB, so that, realistically, salinity further impacts on stream salinity there is 2,121 GL/yr available for extraction on especially in New South Wales and to some a sustainable basis. As a consequence, the extent in Queensland. In addition, some of the GMUs are the focus of this report. solutions to dryland salinity, such as high In the 35 over-allocated GMUs (excluding GAB density tree plantations, have the potential to GMUs), allocations exceed the sustainable further reduce surface water yield. yield by 1,140 GL/yr. In 12 of these 35 GMUs usage exceeds sustainable yield by a total of Economic impacts of unmet 66 GL/yr. This situation is obviously demand due to restrictions on unsustainable and needs to be addressed. groundwater resources In the entire Murray-Darling Basin, groundwater consumers currently use 26% of the Groundwater consumers are using 59% of the sustainable yield of 7,500 GL/yr. Increased sustainable yield of GMUs in the Murray-Darling groundwater consumption over the past two Basin and the rate of consumption has grown decades, due initially to embargoes on the at an average rate of about four per cent per iv Projections of Groundwater Extraction Rates and Implications for Future Demand and Competition for Surface Water 57548_Book 17/6/03 2:14 AM Page v

year, over the past two decades. By far the Present value of foregone irrigated agricultural majority of the growth in use of water resources production over 50 years, due to a ‘cap’ on has been in the irrigation sector. groundwater usage—all MDB ($ million)

While the available data provide estimates Usage Growth 8% discount 12% discount of growth rates over the past couple of Scenario rate rate decades, the future rates of growth are uncertain and three scenarios have been Low 159 82 adopted. A ‘medium growth’ scenario has Medium 441 203 been adopted, based on a slightly slower rate of growth than assessed for the past two High 802 367 decades. Low and high growth scenarios have also been developed in order to The cost estimates are aggregated Basin-wide accommodate a wide range of growth rates: estimates and include very large resources (the UAs) with low usage rates. The estimated Groundwater usage growth scenarios impact across the entire Murray-Darling Basin represents a sum of $80 to $800 million over Sector Low Medium High a 50 year period, depending on which growth Growth Growth Growth scenario and discount rate is used. This (%/yr) (%/yr) (%/yr) represents approximately a 25% reduction in Urban/Industrial 0 1 2 the value of irrigated production using groundwater in the Murray-Darling Basin. Rural -0.5 0 0.5 The actual situation varies greatly between Irrigation 1 3 5 GMUs. Some GMUs would be faced with an extremely high reduction in water usage. For These scenarios are assumed to be uniform example, some GMUs would face a reduction across the Murray-Darling Basin and are of greater than 50%. On the other hand, applied to all GMUs. In reality the growth will groundwater usage would not be affected for vary between GMUs, however no information about 30% of GMUs. As such the economic was available to allow discrimination between impact of $80 to $800 million would be felt by the remaining 70% of GMUs. individual GMUs or regions. A spreadsheet model has been developed for extrapolating It is recommended that the MDBC assesses groundwater usage rates in each of the whether the environmental and social benefits GMUs based on the above scenarios. of a ‘cap’ would be sufficient to justify those impacts on groundwater users. In developing a Basin groundwater strategy for It is beyond the brief for this study to estimate the Basin, many options are likely to be the benefits of a ‘cap’, but we note that they considered and each of those would affect the are likely to be very substantial. availability of groundwater resources. For example, a ‘cap’ on groundwater extractions An important benefit of a ‘cap’ would be limiting use to within sustainable yields would be increased security of supply to groundwater considered. In order to evaluate such proposals, and surface water users. The benefits it is important to consider the economic costs to associated with increased security of supply industry that would arise due to any reductions for groundwater users alone might be in the availability of groundwater resources. sufficient to justify the impacts on some users. However a ‘cap’ on groundwater usage A first cut attempt has been made to would also improve the security of supply for estimate the Basin-wide costs to irrigation of users of surface water resources. As the imposition of a Basin-wide ‘cap’ on scale of consumption from surface waters is groundwater extractions (the assumption much greater than for groundwater, this being that irrigation will be primarily affected suggests that the benefits for increasing by a groundwater ‘cap’). The cost has been security of supply for surface water resources estimated as the difference between the might be very much greater than the benefits marginal value of irrigated output with and associated with increasing security of supply without a ‘cap’ on groundwater extractions. for groundwater resources. The discounted value of the foregone There are also other benefits, such as: production over the next 50 years has been • Increased reliability of stream flows through calculated, using eight and 12 per cent real accounting for groundwater reductions to discount rates: inflows to streams in areas of high groundwater/surface water connection

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• Increased reliability of groundwater yields 2. By the level of connection: listed as high, through the determination of potential for medium or low aquifer salinisation to ensure sustainability 3. By the potential for groundwater extractions of the resource. to impact on stream flows. Both of these impacts on water resources have The dependency of stream flows on been estimated in terms of the potential groundwater is highly variable. In the upper economic losses to the Murray-Darling Basin, highlands it varies from four to 76 per cent, and and they were estimated at $14 million per on average 25% of stream flows is sourced annum and $13 million per annum for the from groundwater (SKM 2001). In the Riverine groundwater/surface water impacts and aquifer Plains and , this dependency reduces to salinisation impacts, respectively. The net present less than ten per cent of stream flows. value of these losses due to both factors over It is estimated that between ten and 90 per cent the 50 year period is estimated at between $230 of groundwater extractions are sourced from and $330 million for discount rates of 12 and water that would otherwise flow to streams. This eight per cent per annum respectively. is either through reduction of inflows to gaining streams from groundwater extraction, or from Groundwater/surface water induced recharge from losing streams. The total interaction volume lost from streams to groundwater since the introduction of the Cap has been estimated The connection between groundwater and for the Murray-Darling Basin. This estimate is surface water has been assessed for the based upon an assumed 60% of groundwater Murray-Darling Basin. It appears that most of extractions coming from streams, which the areas where there is high potential for equates to 186 GL/yr, or currently a two per impacts on stream flows from groundwater cent undermining of the Cap. Under the pumping lie within the GMUs, which are highly groundwater development scenario considered developed and in many cases over-allocated above, this is expected to grow to seven per and overused. cent over the next 50 years. The main source of information on Out of the 29 GMUs (there are 88 GMUs in the groundwater/surface water connection is from Basin) that are highly or over developed by use literature and State supplied data. This in the Murray-Darling Basin, 60% (17 GMUs) information provided qualitative assessments of have a high level of connection with streams. the connection between streams and aquifers in This is because a majority of GMUs cover the Basin, but it rarely gave quantitative watertable aquifers which have high levels of assessments. As such, the analysis here is a connection with streams. qualitative analysis based on a broad brush Any conjunctive management of groundwater assessment. and surface water will need to consider more River reaches in the Basin have been assessed detailed analyses on a GMU basis. It should for the level of connection with groundwater, consider all situations in which the river changes and the potential of groundwater extractions from losing to gaining, either due to changed reducing stream flows. The river reaches are river level, reduced watertables along that reach, based on the ‘given river reaches’ defined in the seasonal effects and pumping induced effects. Sustainable Rivers Audit (Cooperative Research Centre for Freshwater Ecology 2001), and have The way ahead been adjusted to a more appropriate scale at To date the Cap has provided substantial which each tributary within a GMU/UA is economic, environmental and social benefits. described by its interaction between However, from an environmental perspective, groundwater and surface water. there is little doubt that surface water diversions Much of the baseflow for rivers comes from will need to be reduced to achieve groundwater in the upper reaches in the sustainability. Such a decision will, inevitably, not highlands. Many of these reaches were not be well received by the irrigation community. included in the given river reaches and hence So, for the Murray-Darling Basin, and from a are also missing from the adjusted river broader water resources management and reaches. The level of detail of this study must sustainability perspective, irrespective of the be kept in mind when looking at the results final level of the Cap on surface water the on a regional scale. implications for groundwater are significant, The groundwater/surface water interaction is as the demand for access to it in a climate of described in this study in three ways: increasing water scarcity, will continue to increase. With current groundwater 1. By the type of connection the stream has development levels already high, sustainable with groundwater: listed as gaining, losing or total water resource management is seasonal absolutely crucial to the future of the Basin.

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Recommendations • to have a systematic process that GMUs progress through (Following is a summary of recommendations • to, as part of this process, to initially set listed in the report. For more details please sustainable yields (SY) conservatively refer to Chapter 11.) (i.e. on the low side) 1. The States should reduce groundwater •to have a pre-determined level of allocations (and consequently, groundwater allocation suggested as being 70% of use) to sustainable yield levels in SY, at which more intensive overallocated GMUs as a matter of urgency. management, including the installation 2. In the short term, groundwater should be of meters, is instituted accounted for within the spirit of the Cap. • to have a process for equitable allocation In the long-term, groundwater should be of the remaining sustainable yield once included in an expanded ‘cap’. It is allocations are ‘within sight’ of full proposed that this should be implemented allocation, and to note that auctioning in a different manner to the way the appears to be the most equitable surface water Cap was introduced. This method, and that it may provide funds should be implemented on the basis of for management purposes. revised sustainable yield values for each 5. In regard to management of UAs, the GMU, taking into account the known MDBC encourage State jurisdictions: deficiencies in the existing sustainable yield • to have a systematic approach to approaches. In the short term the surface allocations in UAs, which would water Cap and the groundwater probably be based on a conservative sustainable yield volumes would be kept estimate of allocation per unit area separate. Cuts in both surface water and • to monitor development, and as groundwater allocations would be required appropriate, delineate as GMUs areas that to end double accounting. The are becoming the focus of development. environmental component of the stream flow under the Cap would not be affected. 6. In regard to possible displacement of In the long-term groundwater should be unsatisfied demand for groundwater onto fully integrated into an expanded ‘cap’. surface waters, the MDBC recognise that this is a problem that can be managed by 3. In regard to over-allocated GMUs, the trading of entitlements such that all water MDBC encourage State jurisdictions to: moves to high value uses. • ensure that all large bores are metered •pro-actively set and publicise the future 7. In regard to the physical capture of stream sustainable levels of allocation and the baseflow, the MDBC recognise that the time frame in which this is to be achieved most appropriate approach is not to seek • develop with groundwater users to limit groundwater development by being appropriate allocations and the too prescriptive on baseflow capture. apportionment of the necessary 8. The MDBC and the States should support reductions across users further investigations and assessment on •refrain from holding out the prospect of groundwater/surface water interactions. monetary compensation for 9. In areas of land salinisation encouraging relinquished entitlements groundwater use is strongly supported • make sure that allocation reductions are and through salinity/groundwater not linked to allowing transferable water management plans closer management entitlements to operate in GMUs •recognise that a step on the way towards to ensure minimum pumping volumes is a permanent reduction in allocations in often required. This especially applies to overused areas could be the imposition of the southern Murray-Darling Basin. rostering/restrictions when the watertable Most of the above recommendations are appears to be declining below a specified focussed on addressing the problem of over- level, or the setting of annual allocations allocation of groundwater resources in the aimed at pushing usage back to Murray-Darling Basin to ensure long-term sustainable levels sustainability. To address the problem of the • give priority to management change in undermining of the Cap by groundwater use, GMUs that are both over-allocated and two options are recommended. These overused and where there is a high level reforms are necessary to ensure both the of surface water groundwater interaction. integrity of the existing surface water and 4. In regard to ensuring that all other GMUs groundwater licences and also to ensure the remain within sustainable limits, the long-term sustainability of the dependent MDBC encourage State jurisdictions: ecosystems of the Murray-Darling Basin.

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Table of Contents

Foreword i

Acknowledgments ii

Executive Summary iii

1. Introduction 1 1.1 Context for the study 1 1.2 Background 1 1.3 Scope of project 2 1.4 Overview of the report 2

2. Scales of reporting 4 2.1 Groundwater scales of reporting 4 2.2 Surface water scales of reporting 6 2.3 Given river reaches 8

3. Basin overview 9 3.1 Basin geology 9 3.1.1 Introduction 9 3.1.2 Highlands 9 3.1.3 Murray Basin 9 3.1.4 Great Artesian Basin 9 3.2 Basin hydrogeology 9 3.2.1 Introduction 9 3.2.2 Murray Basin 10 3.2.3 Great Artesian Basin 10 3.2.4 Alluvial/surficial aquifers outside of the Murray and Great Artesian Basins 10 3.2.5 Highlands fractured rock aquifers 10

4. Data collated for this project 12 4.1 General 12 4.2 Groundwater use, allocation and sustainable yield volumes 12 4.3 Groundwater management data 12 4.4 Sustainable yield methodology, incorporation of groundwater dependent ecosystems and description of possible aquifer salinisation in GMUs 13 4.5 Apportionment of GMUs to each surface water Cap region & references/comments on groundwater/surface water interaction 13 4.6 Groundwater management unit characteristics 13

5. Groundwater resource status in 1999-2000 15 5.1 Groundwater availability in 1999-2000 15 5.1.1 Sustainable yield definition 15 5.1.2 Sustainable yield methodology 16 5.1.3 Impact of groundwater dependent ecosystems on sustainable yield 16 5.1.4 Impact of aquifer salinisation on sustainable yield volumes 17 5.1.5 Sustainable yield volumes 21 5.1.6 Other factors influencing sustainable yield: recharge reduction 22 5.1.7 Summary of sustainable yield estimates 22

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5. Groundwater resource status in 1999-2000 (continued) 5.2 Groundwater use in 1999-2000 22 5.2.1 Reliability of use data 22 5.2.2 Groundwater use in 1999-2000 24 5.2.3 Summary of groundwater use within the MDB 25 5.3 Groundwater allocations and licensing policy (1999-2000) 28 5.3.1 Groundwater licensing policy 28 5.3.2 Allocated volumes in 1999-2000 within the MDB 28 5.3.3 Number of licensed bores within the MDB 29 5.3.4 Summary of groundwater allocations and licensing policy 29 5.4 Current development status 31 5.4.1 Introduction 31 5.4.2 Development status by groundwater use 31 5.4.3 Development status by allocation 36

6. Groundwater use projections 40 6.1 Introduction 40 6.2 Trends in water consumption 40 6.2.1 Australian Water Resources Assessment 2000 40 6.2.2 Water account for Australia 42 6.2.3 Murray-Darling Basin Commission 43 6.2.4 Other indicators of water consumption 44 6.3 Summary 45 6.4 Economic forecast model used for growth predictions 46 6.4.1 Scenarios 46 6.4.2 Projections 47 6.5 Economic cost to industry due to inability to meet demand for water 50 6.5.1 Introduction 50 6.5.2 Analytic framework 50 6.5.3 Results 50 6.5.4 Discussion 51 6.6 Summary 52

7. Total water use in the MDB in 1999-2000 54

8. Surface water and groundwater interaction 59 8.1 Introduction 59 8.2 General description of the physical process of connection between surface water and groundwater 59 8.2.1 Connections between groundwater and streams 59 8.2.2 Gaining or losing streams 60 8.3 Given river reaches 62 8.4 Literature review on surface water and groundwater interaction 64 8.4.1 Discussion of articles reviewed 64 8.4.2 Literature review summary 67 8.5 River baseflow project 67 8.6 Connection between adjusted river reaches in the MDB and GMUs/UAs 67 8.6.1 Methodology for determining connection between river reaches and GMUs and UAs 68

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8. Surface water and groundwater interaction (continued) 8.6.2 Adjusted river reach groundwater/surface water interaction categories 68 8.6.3 Results and discussion of results 69 8.6.4 Summary of groundwater/surface water connection results 71 8.6.5 Implications for the Cap 72

9. Groundwater management and policy 76 9.1 Introduction 76 9.2 The institutional arrangements 76 9.2.1 Overview 76 9.2.2 State licensing practice 77 9.3 The range of policy issues 78 9.3.1 Over-allocated GMUs 78 9.3.2 Ensuring all other GMUs remain within sustainable limits 80 9.3.3 Displacement of unsatisfied demand for groundwater onto surface waters 81 9.3.4 The physical capture of stream baseflow 81 9.4 Integration of groundwater issues into the cap 85 9.5 Greenhouse effects 87 9.6 MDBC and State roles 87 9.7 Conclusions 87

10. Conclusions 89 10.1 Key conclusions 89 10.2 Current development status of groundwater in the MDB 89 10.3 Predicted water demands and groundwater growth in the MDB 89 10.4 Groundwater/surface water interaction 90 10.5 Groundwater management and policy 90

11. Recommendations 92 11.1 Key recommendations 92 11.2 Current development status of groundwater in the MDB 92 11.3 Predicted water demands and groundwater growth in the MDB 92 11.4 Groundwater/surface water interaction 92 11.5 Groundwater management and policy 93

12. References 94

Appendix A Use & allocation volumes per groundwater management unit/unincorporated area 96

Appendix B Forecast demands for Murray-Darling Basin 106

Appendix C Groundwater cost model 109

Appendix D River reaches 111

Appendix E Jurisdictions’ responses to the recommendations of the Report 123

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LIST OF FIGURES Figure 2-1 Watertable groundwater management units and given river reaches in the Murray-Darling Basin 5 Figure 2-2 Groundwater province boundaries and groundwater management units superimposed with Cap regions 7 Figure 3-1 Aquifer systems in the Murray-Darling Basin 11 Figure 4-1 Irrigation areas in the Murray-Darling Basin 14 Figure 5-1 Sustainable yields across GMUs, GAB and UAs 21 Figure 5-2 Sustainable yield by salinity category within the Murray-Darling Basin 21 Figure 5-3 Groundwater use (%) by use types in the Murray-Darling Basin for 1999-2000 25 Figure 5-4 Groundwater use (ML/yr) in 1999-2000 within the Murray-Darling 25 Basin across GMUs, the GAB and UAs Figure 5-5 Groundwater use by Cap regions in the Murray-Darling Basin 27 Figure 5-6 Groundwater allocations in 1999-2000 in Murray-Darling Basin by use type 29 Figure 5-7 Groundwater allocations (ML/yr) in 1999-2000 in the Murray-Darling 29 Basin by GMU type Figure 5-8 Groundwater allocation volumes for all GMUs/UAs for 1999-2000 by Cap regions 30 Figure 5-9 GMU (including GAB units) development status by use for 1999-2000 32 Figure 5-10 Development status by use of watertable groundwater management units 33 Figure 5-11 Development status by use of confined groundwater management units 34 Figure 5-12 Development status by use of Great Artesian Basin 35 Figure 5-13 Development status of GMUs (including GAB) by allocation 36 Figure 5-14 Development status by allocation of watertable groundwater management units 37 Figure 5-15 Development status by allocation of confined groundwater management units 38 Figure 5-16 Development status in 1999-2000 by allocation of the Great Artesian Basin 39 Figure 6-1 Net water consumption 1993-94 to 1996-97 (and trend line) 43 Figure 6-2 MDB surface water diversions (1961-99) smoothed series 43 Figure 6-3 Unrestricted and restricted model scenarios 47 Figure 6-4 MDB groundwater usage projections—low, medium, high scenarios— unrestricted case 48 Figure 6-5 Value of foregone irrigated agricultural production ($ millions) due to a ‘cap’ on groundwater usage in the MDB 50 Figure 6-6 Percentage reduction in water use by year 50 for each GMU, due to ‘cap’ that restricts usage to sustainable yield 52 Figure 7-1 Comparison of water resources in the Murray-Darling Basin by resource type in 1999-2000 54 Figure 7-2 Comparison of sustainable yield, allocation and use in GMUs (excluding the GAB GMUs) in the Murray-Darling Basin 55 Figure 8-1 Connections between streams and aquifers (a) unsaturated flow (b) saturated flow and bank storage conditions (Winter et al. 1998) 60 Figure 8-2 Characterisation of gaining (a) and losing (b) streams (Winter et al. 1998) 61 Figure 8-3 Effects of groundwater pumping on connection between surface water and groundwater 61 Figure 8-4 Given river reaches from sustainable rivers audit 63 Figure 8-5 Adjusted river reaches and classification of groundwater/surface water interaction by adjusted river reach 75 Figure C-1 Cost of groundwater—shallow, medium depth and deep bores, illustrative example 110 LIST OF TABLES Table 5-1 State sustainable yield methodologies and level of inclusion of groundwater dependent ecosystems 16 Table 5-2 Potential for aquifer salinisation within the MDB and GMUs affected 19 Table 5-3 Namoi groundwater salinisation trends 20 Table 5-4 Split of sustainable yield in ML/yr by GMU/UA types and salinity categories in mg/L 21 Table 5-5 Methods used to derive use data in the NLWRA (2000), by number of GMUs 24 Table 5-6 Examples of uses within each use type category 24 Table 5-7 Groundwater use by use type for 1999-2000 in the MDB 24 Table 5-8 Groundwater allocation volumes by use type for 1999-2000 28 Table 5-9 Number of abstraction bores/licenses within the MDB 29

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LIST OF TABLES (continued) Table 5-10 GMU/UA development categories by use 31 Table 5-11 GMU/UA development categories by allocation 36 Table 6-1 Percent change in annual water consumption between 1983-84 and 1996-97—by type of consumer 40 Table 6-2 Percent change in annual water consumption between 1983-84 and 1996-97—by water source 41 Table 6-3 Surface water and groundwater usage as a percent of total use— 1983-84 and 1996-97 41 Table 6-4 Percent change in groundwater consumption between 1983-84 and 1996-97—MDB groundwater provinces 42 Table 6-5 Groundwater use intensity for MDB States 42 Table 6-6 Trend change in net water consumption between 1993-94 and 1996-97— by sector 43 Table 6-7 Water use intensity ratio by State (= gross State product/water consumption) 44 Table 6-8 Growth in physical output of agricultural commodities in Australia— 1983-84 to 1996-97 44 Table 6-9 Growth in population and urban water use: 1983-84 to 1996-97 45 Table 6-10 MONASH projections for growth in real value, 2000 to 2020 45 Table 6-11 Groundwater demand growth scenarios 46 Table 6-12 Distribution of numbers of GMUs by development category— unrestricted demand: low, medium and high scenarios 49 Table 6-13 Distribution of GMUs by development category (%)—restricted demand: low, medium and high scenarios 49 Table 6-14 Net present value of foregone irrigated agricultural production over 50 years, due to a ‘cap’ on groundwater usage—all MDB ($ millions) 51 Table 7-1 Basin-wide groundwater data for 1999-2000 aligned along the designated Cap valleys (GL) 56 Table 7-2 Water use within surface water Cap regions, and groundwater contributions and development status in the Cap region 57 Table 7-3 Water allocations within surface water Cap regions, and groundwater contributions and development status in the Cap region 58 Table 8-1 Calculated groundwater inflow rates to Goulburn and Broken Rivers in northern Victoria (Hydrotechnology 1995) 65 Table 8-2 Summary of groundwater/surface water hydraulic connection based on water chemistry, northern MDB (McNeil & Horn 1997) 65 Table 8-3 Groundwater/surface water interaction categories 68 Table 8-4 Recommended priority GMUs for more detailed studies on stream-aquifer interaction 71 Table 9-1 Hypothetical degree of baseflow capture associated with groundwater development 84 Table 9-2 Baseflow corrections to groundwater use volumes allowing for no reduction in stream flow 84 Table A-1 GMU/UA use by use type category 96 Table A-2 GMU/UA allocation by use type category 100 Table A-3 Groundwater use and level of development within surface water Cap regions 104 Table C-1 Groundwater cost model—illustrative example 110 Table D-1 Adjusted river reaches used in analysis 111 Table D-2 Physical connection between surface and ground water resources (watertable aquifers only) 116

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1. Introduction

1.1 Context for the study 2. A Murray-Darling Basin Groundwater Management Strategy be developed by Groundwater is generally seen as the ‘poor the Groundwater Technical Reference cousin’ to surface water in the Murray-Darling Group (GTRG) that is based on Basin. The major water resource planning jurisdictional management of groundwater initiatives of the Murray-Darling Basin through sustainable yields and include Commission (MDBC) have all been focused on investigations clarifying how groundwater surface water. This is no better illustrated than management practices may impact upon in the introduction of ‘the Cap’. The Cap on the integrity of the Cap in the future surface water diversions was put in place in (Recommendation 21).’ June 1995 with the aim of limiting development to that which existed in 1993-94. It is recognised that growth in groundwater use may lead to further deterioration in The fundamental understanding and surface flows and surface water supply recognition that in many cases groundwater security as a result of reduced base flow. In and surface water are interconnected and addition the long-term integrity of the Cap interchangeable resources did not exist. Hence and effective management of surface although a Cap on surface water has been in waters is unlikely to be achieved in place for six years, no similar complementary absence of parallel and sympathetic concept exists for groundwater. In recent years management of groundwater. there has been a growing understanding that Consequently this project provides a key groundwater development can undermine the input to the development of a Basin integrity of the Cap and can put indirect Groundwater Management Strategy. pressure on the Cap. The direct effects of groundwater development are where significant groundwater-surface water 1.2 Background interaction results in reduced groundwater The Murray-Darling Basin covers over a discharge (or even direct groundwater million square kilometres, or approximately recharge) and hence acts to reduce the 14% of the Australian continent. The region availability of surface water. However perhaps it covers is a semi-arid environment in a more significant and indirect pressure is which most of the surface water is sourced where groundwater use acts as an alternative from the highlands along the Great Dividing to surface water. The significant groundwater Range, with little rainfall in the western resources of the Murray-Darling Basin are portions of the Basin. nearing full development and as this gradually occurs, there is political pressure transferred Australia’s climate is such that the reliability from groundwater to increase surface water of water in-stream historically was not use and hence acting to undermine the Cap. conducive to development within the Basin. Extensive regulation of these The general recognition of this process led streams has taken place over the last 100 the Murray-Darling Basin Ministerial Council, years, along with development of at their 25 August 2000 meeting, to agree groundwater resources within the Basin. with the MDBC recommendations detailed in This development reached a critical point in the Executive Summary of the Review of the mid 1990s when surface water the Operation of the Cap (MDBC 2000). resources were depleting and rivers were These recommendations included: noted to be under stress. The ‘The Commission recommends that: environmental implications of overuse of the water resource were becoming clearer. 1. Groundwater be managed on an integrated basis with surface water within the spirit of the Cap (Recommendation 20)

1 Projections of Groundwater Extraction Rates and Implications for Future Demand and Competition for Surface Water 57548_Book 17/6/03 2:15 AM Page 2

There were many indications of the river 2. Identify extraction and quality thresholds systems being under stress. For example: for the groundwater resources of the Basin beyond which current usage •Wetlands and red gum forests were becomes void noted to be diminishing along river courses due to reduced flood frequencies 3. Predict the rate at which groundwater resources will be exhausted due to • Numbers of native fish were noted to be extraction or deterioration of resource in decline quality •Toxic outbreaks of blue-green algae 4. Predict trends for any subsequent occurred along the Darling in 1991 displacement of demand for water to (MDBC, 2000) and in portions of the surface water and other tributaries throughout the 1990s. 5. Provide estimates for the economic cost of industry lost due to limited These signs of stress indicated that in-stream groundwater resources (within context of uses of water had to be provided to ensure the Cap) the sustainability of the riverine environment, 6. Outline potential progressive implications along with ensuring reliability of supply for of tension resulting from any increased existing users. demand on surface water due to loss of In response to this recognition, the Cap on groundwater resources surface water diversions was put in place in 7. Define in qualitative terms the degree of June 1995, to limit development to the divertible connection between stream and aquifer yield from the rivers in 1993-94. This was then for given river reaches. reviewed in June 2000, with some administrative changes made, but in essence, in It is emphasised that following discussions terms of the volume of water able to be diverted with the MDBC project manager the last from the system, this has remained at the same objective (dealing with groundwater-surface levels as 1993-94 development status. water interaction) is included primarily to provide guidance in the event of more Parallel to the development of surface water detailed assessments in the future. resources within the Basin, groundwater resources too have been extensively developed throughout the region, and now 1.4 Overview of the report also approach the upper limit of sustainable The report has been structured to provide development. This project assesses the a sequential description of the project results: current development status of groundwater resources within the Basin, and looks at Chapter 1 (this chapter) provides an future trends and the implications of high overview of the project and provides a development of groundwater resources on background to the context of the study. the surface water Cap. Chapter 2 presents the various scales of reporting of data and information which have 1.3 Scope of project been used in the Murray-Darling Basin. The reporting scales control the overall direction The principal aim of the project is to of the project and enable, for better or determine areas where groundwater worse, comparisons with the surface water extractions may exceed sustainable limits Cap reporting regions. over the next 50 years and to assess the impact on surface water resource availability, Chapter 3 outlines the Basin wide and hence the integrity of the Cap. hydrogeological framework upon which detailed data is based. The objectives of the project, as specified in the project brief, are: Chapter 4 details of the types of data gathered to describe the extent of 1. Project future groundwater extraction development of the groundwater resources rates over the next five, ten, 20 and of the Murray-Darling Basin. 50 years

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Chapter 5 contains a detailed review on a Groundwater Management Unit (GMU) basis of the resource status in 1999-2000, the base year used for this project. The three key data types of availability (sustainable yield), use and allocation and hence development status are presented.

Chapter 6 provides projections of groundwater use over a five, ten, 20 and 50 year planning horizon and presents an economic argument to justify demand forecast and hence the cost of industry lost due to the finite nature of the groundwater resource.

Chapter 7 reviews the total water use in the Murray-Darling Basin.

Chapter 8 provides a literature review and overview of the significance of surface water- groundwater interaction in the Murray-Darling Basin. This chapter uses data from a complimentary project assessing the base flow component of unregulated streams, predominantly in the highlands of the Murray- Darling Basin.

Chapter 9 presents a strategic and policy discussion of the implications of the previous data considering social, economic and political factors driving groundwater management in the Murray-Darling Basin.

Chapter 10 documents and summarises the key findings of the project.

Chapter 11 provides recommendations for the future management of the groundwater resources of the Murray-Darling Basin so that the current and future undermining of the integrity of the Cap can be minimised and managed.

(Whenever reference to the States is made, it should be taken to include the Australian Capital Territory.)

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2. Scales of reporting

Information for this project was collated on A Groundwater Province is defined as: varying scales, depending on the use of the ‘An area having a broad uniformity of information. Groundwater information was hydrogeological and geological conditions collated on the basis of Groundwater identified as either predominantly Management Units (GMUs) and sedimentary or fractured rock as defined Unincorporated Areas (UAs), whilst surface by the former Australia Water Resources water information was collated on Cap Council.’ (NLWRA 2000) regions, as defined by the Murray-Darling The main emphasis of the project is on the Basin Commission (MDBC) for the Cap GMUs, which is where the majority of the reporting. ‘Given river reaches’ and the development has occurred to date. The UAs ‘adjusted river reaches’ were used to report are in many instances of poorer quality on how groundwater and surface water and/or more remote from the water interactions occur. All scales are described demand centres. below, and the given river reaches and watertable GMUs are shown in Figure 2-1. The Great Artesian Basin (GAB) is also included in this study, although it is 2.1 Groundwater scales of separated from the other GMUs due to different management and policy restrictions reporting on the use of groundwater from the GAB.

The GMUs and UAs have been based on the There are 88 GMUs (excluding the GAB), areas defined for the National Land and Water 16 UAs and ten GAB GMUs located either Resources Audit (referred to in this report as wholly or partly within the Murray-Darling ‘the Audit’) (NLWRA 2000), and have been Basin that is, 114 GMU/UAs in the Basin. updated according to information supplied by the States. All information is supplied either on The south-western portion of the Murray a GMU or UA basis. This is collated up to Cap Basin, although outside the Murray-Darling regions, where appropriate. Basin as defined by the surface water drainage Basins, is included in this project for A GMU is defined as: completeness. This covers portions of South ‘A hydraulically connected groundwater Australia and Victoria, in which there are system that is defined and recognised by several GMUs and highly developed State and Territory agencies. This groundwater resources. definition allows for management of the groundwater resource at an appropriate UAs in New South Wales and Queensland scale at which resource issues and have been defined on the basis of the total intensity of use can be incorporated into area remaining within a Province, less the local groundwater management GMUs. This definition does not allow for the practices.’ (NLWRA 2000) separation of aquifers within the Province, and so makes it more difficult to undertake A UA is defined as: some of the analysis required for this project. ‘A groundwater resource that is defined This is discussed further in the Section 8. geographically by a groundwater province and excludes any designated groundwater management units within the groundwater province. Within the unincorporated area, low level input is required to provide effective management of the groundwater resource due to low levels of current or potential use or development.’ (NLWRA 2000)

4 Projections of Groundwater Extraction Rates and Implications for Future Demand and Competition for Surface Water 57548_Book 17/6/03 2:15 AM Page 5

See enclosed CD for this map in more detail—PDF format

Figure 2-1 Watertable groundwater management units and given river reaches in the Murray-Darling Basin. Source: MDBC.

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2.2 Surface water scales of influenced by the Wenthworth Weir Pool reporting 11. Condamine-Balonne water supply system 12. Queensland portion of The Murray-Darling Basin covers 26 river Basins, plus the Barwon Darling 13. Queensland portion of Valley Management Area (NWLRA 2000). These 14. Queensland portion of Valley Basins are categorised into 22 Cap regions 15. Queensland portion of Valley (MDBC 2000) and 54 Surface Water Management Areas (SWMA). 16. Goulburn-Broken-Loddon water supply system The groundwater information, collated by 17. Campaspe River Valley GMU, is presented in Cap regions, however, some information from the NLWRA is 18. Wimmera-Mallee water supply system collated from SWMAs. This is the scale at 19. Victorian portion of the Murray Valley which comments on groundwater and including Kiewa and Ovens River Valleys surface water interaction were made for the 20. South Australia—River Murray NLWRA. 21. Australian Capital Territory (ACT) The Cap regions in some areas cover several 22. South Australia — reclaimed swamps drainage Basins. Groundwater information has been collated on the same scale, 23. South Australia — SE Murray Province however, in doing so the smaller scale at 24. Victoria —SW Murray Province which groundwater development occurs is lost over the Cap region, especially when There are two additional areas which will be UAs are also included in the determination reported on as Cap Regions, to include the (see Figure 2-2). south-western portion of the Murray Groundwater Province which lies outside of The reporting of groundwater development the Murray-Darling Basin. This includes status on surface water scales is to ensure portions of Victoria and South Australia, and that the implications for surface water Cap are referred to as Cap regions 23 and 24. regions is clearly evident in each area. This is to ensure that those areas where groundwater resources are unable to meet demand do not transfer this demand to surface water resources, which are under the Cap.

The Murray-Darling Basin Cap Regions are as follows:

1. New South Wales portion of the Border Rivers 2. New South Wales portion of Moonie 3. Valley 4. Valley 5. Macquarie-Castlereagh-Bogan water supply system 6. Barwon-Upper Darling water supply system 7. Valley 8. Valley 9. Lower Darling from the furthest upstream reach of the to the furthest upstream reach of the Wentworth Weir Pool 10. New South Wales portion of the Murray Valley including portion of Lower Darling

6 Projections of Groundwater Extraction Rates and Implications for Future Demand and Competition for Surface Water 57548_Book 17/6/03 2:15 AM Page 7 See enclosed CD for this map See enclosed CD for this detail—PDF format in more

Figure 2-2 Groundwater Province boundaries and Groundwater Management Units superimposed with Cap Regions. Source: MDBC.

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2.3 Given river reaches

This project has identified in broad terms those areas in which groundwater and surface water are physically connected. This involves splitting up the rivers into smaller reaches, to appropriately annotate each river. The basis of the reaches is from those defined for the Sustainable Rivers Audit (CRC for Freshwater Ecology 2001), which are based on geomorphological and ecological zones. These are not appropriate in this case and hence have been altered where required to ensure that the groundwater and surface water connections are appropriately annotated along each river. The final set of given river reaches, referred to as the ‘adjusted river reaches’ are described in more detail in Section 8.3.

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3. Basin Overview

3.1 Basin geology 2. underlying limestone in the south western region of the Murray Basin 3.1.1 Introduction 3. basal Olney Formation sands, silts and clays. Even though there are seven geological provinces in the Murray-Darling Basin, as shown in Figure 2.2, the Basin consists of 3.1.4 Great Artesian Basin three main zones: The Great Artesian Basin (GAB) is one of the 1. the eastern and south eastern edge of the largest sedimentary Basins in the world. The Basin, the geology dominated by fractured various sedimentary layers are over 65 million rocks of the Great Dividing Range years old, and are either Cainozoic, 2. west of the highlands, the Murray Basin Cretaceous, Jurassic or Triassic in age, and comprising two major units: the alluvial consists mainly of sandstone alternating with Riverine Plains in the east and the Mallee siltstones and mudstones. It is up to 3,000m region comprising predominantly marine thick and is confined. There are three sub- sediments in the west Basins within the GAB, with the southern portions of the Eromanga Basin and Surat 3. underlying these areas in the northern Basin lying under the Basin. region of the Basin, is the sedimentary The GAB is a major groundwater resource in Great Artesian Basin (GAB) which Australia, and is treated separately in this outcrops on the eastern edge. report due to the nature of its use. 3.1.2 Highlands 3.2 Basin hydrogeology The highlands predominantly consists of sedimentary and igneous rocks of: 3.2.1 Introduction 1. Devonian granite, granodiorite and basic The main distinct groundwater systems intrusive rocks, in the central Victorian within the Basin, as shown in Figure 3-1 are: highlands and scattered along the highlands into New South Wales, with 1. the Murray geological Basin which covers Devonian rhyolite, tuff, chert, sandstone, approximately 30% of the Murray-Darling mudstones and other interbedded marine Basin sandstones and siltstones 2. the GAB (including alluvial aquifer 2. Triassic and Ordovician sandstones, systems overlying the GAB) mudstone, shales and siltstones in 3. the Adelaide geosyncline on the western Queensland, New South Wales and Victoria. edge of the Murray Basin, and shallow There are other formations present, but they aquifers of the Darling River Basin in the are more locally represented rather than northern and eastern parts of the Basin regional geological units. These sequences (outside of the Murray Basin) form the fractured rock aquifers of the 4. local systems in the fractured rocks along highlands along the south, south eastern and the Great Dividing Range, incorporated in eastern edge of the Murray-Darling Basin. the Lachlan Province, and portions of the Sydney, Clarence Morton and New 3.1.3 Murray Basin England Basins along the New South Wales central and northern coast. The Riverine Plains and Darling River Basin area consist of Quaternary and Tertiary sedimentary sequences of: 3.2.2 Murray Basin 1. marine and fluvio-lacustrine deposits such The Murray Basin is bounded on all sides by as the Parilla Sands, Loxton Sands, Calivil low permeability materials such that the Basin Formation, Shepparton Formation and is disconnected from neighbouring Basins. the Bookpurnong Beds Hence for most practical purposes whatever

9 Projections of Groundwater Extraction Rates and Implications for Future Demand and Competition for Surface Water 57548_Book 17/6/03 2:16 AM Page 10

groundwater enters the Basin remains within These units vary enormously across the Basin, it, and the Murray and Darling rivers often act nearly all units outcrop at either the as ‘drains’ for large volumes of groundwater eastern/north eastern or the western/south that discharge into these rivers. western edges. Most of the recharge to the units occurs on the eastern outcrop zones, with The main aquifer systems within the Murray some leakage between units within the Basin. Basin are: Within the Murray-Darling Basin the main 1. The Shepparton/Calivil/Parilla Sands (also recharge occurs on the eastern outcrop zones referred to as the Pliocene Sands) as the in Queensland. Extensive springs lie within the predominant watertable aquifer through Basin from Bourke, Walgett up to Cunnamulla the eastern and central portions of the and Eulo. This is how much of the Basin waters Basin. are discharged, outside for aquifer leakage and extractions (GABCC 1998). 2. The Murray Group predominantly occurs under the Mallee regions in the western 3.2.4 Alluvial/surficial aquifers portion of the Basin. It consists of marine sediments (shallow water limestones), and outside of the Murray and is up to 100m thick. It forms the Great Artesian Basins watertable aquifer in the western portion Outside of the Murray Basin, many alluvial of the Basin, and is a major groundwater aquifers exist close to the main rivers and source for the region. The salinity of this streams. These aquifers form the main aquifer is variable, with high quality waters aquifer systems used in New South Wales, in recharge zones and highly saline waters outside of the Murray Basin. They are very in other parts of the aquifer. The deeper localised and often shallow, with aquifer Renmark Group Aquifer also recharges thicknesses less than 50m. These are the this aquifer through upward leakage. resources that have been highly utilised in the 3. The Renmark Group consists of Tertiary latter portion of the 20th century, and are sediments of riverine sand, silt and clay now showing signs of stress in some areas. deposits, which are up to 200m thick in the In the eastern and northern portions of New centre of the Basin. This aquifer is confined South Wales within the Murray-Darling Basin and is recharged along the margins of the these alluvial aquifers overly older fractured Basin. It discharges into the lower Murray rock systems, the GAB, or portions of the reaches, along with contributing upward northern New South Wales coastal geological leakage into the Murray Group aquifer. The Basins of New England and Sydney, and salinity of this aquifer varies from fresh in Clarence-Morton in southern Queensland. the recharge zones to 50,000 EC. The salinity is layered within the aquifer and 3.2.5 Highlands fractured rock differences between the upper and lower Renmark Group are also noted. aquifers The highland fractured rock aquifers are 3.2.3 Great Artesian Basin generally local systems which contribute a high proportion of river baseflow. In the The GAB consists of many sedimentary units upper regions of the Great Dividing Range deposited over 65 million years ago. The key they are the major source of many tributaries artesian aquifer units include: that feed the rivers of the Murray-Darling • Cadn-Owie Formation and Hooray Basin. These aquifers are comprised of Sandstone/Gilbert River formation/Mooga basalts, granites, shales, cherts, siltstones, Sandstone, confined by the Rolling sandstones and mudstones, and the Downs group variability of porosity within these aquifers is high. Those areas that contribute high • The Adori/Springbok/Pilliga Sandstone proportions of baseflow in the rivers have a Aquifers high secondary porosity due to fractures, • The Hutton Sandstone aquifer whilst other regions may have less significant •Precipice Sandstone and basal Jurassic fracturing and hence lower total porosity. formation and the clematis sandstone in These aquifers lie in the Lachlan Province. the eastern and north eastern areas.

10 Projections of Groundwater Extraction Rates and Implications for Future Demand and Competition for Surface Water 57548_Book 17/6/03 2:16 AM Page 11

Figure 3-1 Aquifer systems in the Murray-Darling Basin. Source: Murray-Darling Basin Resources, 1997.

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4. Data collated for this project

4.1 General 4.3 Groundwater

The information on groundwater and surface management data water resources within the Murray-Darling Where GMUs are highly developed Basin was predominantly sourced from management strategies are required in order National Land and Water Resources Audit to avoid overuse and unsustainable (NLWRA) (2000), along with information development, along with protecting existing obtained from the States. The key users rights, including surface water users quantitative data required for the project where groundwater may reduce baseflow to included estimated volumes of abstraction, rivers. As such, information on the allocation and sustainable yields for each groundwater management in each State was Groundwater Management Unit (GMU) and obtained. Information was collated on: Unincorporated Area (UA). •management costs of groundwater in There was also considerably qualitative GMUs information required including descriptions of: • management plans for some GMUs • methodology in determining sustainable including the: yields – Condamine Groundwater •inclusion of groundwater dependent Management Area (GMA) ecosystems in sustainable yield estimates – Oakey Creek GMA • potential for aquifer salinisation for each – Upper Hodgson Creek GMA GMU • trading policies within GMUs and external • potential for water quality to impact on to the GMUs groundwater use in each GMU •groundwater infrastructure costs •extraction License costs in each State •groundwater allocation and management •groundwater trading policy in each State policy for the Great Artesian Basin (GAB) •groundwater licensing policy in each • DNR Audits of Toowoomba City Basalt State. GMU and Dalrymple Creek Alluvium The following information was obtained for • other information obtained informally from use in this project. the States.

4.2 Groundwater use, 4.4 Sustainable yield allocation and sustainable methodology, incorporation yield volumes of groundwater dependent ecosystems and description To understand the current level of development of groundwater within the Basin of possible aquifer estimates of groundwater use, allocation and salinisation in GMUs sustainable yield volumes were required. To determine the level of development in a These estimates were provided for the year GMU, the sustainable yield should be of 1999-2000 (the most recent and up to accurately known, along with the date data set). This included information on assumptions made in the calculation of the use and allocations by use types, and in sustainable yield. As such, not only the some cases, extensive information on sustainable yield volumes were required, but irrigation types within the GMUs. Much of the also a description of how and whether data was sourced from NLWRA (2000) which groundwater dependent ecosystems and/or collated data on a GMU basis.

12 Projections of Groundwater Extraction Rates and Implications for Future Demand and Competition for Surface Water 57548_Book 17/6/03 2:16 AM Page 13

aquifer salinisation was considered in the estimation of the sustainable yield volumes. This information is given in Section 5.1.3 and 5.1.4.

4.5 Apportionment of GMUs to each surface water cap region & references/ comments on groundwater/ surface water interaction

To determine what impact the development of groundwater resources within the Basin will have on the Cap, an assessment of the physical and policy connection between groundwater and surface water is required. The given river reaches (functional process zones and valley process zones), by which the connection between groundwater and surface water has been analysed, were supplied by the Murray-Darling Basin Commission (MDBC) and were obtained from the Sustainable Rivers Audit project.

The areas in which both groundwater and surface water are highly or over developed is also needed to determine those areas most in need of investigation or management directives. This information has been collated on Surface Water Cap Regions, as supplied by the MDBC, with each GMU assigned to a Surface Water Cap Region. The results are given in Section 7.

4.6 Groundwater management unit characteristics

Information on the location, both spatially and in terms of aquifers and depth to aquifers, has been collated for each GMU. This information completes the picture of groundwater development within the Basin, especially in terms of the implication of groundwater quality and depth to the resource on the development of groundwater within the Basin. Irrigation regions in the Basin were also used in some instances to determine the high demand areas for surface water, and where there may also be instances of high recharge to the groundwater system from irrigation. The major irrigation areas are shown in Figure 4-1.

13 Projections of Groundwater Extraction Rates and Implications for Future Demand and Competition for Surface Water 57548_Book 17/6/03 2:16 AM Page 14

See enclosed CD for this map in more detail—PDF format

Figure 4-1 Irrigation areas in the Murray-Darling Basin. Source: MDBC.

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5. Groundwater resource status in 1999-2000

5.1 Groundwater availability Updates on some of the sustainable yield in 1999-2000 volume estimates were given for 1999-2000, because the Audit referred to 1996-97 as the base year for reporting of 5.1.1 Sustainable yield definition information. These updates have meant The sustainable yield values used in this project that some of the GMUs have changed have been sourced predominantly from the development status in those three years. National Land and Water Resources Audit Development status is determined for both (NLWRA) (2000). The definition used in the allocation and use and is discussed in Audit was: Section 5.4. ‘The level of extraction measured over a It should be noted that the sustainable specified planning timeframe that should not yield values are used as the level at which be exceeded to protect the higher value groundwater is ‘capped’ in the Murray- social, environmental and economic uses Darling Basin. This cap is based on very associated with the aquifer.’ (NLWRA 2001) different assumptions to the surface water Each State adopted a different version of Cap. The main differences are: this definition in accordance with their 1. The surface water Cap is based on current policy and management practices. a fixed level of development as at In some Groundwater Management Units 1993-94, whilst the sustainable yield (GMUs) mining of the resource is allowed values for groundwater are based on at a set rate (e.g. 5 cm/yr), in others the current state of knowledge of groundwater dependent ecosystems were aquifers in the Murray-Darling Basin allowed for and the sustainable yield was 2. The groundwater sustainable yield will set at a level which did not foreseeably change over time as knowledge of impinge on these groundwater dependent groundwater resources and aquifer ecosystems. There is high variability in how response to stress changes the definition is put into practice, and the methods vary from State to State. It must 3. The groundwater sustainable yield be emphasised that the sustainable yield volumes are generally based on the values used throughout this report are premise of ‘sustainability’ to allow for frequently not necessarily actually inter-generational equity sustainable, in the strict sense of the word. 4. Compliance requirements of the surface There is considerable national debate water Cap would be very different from underway concerning a common definition the groundwater cap. Compliance for a and understanding of sustainable yield. groundwater cap would be based upon A title such as ‘provisional sustainable yield a recognition that the SY values will estimate’ is perhaps more appropriate. change over time Nonetheless for the purpose of this report the words ‘sustainable yield’ (SY) are used The data presented in this report was for consistency and simplicity purposes. correct as of October 2001. However much of the data (especially usage) is being continually updated.

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TABLE 5-1 State sustainable yield methodologies and level of inclusion of groundwater dependent ecosystems (GDEs)

State/Territory Sustainable yield methodology Groundwater dependent ecosystems (GDE)

Australian Capital Territory Based on groundwater modelling Nominal 90% of recharge assigned and rainfall recharge estimates. to GDEs due to lack of information on recharge and aquifer yields. Includes allowance for in-cave systems and terrestrial vegetation.

New South Wales Based on rainfall recharge, river 30% of recharge assigned to recharge and any other available GDEs (according to precautionary information principle)

Queensland Rainfall recharge, aquifer GDEs included in assessment, throughflow rates and extractions except in sub-artesian aquifers. used to determine net recharge In GAB where artificial ecosystems (or sustainable yield) have developed around mound springs, GDEs are considered. Allowance also made for cave and aquifer systems in some GMUs.

South Australia Mining allowed in some GMUs. GDEs allowed for, including mound Sustainable yield estimates based springs in the GAB. on groundwater use, water level and salinity information, and recharge analyses. The recharge analyses included rainfall recharge estimates, lateral throughflow, chloride analyses and numerical groundwater modelling.

Victoria Based on rainfall recharge, Environmental allowances for throughflow rates, river groundwater dependent recharge/discharge, and numerical ecosystems are made for each groundwater modelling (where GMU according to conditions in available). Allowances made for that GMU. Systems included in the well interference and sea water calculation include: river baseflow; intrusion. wetlands; and marine and estuarine systems (in terms of saltwater intrusion limits only).

5.1.2 Sustainable yield methodology be considered in their groundwater allocation planning process. The methodology used across the Murray- Darling Basin for each State is listed in New South Wales has stated a policy that Table 5-1. provision for GDEs have been specified for all aquifers for which plans have been 5.1.3 Impact of groundwater developed. There is a blanket 30% allocation of the assessed recharge volume reserved dependent ecosystems on for GDEs. This typically means that the sustainable yield sustainable yield is taken to be 70% of the The assessment of the potential impacts recharge volume. The sustainable yield of making an Environmental Water volumes quoted have reportedly been Provision (EWP) for Groundwater adjusted to allow for an EWP for GDEs. Dependent Ecosystems (GDEs) is at a In Queensland, the majority of groundwater relatively rudimentary level throughout the levels are already well below ground surface Murray-Darling Basin. The EWP for GDE is levels and hence it is assumed that there is directly analogous to the environmental little impact on GDEs. The Border Rivers, flow requirement concept of surface water Upper Condamine and tributary streams have dependent ecosystems. Most States in some interaction with surface waters. This the Murray-Darling Basin require GDEs to applies to Toowoomba City Basalt (Q52),

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Condamine (Q63), Glengallen Creek (Q66), This will be compounded by land use Dalrymple Creek (Q67), Kings Creek (Q68), changes (e.g. reforestation) which will Seven Creek (Q69) and Border Rivers (Q73). complicate technical, management and It is believed that upstream sections of these policy matters. The potential impacts cannot systems exhibit close interaction between be determined with the data currently surface water and groundwater at different available and significant investigation would (climatic) times of the year. However it is be required to better define this possible believed that the sustainable yield values long-term problem. This possible issue could adopted are conservative and hence do not be guarded against by early identification of need to be reduced further to allow for GDEs. GMUs in what are currently unincorporated areas and a conservative allocation and For the Great Artesian Basin (GAB), it is licensing approach. believed that the sustainable yield values have been adopted based on protecting key 5.1.4 Impact of aquifer salinisation GDEs (e.g. mound spring communities) and although some mound springs have been on sustainable yield volumes affected, further deterioration is not likely with Aquifer salinisation has the potential to the sustainable yield values adopted. reduce groundwater sustainable yields However as usage is generally greater than significantly, due to reductions in the the sustainable yield values, it remains to be beneficial use of the water. Groundwater is seen if usage can be reduced to sustainable generally only used in areas where it is of a yield levels within a time frame that does not high quality, and if this quality is affected the have further impacts on GDEs. potential resource use will be reduced, as the In Victoria the sustainable yield values have number of options for use decrease with been theoretically adopted based upon increased salinity. Hence, a brief introduction ensuring no impacts on surface waters. Other in the mechanisms of aquifer salinisation, and GDEs have not been considered. In some the areas in the Murray-Darling Basin that are GMUs, there is potentially significant impacts at risk is given in this section. Aquifer on stream flows and although the generally salinisation is a factor which needs to adopted sustainable yield methodology is considered in future sustainable yield theoretically satisfactory, it will not always calculations, and the overall assessment of prevent major development close to rivers the risk of impact on the ‘cap’ due to from impacting on stream flows. displaced demand from groundwater to surface water streams. Another possible In South Australia, the Water Resources Act impact to be considered, is that if specifically requires that GDEs must be groundwater becomes more saline in areas considered in the Water Allocation Plans. For where it contributes to stream flow, the example, the Naracoorte Ranges requires a stream flow quality will also be impacted on, specific allocation for GDEs of ten per cent of along with possible reductions in contribution the sustainable yield (or 8,000ML/yr). Although to flow from reduced groundwater levels. other GMUs have significant GDEs, it is believed these are currently adequately considered. 5.1.4.1 Aquifer salinisation mechanisms

Overall, it is concluded that within the planning There are many mechanisms which may time-frames of this project, future considerations cause the salinity of groundwater to increase. of the EWP for GDEs will not have a significant However it is believed that in the Murray- impact on reducing the sustainable yield Darling Basin the principal mechanisms are: estimates throughout the Murray-Darling Basin. However it is believed that development of 1. Increased Recharge: This clearing of some highland areas (especially in basalts) will deep rooted native vegetation (principally gradually reduce stream base flow in the trees) over large parts of the Murray- highland catchments. This is an issue that Darling Basin and replacement with needs addressing now before it becomes a shallow rooted grasses has resulted in problem as groundwater development increases a major increase in recharge. Thick in these areas and impacts on stream flows. unsaturated zones also exist which have high salt storages, often at a depth of

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2 to 4 metres, within the root zone of the Where groundwater use is intense and original native vegetation. The increased recycling is the primary mechanism, the vertical recharge mobilises the salt stored potential for groundwater salinisation to have in the unsaturated zone which is flushed a significant impact on the sustainable yield down to the water table resulting in within a relatively short time frame increased groundwater salinity. (i.e. a decade or two) is high.

2. Recycling: The pumping of groundwater Groundwater salinisation in the semi-arid to to the surface for irrigation causes a temperate regions of South Australia and gradual increase in the salinity of the western Victoria is relatively well documented groundwater by recycling. In this case, and several mechanisms are involved. the irrigated pasture, trees or crops use the ‘fresh’ water leaving the salt in the In the Border zone region (covering Angus groundwater to be flushed downwards to Bremer, Padthaway, Naracoorte Ranges, the aquifer by both excess irrigation water Camaum Caroline and Neuarpur) all three and by rain water. It is currently mainly mechanisms for aquifer salinisation are occurring in areas where the aquifer is at though to be occurring. However the shallow depths (<10m). principal mechanism is believed to be 3. Migration: Pumping good quality increased recharge. This mechanism can groundwater which is surrounded, vertically result in deceptive field observations because and horizontally, by adjacent poor quality of the potentially significant time delay before groundwater causes the migration of the major salinity increase occurs, after which the poor groundwater and results in quality rate of increase can be high. degradation of the pumped groundwater. Considering the entire Murray-Darling Basin, This degradation can be relatively rapid, in it is concluded that aquifer salinisation will the order of only a few years. likely be a major long-term problem, but is not likely to have a major impact in the next 5.1.4.2 Aquifer salinisation in the MDB few decades. In a few specific areas the sustainable yield will be effectively reduced The geographic extent and rates of by approximately ten per cent over the next groundwater salinisation are not well known 20 years. Over the 50 year planning horizon across the Murray-Darling Basin. of this project, the sustainable yield is Nonetheless sufficient data is available expected to be reduced by approximately across a range of hydrogeological 10–20% in the GMUs identified below. environments to provide policy direction for dealing with this important process. In many The currently documented extent of situations the deterioration in quality over groundwater salinisation in the Murray- typically decades acts to change the Darling Basin is listed in Table 5-2. beneficial use categorisation of the groundwater resource. As such the sustainable yield of the total resource may not change, but rather the sustainable yield within the beneficial use category may change. This effectively amounts to a reduction in the sustainable yield.

Deteriorating groundwater salinity has been noted in several of the large alluvial valleys of New South Wales. Throughout the Riverine plains of New South Wales and Victoria extensive surface water and groundwater based irrigation areas increasing shallow and deep aquifer salinisation has been reported. It is believed that although recycling is the primary mechanism, in some cases migration may also be important.

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TABLE 5-2 Potential for aquifer salinisation within the Basin and GMUs affected

Groundwater Reference Salinisation method Potential reduction in Management Unit sustainable yield (SY) due to altered beneficial use categories and time frame in which aquifer salinisation may occur

Condamine River GMUs, McNeil & Rising groundwater salinity at Dalby. ? including northern Horn anabranch & main (1997) channel

Myall Creek (Q54) David Free, Slowly rising salinity levels, possibly due Reduction of 5 to 10% of Condamine (Sub (pers.comm.) to migration of poorer quality SY likely. Increase in NO3 Areas 1 & 2 = Q57 groundwater from adjacent lithologies. levels also possible and a & Q58) problem for town water Kings Creek (Q68) supply bores. Dalrymple Creek (Q67) 20 years

Namoi Valley (N09),} NLWRA Horizontal and vertical migration of poor ? Upper Namoi (N12) (2000), quality groundwater from adjacent J Ross bedrock aquifers is causing salinity (pers.comm.) increases.

Lower Gwydir (N11) NLWRA Groundwater salinity increases noted. ? (2000), Lower Macquarie J Ross (N16) (pers.comm.) Collaburragundy- Talbragar Valley (N27)

Shepparton GSPA Dept. of Rates of 65 EC/yr have been recorded ? (V43) Agriculture, over 10 years due to recycling where 1992 relatively intensive use (and reuse) of groundwater occurs.

Lower Murrumbidgee NLWRA Increase groundwater salinity noted, ? (N10) (2000) most likely due to recycling as the Upper Lachlan (N19) primary mechanism, and in some Lower Lachlan (N20) cases (e.g. Campaspe) migration may (N22) also be important. Lower Murray (N24) Mid & Upper Murrumbidgee (N46) Shepparton (V43) Campaspe (V42)

Tintinara (S30 & S31) Leaney Salinity predicted to rise from 2,700 EC Variable timeframe (2000) to 15,000 EC in irrigation areas due to dependent on many flushing of unsaturated zone salt factors, but primarily following clearing. water table depth. Barnett (pers. GW salinity increasing at 250 EC/yr comm.) due to recycling, from flood irrigation.

Tatiara (S24 & S25) Barnett (pers. 50% cut in allocations currently ? comm.) considered in one zone due to falling gw levels and rising salinity due to NLWRA recycling of salt in shallow aquifer (2000) (<5m deep).

Angas Bremer (S18) NLWRA GW salinisation noted as a problem in ? Padthaway (S26) (2000) these GMUs. Three mechanisms Naracoorte Ranges involved: increased recharge; recycling; (S28) and migration throughout the region. Camaum Caroline Principal mechanism thought to be (S34) increased recharge. Neuarpur (V52) Increases of up to 40 EC/yr common Walker et al. in SA/VIC Border zone observed (2001) over last 15 years.

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Table 5-3 Namoi groundwater salinisation trends

Location Bore number Salinity trend

Upper Namoi Zone 3 30430 9 EC/yr increase Upper Namoi Zone 4 30344 0 Upper Namoi Zone 8 30064 7 EC/yr increase Upper Namoi Zone 1 30030 2 EC/yr increase Upper Namoi Zone 5 36055 3 EC/yr increase

Lower Namoi 25325 0 Lower Namoi Zone 3 30265 9 EC/yr increase Lower Namoi 36280 Variable, Deep: 145 EC/yr increase Lower Namoi 36314 450 EC/yr increase Lower Namoi 36060 3 EC/yr increase

More specific data on the Upper and $120 and $170 million for discount rates of Lower Namoi (R. Brownbill, pers. comm.) 12 and 8 per cent per annum respectively. is given below, and indicates the possible level of increase in each groundwater zone This is based on the following assumptions: due to aquifer salinisation. • That it will take 20 years before the Use of linear extrapolation is often not valid aquifers at risk reach salinity levels that with such data. Rigorous sampling and result in a drop in beneficial use of the interpretation over an extended period is water generally required. Nonetheless, if a salinity • That the lost sustainable yield will be increase of about 5 EC/yr is considered, over static over the period of 2020 to 2050 the 50 year planning horizon for this study, (this study does not look beyond the next a 250 EC rise would cause a significant 50 years). reduction in the sustainable yield within the • That the lost revenue comes from the beneficial use category. However this would following water uses: livestock pasture not be expected to become a major issue for (20%); viticulture (5%); dairy (30%); cereal several decades. crops (15%); cotton (25%); and horticulture (5%). 5.1.4.3 Economic impacts on reduced • The assumed marginal value product of sustainable yield volumes due water for each of these water uses is: to aquifer salinisation livestock ($30/ML); viticulture ($300/ML); Indicative estimates of the potential for dairy ($90/ML); cereal crops ($50/ML); aquifer salinisation to reduce the available cotton ($60/ML) and horticulture groundwater resource indicate that ($120/ML). 175,000 ML/yr are at risk within the Murray- • The current recharge will not be captured Darling Basin. This is based on ten per cent by other means. reduction in sustainable yields in the 25 GMUs (28% of the 88 GMUs, excluding Based on these assumptions it was then the GAB and UAs) at risk, which are listed possible to determine the split of use types in Table 5-2. of the estimated 175,000 ML/yr lost in sustainable yield volumes, and estimate the The impact of this reduction in sustainable lost revenue from this water. In some GMUs yield and the implications of taking back if this problem is not identified early enough, 175,000 ML/yr across the Basin is that the the impact may be even more significant. demand on surface water resources will increase. The potential economic loss to the Basin from lost revenue has been estimated at $13 million per annum, or $390 million over the next 50 years. The net present value of these losses over the 50 year period is estimated at between

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5.1.5 Sustainable yield volumes

Each State estimated the volume of * * groundwater that could be sustainably * extracted within each GMU. These volumes are referred to as the ‘sustainable yield’. Note that the range of estimation techniques between jurisdictions means that it is strictly not sensible to sum the data. Nonetheless this has been undertaken, albeit the limitations of this approach must be kept in mind. * ML/yr

In spite of the above discussion of the Figure 5-1 Sustainable yields across GMUs, GAB implications of aquifer salinisation on the and UAs. potential to downgrade sustainable yield estimates, the following presentation of

sustainable yield data does not include any * adjustments as a result of aquifer salinisation. * This is due to directions from the States not to alter the supplied data. * * The total sustainable yield within the Murray- * Darling Basin is 7,462 GL/yr. Over 67% of this lies within UAs where there is little * demand for groundwater, and is of poorer * quality in most regions, with salinities of over 3,000 mg/L total dissolved solids. The development potential of groundwater lies in Figure 5-2 Sustainable yield by salinity category the GMUs, including the GAB, so from this within the Murray-Darling Basin. perspective there is actually 2,451 GL/yr available for extraction under sustainable Most of the sustainable yield volumes with development practices. This is the volume of salinity greater than 3,000mg/L is within UAs groundwater that this report will concentrate (98%), and all UAs have salinity levels higher on in terms of development potential. It is than 1,000 mg/L. This is the limiting factor on also where the States need to concentrate groundwater development in many regions, policy development and resource but if groundwater extractions cause aquifer management skills to ensure the future salinisation within some of the GMUs, some of sustainability of groundwater resources and these UAs may become more desirable in surface water resources in those regions. terms of resource quality.

TABLE 5-4 Split of sustainable yield in ML/yr by GMU/UA types and salinity categories in mg/L

Spatial unit 0-500 501- 1001- 1501- 3001- 5001– > 14,000 Total 1000 1500 3000 5000 14,000

Groundwater 304,915 555,965 808,030 413,643 9,770 29,272 - 2,121,595 Management Units (GMUs)

Great Artesian 32,450 157,230 102,510 32,370 5,750 - - 330,310 Basin

Unincorporated - - 2,638,544 47,000 789,900 - 1,535,160 5,010,604 Areas (UAs)

Murray-Darling 337,365 713,195 3,549,084 493,013 805,420 29,272 1,535,160 7,462,509 Basin Total

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5.1.6 Other factors influencing Another factor to consider is where there are sustainable yield: recharge highly valuable resources in fractured rock reduction systems, such as the Lachlan groundwater province. In these regions there is frequently There is limited evidence to suggest that there a high connection between groundwater and may be a reduction in recharge in many surface water with baseflow acting as a alluvial systems. Work under way in Glengallon significant contributor to the stream flow, Creek (David Free, pers. comm.) suggests a so development of groundwater would have 30% reduction in recharge potential since the to be undertaken with care. early 1970s due to alluvial recharge systems The data on sustainable yield supplied from being clogged by silt and clay from agricultural the States includes significantly different activity. This possible factor has not been quality water. Some States specifically do not considered in the assessment of sustainable include water greater than 3,000mg/L in their yield in this project. calculations. Hence, direct comparisons between States are generally not valid. It is 5.1.7 Summary of sustainable yield believed that a common approach to estimates calculating sustainable yield across the Murray-Darling Basin is required, which The sustainable yield estimates for the GMUs specifically deals with the same quality have been determined from basic recharge groundwater. estimates, with little or no allowance for groundwater dependent ecosystems or impacts of aquifer salinisation. The 5.2 Groundwater use in sustainable yield estimates are hence not 1999-2000 necessarily conservative, and until the groundwater use approaches the sustainable 5.2.1 Reliability of use data yield estimate it is not often known how accurate the sustainable yield estimates are. The reliability of groundwater use estimates are based upon the methodology used to If allocation and use is near the sustainable yield estimate the use. This varies from metered limit and it is found that it is an over-estimate, information in some GMUs, to crop estimates, this poses considerable problems in pulling farm surveys and other derived estimates of back allocation volumes and reducing use in the use for each licensee. Even in those areas area once the infrastructure is in place for the where bores are nominally metered, not all extractions. It may also pose a problem for bores are actually metered. Rather a stream flows with some portion of the baseflow percentage of bores of differing use types reduced in stressed groundwater systems across the GMU are metered and taken to where use exceeds the sustainable yield. represent the norm within that GMU. These volumes are used to calculate the percentage Another problem is that it is often only when the of use to allocations for each use type and groundwater system becomes stressed that the then this is assumed for all other licensees of groundwater dependent ecosystems are noted that use type. This assumption is based on (and seen to be dependent on groundwater). the fact that climatic conditions are the If it is only after the fact that the system is noted predominant factor in water demands in many to be dependent on groundwater, including the areas, and particularly within the Murray- baseflow contribution to stream flows, it may be Darling Basin where 65% of groundwater is too late to rectify the damage to the ecosystems used for irrigation. Another 26% is used for or inflict considerable hardship on existing stock and domestic purposes (as denoted by groundwater and possibly surface water users. the rural use type category). The assumption For this reason alone, sustainable yield is made that if five or ten groundwater users estimates should be conservatively estimated in respond in a similar way to climatic factors, order to avoid an overused system and impacts it is assumed that other users will have also on groundwater dependent ecosystems, along responded in this way, and hence the with socio-economic impacts on the proportion of use to allocations from metered communities reliant on the groundwater. bores are taken to represent the entire GMU.

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It should be noted that different methods to Rural estimates are generally based on an assess use are used in each State and hence assumption of use of between one and two the above discussion does not necessarily ML/yr per licence. Many rural (i.e. stock and apply to any particular State. domestic) bores are not formally licensed and are only documented through bore Another factor in the reliability of the data is construction licences. The right to stock and where it is sourced from. Some assessments domestic use comes from historical riparian involve a qualitative component, and when water rights for land owners, which have there are multiple sources of data, this been diminished by statute in most States increases the differences between regions down to what are commonly now termed and States. These errors cannot be ‘stock and domestic’ users. However, little is quantified though, and merely need to be known about the actual volumes required by noted when using the use data. rural users, or how much they actually use. The clearest indication of the variability In New South Wales the licences are formally in groundwater use data, and increased issued in perpetuity. This enables the rights reliability since 1985 Review of Australia’s of stock and domestic users to be explicitly Water Resources and Water Use (Water addresses in management plans. Review 1985), is that the groundwater use Other estimates may be based on assumed volumes estimated show a 58% increase proportions of use to allocation volumes, since 1985, when compared with the NLWRA depending on the year. As previously 2000 data (NLWRA 2000). There are mentioned, metered estimations for a GMU considerable differences in opinion do not mean that all bores in that GMU are concerning whether Water Review 1985 over metered, rather that a selection of bores are or under estimated use. In some parts of the metered within the GMU. This is the most Murray-Darling Basin recent data for water reliable of all estimates of use data. sharing plans suggests that Water Review 1985 significantly overestimated use. Users The methods used to derive the use data for supposedly overestimated use for a variety of the NLWRA are shown in Table 5-5. It is reasons including establishing a history of use evident that most use volumes are estimated, and even simple arithmetic errors. Others with approximately 83% estimated and 16% believe that even though growth rates have metered. The only GMUs in which crop area increased significantly in some regions, the estimates were used lie along the Border greatest disparity in use is due to the Zone region of South Australia and Victoria, underestimate of use in 1985. This could be and the three ‘Other’ categories relate to due to many factors, including the lack of irrigation area estimates from aerial information on the number of bores in each photography and a geographic information area, and also altered licensing rules and the system analysis. It should be noted that there incorporation of older previously unlicensed are also some GMUs that do not have a use bores. The increased number of metered estimate as there is no information on use in bores in which a ‘true’ indication of use is the GMU at all. given, is the most significant factor in the increased use estimates. Historically in some areas farm surveys have been used, and still are. In these surveys it is considered unlikely that groundwater users will overestimate their use compared with their licensed allocation in case of increased charges, so underestimates are assumed to have occurred in some instances. For these reasons the accuracy of the Water Review 1985 data set is debatable.

Crop area estimates are based on an assumed consumption by the crop, with the addition of leaching fractions in some regions to ensure salt build up in the root zone does not occur.

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TABLE 5-5 Methods used to derive use data in the NLWRA (2000), by number of GMUs

Use type Metered use Crop area Other Estimated estimates estimates

Irrigation 10 6 3* 29

Urban domestic 12 0 0 23

Rural 3 0 0 46

Industrial 1 0 0 22 commercial

* These were derived from irrigated area estimates from aerial photos, matching each licence with the irrigated areas and determining use based on crop area estimates.

5.2.2 Groundwater use in 1999-2000

Groundwater use volumes by use category are given in Table 5-7, and by individual GMUs and UAs in Table A1 in Appendix A. The use type categories are described in Table 5-6.

TABLE 5-6 Examples of uses within each use type category

Irrigation Urban Industrial/commercial Rural

Grapes Urban Industrial Stock and domestic Vegetables Domestic Mining & minerals users (informally Crops Power generation licensed) Sugar Cane Commercial Cereal Salinity dewatering Pasture Mine dewatering Fruit Fire fighting Other Crops Dairy and intensive agricultural industries

TABLE 5-7 Groundwater use by use type for 1999-2000 in the Murray-Darling Basin

Unit Irrigation Urban (ML) Industrial/ Rural (ML) Total use (ML) (ML) commercial (ML)

GAB Total 11,840 37,420 - 367,450 416,710

Other GMUs 1,132,073 24,423 57,772 54,240 1,268,508

GMU Total 1,143,913 61,843 57,772 421,690 1,685,218

Uunincorporated Area Total 117,913 20,599 29,627 74,239 242,378

Total Murray-Darling 1,261,826 82,442 87,399 495,929 1,927,596 Basin Use

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It is clear from Figure 5-3 that the majority of use is for irrigation and rural purposes, totalling 91% of the groundwater use within the Irrigation Murray-Darling Basin. 87% of the groundwater use occurs in the GMUs and the GAB (see Urban Figure 5-4). As previously mentioned, this is where the development has occurred and will Industrial continue to occur due to lesser quality water in Commercial the UAs. Some of the UAs do contain higher Rural quality water. Generally these UAs are located

in areas in which there is either sufficient Figure 5-3 Groundwater use (%) by use types in the surface water to meet demands, or in the Murray-Darling Basin for 1999/2000. more remote regions where demand for water is lower, or they are located in fractured rock

systems which historically have not been * * economic to develop.

The GAB has historically only been used for stock and domestic bores, with little extracted for irrigation purposes. More recently some

irrigation use has begun to occur in some * parts of southern Queensland (David Free, * ML/yr pers. comm. June 2001). New South Wales has permitted irrigation from GAB intake beds Figure 5-4 Groundwater Use in 1999/2000 within west of Narromine and at North Star in the the Murray-Darling Basin across GMUs, the GAB and UAs. Southern Recharge GAB GMU (where in the latter 26 GL/yr is allocated and eight to ten used, and 126% of the GAB resources are GL/yr is used). used. Development within the UAs is less, at only five per cent of the resource, indicating a Figure 5-5 shows the spatial distribution of large resource which is currently under-utilised. groundwater use in the Murray-Darling Basin by This is most likely due to location of the Cap Regions for 1999-2000. The use volumes resources in areas where there is little demand include use within the GMUs, GAB and UAs. or demand is currently satisfied by surface Most of the UAs have developed little, aside water, or the water is poorer quality or more from the Mt Lofty Ranges in South Australia, expensive to extract. where most of the use is thought to be occurring outside of the Murray-Darling Basin, Current groundwater use within the Basin is and in the Clarence-Morton UA in Queensland reaching critical levels in some areas, with where there are smaller regions within the UA of current development potential already limited high development status. These areas may be in parts of the Basin. Currently over 1,900 GL designated as GMUs in the near future. per annum is extracted from groundwater which represents 15% of the total water 5.2.3 Summary of groundwater use used within the Murray-Darling Basin. within the MDB The major areas of groundwater use by Cap regions are: Groundwater use within the Murray-Darling 1. Murrumbidgee River Valley with 16% of Basin is dominated by irrigation and stock use, groundwater use within the Basin and occurs in an area covering less than 20% of the Basin (including all watertable GMUs). 2. Namoi Valley with 15% of groundwater These GMUs represent 74% of all GMUs within use within the Basin the Basin, excluding the GAB, indicating that 3. Condamine- Valley and the the development of groundwater has occurred Goulburn-Broken-Loddon River Valleys, in discrete pockets within the Basin (see Figure both with 14% of the total groundwater 5-10 for location of watertable GMUs). This use in the Basin. development is also highly intensive since 60% of the resources in the GMUs are currently

25 Projections of Groundwater Extraction Rates and Implications for Future Demand and Competition for Surface Water 57548_Book 17/6/03 2:17 AM Page 26

These four river valleys hence account for There is one exception though, which is nearly 60% of groundwater use in the where groundwater extractions lower the Murray-Darling Basin. They also coincide watertable and hence reduce land with many of the irrigation districts in the salinisation. This is a major plank of many Murray-Darling Basin, which is where the of the salinity management plans in the highest demand for water occurs. In the Murray-Darling Basin. This occurs in Murrumbidgee Cap region 60% of some parts of the Goulburn-Broken- groundwater resources from the GMUs is Loddon Cap region, in the Murrumbidgee currently used, with only 145 GL not Cap region and elsewhere. Groundwater used. In the Namoi Cap region 90% of extractions lower the water table, but groundwater from the GMUs is used, with unless it is near the end of the flow path only 38 GL not used. Similarly, the (i.e. just about to discharge into the Condamine-Balonne Cap region uses stream) then the ‘void’ in the aquifer will 72% of groundwater from its GMUs, often be filled by lateral migration of more leaving only 31 GL not used. The saline groundwater and/or increased Goulburn-Broken-Loddon Cap region too recharge. This in turn can have the effect is highly developed, with 80% of its of causing increased discharge of more groundwater resources used, leaving only saline groundwater into streams and 39 GL unused. See Figure 5-5 for the hence have an adverse impact on salinity distribution of groundwater use in the levels in streams. This possible Cap regions. mechanism needs to be considered further. Encouraging groundwater use for This level of development, as at 1999- salinity control is strongly supported and 2000, indicates that the impact on the in many cases setting minimum pumping Cap due to groundwater extractions is targets is required. However the possible occurring now. Future demands will make impacts on stream salinities need to be the situation worse, but it is already at also considered. critical levels, with only 240 GL unused in these four river valleys and all except the Goulburn-Broken-Loddon are over- allocated (the level of allocations are discussed further in the next section).

26 Projections of Groundwater Extraction Rates and Implications for Future Demand and Competition for Surface Water 57548_Book 17/6/03 2:17 AM Page 27

See enclosed CD for this map in more detail—PDF format

Figure 5-5 Groundwater use by Cap Regions. Source: MDBC.

27 Projections of Groundwater Extraction Rates and Implications for Future Demand and Competition for Surface Water 57548_Book 17/6/03 2:18 AM Page 28

5.3 Groundwater allocations described in some cases where there are and licensing policy many such users. These users are denoted by the ‘rural’ use type category, and in some 1999-2000 GMUs, especially within the GAB, they are the greater proportion of users. It should be 5.3.1 Groundwater licensing policy noted though, that in many GMUs stock and Licensing policy in each State differs, domestic ‘allocations’ are not included in the although in some areas it is the same (e.g. assessment of allocations for a GMU, and for the GAB where an inter-state agreement hence licenses may be issued in that GMU exists). Stock and domestic bores are up to sustainable yield without consideration licensed in about half of the Murray-Darling of stock and domestic users. Basin (in New South Wales), and they are acknowledged as users with rights to extract 5.3.2 Allocated volumes in groundwater in the other States. It is often 1999-2000 within the MDB assumed that they use in the order of one to two ML per annum. This right comes from The volume allocated to groundwater users historical riparian rights where owners of land within the Murray-Darling Basin totals nearly were entitled to use the water on that land 3,500 GL/yr (see Table 5-8 for the breakdown) whether it was from groundwater or streams. which accounts for 46% of the groundwater All other riparian rights have been rescinded resources within the Basin. In terms of the total with Water Acts in each State and the Crown water allocations in the Basin, groundwater acquiring all rights over water. allocations account for 3,471 GL/yr, or 24% of the allocated water resources within the A licensed groundwater user receives an Murray-Darling Basin, with surface water entitlement to ‘use’ X ML of water from a accounting for 10,875 GL/yr. given source (an aquifer, river reach or irrigation district). These are the licences that Irrigation accounts for 82% of the groundwater are the primary focus of attention, as they are allocations with 12% allocated for stock and the more substantial uses of groundwater, domestic purposes (see Figure 5-6). and are the users that are restricted by the This means that only six per cent of the management policies of a groundwater allocations are assigned to non-agricultural management plan. Other users, such as purposes. stock and domestic bore users are also

TABLE 5-8 Groundwater allocation volumes by use type for 1999-2000

Unit Irrigation Urban Industrial/ Rural Total (ML) (ML) Commercial (ML) Allocations (ML) (ML)

GAB Total* 155,230 0 34,150 252,330 441,710

Other GMUs 2,659,904 62,185 40,853 98,370 2,861,312

GMU Total 2,815,134 62,185 75,003 350,700 3,303,022

UA Total 63,889 19,725 8,770 75,894 168,278

Total Murray-Darling 2,879,023 81,910 83,773 426,594 3,471,300 Basin Use * Most of the ‘allocations’ in the GAB are not formally licenced and are regarded as ‘informal’ allocations, such as the stock and domestic bores. They are, however, considered the same as a licenced ‘allocation’ in this report.

28 Projections of Groundwater Extraction Rates and Implications for Future Demand and Competition for Surface Water 57548_Book 17/6/03 2:18 AM Page 29

GMUs incorporate 95% of the total groundwater allocations within the Basin, clearly indicating where the focus of groundwater management is required within the Basin (see Figure 5-10 and Figure 5-11 for location of GMUs in the Murray-Darling Basin).

5.3.3 Number of licensed bores within the MDB

The number of abstraction bores per GMU was reported in NLWRA Data (2000). Not all Figure 5-6 Groundwater Allocations in 1999-2000 in GMUs had the information reported on, and Murray-Darling Basin by use type. within the Murray-Darling Basin only 85 of the 114 GMUs and UAs reported on this * data. The number of abstraction licences * reported are given in Table 5-9. It has been assumed that there is one licence per abstraction bore, although in some areas it is common to have multiple abstraction bores per licence. The method of derivation of this information by the States for the * * ML/yr

TABLE 5-9 Number of abstraction bores/ Figure 5-7 Groundwater Allocations in 1999-2000 in the Murray-Darling Basin by GMU type. licences within the Murray-Darling Basin

GAB 4,019 because that is where most of the Other GMUs 21,649 development has occurred, and secondly because some States do not license bores UAs* 7,054 or monitor development in UAs and so there Murray-Darling Basin Total 32,542 is no record of what bores are in those areas. It is clear from what is known of NLWRA is not known. groundwater use in UAs though, that there * The only Unincorporated Areas with the number is considerable more use in some of the of abstraction bores reported in the NLWRA (2000) are located in New South Wales. UAs than that which is formally licensed. When referring to allocation volumes for UAs Based on this number of licences, the this should be kept in mind as the volumes average allocation volume per licence is 93 listed may not be representative of the level ML/yr. This calculation does not include rural of development within that UA. users which are, in general, not formally licensed. As such the volume of rural Groundwater allocations are heavily allocations have been removed for the dominated by irrigation licences, which calculation, reducing the allocation volume account for 82% of the total allocation down to 3,044,706 ML. volume in the Basin. This is very localised, with those regions with high use proportions, in many cases being already 5.3.4 Summary of groundwater fully developed. This is discussed further allocations and licensing policy in Section 5.4.3. Nearly 46% of the groundwater resources (of whatever quality the States choose to include in sustainable yield estimates) are allocated in the Basin, most of which lie in the GMUs, with only five per cent of groundwater allocations not located in GMUs. This is for two reasons, firstly

29 Projections of Groundwater Extraction Rates and Implications for Future Demand and Competition for Surface Water 57548_Book 17/6/03 2:18 AM Page 30

See enclosed CD for this map in more detail—PDF format

Figure 5-8 Groundwater allocation by Cap Regions. Source: MDBC.

30 Projections of Groundwater Extraction Rates and Implications for Future Demand and Competition for Surface Water 57548_Book 17/6/03 2:18 AM Page 31

5.4 Current development use, and within the GMUs 40% are over or status highly developed. Over 70% of the groundwater resource within the GMUs and 5.4.1 Introduction GAB are currently used, leaving little room for development in the Basin. The development status refers to the determination of the status of development Of those GMU/UAs that are overused within the GMU according to its allocation (in category 4): and use volumes. This is calculated as a 1. 86,400 ML/yr is extracted above the percentage of the sustainable yield (which is sustainable yield within the GAB across assumed to be the maximum level of 10 GMUs development allowed within a GMU). 2. 65,911 ML/yr is extracted above the The categories are: sustainable yield within 14 GMUs

0–30% = low development (category 1) 3. 60,000 ML/yr is extracted above the 31–70% = medium development (category 2) sustainable yield in the Yarraman 71–100% = high development (category 3) Unincorporated Area. > 100% = over developed (category 4) Therefore, across the Basin there is 212,311 The areas of principal interest are those in ML/yr currently used in category 4 categories 3 and 4 which are currently high or GMUs/UAs above the sustainable yield. over developed. This gives a clear indication It should be noted that the GAB is managed of what status the groundwater resources are by water pressure largely for social reasons. in, within the Murray-Darling Basin. If it were managed on volumes like other groundwater systems in the Basin then it 5.4.2 Development status by would move from category 4 to a lower groundwater use category.

The number of GMUs that are over or highly developed are listed in Table 5-10. Over 35% of GMU/UAs are in category 3 or 4 by

TABLE 5-10 GMU/UA development categories by use

Unit No. GMUs in No. GMUs in No. GMUs in No. GMUs No. of category 1 category 2 category 3 in category 4 GMUs/UAs development development development development by use by use by use by use

GMU 34 25 17 12 88

GAB 0 0 0 10 10

Total GMUs 34 25 17 22 98

UA 14 0 0 1* 16

Murray-Darling 47 25 16 26 114 Basin Total

* The UA that is overused is in Queensland (Yarraman UA) where there may be future GMUs designated to cover particular zones of high development.

31 Projections of Groundwater Extraction Rates and Implications for Future Demand and Competition for Surface Water 57548_Book 17/6/03 2:18 AM Page 32

Category 1 Category 2 Category 3 Category 4

Figure 5-9 GMU (including GAB units) development status by use for 1999-2000.

It is clear from the data that 40% of the The average groundwater use per licenced GMUs, including the GAB, are highly or bore (excluding rural use) is estimated at overused, in comparison with the 44 ML/yr. This is based on the total use sustainable yield. Of these 40% that lie volume (excluding rural use) of 1,431 in category 3 or 4, 85% are shallow GL/yr (see Table 5-7) and 32,542 licences watertable aquifers. This comes as no (see Table 5-9). This means that with over surprise since the shallowest resources 212,000 ML/yr in groundwater savings are generally the cheapest to develop, required in the overused regions, that and so have developed prior to other groundwater licences will have to be groundwater resources, assuming the reduced in order to ensure sustainability of salinity is low. In areas where there are the resource in the long-term. In those deeper groundwater resources of high areas where the system is overused, quality, these are now developing at a further investigations may be required to rapid pace having displaced demand on ensure the integrity of the sustainable yield to these deeper systems. volumes, and use estimates, prior to any management intervention. In respect of the implications on surface water resources this means that those GMUs in high hydraulic connection with streams may already be impacting on the availability of surface water resources. It also means that once the deeper aquifer systems have been utilised, there will be an even greater demand on the surface water resources, and requirements for increased efficiencies and water savings made across each region.

32 Projections of Groundwater Extraction Rates and Implications for Future Demand and Competition for Surface Water 57548_Book 17/6/03 2:18 AM Page 33

See enclosed CD for this map in more detail—PDF format

Figure 5-10 Development status in 1999-2000 by use of watertable groundwater management units. Source: MDBC.

33 Projections of Groundwater Extraction Rates and Implications for Future Demand and Competition for Surface Water 57548_Book 17/6/03 2:18 AM Page 34

See enclosed CD for this map in more detail—PDF format

Figure 5-11 Development status in 1999-2000 by use of confined groundwater management units. Source: MDBC.

34 Projections of Groundwater Extraction Rates and Implications for Future Demand and Competition for Surface Water 57548_Book 17/6/03 2:19 AM Page 35

See enclosed CD for this map in more detail—PDF format

Figure 5-12 Development status in 1999-2000 by use of Great Artesian Basin. Source: MDBC.

35 Projections of Groundwater Extraction Rates and Implications for Future Demand and Competition for Surface Water 57548_Book 17/6/03 2:19 AM Page 36

TABLE 5-11 GMU/UA development categories by allocation

Unit No. GMUs in No. GMUs in No. GMUs in No. GMUs No. of category 1 category 2 category 3 in category 4 GMUs/UAs development development development development by allocation by allocation by allocation by allocation

GMU 18 12 23 35 88

GAB 0 0 0 10 10

Total GMUs 18 12 23 45 98

UA 16 0 0 0 16

Murray-Darling 33 12 23 46 114 Basin Total

Category 1

Category 2

Category 3

Category 4

Figure 5-13 Development status of GMUs (including GAB) by allocation.

5.4.3 Development status above the sustainable yield within the by allocation GAB across 10 GMUs; and 1,139,628 ML is over-allocated within the 35 over- In the Murray-Darling Basin 69 out of 114 allocated GMUs. GMU/UAs are either highly or over developed, 68 of which are GMUs or part of the GAB, and As can be seen from these statistics, the 80% of these GMUs cover shallow aquifer magnitude of the problem has already systems. By volume, 135% of the sustainable reached a critical point where long-term yield in GMUs (excluding the GAB) has been management policies are required for each allocated! However, some GMUs are not fully over-allocated system to ensure the allocated yet, with most of those that aren’t fully sustainability of the resource, and the allocated either located further inland where economic sustainability of those communities there is less demand, or within deeper aquifer affected by these changes. systems which are more costly to develop. Figure 5-14 to Figure 5-16 clearly indicates Table 5-11 and Figure 5-13 clearly show the spatial variability in allocation development that majority of the GMUs in the Murray- within the Basin. The watertable aquifers are Darling Basin are highly or overallocated. In clearly the most allocated resources, with few terms of the ability to obtain a water right (or GMUs of low development status that have a groundwater abstraction license), this means significant resource available still to use. there is limited potential for further development in the Basin.

Of those GMU that are overallocated (i.e. allocations exceed sustainable yield volumes): 111,400 ML/yr is allocated

36 Projections of Groundwater Extraction Rates and Implications for Future Demand and Competition for Surface Water 57548_Book 17/6/03 2:19 AM Page 37

See enclosed CD for this map in more detail—PDF format

Figure 5-14 Development status in 1999-2000 by allocation of watertable groundwater management units. Source: MDBC.

37 Projections of Groundwater Extraction Rates and Implications for Future Demand and Competition for Surface Water 57548_Book 17/6/03 2:19 AM Page 38

See enclosed CD for this map in more detail—PDF format

Figure 5-15 Development status in 1999-2000 by allocation of confined groundwater management units. Source: MDBC.

38 Projections of Groundwater Extraction Rates and Implications for Future Demand and Competition for Surface Water 57548_Book 17/6/03 2:19 AM Page 39

See enclosed CD for this map in more detail—PDF format

Figure 5-16 Development status in 1999-2000 by allocation of Great Artesian Basin. Source: MDBC.

39 Projections of Groundwater Extraction Rates and Implications for Future Demand and Competition for Surface Water 57548_Book 17/6/03 2:19 AM Page 40

6. Groundwater use projections

6.1 Introduction 6.2.1 Australian Water Resources Assessment 2000 Projections of groundwater extraction rates in the Murray-Darling Basin are required to The Australian Water Resources Assessment assist with an examination of the impacts of 2001 (NLWRA 2001) compares consumption a reduction in the availability of groundwater statistics data from 1996-97 with data resources. The methods and the results collected for 1983-84 as part of the Water which has been used to develop projections Review 1985. The years selected for the data of groundwater extraction rates for collection represent, as far is possible, Groundwater Management Units (GMUs) in climatically ‘average’ years. Comparing the two the Murray-Darling Basin over the next 50 points thus provides an indication of the rate of years are presented. water consumption growth experienced in the previous two decades. In this chapter, when data is presented for the States, it refers to the whole State, as The results of this comparison show that total that was the only data available. (This is in water consumption in the five States and contrast to the rest of this report where the Territories of the Basin grew at a compound data refers to that portion of the State within rate of 3.6% per year over the period 1983-84 the Murray-Darling Basin.) to 1996-97 (see Table 6-1). By far the majority of the growth in use of water resources has 6.2 Trends in water been in the irrigation sector. Irrigation consumption grew by 4.3% per year, urban by consumption 2.4% and rural consumption remained static.

Groundwater supplies are a significant and Consumers sourced water supplies from expanding component of total water surface and groundwater water resources. consumption in all States of the Basin. Over the period 1983-84 to 1996-97 This section of the report contains an groundwater consumption in the Murray- analysis of two recent water use surveys Darling Basin States grew at rate of 4.1 per and other data sets on groundwater use cent per annum compared to 3.6 per cent trends in the Murray-Darling Basin. for surface water resources (see Table 6-2).

TABLE 6-1 Percent change in annual water consumption between 1983-84 and 1996-97— by type of consumer

Irrigation Urban Rural Total (%/yr) (%/yr) (%/yr) (%/yr)

Australian Capital N/A N/A N/A N/A Territory

New South Wales 4.4 0.8 -1.9 3.7

Queensland 7.2 4.0 0.8 5.4

South Australia 1.0 1.4 -2.1 0.9

Victoria 3.2 3.0 1.2 3.0

Total 4.3 2.4 0.0 3.6 (excluding ACT) * ACT data was not reported on separately in the Water Review 1985 study.

40 Projections of Groundwater Extraction Rates and Implications for Future Demand and Competition for Surface Water 57548_Book 17/6/03 2:19 AM Page 41

TABLE 6-2 Percent change in annual water consumption between 1983-84 and 1996-97— by water source

State/Territory Surface Water Groundwater Total

Australian Capital Territory N/A N/A N/A

New South Wales 3.3 9.3 3.7

Queensland 7.2 2.9 5.4

South Australia 3.2 -1.9 0.9

Victoria 2.6 8.9 3.0

Total 3.6 4.1 3.6 * Australian Capital Territory did not have data provided in the Water Review 1985 assessment.

Looking at the individual States, groundwater Because growth rates in consumption from consumption has grown fastest in Victoria and the two sources have varied, the relative New South Wales. These are regions with share in total water consumption has mature surface water resource systems. changed slightly, between groundwater and Queensland in contrast has witnessed much surface resources, over the period 1983-84 higher growth in the consumption of surface and 1996-97 (see Table 6-3). As of 1996-97, water. This reflects new developments in 83% of the water consumed in the Murray- surface water systems, both within the Darling Basin States was sourced from Murray-Darling Basin and elsewhere in the surface water resources and 17% from State. The decline in groundwater groundwater resources. Groundwater consumption in South Australia is possibly a represents about 35% of total water usage in result of increased restrictions on groundwater South Australia and Queensland, but 11% or exploitation in some areas of the State. less for the remaining States/Territory.

Table 6-3 Surface water and groundwater usage as a percent of total use—1983-84 and 1996-97

State/Territory 1983-84 1996-97

Surface Water Groundwater Surface Water Groundwater (%) (%) (%) (%)

Australian Capital N/A N/A 94 6 Territory

New South Wales 95 5 90 10

Queensland 52 48 65 35

South Australia 48 52 64 36

Victoria 95 5 89 11

Total 84 168317

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Groundwater consumption growth in the Figure 6-1). Strong growth trends are evident major groundwater provinces within the in both New South Wales and Victoria where Basin is set out in Table 6-4. This result the trend growth over the period averaged suggests that groundwater consumption 7.0% and 7.2% per annum respectively. This growth within the Basin may be higher than outcome is somewhat higher than the growth the State average. estimates derived from the NLWRA data set but is consistent with the overall conclusion of TABLE 6-4 Percent change in groundwater an expansion in water consumption in these consumption between 1983-84 and States. The ABS data for South Australia 1996-97—Murray-Darling Basin groundwater shows a trend growth rate of 0.7% per provinces annum, which is consistent with the NLWRA Groundwater Groundwater data. In the case of Queensland, the NLWRA province consumption rate and ABS data provide contradictory increase between conclusions with the ABS data showing 1983-84 & 1996-97 (%/yr) slightly negative trend growth (-0.4%) compared to the longer term NLWRA data Lachlan 7.9 trend of 5.4% per annum. However, because Murray 7.2 water use is variable year on year, the trend derived from data covering only four years Great Artesian Basin 2.9 must be treated with caution. All 5.0 The majority of the rise in water consumption shown in the ABS data is accounted for by Irrigated agriculture was the main use of the agricultural sector (see Table 6-5). In groundwater in 1996-97 for all the States in New South Wales and Victoria, the trend the Murray-Darling Basin (see Table 6-5). change in agricultural water use was nine Overall 75% of the groundwater consumed in and ten per cent per year respectively over the Murray-Darling Basin groundwater the four years in the ABS data set. provinces was used for irrigation. The Comparing this result with the data collected proportion of irrigated use was highest in by the NLWRA and reported in Table 6-3 South Australia then Queensland and above would suggest that there has been followed by New South Wales and Victoria. acceleration in the growth of agricultural water consumption in recent years. TABLE 6-5 Groundwater use intensity for Conversely the outcome for Queensland Murray-Darling Basin States agricultural—a slight decline in trend State/Territory Irrigation Other growth—would seem to contradict the (%) (%) NLWRA data. On the other hand the South Australia water data from both data sources Australian Capital Territory N/A N/A would seem to be consistent. New South Wales 74 26

Queensland 79 21

South Australia 84 16

Victoria 69 31

Total 75 25

6.2.2 Water account for Australia

In May 2000, the Australian Bureau of Statistics (ABS) released a set of statistics on water resources for the years 1993-94 through to 1996-97. Over the period, the net water consumption in the Murray-Darling Basin States varied from year to year but showed an increasing or static trend (see

42 Projections of Groundwater Extraction Rates and Implications for Future Demand and Competition for Surface Water 57548_Book 19/6/03 10:38 AM Page 43

TABLE 6-6 Trend change in net water consumption between 1993-94 and 1996-97—by sector

Sector NSW (including Queensland (%/yr) South Australia Victoria (%/yr) ACT) (%/yr) (%/yr)

Agriculture 9 -1 1 10

Mining -8 -4 -14 -2

Manufacturing 1 -2 -2 2

Services 1 -2 -6 2

Domestic 0 2 0 4

Utilities 3 0 2 3

Total 7017

In other sectors the trends are mixed. Utility consumption—e.g. power generation, wastewater disposal services etc.—was a major source of consumption growth in three of the four States in the Murray-Darling Basin. Consumption in the mining sector declined in all jurisdictions. Not surprisingly, given the changes to water pricing and the emphasis on conservation, water use in domestic sector either remained stable or grew at the rate of population growth—with the exception of Victoria where consumption grew by a trend rate of four per cent per year.

6.2.3 Murray-Darling Basin Commission

The Murray-Darling Basin Commission (MDBC) Figure 6-1 Net Water Consumption 1993-94 to 1996-97 (and trend line). publishes a smoothed time series of data on surface water diversions from the Basin that goes back to 1960 (see Figure 6-1). The data is sourced from the MDBC but the specifics of the smoothing method used to compile the data are unknown (Awadhesh Prasad, pers. comm.). Nevertheless, the time series provides useful information on surface water usage that is otherwise unavailable to this study.

Using these data, the rate of growth in surface water diversions between the years 1983-84 and 1996-97 was 1.7 per cent per annum. This is considerably lower than the estimates for surface water growth in the Basin States reported above (see Table 6-6). For analytical purposes this value probably reflects a low estimate of surface water diversion growth and provides a lower bound for the projections. Figure 6-2 MDB Surface Water Diversions (1961-99) Smoothed Series. Source: N Hall, pers. comm.

43 Projections of Groundwater Extraction Rates and Implications for Future Demand and Competition for Surface Water 57548_Book 17/6/03 2:20 AM Page 44

TABLE 6-7 Water use intensity ratio by state (= gross State product/water consumption)

State/Territory Gross state product Water consumption Ratio (%) (%)

Australian Capital 3.7 N/A N/A Territory

New South Wales 4.1 3.7 0.9

Queensland 5.3 5.4 1.0

South Australia 3.1 0.9 0.3

Victoria 4.3 3.0 0.7

Total 4.1 3.6 0.9

Source: ABS (2000), NLWRA (2001)

6.2.4 Other indicators of water TABLE 6-8 Growth in physical output of consumption agricultural commodities in australia— 1983-84 to 1996-97 Water is a key input into most economic activities. Accordingly, water consumption Commodity Annual rate of growth (%) tends to be linked to the level of activity in the economy. Between 1983-84 and 1996- Cotton 11.9 97, Gross State Product (GSP) in the four Milk 3.3 Murray-Darling Basin States grew on average by 4.1 per cent per year (see Table 6-6). Rice 8.1

Over the same time total water Grapes 2.5 consumption grew by 3.6 per cent. This Wool 0.0 gives a ratio of water consumption to GSP Wheat 0.6 growth of approximately 0.9. That is for every one per cent growth in GSP, water Beef 1.2 consumption has grown by 0.9 per cent. Source: ABARE (2000)

A ratio of less than one suggests the Population, a major driver of water economic activity is shifting to less consumption, grew at a rate of 1.5 per cent intensive water-use activities over time. per annum. Interestingly, despite the trend This is consistent with the increased towards the conservation of water resources representation of service industries in the in urban water supply systems, the growth in composition of economic output in urban water use in the Murray-Darling Basin Australia (ABS 2000). However, growth in States outpaced the rate of population the agricultural sector has been biased growth in total (see Table 6-9). towards more intensive water-using industries. Between 1983-84 and 1996- 97, the output of commodities principally associated with irrigation grew by 6.8 per cent per year (see Table 6-7). Over the same period, output of non-irrigated crops grew at a slower rate or remained relatively constant.

44 Projections of Groundwater Extraction Rates and Implications for Future Demand and Competition for Surface Water 57548_Book 17/6/03 2:20 AM Page 45

TABLE 6-9 Growth in population and urban water use—1983-84 to 1996-97

State/Territory Population growth Urban water usage Ratio (%/yr) (%/yr)

Australian Capital 2.1 N/A N/A Territory

New South Wales 1.2 0.8 0.7

Queensland 3.0 4.0 1.4

South Australia 0.7 1.4 2.2

Victoria 0.9 3.0 3.2

Total 1.5 2.4 1.6

Source: ABS (1996), NLWRA (2001). Forecasts of economic growth are also a 6.3 Summary useful indicator of the likely growth in water consumption and are commonly used to Groundwater consumers are using about forecast water consumption. Australian 70% of the sustainable yield of aquifers in the Academy of Technological Sciences and Murray-Darling Basin and the rate of Engineering (ATSE) (1999) took this approach consumption has grown at an average rate in their study of the Australian water of about four per cent per year, over the past economy. Their forecasts drew on projections two decades. By far the majority of the of economic activity prepared growth in use of water resources has been in by Monash University using MONASH the irrigation sector. general equilibrium model of the Australian Increased groundwater consumption has economy. Recent MONASH forecasts for coincided with a period of expansion in the growth in irrigated agriculture are set out in output of irrigated agriculture. Between Table 6-10 (Centre of Policy Studies, 1983-84 and 1996-97 irrigated agricultural Monash University 2001). output grew as follows:

TABLE 6-10 MONASH projections for growth • cotton production grew by over 300% in real value—2000 to 2020 • rice production by 150% Industry Growth (%/yr) • milk production by 54% • grape production by 37% (ABARE 2000). Rice 4.3 Water usage for stock & domestic purposes Whole milk 2.6 did not grow. Output growth from dryland Cotton 1.5 farming has been modest:

Grapes 3.2 • wool, 0% Citrus 4.0 • beef, 8% • wheat, 17% (RBA, 2001). Vegetables 2.3 The number of farm properties fell by 35% The weighted average of the Monash (ABARE 2000). projections is 2.8% per annum. If the water use intensity ratio is one or thereabouts (see Water consumption in the urban and Table 6-9) this would imply a growth industrial sector grew by 37%. Population projection of 2.8% per annum for water use growth over the same period was 21%. The by these industries. fact that it costs so much to deliver treated water to consumers has dampened urban and industrial growth. Industrial usage tends to vary depending on whether new industrial (and mining) works open up or close down. Metering of urban and industrial water

45 Projections of Groundwater Extraction Rates and Implications for Future Demand and Competition for Surface Water 57548_Book 17/6/03 2:20 AM Page 46

consumption means it is easier to implement • high rates of productivity growth in conservation pricing. Industrial and urban dairy, rice, cotton sectors consumers can save money by making • favourable currency exchange rate improvement to the water use efficiency of dynamics for dairy, rice and cotton their equipment and appliances. water sectors • favourable commodity prices for dairy, The ABS data covers the four years between rice and cotton water sectors 1993-94 and 1996-97. In these years total •greenfields viticulture and horticultural water consumption in the Murray-Darling development Basin States grew by a trend amount of • mining and industrial demand 5.1 per cent per annum. Irrigated agriculture •relative costs of alternative water grew by 6.5 per cent per annum while water sources such as water conveyance use by urban and rural consumers grew by and application efficiency measures, 1.7 per cent per annum. desalination, reuse etc. • costs of machinery pumps and power 6.4 Economic forecast model supplies used for growth predictions • energy prices • taxation benefits for investment in water production 6.4.1 Scenarios • structural adjustment in agriculture While the available data provide estimates of • water quality problems in surface growth rates over the past couple of decades, water resources—due to dryland the future rates of growth are uncertain and salinity or algal blooms. three scenarios have been adopted. Given the difficulty of determining the impact One approach would be to model the of each of these factors on future demand, components of demand for groundwater. it is not appropriate to attempt a detailed For example, the following factors are model of demand for this study. possible drivers of groundwater usage: A ‘medium growth’ scenario has been • the security and nature of property adopted, based on a slightly slower rate of rights to groundwater growth than assessed for the past two • open access conditions applying in decades. Low and high growth scenarios some areas have also been developed in order to • rapid rise in water prices in regulated accommodate a wide range of growth rates. surface water systems The scenarios are set out in Table 6-11. The • more restrictions on surface water scenarios are consistent with the trend usage harvesting in upper catchments data reviewed in the previous section.

TABLE 6-11 Groundwater demand growth scenarios

Sector Low Growth (%/yr) Medium Growth (%/yr) High Growth (%/yr)

Urban/industrial 0.0 1.0 2.0

Rural -0.5 0.0 0.5

Irrigation 1.0 3.0 5.0

46 Projections of Groundwater Extraction Rates and Implications for Future Demand and Competition for Surface Water 57548_Book 17/6/03 2:20 AM Page 47

These scenarios are assumed to be uniform 3. Consumption is defined in volumetric across the Basin and are applied to all terms and for three categories of use— GMUs. In reality the growth will vary between urban, rural and irrigation (NLWRA 2000). GMUs, however no information was available 4. Maximum extractable yield in the to allow any discrimination between individual unrestricted scenario is three times GMUs or regions. (300%) the sustainable yield, as shown in Figure 6-3. 6.4.2 Projections 5. Maximum extractable yield in the A spreadsheet model has been developed restricted scenario is 100% of the for extrapolating groundwater usage rates in sustainable yield, as shown in Figure 6-3. each of the Murray-Darling Basin GMUs 6. For those GMUs where use currently based on the above scenarios. exceeds the sustainable yield (case A), the GMUs are allowed to develop for a 6.4.2.1 Data sources further two years, and then yields decline for the next ten years, stabilising at 100% The primary source of data for the of the sustainable yield (see Figure 6-3 projections is groundwater management unit Restricted case). (GMU) sustainable yield and consumption data sourced from the Water Resource Assessment 2000 (NLWRA 2001). Other data sources used include the: Water Account for Australia (ABS 2000), Water in the Australian Economy (AATSE 1999), Reserve Bank and ABARE published time- series on State GSP, population, production output and composition.

6.4.2.2 Model assumptions

Two scenarios were considered in determining the demand for water that cannot be met from groundwater resources: a restricted scenario (where use cannot Figure 6-3 Unrestricted and restricted model scenarios. exceed the sustainable yield) and an unrestricted scenario (where the growth in The scenarios shown in Figure 6-3 show the demand is unlimited). For these two implications of introducing a cap on scenarios it is necessary to consider two groundwater with respect to the decline in different cases: those GMUs in which use is use, as a proportion of the sustainable yield. currently greater than sustainable yields; and Those GMUs that are currently overused will where use is currently less than sustainable be allowed to develop for a further two years yields. These two cases are denoted as ‘A’ (in order for management policies to be and ‘B’ respectively in Figure 6-3 for the implemented), and then are reduced back to overused and currently under-used cases for sustainable limits over a ten year period. In both the restricted and unrestricted the unrestricted case, the use is allowed to scenarios. The following assumptions were increase up to three times the sustainable made in forecasting the demand for water in yield assuming that there is physical capacity the Murray-Darling Basin: to do so and the aquifer storage has not 1. Three rates of growth were used to been totally consumed. In smaller GMUs it is estimate the increase in consumption likely that the 300% of sustainable yield limit over time. These rates of growth are in the unrestricted case is greater than what shown in Table 6-11. can actually be obtained from the aquifer. This complexity has not been included in the 2. Sustainable yield is defined in volumetric determination of demand, as this assessment terms for each GMU (NLWRA 2000). is a Basin-wide assessment and does not take local effects into account.

47 Projections of Groundwater Extraction Rates and Implications for Future Demand and Competition for Surface Water 57548_Book 17/6/03 2:20 AM Page 48

6.4.2.3 Results fully exploited by year 20 in the high growth scenario and 79% will be fully exploited by The projections from the model are set out in year 50. In the medium scenario Figure 6-4, which shows projections of total approximately 32% of the GMUs are fully groundwater usage over the next 50 years. exploited by year 20 and 53% by year 50. These projections include all GMUs and In the low scenario 21% are fully exploited in Unincorporated Areas (UAs) in the Murray- year 20 and 22% by year 50. Darling Basin. The estimates clearly show that under a high growth scenario over 90% The restricted case, where a cap on of groundwater resources in the Basin will be groundwater resources is used so that usage utilised in 2050. In the other extreme, under cannot exceed sustainable yield limits in a a low growth scenario only 30% of GMU, the level of development in the GMUs groundwater resources will be used in 2050. is capped so that there can be no overused GMUs (see Table 6-13). Data on total usage, as shown in Figure 6-4 hides considerable variation in exploitation Those GMUs that are currently overused rates across the 98 GMUs in the Basin. Even though, are given a period of ten years to for the low growth scenarios, approximately reduce usage back to sustainable limits, 20% of present groundwater usage is sourced which is why by 2020 all currently overused from aquifers where usage already exceeds GMUs will be either at or within sustainable the sustainable yield (see Table 6-12). yield limits. This limits growth in those areas currently highly or overdeveloped, which has As shown in Table 6-12, in the base year of implications on the potential revenue earned the analysis, 20% of the Basin’s GMUs were from groundwater resources in the Basin. fully exploited (consumers used more than It conversely, also has some benefits which 100% of the resource’s sustainable yield). are described along with the economic cost About 46% of the GMUs in the Basin will be to industry in Section 6.5.

Total Groundwater Sustainable Yield in Murray-Darling Basin

high

medium

low

Figure 6-4 Murray-Darling Basin Groundwater Usage Projections Low, Medium, High Scenarios—Unrestricted Case.

48 Projections of Groundwater Extraction Rates and Implications for Future Demand and Competition for Surface Water 57548_Book 17/6/03 2:20 AM Page 49

TABLE 6-12 Distribution of numbers of GMUs by development category—unrestricted demand: low, medium and high scenarios

Scenario Development Year category (use as % of sustainable 0 5 10 20 30 50 yield)

High 0-30 49 41 35 28 23 20

30-70 28 28 28 21 14 4

70-100 10 12 12 12 12 4

> 100 20 26 32 46 58 79

Medium 0-30 49 46 39 35 30 23

30-70 28 25 29 24 23 14

70-100 10 14 11 14 15 13

> 100 20 22 28 34 39 57

Low 0-30 49 48 48 45 41 37

30-70 28 25 25 27 29 29

70-100 10 12 12 12 14 17

> 100 20 22 22 23 23 24

TABLE 6-13 Distribution of GMUs by development category (%)—restricted demand: low, medium and high scenarios

Scenario Development Year category (use as % of sustainable 0 5 10 20 30 50 yield)

High 0-30 49 41 35 28 23 20

30-70 28 28 28 21 14 4

70-100 10 17 23 58 70 83

> 100 20 21 21 0 0 0

Medium 0-30 49 46 39 35 29 23

30-70 28 25 29 25 23 15

70-100 10 14 17 47 55 69

> 100 20 22 22 0 0 0

Low 0-30 49 48 48 45 41 37

30-70 28 25 25 27 29 29

70-100 10 14 14 35 37 41

> 100 20 20 20 0 0 0

49 Projections of Groundwater Extraction Rates and Implications for Future Demand and Competition for Surface Water 57548_Book 17/6/03 2:20 AM Page 50

6.5 Economic cost to industry comprises by far the dominant use of due to inability to meet groundwater, surface water resources are tradeable and can be purchased at a price demand for water which reflects the value of water being used in the irrigation sector. 6.5.1 Introduction

In developing a Basin Groundwater Strategy, 6.5.3 Results many options are likely to be considered and A first cut attempt has been made to each of those would affect the availability of estimate the Basin-wide costs to irrigation of groundwater resources. For example, the imposition of a Basin-wide ‘cap’ on avoidance of extractions beyond sustainable groundwater flows (the assumption being yields would be considered. In order to that irrigation will be primarily affected by a evaluate such proposals, it is important to groundwater ‘cap’). The cost has been consider the economic costs to industry that estimated as the difference between the would arise due to any reductions in the marginal value of irrigated output with and availability of groundwater resources. without a ‘cap’ on groundwater extraction.

6.5.2 Analytic framework The information and method used to formulate this estimate is as follows: The impact of changes to water availability would depend on the type of industry and 1. Pattern of irrigated groundwater use in the flow-on impacts in the regions where the Murray-Darling Basin is: they are located: • 30% dairy pastures • 15% cereal crops 1. Limited surface water resources would • 25% cotton affect industries using large volumes of • 20% livestock pasture water per unit of output or whose • 5% viticulture production is limited by water availability. • 5% horticulture (Mark Nayar, pers. Examples of this type of industry in the comm. July 2001). Murray-Darling Basin include: steam 2. Marginal value product of water is: power generation, irrigated agriculture and • $90/ML dairy dredge mining. Any changes to costs in • $50/ML cereal crops these industries might also have negative • $60/ML cotton flow-on effects in other industries involved • $30 ML livestock pasture in output processing or input supply. • $300 ML viticulture 2. Conversely access to water resources • $120 ML horticulture (Mark Nayar, is probably not an important reason why pers. comm. July 2001). some types of industries have chosen 3. A ‘cap’ is introduced in year 3, whereby to locate in the Murray-Darling Basin. usage is constrained to the sustainable For example water is probably not critical yield, and users have ten years to adjust for: call centres, telecommunications their usage to the sustainable level. providers, textile clothing and footwear manufacturers, electronics manufacturers 4. Capping groundwater usage will restrict or motor vehicle parts manufacturers. water usage in each GMU to the sustainable yield. For those industries where water is a limiting constraint, the effect of reducing the supply 5. The volume of water that would no longer of groundwater would be either to reduce be used due to imposition of the ‘cap’ is output (if they did not compensate by calculated for each GMU as the difference purchasing surface water) or to increase between the consumption expected without costs (if they compensated by purchasing a ‘cap’ (see earlier scenarios) less the surface water). Either way the economic sustainable yield. value of that impact can be measured as the 6. The cost to industry is the volume of marginal value of the water. For example, water that is no longer available under the in the case of the irrigation sector, which ‘cap’ multiplied by the value of water.

50 Projections of Groundwater Extraction Rates and Implications for Future Demand and Competition for Surface Water 57548_Book 17/6/03 2:20 AM Page 51 Annual lost revenue ($ millions) Annual lost revenue

Year

Figure 6-5 Value of foregone irrigated agricultural production ($ millions) due to a ‘cap’ on Groundwater Usage in the Murray-Darling Basin.

The results of this calculation using the usage dollar terms (i.e. it removes the effect of forecasts described above are set out in interest rate rises, inflation, increased costs of Appendix B. The value of lost revenue from production and economic changes which may irrigated agricultural production for the three reduce agricultural revenue from agricultural growth rate scenarios is shown in Figure 6-5. production over the next 50 years). It is evident that the losses are substantial, ranging from $100 million to $500 million in 6.5.4 Discussion 2050 due to lost agricultural production. The impact of this lost revenue on the local The cost estimates in Table 6-14 are communities could be significant. However, it is aggregated Basin-wide estimate and include most likely offset by the benefits of reliability of very large resources (i.e. the unincorporated supply for existing users, and sustainability of areas) with low usage rates. The analysis the resource over the next 50 years, which may presented in Figure 6-5 and Table 6-14 is not be assured if groundwater development is therefore not representative of the situation not curtailed back to sustainable yield limits in for individual GMUs. The estimated impact GMUs in the Murray-Darling Basin. across the entire Basin represents a sum of $80 to $800 million over a 50 year period, Over the 50 year period shown in Figure 5-6, depending on which growth scenario and the present value of the foregone production discount rate is used. This represents at eight and 12 per cent real discount rates is approximately a 25% reduction in the value set out in Table 6-14. This illustrates the total of irrigated production using groundwater in revenue lost over the 50 year period at current the Murray-Darling Basin. The actual situation varies greatly between GMUs. Figure 6-6 presents the actual percentage reduction in TABLE 6-14 Net present value of foregone irrigated agricultural production over water use in year 50 for each GMU (that is, 50 years, due to a ‘cap’ on groundwater compared to the situation where usage grew usage—all MDB ($ millions) according to each scenario rather than being Usage 8% discount 12% discount restricted to the sustainable yield). The plot growth rate rate shows all GMUs and UAs with use greater scenario than 0ML/yr, which reduces the number of

Low 159 82 GMUs/UAs down to 107.

Medium 441 203

High 802 367

51 Projections of Groundwater Extraction Rates and Implications for Future Demand and Competition for Surface Water 57548_Book 17/6/03 2:21 AM Page 52

Scatter plot of reduction in water use in restricted scenario % reduction of water use % reduction

GMU

Figure 6-6 Percentage reduction in water use by year 50 for each GMU, due to ‘cap’ that restricts usage to sustainable yield. Note that the maximum reduction in water 6.6 Summary use in Figure 6-5 is 67% because of the artificial limit placed on use in the unrestricted A desk analysis of the rate of growth in demand scenario. As such it can only ever groundwater consumption has been be reduced from 300% sustainable yield to undertaken for the purpose of projecting the 100% sustainable yield. In actual fact there rate at which groundwater resources are are some GMUs which currently exceed being utilised in the Murray-Darling Basin. 300% of the sustainable yield, so there will These projections are based on a desk be cases of even greater reductions in use. analysis of water use and sustainability data Some GMUs would face an extremely high collected as part of two recent surveys of reduction in water usage of greater than 50% water resources in Australia as well as other (see Figure 6-6). published information.

The Murray-Darling Basin would need to The analysis of water consumption data from assess whether the benefits of the ‘cap’ the above sources suggests growth rates in were sufficient to justify those impacts on groundwater consumption are high. The groundwater users. It is beyond the brief for growth has been primarily driven by irrigated this study to estimate the benefits of a ‘cap’, agriculture, which is both the largest but we note that they are likely to be groundwater user in the Basin and the substantial and to include mainly: fastest growing.

• increased security of supply to Based on the assumptions discussed in the groundwater (and surface water) users report, the Murray-Darling Basin’s sustainable yield of groundwater will be fully exploited •protection of groundwater dependent within 25 years under the high growth ecosystems scenario, 28 years under the medium • gains for economic efficiency, particularly growth scenario and 50 years in the low if tradeable rights to groundwater are growth scenario. assigned to users, thereby ensuring that water will move to its highest value use Forecasts are by their nature subject to resulting in an increase in the overall uncertainty. Some of the main source of economic productivity of the irrigated uncertainty concern: the quality of the sector historic data on water consumption; the likely impacts of magnitude and composition of economic growth on

52 Projections of Groundwater Extraction Rates and Implications for Future Demand and Competition for Surface Water 57548_Book 17/6/03 2:21 AM Page 53

water consumption; and the impact of technology changes on per unit water demand.

It is important to point out that this study is a desk analysis using existing published data and information. The forecasts presented here are preliminary estimates to be used in the first stages of the development of the Basin Groundwater Management Plan (BGMP). As the development of the BGMP progresses more data will become available to refine and improve the forecasts.

As part of this project a computer model has been developed for undertaking the calculations underpinning the projections. This model is incorporated in Appendix C and shows the variability in groundwater infrastructure costs and hence the variability in predicted demand due to cost of groundwater development. This is one of the main reasons why shallow aquifers have been predominantly fully developed in the Murray-Darling Basin, since it is cheaper to develop these resources.

53 Projections of Groundwater Extraction Rates and Implications for Future Demand and Competition for Surface Water 57548_Book 17/6/03 2:21 AM Page 54

7. Total water use in the MDB in 1999-2000

As already noted in section 5.2.3 and 5.3.4, development will stress the Cap even more, groundwater use and allocation within some by deflecting unmet demand from of the Cap regions is already highly or over groundwater resources onto surface water developed in the Groundwater Management resources. Units (GMUs). Most existing GMUs have been defined on the basis of areas in which there is The groundwater resource is modest in a high potential for development, or existing comparison with the surface water volumes high levels of development. From the (see Figure 7-1). It makes up 41% of the assessment of the current status of total water available in the Basin, of which groundwater development within the Murray- 24% is allocated and 15% is used. If we look Darling Basin, it is apparent that there are however to the different groups which make limited opportunities for further development of up the total groundwater resource it is clear groundwater resources in the Murray-Darling that many of the GMUs, including the GAB Basin. This is especially so in some of the Cap GMUs, are already highly or over developed. regions where existing use is greater than It is only the Unincorporated areas (UAs) that 70% of the GMU resources (see Table 7-1 for are not developed. breakdown of groundwater use and allocations by Cap regions, and surface water Figure 7-1 gives the impression that all GMU use by ‘cap’ region). Allocations too are highly resources are fully allocated. This is not the developed in most of the GMUs such that case, with some GMUs more developed than groundwater resources are scarce outside of others. To illustrate this further the GMUs the Great Artesian Basin (GAB) and GMUs. It (excluding the GAB GMUs) have been split is evident that many of the Cap regions are according to the level of development by currently under stress. Any further allocation, as shown in Figure 7-2.

Figure 7-1 Comparison of Water Resources in the Murray-Darling Basin by Resource Type in 1999-2000.

54 Projections of Groundwater Extraction Rates and Implications for Future Demand and Competition for Surface Water 57548_Book 17/6/03 2:21 AM Page 55

Figure 7-2 Comparison of Sustainable Yield, Allocation and Use in GMUs (excluding the GAB GMUs) in the Murray-Darling Basin.

Figure 7-2 clearly shows that most of the These issues include: GMU resources are either highly or over developed. Category 1 and 2 GMUs include 1. double accounting of groundwater and only 20% of the groundwater by volume in surface water (see Chapter 8 for the GMUs (excluding GAB GMUs). In the discussion on this). category 1, 2 and 3 GMUs (as shown in 2. possible reductions in sustainable yield Figure 7-2) there is 425 GL/yr not allocated, estimates to allow for groundwater and 600 GL/yr not used. Outside of these dependent ecosystems, groundwater GMUs the only other resources not fully salinisation and many other factors. allocated lie in the UAs, areas which are unlikely to develop due to location of the Both of these issues may result in a resource or quality. reduction in sustainable yield of greater than three to five per cent which means that the The groundwater resources in the GMUs not current level of development for the Basin currently allocated or used represent may not be sustainable. Certainly in the approximately three to five per cent of the overallocated GMUs and Cap regions the total water available in the Basin. This does current level of development is not not leave much room for error in the sustainable. accounting of water in the Murray-Darling Basin. Currently, there are several issues which need resolving to ensure that the accounting of water is accurate.

55 Projections of Groundwater Extraction Rates and Implications for Future Demand and Competition for Surface Water 57548_Book 17/6/03 2:21 AM Page 56

TABLE 7-1 Basin-wide groundwater data for 1999-2000 aligned along the designated Cap valleys (GL)

Cap Surface water cap region Total Groundwater Groundwater Groundwater Surface region groundwater sustainable use* inallocations water use number sustainable yields in 1999-2000 in in 1999-2000 (GL) yield in 1999-2000 in GMUs only in GMUs 1999-2000 GMUs only only

1 Border Rivers (NSW) 402 23 5 18 197

2 Moonie (NSW) 45 0 0 0 Not available 3 Gwydir River Valley (NSW) 426 44 52 120 444 4Namoi River Valley (NSW) 1,068 225 201 527 299 5 Macquarie-Castlereagh-Bogan 318 119 55 235 417 water supply system (NSW) 6 Barwon-Upper Darling water 372 0 0 0 175 supply system (NSW) 7 Lachlan River Valley (NSW) 521 338 96 469 296 8 Murrumbidgee River Valley 524 524 226 442 1,910 (NSW) 9 Lower Darling from the 95 0 0 0 85 Menindee Lakes to Wentworth Weir Pool (NSW) 10 Murray Valley (NSW) including 305 166 116 371 1,576 portion of Lower Darling influenced by the Wentworth Weir Pool Total New South Wales 4,076 1,439 751 2,182 5,399 11 Condamine-Balonne water 219 114 84 137 366 supply system (QLD) 12 Border Rivers (QLD) 58 15 3 15 162 13 Moonie River Valley (QLD) 11 0 0 0 8 14 Warrego River Valley (QLD) 17 0 0 0 3 15 Paroo River Valley (QLD) 9 0 0 0 0 Total Queensland 314 129 87 152 539 16 Goulburn-Broken-Loddon water 677 185 147 79 1,554 supply system (VIC) 17 Campaspe River Valley (VIC) 118 32 35 49 73 18 Wimmera-Mallee water supply 297 1 1 2 116 system (VIC) 19 Victorian portion of the Murray 456 50 40 83 1,573 Valley including Kiewa and Ovens River Valleys

24 SW Murray Province (VIC) 41 41 2 27 Not applicable Total Victoria 1,589 309 225 240 3,316 20 River Murray (SA) 126 65 44 83 364 22 Reclaimed swamps (SA) 0 0 5 0 79

23 SE Murray Province (SA) 203 203 133 204 Not applicable Total South Australia 329 268 182 287 443 21 Australian Capital Territory (ACT) 70 70 2 4 27 Total Murray-Darling Basin 6,384 3,741 1,268 2,861 9,542

There are 17 Cap regions in which GMUs have (excluding GAB GMUs) exceed the sustainable been delineated. In 13 of these Cap regions yield. In the Gwydir and Campaspe Cap region groundwater allocations in the GMUs use also exceeds the sustainable yield. 56 Projections of Groundwater Extraction Rates and Implications for Future Demand and Competition for Surface Water 57548_Book 17/6/03 2:21 AM Page 57

The Cap regions in which there are high be investigated to determine the accuracy of levels of usage and high allocations should the usage and sustainable yield estimates.

TABLE 7-2 Water use within surface water Cap regions, and groundwater contributions and development status in the Cap region

Cap Surface water cap region Groundwater Surface Total Groundwater Groundwater region use* in water use water use use as % of development number 1999-2000 in 1999-2000 total use status in ‘cap’ region (gw use/ gw sy)

1 Border Rivers (NSW) 19,734 195,800 215,534 9% 1 2 Moonie (NSW) 54,107 - 54,107 100% 4 3 Gwydir River Valley 70,861 359,923 430,784 16% 1 4Namoi River Valley 229,095 226,164 455,259 50% 1 5 Macquarie-Castlereagh-Bogan 89,748 406,840 496,588 18% 1 water supply system 6 Barwon-Upper Darling water 20,682 - 20,682 100% 1 supply system 7 Lachlan River Valley 102,020 258,769 360,789 28% 1 8 Murrumbidgee River Valley 226,064 2,144,270 2,370,334 10% 2 9 Lower Darling from the Menindee 385 146,324 146,709 0% 1 Lakes to Wentworth Weir Pool 10 Murray Valley (NSW) incl portion 119,228 1,913,600 2,032,828 6% 2 of Lower Darling influenced by the Wentworth Weir Pool 11 Condamine-Balonne water 250,416 514,563 764,979 33% 4 supply system 12 Border Rivers (QLD) 98,567 94,197 192,764 51% 4 13 Moonie River Valley (QLD) 15,406 1,209 16,615 93% 4 14 Warrego River Valley (QLD) 20,693 112,920 133,613 15% 4 15 Paroo River Valley (QLD) 11,880 233 12,113 98% 4 16 Goulburn-Broken-Loddon 159,950 2,992,425 3,152,375 5% 1 water supply system 17 Campaspe River Valley 38,004 441,980 479,984 8% 2 18 Wimmera-Mallee water supply 9,477 130,030 139,507 7% 1 system 19 Victorian portion of the Murray 51,368 480,795 532,163 10% 1 Valley incl Kiewa and Ovens River Valleys 20 River Murray (SA) 62,145 469,094 523,845 10% 2 21 Australian Capital Territory (ACT) 1,560 - 1,560 100% 1 22 Reclaimed swamps (SA) 5060 67,500 67,500 0% 1 23 SE Murray Province (SA) 133,630 - 126,100 100% 2 24 SW Murray Province (VIC) 21,610 - 21,610 100% 2 Total use 1,813,889 10,956,636 12,748,341 14% * The groundwater use by Cap region is apportioned by GMU by area within the Murray-Darling Basin. Hence some GMUs are not wholly within the Murray-Darling Basin, and hence only part of the groundwater abstraction in that GMU is included in a Cap region. The main example where this occurs is the GAB, where between 50% and 85% of the GMU lies spatially within the Murray-Darling Basin. The groundwater use figures for this project use the total groundwater use of those GMUs listed as within the Basin unless otherwise advised by the States. This creates some discrepancy in the total groundwater use figures listed in Chapter 5 and Appendix A, when compared with the Cap region figures above.

57 Projections of Groundwater Extraction Rates and Implications for Future Demand and Competition for Surface Water 57548_Book 17/6/03 2:21 AM Page 58

TABLE 7-3 Water allocations within surface water Cap regions, and groundwater contributions and development status in the Cap region

Cap Surface water cap region Groundwater Surface Total water Groundwater Groundwater region allocations water allocations allocation development number in 1999-2000 allocations as % of total status in in use ‘cap’ region 1999-2000 * (groundwater allocation/ groundwater sustainable yield) 1 Border Rivers (NSW) 38,280 70,400 108,680 35% 2 2 Moonie (NSW) 54,107 - 54,107 100% 3 3 Gwydir River Valley 143,718 529,007 672,725 21% 1 4 Namoi River Valley 571,504 263,977 835,481 68% 2 5 Macquarie-Castlereagh-Bogan 289,155 673,611 962,766 30% 1 water supply system 6 Barwon-Upper Darling water 25,508 - 25,508 100% 3 supply system 7 Lachlan River Valley 479,388 664,526 1,143,914 42% 2 8 Murrumbidgee River Valley 442,061 2,789,721 3,231,782 14% 2 9 Lower Darling from the Menindee 386 48,562 48,948 1% 1 Lakes to Wentworth Weir Pool 10 Murray Valley (NSW) including 376,252 2,230,369 2,606,621 14% 2 portion of Lower Darling influenc- ed by the Wentworth Weir Pool 11 Condamine-Balonne water 240,081 219,011 459,092 52% 2 supply system 12 Border Rivers (QLD) 30,502 103,137 133,639 23% 1 13 Moonie River Valley (QLD) 15,406 1,209 16,615 93% 3 14 Warrego River Valley (QLD) 20,693 112,920 133,613 15% 1 15 Paroo River Valley (QLD) 11,880 233 12,113 98% 3 16 Goulburn-Broken-Loddon 98,042 2,084,000 2,182,042 4% 1 water supply system 17 Campaspe River Valley 53,201 121,000 174,201 31% 2 18 Wimmera-Mallee water supply 11,226 94,250 105,476 11% 1 system 19 Victorian portion of the Murray 98,593 62,330 160,923 61% 2 Valley including Kiewa and Ovens River Valleys 20 River Murray (SA) 83,667 736,000 819,667 10% 2 21 Australian Capital Territory (ACT) 3,595 - 3,595 100% 3 22 Reclaimed swamps (SA) - 70,400 70,400 0% 1 23 SE Murray Province (SA) 204,300 - 204,300 100% 3 24 SW Murray Province (VIC) 27,890 - 27,890 100% 3 Total allocations 3,319,434 10,874,663 14,194,097 23% * The groundwater allocations by Cap region is apportioned by GMU by area within the Murray-Darling Basin. Hence some GMUs are not wholly within the Murray-Darling Basin, and hence only part of the groundwater allocation in that GMU is included in a Cap region. The main example where this occurs is the GAB, where between 50% and 85% of the GMU lies spatially within the Murray-Darling Basin. The groundwater allocation figures for this project use the total groundwater use of those GMUs listed as within the Basin unless otherwise advised by the States. This creates some discrepancy in the total groundwater use figures listed in Chapter 5 and Appendix A, when compared with the Cap region figures above.

58 Projections of Groundwater Extraction Rates and Implications for Future Demand and Competition for Surface Water 57548_Book 17/6/03 2:21 AM Page 59

8. Surface water and groundwater interaction

8.1 Introduction 8.2 General description of the

Surface water and groundwater interactions physical process of are complex and varied, both spatially and connection between surface temporally. There are many factors which water and groundwater influence groundwater/surface water interactions such as geology, geomorphology 8.2.1 Connections between and climate. An introduction to these groundwater and streams processes is given below, along with the categorisations that will be used to describe Groundwater and surface water are surface water/groundwater interactions within fundamentally interconnected. In fact, it is the Murray-Darling Basin. often difficult to separate the two because they ‘feed’ each other. Site specific data from existing literature and State information is reviewed. A methodology One interesting feature of surface water is developed to assess the level of bodies is that they often provide the physical connection between groundwater and boundaries for groundwater flow systems, surface water for different reaches within the and therefore provide the mathematical Murray-Darling Basin. The methodology is boundary conditions for groundwater flow presented along with a discussion of the models. Given the range of problems that advantages and disadvantages of using such could be classed as surface water— a method. groundwater interaction, and given their importance in defining boundary conditions Groundwater/surface water interaction is for aquifers, it is apparent that a large important in the context of this study proportion of practical groundwater because of the possibility of reducing surface problems involve some form of interaction water flows due to groundwater abstraction. with surface water. This is approximately quantified where information was available, and qualitatively Unsaturated flow (as shown in Figure 8-1), assessed in other areas to assess the extent whether from rainfall or surface water bodies, of risk of impact on the Cap within the Basin. is difficult to predict. Saturated flow (also Each stream or given river reach is shown in Figure 8-1) between surface water categorised within each groundwater bodies and aquifers may appear to be management unit (GMU) according to simple, but the details are very complex. whether it is a gaining or losing stream, and Bank storage increases this complexity, with the level of dependence, including any the stream losing water during high flows to seasonality in this dependence. both banks and groundwater. When the This project identifies ‘hotspot’ areas which stream levels decrease, water stored in the need further investigation to determine how banks then flows into either the groundwater much of an impact groundwater extractions or stream. The stream is now gaining from may have on surface water flows. water stored in the banks, and may also be gaining from groundwater, depending on the groundwater levels.

59 Projections of Groundwater Extraction Rates and Implications for Future Demand and Competition for Surface Water 57548_Book 17/6/03 2:21 AM Page 60

Figure 8-1 Connections between streams and aquifers (a) unsaturated flow (b) saturated flow and bank storage conditions (Winter et al. 1998).

Surface water bodies act as sources and surface water body may be small relative to sinks for aquifers, with the net flux from the total flow, groundwater does have a water body to the aquifer varying profound influence on surface water quality, dynamically in response to individual rainfall particularly on nutrient status within this events or longer term seasonal cycles. sensitive environment. Some water bodies act as recharge water bodies, such that surface water recharges 8.2.2 Gaining or losing streams the aquifer over the whole bottom surface of the water body. Others act as discharge Depending upon whether the groundwater water bodies, receiving groundwater over is entering or leaving the river channel, the the whole bottom surface. Many water channel is either called an effluent (gaining) bodies act as flow-through water bodies, stream or influent (losing) stream such that groundwater discharges to the respectively. The same channel may water body over some part of the bed and behave as an effluent stream as well as an surface water recharges the aquifer over influent stream with changing seasons, and the remaining part of the bed. The net flux some streams can behave as effluent between an aquifer and a flow-through streams or as influent streams in different water body can be either upward or places along their length, particularly near downward. The groundwater flow regime meanders. This is shown in Figure 8-2. near a surface water body depends on a Seasonal effects can alter the type of number of geometrical factors, but also on connection between groundwater and surface the relative magnitudes of regional water, with streams gaining in summer groundwater flows near the water body months and losing in winter in some regions. and on recharge or evapotranspiration. This can also be altered due to pumping It should also be noted that groundwater where a gaining stream receives reduced inflow to streams can cause a reduction in discharge (Figure 8-3b), or in some cases, quality of the surface waters due to the the flow is reversed and the stream-aquifer higher salinities and naturally occurring interaction is reversed due to groundwater constituents within groundwater such as pumping (Figure 8-3c). This scenario is

NO3, metals and other compounds. High referred to as induced recharge, with the concentrations of ammonium and other stream noted as a losing stream. These types constituents in pore water in river of system are designated as ‘seasonal’ sediments are also flushed into the aquifer interactions in Section 8.6, where some of and subject to similar convective flow and the seasonality may be induced by eventual discharge into the river with groundwater pumping. fresher groundwater (Turner et al. 1999). Thus although groundwater fluxes into the

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(a)Gaining Stream (b) Losing Stream Flow direction Flow direction

Figure 8-2 Characterisation of Gaining (a) and Losing (b) Streams (Winter et al. 1998).

Figure 8-3 Effects of groundwater pumping on connection between surface water and groundwater (Winter et al. 1998).

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8.3 Given river reaches regionally the impact of groundwater use on the ‘cap’, and hence, from a regional The ‘Given River Reaches’ are derived from perspective it was thought that the largest the Sustainable Rivers Audit reaches (CRCFE scale required would be by GMU. This is also 2001), which are based on ecological and the largest scale at which groundwater use geomorphological processes of the streams. information is available. To correlate the Only the major tributaries and reaches are impact of groundwater use on the ‘cap’, the included in this categorisation, with the river reaches had to match the scale of upland creeks and minor tributaries not groundwater use data. The downside of this included. methodology is that because it is so broad scale, it can not be used for practical There are 12,934 given river reaches in the management purposes. If more detailed Murray-Darling Basin, with some rivers split information in a GMU/UA is required, a more into hundreds of sections, and others, split detailed investigation would have to be into less than ten. Reach length also varies undertaken, rather than a broad brush considerably, with some only metres long, analysis as undertaken here. and other hundreds of kilometres long. As such the reaches are not consistent in The final set of ‘adjusted river reaches’ length and do not relate to GMUs or regions analysed is listed in Table D-1 in Appendix of groundwater/surface water interaction. D for each GMU and UA. The ‘adjusted river This poses a problem in analysing the reaches’ are shown in Figure 8-5, and information as the level of data available to consist of 179 reaches, compared with the categorise each reach is not detailed enough original 12,934 ‘given river reaches’. to categorise at the level of given river reaches supplied. For this reason, the river reaches have been analysed on an alternative set, which will be referred to as the ‘adjusted river reaches’ (see Figure 8-5).

The ‘adjusted river reaches’ are based on the same rivers and tributaries as given in the ‘given river reaches’, they are however split by tributary for each Unincorporated Areas (UAs) and GMU. As such each river or tributary is only listed once per GMU or UA, as this is the level of detail that data was available for. This allows for the level of groundwater and surface water interaction to be noted in each managed groundwater area so that the ‘hotspots’ can be identified, and more intensive investigations undertaken where required.

All information from the original ‘given river reaches’ has been kept in the ‘adjusted river reach’ layer.

The ‘given river reaches’ were not a useable scale at which to undertake the surface water groundwater interaction analysis. Information was not available at this large scale, with the information from the literature review and States predominantly on larger reaches or regions, which either could not be easily translated to ‘given river reaches’, or was so specific that it meant little in the regional context. This study aims to assess

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See enclosed CD for this map in more detail—PDF format

Figure 8-4 Given river reaches from Sustainable Rivers Audit.

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8.4 Literature review on Murrumbidgee River over the same period. surface water and However, the significant thing to note is that 90% of the groundwater extraction is actually groundwater interaction losses from stream flow, and hence groundwater extraction in this area is already 8.4.1 Discussion of articles impacting on the ‘cap’. This means that reviewed resources need to be managed conjunctively, and allowances made for these stream A literature review on groundwater and losses to groundwater. surface water interactions within the Murray- Darling Basin has been undertaken. This The Goulburn and Broken Rivers in Victoria information has also been translated into were assessed for nutrient loads by GMU and adjusted river reaches to match Hydrotechnology (1995). The significance of the study with the scales of reporting for this this project is that estimates of groundwater project. inflows to streams is available for these streams (as listed in Table 8-1). The There are relatively few published papers on implication of this study is that both the groundwater/surface water interaction within Goulburn and Broken Rivers are gaining the Murray-Darling Basin. Many of these streams in the lower reaches where the study articles discuss the implications of land was undertaken. The level of groundwater salinisation due to rising watertables, along inflow varies with each reach, with those with increased river salinities due to reaches closer to the Murray River gaining at groundwater inflows. The assessment of the a higher rate near McCoys Bridge and actual connection between groundwater and downstream of the Goulburn Weir. Because streams has not been dealt with in detail, these river reaches are gaining the likelihood except for the following four cases: of groundwater impacting on river flows is • Murrumbidgee River at Wagga Wagga not significant, although if inflow to either in New South Wales stream is significantly reduced due to • Goulburn and Broken Rivers in northern groundwater extraction, this may impact on Victoria existing surface water users and the ‘cap’.

• Northern Murray-Darling Basin catchment The downstream reaches of the Goulburn streams and Broken Rivers lie within a series of • Ovens River in northern Victoria GMUs, including the Shepparton These are discussed below. Groundwater Supply Protection Area (GSPA) (covering the Shepparton Formation aquifer), Part of the Murrumbidgee River has been Katunga GSPA (covering the deep leads) and documented as a losing stream (DPW 1992; the Avenel and Kialla GMUs which also cover Lawson and Kulatunga 1998). Modelling of the deep lead systems. There is potential for the river and aquifer system indicates that conjunctive management of groundwater and groundwater volumes extracted from the surface water resources in this area. Most of Gumly Gumly borefield is greater than the these systems interact with the local streams loss in storage in the aquifer. either directly or indirectly via aquifer leakage to the deeper systems. Some allowance is ‘The groundwater system works by currently made for aquifer stream interaction inducing downward leakage of water from in these GMUs sustainable yield estimates the Murrumbidgee River through the (NRE, 1998). shallower layers and into the deeper sand layers where the bore screens are placed’ (DPW 1992).

Over a period of four and a half years of continuous pumping it was estimated that 90% of losses from the Murrumbidgee River were due to induced recharge caused by groundwater extraction. This represents only 0.23 per cent of the average river flow in the

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TABLE 8-1 Calculated groundwater inflow rates to Goulburn and Broken Rivers in northern Victoria (Hydrotechnology 1995)

Catchment or river segment Groundwater inflow to stream (m3/km/day)

Moonee Ck (Bt) 80

Hollands Ck (Bt) 40

Upstream of Casey’s Weir (B) 46

Upstream of Orrvale (B) 60

Sugarloaf Ck (G) 138

Upstream of Murchison (G) 107

From Goulburn Weir to Murchison (G) 1720

From Murchison to McCoy’s Bridge (G) 780

Upstream of McCoy’s Bridge, including (GB) 129

* Key: B = Broken Catchment; G = Goulburn Catchment; t = tributary stream

Several rivers in the northern Murray-Darling variable according to the data available for the Basin have been assessed with respect to assessment, with only a qualitative their groundwater salinity trends and river assessment given. This at least gives an interaction (McNeil and Horn 1997). The assessment of the nature of the relationship information on the connection between between groundwater and surface water, surface water and groundwater from this it does not however, indicate whether the article is listed in Table 8-2. The information is streams are losing, gaining or seasonal.

TABLE 8-2 Summary of groundwater/surface water hydraulic connection based on water chemistry, northern Murray-Darling Basin (McNeil & Horn 1997)

Area Groundwater/surface water hydraulic connection

Western Basin Generally weak hydraulic connection (though very poor data set)

St. George Insufficient data

Condamine River, Dalby to Chinchilla Chinchilla to Warra—moderate hydraulic connection Dalby to Warra—poor hydraulic connection

Dalby south to the convergence of the north Poor hydraulic connection anabranch and main channel of the Condamine River (approximately 5km north of Cecil Plains)

Convergence of the north anabranch and main Good hydraulic connection channel of the Condamine River (approximately 5km north of Cecil plains) south to Pampas

Condamine River (Pampas to Allora and Pratten) Good hydraulic connection

Pratten to Warwick Good hydraulic connection close to streams

East of Warwick Good hydraulic connection near streams

Mid to upper Oakey Creek Poor hydraulic connection towards Jondaryan

Oakey to Toowoomba and Cambooya Significant hydraulic connection

Clifton Good hydraulic connection east of Clifton

Border Rivers Insufficient data

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Extensive studies have been undertaken on between 8,000 and 50,000 m3/d flowed from the Ovens, Buffalo and Buckland Rivers in groundwater to streams in south-west New northern Victoria (Shugg 1987, Shugg & Slater South Wales in the Murray and Darling Rivers 1987). These studies indicate that these under current land use practices, and then streams are gaining streams, with estimated what changed land use practices groundwater discharge maintaining baseflow would do to the inflows to streams. The in the streams for the whole year. The changed land use scenarios are not assessment has indicated that around seven discussed in this analysis as they were per cent of average annual stream flow near hypothesised scenarios that may not have Myrtleford is accounted for from groundwater. changed the current land use practices. River The hydrographs of bores in the region show reach length was not stated in the paper, so a clear seasonal pattern with September the level of connection per kilometre reach through to March showing significant declines, could not be determined to assign a rating to due to loss to rivers. Groundwater extractions the streams. These types of studies give an are managed carefully to ensure that river indication of the type of connection but not flows are not impacted on by the extractions, the magnitude of the interaction between and sustainable yields of the aquifers in this groundwater and streams, and so are limited region have been reduced accordingly in order in their use in this study. to avoid reducing stream flows (NRE 1998). Similiarly the impact of possible interception Studies in the Lower Namoi River have schemes on stream salinities have also been indicated that it is a losing stream (Kalaitzis et investigated. This includes studies on Pyramid al. 1999). This report assessed the likelihood Creek by Linke and Kendall (1995); a study on of whether groundwater pumping would the Murray River at Lambert Island, Lindsay impact on stream flows in the future, and River and Chowilla Creek by Evans (1987); comments were made to indicate that the and another study on the Woolpunda level of loss from streams is not likely to interception scheme on the Murray River is increase with declines in groundwater level. described by Telfer (1987). This latter study by 3 ‘Groundwater modelling indicated that Telfer estimated that 10,000 m /day flowed to river leakage to groundwater is not the River from groundwater. This interaction significantly affected by groundwater may have occurred over a 30km stretch from pumping, and further declines in Lock 3 to Waikerie (the report did not clearly groundwater levels were not expected to state over what reach the estimate is for), increase the rate of river leakage since it which would result in stream flow gaining at a 3 is already thought to have reached its rate of approximately 300 m /day/km reach. maximum limit. Average stream flows are These papers and discussion of possible expected to remain stable in the long- interception schemes relate to groundwater term’ (Kalaitzis et al. 1999). inflows to the Murray River, either directly or This means that the stream is not likely to be indirectly via tributaries in north-western impacted on by additional groundwater Victoria and South Australia. These flows are extractions, however the current loss needs significant in terms of the salinity loading on to be accounted for in either the stream the streams, however, the actual significance diversions or the groundwater sustainable of the hydraulic connection between the yield to ensure that it is not allocated out as aquifers and the Murray River and tributaries both groundwater and stream flow licenses. is not discussed. What is known from these papers is that the Murray River and tributaries Land management changes and the from near Swan Hill to the mouth of the River implications for streamflow salinities are are gaining streams, however, the magnitude discussed in many papers (Linke et al. 1995; of this connection is not known. Prathapar et al. 1994; Schache et al. 1995; Jolly 1990), however, in most cases they do The Darling River at Bourke has been not discuss the level of connection between described as having ‘highly dynamic’ groundwater and surface water aside from interactions, with a reliance on streamflow the aspect of describing the stream as levels as to whether the stream is gaining or gaining. Prathapar et al. estimated that losing (Williams 1994). If river flows exceed

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4,500 ML/d there are no inflows with groundwater/surface water interaction was hydrostatic pressure reached between not dealt with on its own in most cases. The groundwater and the stream. Less than 750 information used to make the assessments is ML/d stream flow and the river is highly therefore predominantly based on qualitative dependent on groundwater flows. This assessments. As such, the river reach seasonality is described as occurring only assessment here will also be a qualitative within a narrow 3km reach near Bourke, assessment. which implies that it may not occur in other reaches of the Darling River. Comments were It must be kept in mind too that it is not only also made on the fact that the deeper semi- the watertable aquifers that interact with the confined system leaks into the River during streams. Many deeper aquifers rely on low flows contributing highly saline leakage from either the watertable aquifer or groundwater through parts of this reach. streams for recharge to the system, and in other cases may discharge to streams in low flow, such as the Darling River near Bourke 8.4.2 Literature review summary (Williams 1994). The literature review has indicated that many of the streams within the Murray-Darling Basin 8.5 River baseflow project are gaining streams in the Mallee (Murray River from Swan Hill and downstream). The Riverine A survey of baseflows in unregulated Plains region where many of the tributaries catchments in the Murray-Darling Basin (SKM and GMUs in New South Wales lie, seem to 2001) analysed 178 river sites and found correlate with losing streams. For example, the annual baseflow indices ranging from four per Murrumbidgee River is noted as a losing cent up to 76%, with a median annual baseflow stream. This is because of groundwater index of 25%. Baseflow contributed more than pumping in some reaches, whilst in others 50% of the total summer flow at 36% of the it is naturally occurring. sites and contributed more than 50% of the total autumn flow at 44% of the sites. As In other parts of the Murray-Darling Basin, expected, the study showed that groundwater such as the northern regions of the Basin in discharge to streams is the greatest proportion Queensland and New South Wales of streamflow during the autumn. Most of the groundwater/surface water interaction is unregulated catchments analysed in this study described as high (McNeil and Horn 1997). were in the fractured rock aquifers of the In the southern parts of the Murray-Darling eastern highlands. The 25% median baseflow Basin in Victoria, there is also a high index confirms that groundwater discharge is a connection between groundwater and the significant component of the stream flow. Ovens, Buckland, Buffalo, Goulburn and Groundwater extraction near these streams Broken Rivers. The same can be said of the would be expected to have a major impact on Darling River at Bourke in New South Wales. stream flow. The results only cover a small portion of the Murray-darling Basin, but From these articles it appears that there are contribute quantitative data on the level of many areas of consistently high connection dependency of streams in the highlands. between groundwater and surface water in the Murray-Darling Basin. With respect to impacts on the Cap in the Basin though, it is only when 8.6 Connection between there is a significant connection that adjusted river reaches in groundwater extractions will make a notable the MDB and GMUs/UAs impact on the Cap. The level of the impact however, is not as well known, and is only The connection between GMUs and UAs described in detail in some specific cases. and the adjusted river reaches has been determined based on the rating system In general, there is not enough information on described in Table 8-3. The ratings are the level of connection between groundwater indicative only since in most areas the actual and surface water. The information sought for rate of inflow to streams from groundwater is this study was often a side issue in a paper not known. The assessment is based on the addressing land use change or groundwater following methodology. interception schemes. The actual

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8.6.1 Methodology for determining river/aquifer was made, and categorised as connection between river either low, medium or high. reaches and GMUs and UAs The depth to watertable and geomorphological zones (as an indication of The methodology used to determine the river gradient and energy) were used to physical connection between river reaches estimate whether the river would be a gaining and the GMUs and UAs was subjective, but or losing stream, or if it was a seasonal included many inputs to obtain the final rating. stream in which it could be both at different The general inputs to the method were: times of the year. • adjusted river reaches • lithology close to the rivers Watertable depth is an important factor in determining stream aquifer interaction, • depth to watertable in the Basin in the however, it is often the river level which Murray and Darling groundwater dictates whether the stream is losing or provinces (this excludes the highlands gaining at any time. As such, depth to and the Lachlan groundwater province) watertable can really only be used when the • literature review information watertable is deep and the stream can be • data obtained from the States on assumed to be a losing stream. In other groundwater/surface water interaction instances there are too many other variables • National Land and Water Research Audit to consider, such as the river levels, and 2000 data. aquifer pressures to assume any particular type of connection. One of the prime considerations was the actual material connecting the river bed and 8.6.2 Adjusted river reach banks with the aquifer system. In some areas this connection is known to be high where groundwater/surface water the river bed sediments consist of gravels interaction categories and sands. In other areas, there is an The three categories for river reaches within intervening layer of clay between the river the Murray-Darling Basin are: losing, gaining bed and the aquifer, and hence this and seasonal streams. Within each of these connection is reduced. categories there are sub-groups which can The analysis used the lithological zones and be described by high, medium and low other information from the States and categories. These categories correspond to literature review to determine what level of the following classification system, where the connection the aquifer had with the river rating is based on the rate of flux in or out of reach. From this information an estimate of the stream from the groundwater system, the level of connection between the along a given river reach within a GMU or UA.

TABLE 8-3 Groundwater/surface water interaction categories

Main category Sub-category Rate of flux in/out of stream

Losing High > 1000 m3/day/km

Medium > 10 m3/day/km & < 1000 m3/day/km

Low < 10 m3/day/km

Seasonal Naturally occurring or induced All by pumping

Gaining Low < 10 m3/day/km

Medium > 10 m3/day/km & < 1000 m3/day/km

High > 1000 m3/day/km

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The rates given to each of the categories are instream. Studies have been undertaken slightly smaller than recent work undertaken previously (Harrison and Clayton 1970), to try by Department of Land and water to correlate the sediment transport Conservation (DLWC) on regulated and processes in streams to whether it is a unregulated streams and aquifers in gaining or losing stream with some results ministerial water sharing plans (M Williams, indicating that areas of sediment transport pers. comm. 5 July 2001). Other States are are more likely to be gaining streams. The also undertaking studies within high demand results were inconclusive but give some regions such as the GMUs, and this preliminary indication from which to start an information has been used where available. analysis. The lithology and other available information was used to decide on the Basic Darcy’s Law calculations indicate that connection type in these reaches. River beds the rate of seepage into or out of a stream is composed of sand and gravel deposits were 3 in the order of 1 m /day/km reach to 1000 assumed to have a high connection, and any 3 m /day/km reach for hydraulic conductivites silts and clays a low connection. of 0.1 m/day (representing clays and silts) to 100 m/day (representing coarse sands). This Further into the plains and towards the lower is assuming a river bed width of 10 m and a reaches of the Darling, Murrumbidgee, groundwater hydraulic gradient of 0.001. Lachlan and Macquarie Rivers the streams Closest to the stream this gradient may in become flatter and the difference between fact be much higher, and the river bed width groundwater levels and river bed levels will of course vary, along with the sediment becomes greater. Semi-arid regions are type in the river bed and between the aquifer commonly noted as having watertables of and river bed. It does however give indicative 20m depth and greater, and this is the type of rates of seepage from which the magnitude landscape encountered in the south-western of the connection between a river and aquifer parts of the Basin. Since most of the reaches can be estimated. lie in areas of depth greater than 10m, the streams were assumed to be losing in these 8.6.3 Results and discussion of lower reaches. Studies on the Murrumbidgee results indicate that watertable depths and increased groundwater pumping has led to increased The broad assessment of stream and losses from the rivers to the aquifers. groundwater interactions in the Basin comes In the south western portion of the Basin the from the following discretisation of land units. Murray River is heavily incised into the The highlands, riverine plains and the Mallee landscape. The watertables are deeper in this were categorised generally, with additional part of the Basin too, but there is still potential information then used to clarify the for groundwater discharge into the Murray assessment of each adjusted river reach. River, because the river is incised. The In general, the upper reaches in the highlands downstream end of the Murray is heavily were assumed to be gaining streams with incised and is a gaining stream most of the high energy reaches and high river bed way from the South Australian/Victorian border gradients corresponding with erosional zones to the Murray mouth. A considerable portion of in the rivers. The depth to watertable can be the River receives highly saline groundwater high in these parts, although groundwater downstream from Swan Hill. Calculations of springs are common. This is especially so in inflows to the Murray River near Wemen the Lachlan Province where fractured rocks (downstream of Robinvale) estimated aquifers are the common hydrogeological groundwater flows of between 80 and 200 type and at fracture zones, high rates of m3/day/km under high flow conditions, with up groundwater flow can be found. to 10,000 m3/day/km in low flow conditions (NRE 1998). This reach would hence be From the highlands down to the riverine plain categorised as medium to high connectivity and Darling Downs, the river bed gradient and a gaining stream. However, significant becomes lesser, rivers become wider and volumes of water are contributed to the aquifer change form into more meandering streams, during flood, and the stream gains during with small connected floodplains, and median and low flows (NRE 1997). predominantly sediment transport zones

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The amount of information available for each Much of the baseflow for rivers comes from reach in each GMU varies considerably. Little groundwater in the upper reaches in the quantitative data is available for any of the highlands. Many of these reaches were not GMUs except from some information collated included in the given river reaches and hence during the sustainable yield estimations (NRE are also missing from the adjusted river reaches 1998), or in detailed reports on particular which are based on the same set of rivers and GMUs. Qualitative information was collected tributaries. The level of detail of this study must from States such as the recent Stream- be kept in mind when looking at the results on a Aquifer Interaction study by DLWC (Williams regional scale. Small scale details have not been 2001), and from the literature. included in this study, such as the highland tributaries where there is considerable The rankings for the connection, as interaction between groundwater and surface discussed previously give an indication of the water. This also applies to other tributaries of level of contribution to stream flows, or rivers. For example, there are several tributaries losses from streams to groundwater. Those of the that are not included in aquifers in which the connection is seasonal, the adjusted river reaches, and which have are those in which there are either both significant groundwater baseflow contributions, gaining and losing sections of the stream, or such as Sunday Creek. where pumping influences the Another factor to consider is that there are groundwater/surface water connection. some GMUs which have little direct interaction Less than ten per cent of the adjusted river with streams, but can induce stream loss reaches lie in the GMUs, let alone are through regional drawdowns in the watertable. connected to the GMU aquifers (see Depending on the area included in a GMU, it Figure 8-5). The UAs include most of the may not include all rivers or tributaries that can adjusted river reaches, and as previously be affected by groundwater extraction, and mentioned, although there is high hence this interaction may not be identified connection in some of these areas, the correctly. As a minimum, all GMUs that cover connection is usually with more saline watertable aquifers should be assessed for groundwater resources which are less likely possible impacts on nearby streams to ensure to be developed and hence impact on that there is no impact on stream flows if a surface water. localised or regional drawdown in the GMU occurs. Seasonal effects should especially be Some of the tributaries of the Murray and noted, as groundwater is predominantly used Darling Rivers lie within GMUs of the Basin, for irrigation, and used over the summer periods however, a greater proportion lie in regions when streams are often at their lowest level, and where there is minimal management of have the highest potential for impact by groundwater resources, in the UAs. As such, groundwater extractions. there is ready potential for conjunctive Not all GMUs have a high level of interaction management of the resources within the with surface water, or lie in regions where GMUs, but only limited potential outside of surface water is available (e.g. the Border zone these areas, unless these interactions are between South Australia and Victoria). In these included in a catchment management plan areas, there will be no impact of groundwater looking at both groundwater and surface development on the Cap. water resources in that region. The Great Artesian Basin (GAB) is not The need for this analysis of groundwater considered here due to allowances already and surface water connection is in order to made for the mound springs in terms of identify those areas where there is high groundwater dependent ecosystems, and development of both groundwater and the recharge areas of the GAB in the eastern surface water resources, and where there is Queensland highlands (David Free, pers. a high connection between the two. In these comm. GABCC 1998). The watertable areas, a ‘conjunctive’ management option aquifers overlying the GAB have been will be required to ensure that allocations to analysed for connection with streams though, water resources are not duplicated, and that as shown in Figure 8-5. allowances are made for the interactions UAs are listed in Table D-2 in Appendix D with between groundwater and surface water. their groundwater/surface water connections.

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Most of the alluvial valleys are included within the areas where there is high potential for GMUs and hence the areas of high connection impacts on stream flows from groundwater between groundwater and surface water pumping lie within the GMUs, which are highly generally lie outside of the UAs. Also, the developed and in many cases overallocated watertable UAs are highly saline in many areas, and overused. especially in the Murray province. The high salinity of the groundwater resources means There are 29 GMUs (out of 88) that are highly or that they are not likely to be developed in these over developed by use in the Murray-Darling areas, and hence there is little potential for Basin, and 60% (17 GMUs) of these have a impacts on stream flows, aside from the high level of connection with streams. These 29 degradation of quality of the stream flows. GMUs represent 70% of the groundwater use in GMUs in the Basin, and 45% of the available Along the Great Dividing Range in northern New resource. Of these 17 GMUs, eight are South Wales and Queensland the watertable connected to losing streams, one to gaining aquifers in these UAs (which have not been split streams, and another eight are either seasonally from other aquifers in these States) would also varying or both losing and gaining in different have considerable contribution to stream flows reaches within the GMU. The top ten of these in the highlands. The reaches in these areas lie seventeen GMUs have been listed as priority in fractured rock aquifers that have previously areas for investigations into groundwater/surface not been developed, often due to the high water interactions, as given in Table 8-4 below. variability of aquifer yields, and groundwater The prioritised GMUs are mainly those that have quality. Any future development of these areas connection to losing streams where impact will needs to be managed proactively to ensure that be greatest on the Cap. impacts on streams flows do not occur. The main source of information on groundwater surface water connection is 8.6.4 Summary of from literature and State supplied information. groundwater/surface water This information gave qualitative assessments connection results of the connection between streams and aquifers in the Basin, but it rarely gave The connection between groundwater and quantitative assessments. As such, the surface water is extremely important in the analysis here is a qualitative analysis based Murray-Darling Basin. It appears that most of on a broad brush assessment.

Table 8-4 Recommended priority GMUs for more detailed studies on stream-aquifer interaction

GMU GMU name Adjusted river reaches Development Likely number status impact 1999-2000

Q57, Q58, Condamine GMA Sub Condamine River 4 High Q59 Areas 1, 2 & 3

N09 Lower Namoi Alluvium Namoi & Pian Creeks 4 High

N11 Lower Gwydir Gwydir, Mehi & Moomin 4 High Rivers

V39 Katunga GSPA Broken Creek, Goulburn 4 Medium River, Murray River

V42 Campaspe GSPA Campaspe River 4 Medium

N10 Lower Murrumbidgee Lachlan & Murrumbidgee 3 High Alluvium River

N21 Mid Murrumbidgee Alluvium Murrumbidgee River 1 High

N12 Upper Namoi Coxs Creek, Namoi River, 3 Medium , Warrah Ck

N24 Lower Murray Edward & Wakool Rivers 3 Low

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Any conjunctive management of groundwater Some of these streams are also gaining in and surface water will need to consider more other reaches. The analysis here, for both detailed analyses on a GMU basis. It should losing and gaining streams, has been based consider all situations in which the river on the assumption that the entire reach changes from losing to gaining, either due to within a GMU is losing or gaining at the same river level, or reduced watertables along that rate along the reach. reach, and seasonal effects and pumping induced effects should be noted. Any It should also be noted that many streams dependencies on groundwater need also to are gaining streams. The impact of be listed to ensure that groundwater development of groundwater resources will extractions do not impinge on river baseflow be highly variable and any reduction in and reduce environmental flows down the streamflow will constitute an impact on the river, or impact on surface water users. stream. Examples of some of the gaining reaches are listed below, with volumes of inflow to streams shown for each river: 8.6.5 Implications for the Cap • Buckland, Buffalo and Ovens Rivers in The crucial figure for assessing the impact of Murmungee GMU (52,000 ML/yr), current groundwater pumpage on streamflow NRE 1998 in the Murray-Darling River system, and thus • Goulburn River in Alexandra GMU its impact on the Cap, is the amount by (1241 ML/yr), NRE 1998 which the total streamflow is reduced by • Loddon River in Moolort GMU groundwater pumping. The total groundwater (158 ML/yr), NRE 1998 pumpage is known with a reasonable degree of precision, but the amount of leakage from • Pheasant Ck in King Lake GMU streams, and the decrease in inflow, that is (170 ML/yr) NRE 1998 consequent upon this pumpage is unknown. The figures denoted here are volumes of Various estimates of the rate of river losses groundwater inflow to streams, not the attributed to groundwater pumpage have been proportion of groundwater use to made, as referenced in the preceding sections groundwater inflows to the stream, which of this chapter. It is possible to develop gives no indication of the level of stress on arguments which favour either a small or large streams from groundwater extractions. The proportion of the volume of groundwater proportion that would indicate the level of pumped being derived from streams. The two impact of groundwater use on streamflows, extreme arguments are as follows: is the actual reduction in volume gained by streams due to groundwater extractions. Conventional wisdom would favour the This volume however, is not known. relatively small proportion of about ten per cent of the groundwater pumped being The alternative extreme perspective is, derived from streams. This is inferred from however, that the losses from streamflow analysis of river losses. The proportion of induced by groundwater pumping are close groundwater derived from streams within to 100% of the volume of groundwater GMUs has been determined for the following pumpage. All groundwater pumped must be cases of losing reaches of streams: a loss to streamflow, whether the stream is gaining or losing. The diagrammatic •Broken Creek (-23%), NRE 1998 representations in Figure 8-3 illustrate the • Loddon River (-10%), NRE 1998 point. Water pumped from the aquifer results • Campaspe River (-6%), NRE 1998 in either a reduced flow into the stream • Goulburn Rivers (-21% to –35%), NRE (Figure 8-3b), or to direct losses from the 1998 stream (Figure 8-3c). The only water not lost • Serpentine Creek (-12%), NRE 1998 to streamflow is that which would otherwise have left the aquifer as evapotranspiration. • Gwydir River (-19%), assuming a rate of loss of 150 m3/day/km (Williams 2001) The largest reported correlation between • Moomin Creek (-2%), assuming a rate of groundwater use and stream losses comes loss of 30 m3/day/km (Williams 2001) from the study undertaken on the • Murrumbidgee River (-90%), DPW 1992 Murrumbidgee River, where stream losses

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induced by groundwater pumpage were aquifers, groundwater pumping will assessed at an amount equal to 90% of eventually result in stream flow reduction groundwater extractions. The alluvial aquifer resulting from increased recharge in the system along this part of the Murrumbidgee intake areas. Valley is some 100m thick, with thick coarse 3) GMUs located in South Australia and the sand and gravel layers separated by clay and Victorian Wimmera and Mallee are not sandy clay layers. The aquifer layers have a connected to any streams. These GMUs high hydraulic conductivity, and there is good account for five per cent of the total interconnection between the aquifer layers. groundwater sustainable yield in the While the shallowest aquifer is less permeable Murray-Darling Basin. than the deeper ones, it is in direct connection with the river, and rainfall recharge 4) Across the broad alluvial valleys where is limited to some extent by a widespread the river floodplains are wide, (in fact shallow clay unit. Conditions therefore favour across much of the Riverine Plain), there high rate losses from the River in response to is substantial micro relief whereby high rate groundwater pumping. Where such groundwater readily discharges to shallow conditions are not present, high rate depressions and/or is removed by groundwater pumping will be less likely to be evapotranspiration. Hence much possible. The Murrumbidgee example can groundwater which would otherwise therefore be seen as an extreme case to discharge to rivers and streams is lost to adopt initially, for assessing the general the atmosphere. response of river systems to groundwater 5) In surface water based irrigation regions recharge. Adoption of the 90% ratio is of the Murray-Darling Basin, there are therefore suggested as an upper bound significant accessions to groundwater of estimate. That is, the global estimate of irrigation water sourced from surface stream losses in the Murray-Darling River water streams. Notwithstanding that system induced by groundwater pumpage is some of this water produces perched 90% of the total groundwater pumpage. groundwater mounds, a significant amount returns via the groundwater to However, across all the Murray-Darling Basin, rivers. some significant situations exist which must reduce this 90% estimate. These are: The above five mechanisms/situations all act to reduce the proportion of pumped 1. Situations in which the watertable is, groundwater which would otherwise under naturally occurring conditions, discharge to streams. It is clear that across deeper than the river bed for the entire all the Basin there are a broad range of reach. Under these circumstances, situations and both ten per cent and 90% streamflow losses are restricted by an cases exist. Insufficient data exists to unsaturated flow path beneath the river accurately quantify this impact. Nonetheless bed. An increase of watertable depth the ‘90% argument’, with some significant consequent upon groundwater pumpage exceptions as described above, is would not result in increased river losses, considered to be the most appropriate way although such losses might possibly be of viewing the impact of groundwater use on induced further downstream if the water the Cap. It is considered that the above table again becomes coincident with the exceptions would act to reduce the 90% stream bed. figure to approximately 60%. Hence, for 2. For deep aquifers (i.e. non-watertable planning purposes it is proposed that 60% GMUs) which are confined systems the be adopted as the best overall estimate. amount of downward leakage is generally small. In addition ‘down’ aquifer flow The total growth in groundwater usage would tend to produce saline discharge from watertable aquifers since the Cap was introduced in 1993-94 up until 1999- to the Murray River in the Mallee and 2000 has been 310 GL/yr. Adopting the hence is discounted in this assessment. above 60% estimate results in 186 GL/yr Deep GMUs account for 15% of the total of stream flow being captured. That is, the volume of GMUs. There is a counter Cap is being impacted on with losses to argument that even for these confined groundwater due to extraction of around 73 Projections of Groundwater Extraction Rates and Implications for Future Demand and Competition for Surface Water 57548_Book 17/6/03 2:23 AM Page 74

186 GL/yr. This volume represents two per cent of the total surface water Cap usage of 9,997 GL/yr. The 186 GL/yr has an economic value of up to $14 million per annum. The net present value of this amount over the 50 year period is estimated at between $110 million and $160 million for discount rates of 12% and eight per cent per annum respectively.

With increased development of the GMUs that are currently only partly developed, this loss will increase up to 1,395 GL/yr by 2050, assuming all GMUs are fully developed. However if it is assumed that the usage is reduced to sustainable yield levels for those GMUs that are currently over developed, then the loss will be significantly less at 711 GL/yr. This volume would represent seven per cent of the total surface water usage. Hence there is currently a significant impact of groundwater use on the Cap which will only increase.

It is important to note that the Cap is defined as an annual use limit. The question arises as to whether groundwater extraction some considerable distance from a river would actually represent an impact on the strict definition of the Cap. Hypothetically, the groundwater extracted might have taken years to discharge to a river and it might discharge during a flood event and/or when no surface water extraction is occurring. In all these cases it is believed that the groundwater extraction does represent an undermining of the Cap. The security of supply to the existing surface water users would be reduced.

An analysis of groundwater and surface water connection is required in order to identify those areas where there is high development of both groundwater and surface water resources, and where there is a high connection between the two. In these areas, a ‘conjunctive’ management option will be required to ensure that allocations to water resources are not duplicated, and that allowances are made for the interactions between groundwater and surface water. The level of ‘double accounting’ that currently occurs in the Murray-Darling Basin is not known, and will not be known until a comprehensive study into groundwater and surface water interactions in the Basin is undertaken.

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Figure 8-5 Adjusted river reaches and classification of groundwater/surface water interaction by adjusted river reach

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9. Groundwater management and policy

9.1 Introduction 9.2 The institutional

The project objective essentially requires arrangements advice on two major policy issues: 9.2.1 Overview • the implications for the Cap when the use of groundwater reaches the limit of The uniqueness, performance to date, and sustainable development and unsatisfied future potential of the Murray-Darling Basin demand is transferred onto surface Commission (MDBC) institutional waters arrangements, in partnership with its member State agencies, in promoting sustainable • the implications for the Cap through the natural resource management and physical capture of stream baseflow development do not need elaborating here. brought about by increasing In the context of this exercise, clearly the groundwater use. established structure, with the Murray-Darling Basin’s Ministerial Council, Commission, However, more importantly, it has become Community Advisory Committee, permanent apparent that there are two other directly office, and the respective State land, water related issues that should be dealt with. and environment agencies provides the ideal They are: arrangement to address the problems • development of policy options to deal with highlighted in this report, particularly given the numerous Groundwater Management the fact that groundwater basins do not Units (GMUs) where allocations, and in recognise State borders. Whether the many cases usage, has already exceeded essential political commitment and support sustainable limits will be provided is, of course, another matter. • development of management However, notwithstanding the fact that natural arrangements to ensure that in all the resource management is primarily a State other GMUs, allocations and usage responsibility, the MDBC institutional remain within sustainable limits. arrangements of arguably the most important In this chapter issues and statistics exclude (economically) river Basin in Australia, those relating to the Great Artesian Basin supported by the Council of Australian (GAB) because: Governments (COAG) agreements, will inevitably ensure an apolitical response • the GAB issues are relatively separate to the key recommendations to promote from those being considered here for the sustainability. Murray-Darling Basin. The one direct linkage is possibly in the GAB recharge Among other things, the COAG reform areas around the fringe of the Basin, agenda for the water industry was formulated where depletion of the GAB could lower on the basis that all aspects would be based the watertable beneath surface water on good information and the best science, catchments that monitoring the impact of the reform • there are already comprehensive policies process would occur to ensure no unintended in place to deal with GAB issues. consequences, and that the community would be involved to an appropriate and acceptable Nonetheless, as the GMUs in the GAB are all degree. Much has been achieved. More over-allocated and overused, the comments specifically, and in the context of sustainable made in this section regarding over- groundwater management, the package of committed GMUs are relevant to the GAB. reform requires:

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• future investment in new schemes, or entitlement reduction process will be phased extensions to existing schemes, to be in over ten years, and management plans will undertaken only after appraisal indicates it clearly identify the rate of change that will is economically viable and ecologically apply. All trade needs to be approved by sustainable Government. Trades into stressed zones of •formal determination of water allocations aquifers will not be approved, nor will trades or entitlements, including allocations for between aquifers. the environment as a legitimate user of Both the old and new Acts allow the Minister water to change license access conditions. In the •a greater degree of responsibility for local new Act any such change is compensible management of water use unless foreshadowed in the relevant water • public education about water use and management plan. In an emergency situation consultation in implementing the reforms. the Minister has powers to intervene and no compensation is payable.

9.2.2 State licensing practice Groundwater level triggers are considered appropriate management indicators by the 9.2.2.1 New South Wales Department of Land and Water Conservation for announcing annual groundwater New South Wales has changed to a new allocations. Restrictions on water access Water Management Act 2000, but some of can also be imposed due to water quality the licensing provisions will not be enacted deterioration, but this has only been done until 2002. In the new Act domestic and on one occasion. stock bores do not require a licence, only a works approval. All other bores will be given a 15 year licence (previously five years, or ten 9.2.2.2 Victoria for towns). All licensed bores will have a In Victoria all bores must have a bore volumetric allocation. construction licence. Domestic and stock Bores in the GAB will be treated a little bores do not require an extraction licence, differently in that all bores will be required to but all others do. Extraction licences are be licensed. expressed volumetrically, and the usual term is 15 years. In practice, all renewable licences have been rolled over at the end of their term. With the new When the license term expires the act Act, they will have to comply with all of their requires the minister to renew the license licence conditions before renewal will occur. unless he or she has good reason not to.

New South Wales already works in GMUs Throughout the State all foreseeable GMUs (called Groundwater Management Areas have been identified. These are (GMAs) in New South Wales). These are systematically tracked as development stressed areas that require close management. proceeds. When allocation reaches 70% of The Sustainable Yield (SY) value for each of SY, the Minister declares a Groundwater these GMUs has been calculated, and the Supply Protection Area, and closer aquifer is embargoed once entitlements reach management is initiated. This includes the the SY value. A review of SY would have been development of a Groundwater Management triggered when entitlements reached 70% Plan by a representative community group. of SY. There is no uniform policy on the For any aquifer that is over-allocated, a acceptability of transferable water reduction in entitlements will occur. The level entitlements in over-allocated GMUs. to which entitlements will be reduced is still One argument is that transferable water to be decided, although policy advice to entitlements should not occur until groundwater committees has been that allocations have been brought back in line 125% of SY is an acceptable figure. with SY, and all users know their firm long- term entitlements. The opposing argument Trading in over-allocated systems will be is that once allocations cease to be made permitted, on a ‘buyer beware’ basis. The because an over-allocation situation has

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been belatedly found, it is only fair to would- 9.2.2.4 South Australia be entrants to allow them the opportunity of In South Australia, licences are required for purchasing an allocation. all bores except domestic and stock bores. Victoria’s approach to the wind-back of Licences are perpetual, but conditions and entitlements in over-allocated GMUs is to allocations may vary. leave such recommendations to the There is no systematic process for ‘tracking’ community groups who are preparing GMUs as development proceeds, and Groundwater Management Plans. When intensifying management as the allocation such recommendations are made to the nears SY. Minister in Groundwater Management Plans, The approach to over-allocated GMUs is to the Minister has powers under the Water Act reduce allocations to SY. This can be done on to declare a shortage and amend allocations. the basis of individuals’ historic use, or the same However, most over-allocated GMUs in percentage cut across-the-board to everybody. Victoria are still working under ‘Simple’ Management Plans in which the emphasis Groundwater Transferable Water Entitlements is on gathering data upon which to base (TWE) are permitted after allocations have been firm estimates of SY before making the brought back in line with SY. hard decisions.

Groundwater Management Plans can contain 9.3 The range of policy issues provisions for restrictions to be imposed to It is appropriate that the four policy issues be prevent aquifer levels dropping below a dealt with in the following order: specified value. This is a useful interim provision while the long-term over-allocation 1. Over-allocated GMUs is being addressed. 2. Ensuring all other GMUs remain within sustainable limits 9.2.2.3 Queensland 3. Displacement of unsatisfied demand onto surface waters The entire Murray-Darling Basin portion of 4. The physical capture of stream baseflow. Queensland is a proclaimed area under the Water Resources Act 1989. Consequently all Murray-Darling Basin bores in Queensland, 9.3.1 Over-allocated GMUs excluding domestic use, have required a Within the Basin, there are 35 over-allocated licence. Stock bores (free range stock only) GMUs. The excess of allocation over SY do not have an allocation applied to the totals 1,220,000 ML/yr, and in 13 of the licence. Any bore with a purpose of use other GMUs, usage exceeds SY by a total of than stock and domestic will have an 125,000 ML/yr. This situation is unsustainable allocation. in the long-term and needs to be addressed. A new Water Act 2000 is now in force, but From social/community and environmental not fully proclaimed as yet. The new Act has perspectives the problems caused by this introduced a few changes, i.e. a licence is no degree of over-commitment are likely to longer required for shallow stock bores not manifest themselves in: tapping GAB aquifers. The new Act also calls • tension between groundwater and for a licence (for the allocation) and a works surface water users (where there is an approval (for the bore). Metering of bores has obvious physical connection between been introduced on a needs basis as surface and groundwater) groundwater systems exhibit signs of pumping stress. Metering of bores in • tension between groundwater and groundwater management areas surface water users and proponents of commenced in 1978. Since the early 1990s environmental flows a mandatory metering clause has been • the unwelcome prospect, and in some included on all new allocations issued in the cases the existence, of groundwater Murray-Darling Basin in Queensland. salinisation by aquifer depletion drawing in more saline groundwater from adjacent sources.

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9.3.1.1 The ‘buy-back’ option 115,000 ML/yr of usage in excess of sustainable levels. Clearly if action is not There are a number of options that may be already underway to begin to address the taken to reduce usage. In the ‘Buy-Back’ situation in the 22 GMUs, it should be option Governments would purchase commenced without delay. individual allocations or parts thereof in the relevant GMUs, such that in each of those The Agriculture and Resource Management GMUs the total allocation came back into Council of Australia and New Zealand line with SY. It is suggested that (ARMCANZ) (2000) has undertaken a participation would be voluntary, but if the comprehensive overview of methods of price offered was appropriate it is believed reducing allocations and constraining use, that sufficient allocation holders would and Section 3.3.8 of the report gives a surrender their entitlements to achieve summary of options available to reduce sustainability. allocation. Most of the options represent different formulae for proportioning the cuts Points in favour of this option are: (sharing the pain) between types of users. • The problem would be readily solved. Because of the seriousness of the • It would inject hundreds of thousands of problem, Governments need to act now to dollars into the rural economy. set a sustainable level of future allocation, • It would allow some people to retire with and the time frame in which this is to be dignity. achieved. Groundwater users may form a ‘community of interest’ to decide on a fair Points against this option are: method of proportioning reductions across • It would cost an estimated $1.2 billion, the users. Some communities have been based on an ‘indicative’ purchase price of able to agree on a method to reduce $1,000 per ML. allocations, but unfortunately the majority • It would create two classes of rural to date have not been able to agree on a people—those who had a water reduction mechanism. The process, entitlement and were in the right place at although admirable, unfortunately sets one the right time, and everybody else. group against another. In New South Wales • It may create unrealistic expectations the Minister has recently decided that elsewhere in Australia. across the board cuts shall occur with no allowance to be made for history of use. If It is suggested that the arguments against groundwater users can agree in this option substantially outweigh those for it, determining their own collective destiny it is particularly given the high cost and the arguably the most effective groundwater relatively few direct beneficiaries, so that it education/management process known. would not be attractive politically. However, it must be said that the high cost to It is proposed that Governments should Government if the ‘Buy-Back’ option was help the adjustment process by: adopted should serve as a warning against 1. ensuring that all bores in a GMU, other letting this sort of unsustainable situation than minor bores, are metered. The occur elsewhere in the Murray-Darling Basin reason is that a water balance needs to and indeed throughout Australia. be undertaken to refine the estimate of SY—in simple cases this can be a 9.3.1.2 Other options for reducing allocations manual balance, but in more complex cases a computer model of the GMU is As stated previously there are 35 GMUs necessary. The volume of extraction is a that are over-allocated, of which 13 have key parameter that needs to go into the usage greater than SY. That leaves 22 balance. Theoretically only a large over-allocated GMUs where usage is still representative sample of metered bores below SY. However, at current rates of is necessary. However, the metering will growth of usage, and given no bring to light anomalies that cannot be management intervention in the next ten ignored, such as users taking more than years, nine of those will change to the their licensed volume. To ensure equity all ‘over-usage’ category, adding another large bores should be metered 79 Projections of Groundwater Extraction Rates and Implications for Future Demand and Competition for Surface Water 57548_Book 17/6/03 2:24 AM Page 80

2. refraining from holding out the prospect of This example illustrates that the ‘hard’ monetary compensation for relinquished decisions of cutting allocations must be entitlements made prior to any TWE being introduced.

3. making sure that allocation reductions are 4. offering grants to users to tap into deeper not linked to allowing TWE to operate in aquifers, where available, with the water GMUs. TWE is not effective in reducing entitlement swapped from the shallower allocations, but assuming the entitlements to the deeper system. Unfortunately, there are initially reduced then trading has a are few under-allocated deeper aquifers place to ensure that the bigger users can beneath the over-allocated GMUs trade water back to maintain their operation. Trading is not a problem 5. offering grants towards more efficient provided there is clarity in the ‘ramp irrigation systems in exchange for down’ profile. To illustrate that trading by voluntary reductions in water allocation. itself is not effective in reducing However, this is best done after the final allocations, consider a case where resolution of the over-allocation has been allocation overall was SY plus 90%. If a achieved. If done earlier, those who put cut in allocation was made across the their hand up for an improved system board, sustainability would be restored could well have to take a second cut in with everybody taking a cut of 47% in the final resolution process. allocation. In a TWE ‘solution’ the rule Finally, where funds and resources for could be that whenever a transfer took implementing the above overall approach place the transferred entitlement would require priorities to be set for GMUs, be reduced by one third. If half the clearly those that are over-allocated and entitlement was transferred over a period overused and where there is significant of time, the overall allocation would surface water groundwater interaction reduce to SY plus 58%. The problems should have priority. with this are:

• It could well take several decades for 9.3.2 Ensuring all other GMUs half the allocation to come onto the remain within sustainable TWE market. limits •A reduction of one third is probably the upper limit of what sellers would All other GMUs present the greatest consider as acceptable. Even at one opportunity to prevent future problems in a third they could be disinclined to ‘painless’ way. That is, by judiciously setting come onto the market, thus delaying the allocation level now, and by monitoring the ultimate resolution of the over- and review, usage can be managed to climb commitment. slowly until it reaches SY. • Even after the reductions had taken The essentials are: place, the managing authority would • to have a systematic process that GMUs still have an over-commitment of 58% progress through to deal with. • to, as part of this process, initially set SY • The TWE buyers would have to be conservatively i.e. on the low side quarantined from any further •to have a pre-determined level of adjustments. (If they weren’t allocation, suggested to be 70% of SY, quarantined, they would be reluctant at which more intensive management, to enter the TWE market.) The including the installation of meters, implication of this is that any future is instituted. adjustments would fall squarely onto the half of the users who had not traded—they would have to take a cut of 61%. That is, they would be left with 39% of their original allocation.

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An associated consideration is the method of be delineated out as GMUs with their own allocation of the volume in the range 71% to SY as soon as they are identified, and then 100% of SY. With this limited volume treated as any other GMU. available, the allocation policy needs to be equitable. The options are: 9.3.3 Displacement of unsatisfied • first come, first served demand for groundwater onto • allocate only a small parcel of volume surface waters (say, 2.5% of SY) to any one party It is apparent that there are already • advertise for expressions of interest, then substantial parts of the Murray-Darling Basin share the water between those that where groundwater has reached, or is respond reaching, the limit of its development. In 30 • auction the available water in a range of years time, under a medium rate of growth parcel sizes. scenario, it is estimated that 98% of the SY The auction option is probably the one that is of the Basin’s groundwater will be used. most equitable and much relevant experience However, displacement of unsatisfied has been gained with surface water auctions. demand for groundwater onto surface waters It has the added advantage that the funds is seen to be a problem that can be raised can be re-invested in the GMU for managed. metering, for further technical investigations, The necessary factors to keep the situation or for other management purposes. manageable are: In all four options it is highly desirable that •reliable SY values of surface and the SY value be conservative i.e. it is low groundwater systems are known rather than high. If it is high an overuse • Any over-allocations have been ‘managed situation could well eventuate. This would be down’ to sustainable levels, and each particularly hard to rectify in the option where user is certain of his or her long-term water had been sold by auction. entitlement.

Unincorporated A reas In major surface systems, trading of entitlements has developed such that water The Unincorporated Areas (UAs) are not risk can be moved to high value uses. This is free. Risk arises because the SY for specific expected to continue to be the trend within areas (GMUs) are not available. Therefore, over- fully allocated surface systems, and within allocation can happen in the same way that fully allocated groundwater systems. Overall, over-allocation has happened in some of the the migration of resources to higher value present GMUs. uses is very important for regional It will be necessary to become more development and employment, and must be scientific regarding allocations within the UAs. encouraged. Transfers of groundwater within In the first instance this means setting general a GMU will become more common. It is allocation limits per unit area throughout the important to ensure that the rules governing UAs. The suggested unit area is 1.0 km2 where the physical acceptability of transfers of the UAs are likely to comprise narrow valleys, groundwater within a GMU are well-defined. and perhaps 10 km2 in more open terrain.

As is the case for GMUs, these allocation 9.3.4 The physical capture of stream limits need to be set conservatively. The baseflow method that might be most universally useful is to ‘guesstimate’ recharge as a percentage 9.3.4.1 Policy perspectives of rainfall. The factor linking recharge to The physical capture of stream baseflow, rainfall could perhaps be set having regard to brought about by increasing groundwater other nearby developed areas in which SY usage, is an issue that is likely to have has been calculated from water balance important implications for the Cap. An calculations based on good data. indication of the magnitude of this issue can Over time, development may be found to be be gained from considering the fact that focussing in particular areas. These should since the Cap was put in place at 1993-94

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levels of development, usage from watertable independently of any impacts on the Cap, aquifers has increased by an estimated and the allocations must be reduced for 310,000 ML/yr. sustainability reasons. In any process to reduce groundwater allocations, it is very If baseflow capture by groundwater usage as important to make this causal distinction. suggested earlier in this report amounts to 60% of total usage, then since the Cap 9.3.4.2 Calculating the amount of baseflow benchmark year of 1993-94, 186,000 ML/yr capture of stream baseflow has been captured. The estimation of baseflow, and its degree Looking to the future, when usage reaches of capture, is difficult in many situations. the sustainable yield level, the increase in However, these situations could be usage above 1993-94 levels will be an characterised by some or all of the following: estimated 1.12 million ML/yr. Again using the 60% capture figure, this might mean a • The natural flow characteristics of the capture of baseflow of 670,000 ML/yr. stream have been altered by regulation and extraction for consumptive use (virtually all Strictly speaking, whenever the general term streams in the Murray-Darling Basin). ‘baseflow capture’ is used, it is more precise • The hydrogeology close to the stream is to use the term ‘baseflow captured or complex, with various layers of alluvium foregone’, to cover the loss of streamflow and lower permeability sediments caused by groundwater pumping near preventing a ‘clean’ connection of the gaining streams as well as increased losses aquifer to the stream. to losing streams. For the sake of brevity, the • On the riverine plains the groundwater shorter term is used. flow towards the stream might be Sustainable yield values used in this report intercepted by evapo-transpiration. have been deduced using many approaches. • The baseflow rate is variable along the The issue of how much interaction with stream due to changing geology. surface water has been allowed in the calculations is unclear. Nonetheless A further problem with baseflow estimation is depending upon which perspective, surface that close to the stream the flow towards the water or groundwater, is considered, stream can comprise: apparently opposite conclusions can be • Baseflow, i.e. the long-term sustained drawn. It is clear that both groundwater and flow of groundwater from the saturated surface water users have ‘prior rights’ to the (below the watertable) zone total water resource. An extreme perspective • Interflow, being shorter-term lateral flow in is that the Murray-Darling Basin Cap (i.e. the unsaturated zone surface water users) has prior rights over • Bank storage return (preceded by bank groundwater users and hence all the ‘pain’ of storage refill at times of high stream flow). reducing groundwater allocations to sustainable levels, to not significantly impact The component that groundwater managers on the Cap, should be borne by groundwater are concerned with is the flow of users. The alternative view is that just groundwater in the saturated zone. This is because surface water has been over- the component that will vary in response to allocated by including base flow (i.e. extractions from the aquifer. One possible groundwater) in the allocations is not way to estimate this is to measure justification for reducing groundwater groundwater gradients towards, or away allocations. Groundwater users have an from, the stream in bore transects that equal right to the water resource. Hence all extend far enough away from the stream to the ‘pain’ should be borne by surface water get clear of the short term fluxes like interflow users and the Cap should be cut accordingly. and bank storage. If permeability has been Various intermediate positions can also be measured by pumping tests, and there are adopted. The discussion below attempts to enough transects along the length of the adopt an intermediate position. It must be stream, it should be possible to make a emphasised however that many of the GMUs reasonable estimate of groundwater flow to in the Basin are over-allocated, quite or from the stream. However, before installing

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expensive transects, obviously the existing thought should be given as to whether the data should be thoroughly reviewed to baseflow in the particular case is significant extract any possible interpretations and make enough to warrant the expense of initial estimates of baseflow. determining it.

It might be necessary to do supplementary A problem of another kind occurs when calculations to take account of any the extracted groundwater comprises a interception of groundwater flow towards the high proportion of captured baseflow, say stream by terraces, billabongs, or bands of 90% of it is captured baseflow. In a case riparian vegetation. like this, it is questionable whether groundwater development should have Having established a relationship between gone ahead at all. However, the point is gradient on the transects and groundwater that it has gone ahead. flow to or from the stream, it will then be necessary to link that gradient into a wider A final consideration, that might provide an model of the aquifer so that the ‘chain’ of additional perspective to the baseflow consequences is quantifiable, as follows: issues, is that some of the GMUs are associated with large-scale surface water Groundwater extractions Irrigation Areas and Districts. Some of these lead to will have rising watertables. No doubt Aquifer-wide groundwater level responses groundwater pumping will feature to a which determine greater or lesser extent in controlling the Gradients in transects nearer to streams rising watertables. However, it is expected which control that around the fringes of the Areas and Groundwater flow to or from streams Districts watertables will continue to rise, and actually add baseflow to the adjacent rivers. The final step would be to use the newfound It is a moot point whether the added quantification ability to: baseflow is overall positive or adverse •estimate what the groundwater flow when the salt load it contains is taken into to/from the stream was at 1993-94 levels account. However, in pure volumetric of development terms, and considering the Basin as a • estimate what it is at present levels of whole, Irrigation Area and District mounds development could be a significant factor offsetting • estimate what it might be under ultimate baseflow capture. levels of groundwater development. 9.3.4.3 Dealing with baseflow capture However, as discussed later, the ultimate reinstatement of baseflow capture should be The first point to be made is that being too deferred as follows: prescriptive on baseflow capture could • in the case of over-allocated GMUs, preclude development of groundwater up when groundwater allocations have to SY. Unused groundwater within SY is been brought down into line with SY the last remaining ‘safety valve’ for satisfying demand that has been pent up • in the case of GMUs not yet fully by the Cap. A hypothetical example will allocated, when allocations and usage illustrate what is meant here. have approached SY, and the system is fully understood. Consider the example of a GMU with a SY of somewhere between 40,000 and It is clear from consideration of the above 60,000 ML/yr. Assume it provides 10,000 procedure for the determination of ML/yr of baseflow to the stream running baseflow that considerable expense could through it, that is, a hypothetical 16%. be involved. The greatest part of this The degree of baseflow capture expense is likely to be the installation of associated with groundwater development multiple transects near streams, perhaps is given in Table 9-1. with nested piezometers at each bore site. Before embarking on baseflow determination in a particular GMU, some

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A corollary of the statement in the paragraph TABLE 9-1 Hypothetical degree of baseflow capture associated with groundwater above is that if it is desired to reduce the development baseflow loss from the stream after a particular level of groundwater development Level of development Baseflow capture has occurred, the way not to do it is to try (ML/yr) (ML/yr) and reverse the groundwater development. 00Studying the tables shows that, for example, 10,000 500 to reduce captured baseflow from 10,000 ML/yr to 2,000 ML/yr, would require the 20,000 1,000 groundwater development to be reduced 30,000 2,000 from 60,000 ML/yr to 30,000 ML/yr. Needless to say, this would be a very painful 40,000 5,000 exercise. Also, it would mean a substantial 50,000 7,000 under-utilisation of an available resource and, it is a crude method insofar as there would 60,000 10,000 be no control over the pattern of returned baseflow—it would depend on the patterns In the example, if baseflow capture were of usage adopted by the groundwater users. limited to (say) 2,000 ML/yr, then There are several options for ‘paying back’ development would be limited to about captured baseflow. They are: 30,000 ML/yr. On the other hand, allowing a much higher baseflow capture would enable 1. At the appropriate time purchase an amount the full potential of the aquifer system to be of groundwater sufficient to return the more nearly realised. required amount of baseflow. The relevant authority could then construct a bore or The next tabulation illustrated in Table 9-2 bores to extract and return the required that even if the captured baseflow has to amount to the stream. From a social be reinstated in full in some way, the perspective, the potential for an adverse groundwater resource unlocked by reaction to this approach is high, because attempting to fully develop the groundwater the cost of installing the bores to return the far outweighs the volume of baseflow to captured flow could be a significant impost be ‘paid back’. on users; and the need to maintain baseflow might not be fully appreciated. Times when TABLE 9-2 Baseflow corrections to this lack of appreciation could come to the groundwater use volumes allowing for no fore are when groundwater irrigation is reduction in stream flow restricted because of adverse seasonal Level of Baseflow Baseflow Net conditions and when the stream appears to develop- capture paid back available to have plenty of flow in it anyway. ment (ML/yr) (ML/yr) ground- (ML/yr) water 2. At the appropriate time purchase an amount users of surface water sufficient to reinstate the (ML/yr) required amount of baseflow. In all likelihood the quantity involved would be a smaller 0 000 percentage of the surface system yield than 10,000 500 500 9,500 it would of the groundwater system SY; and 20,000 1,000 1,000 19,000 there would be minimal infrastructure and recurrent costs to run the reinstated 30,000 2,000 2,000 28,000 baseflow down the stream. 40,000 5,000 5,000 35,000 3. Reduce both groundwater and surface water allocations (and hence usage) to an 50,000 7,000 7,000 43,000 extent equivalent to the baseflow capture 60,000 10,000 10,000 50,000 and hence naturally reinstate the baseflow at the 1993-94 level. The proportional cuts required between groundwater and surface water would vary from region to region. Significant negotiation would be required.

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A final note on the issue of ‘the appropriate it is the associated regional development time’ in situations when there is over- benefits that might be seen as a public good, allocation of the groundwater and/or surface warranting public purchase of 10,000 ML/yr. systems concerned. The appropriate time is In addition, the baseflow is essentially an after allocations have been brought into line environmental flow—an area where with SY, both in the groundwater system, Government might be expected to be the and also in the surface system. The reasons primary beneficiary or stakeholder on behalf are twofold: of the wider community. 1. The extra time would allow more refined However, the cost of purchasing 10,000 estimates of the captured baseflow to be ML/yr to reinstate baseflow is very sobering made. If the purchasing authority acted i.e. $10 million. Another option is to levy each before everybody’s property rights were groundwater user to provide the $10 million fully determined, and adjustments made, it of capital, that is, a once-off capital levy of would have the dilemma of whether or not $200 per ML/yr of entitlement. Alternatively, to quarantine its purchases from further it could be argued that surface water users downwards adjustments. If the authority could bare all or part of this cost. chose to do this it might be perceived as high-handed by the community. A final option that could apply in GMUs that 2. If baseflow was reinstated while the surface are still developing, is if the last (say) 30% of system was still in a state of adjustment, SY is allocated in an auction system, the it could well be ‘lost’ in the complex funds raised could go towards purchase of accounting trail that would develop as baseflow. In the above case of the 50,000 future negotiations, compromises and ML/yr GMU, if the top 15,000 ML/yr were adjustments took place. auctioned and brought an average price of $750/ML, the total raised would be $11.25 In situations when the allocation and use of million—enough for the baseflow purchase. the groundwater has yet to rise to the SY, ‘the appropriate time’ is after use has hovered around SY for a period of years, and there is 9.4 Integration of groundwater some reliable data on the GMU to more issues into the Cap confidently estimate the baseflow ‘owing’. There are several options available to The third alternative above reflects the view integrate groundwater into the Cap. Prior to that groundwater users have equal prior right discussing these options it is important to to water as surface water users. A sub- emphasise that from a groundwater option is that only a partial attempt at base perspective there are two different issues to flow reinstatement be undertaken. Either way be addressed. Firstly, there are many GMUs this option amounts to cutting the Cap and which are over-allocated and the allocations the ‘pain’ would be shared by both need to be reduced for good groundwater groundwater and surface water users. resource management reasons, quite independently of any interactions with 9.3.4.4 Who should pay for baseflow surface waters. Secondly, surface water reinstatement? baseflow reduction due to groundwater extraction is occurring, and is increasing, and Consideration needs to be given as to this undermining of the Cap needs to be whether purchase of water for baseflow addressed. Much of the above discussion reinstatement has a ‘public good’ element deals with the first issue. Options to address about it. the second issue are: The argument for it being in the public good 1. Freeze all groundwater allocations now. category comes from consideration of the If groundwater allocations, as of say 2001, hypothetical example in the tables above, were ‘frozen’ now many over-allocated which suggests that purchase of 10,000 GMUs would continue at completely ML/yr of baseflow would allow 50,000 ML/yr unsustainable levels and this would of groundwater development to go ahead. significantly hinder rational water While groundwater development of this management. magnitude would have large private benefits,

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2. Freeze all groundwater use now would have to be consistency in how the SY As above, groundwater use in excess of the was calculated and applied between the sustainable yield would be ‘locked in’ and different States. The amount of double this would be completely contrary to rational accounting would need to be identified. It is water management. proposed that the proportion of the baseflow component which would be included in the 3. Include groundwater volume into the groundwater sustainable yield volume, as existing Cap compared to that proportion which would be This would mean no increase in the Cap included in the surface water Cap, would volume and having to ‘accommodate’ all need to be negotiated on a case by case groundwater allocations which impact on basis. It is also proposed that the surface waters into the Cap. The Cap volume environment (i.e. streamflow) not bear any of would be unchanged. In Groundwater the cuts due to double accounting. This Management Plans (GMPs) acknowledge would result in cuts to allocation for both that groundwater use has an impact on the surface water users and groundwater users. Cap. In the GMPs groundwater derived The severity and impact of the cuts would baseflow would be accounted for as a vary across different regions and GMUs. It surface water impact. All post 1993-94 would be important to consider how (and the groundwater allocations which impact on timing of) the reductions in the sustainable surface waters would be treated just like yield volumes, due to overallocation of the another breach of the Cap. This would mean groundwater resource, were integrated into that wind-back must occur. If it is intended to cuts due to being included in the spirit of the use the allocation there must be Cap. The different causal drivers would need compensatory allowances, e.g. TWE. This to be well explained to the community. In would result in massive cuts in groundwater under allocated GMUs new allocations would allocations. It would not be technically nor need to specifically consider the impacts on socially sensible. It would also ignore the reducing base flow. A later stage in this prior rights of groundwater users. process would be the introduction of allowing 4. Cap level increased by groundwater trading between groundwater and surface sustainable yield water, where it was appropriate and This would be equivalent to including necessary. groundwater in the Cap. In many ways options 4 and 5 involve all the The Cap volume would be increased by an same steps. The significant difference is that amount equivalent to the sustainable yield of in option 4 groundwater would be formally all the aquifers in the Basin. The sustainable incorporated in the Cap, while in option 5 it yield volumes would need to be recalculated would not be in the Cap, albeit there would to exclude double accounting and to address be a serious effort to allow for groundwater other issues. Cuts in both surface water and impacts on the Cap. In view of the significant groundwater allocations would occur to the interaction between groundwater and surface extent of the double accounting which exists. water in the Basin it is considered that option The geographic distribution of the SY values 4 is technically the best option. It would best (by GMUs and UAs) would be very important. help to ensure integrated surface water and There would be significant technical and groundwater management. However, very political negotiation required. significant changes in groundwater management need to occur (principally 5. Maintain separate surface water and significant reductions in groundwater groundwater volumes allocations) and these reforms may take This would be equivalent to including many years. Hence it is considered that groundwater in the spirit of the Cap. option 5 is the best short term option, and The surface water Cap would remain largely option 4 is the most appropriate long-term intact. The groundwater sustainable yield option. Both options will involve major policy volumes would need to be recalculated to and management changes. identify the base flow component and to address other issues (e.g. only using groundwater up to a defined quality). There

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9.5 Greenhouse effects Darling Basin and hence needs to be factored into the long-term planning framework. Recently the CSIRO dramatically increased its projections of the extent of global warming suggesting that average Australian 9.6 MDBC and State roles temperatures could rise by as much as six Many of the actions from this report involve degrees by 2070. In its last series of climate shared responsibilities which will only be projections, five years ago, the temperature successful if carried out in a spirit of range estimated for 2070 was 0.6˚C to 3.8˚C. cooperation. In general the MDBC role is to The current forecasts are for warming of set targets and to monitor adoption under between 1˚C and 6˚C. the Cap. The role of the jurisdictions is to Such changes would have a significant impact decide how to meet the targets. Within this on agricultural production and natural context most of the recommendations are ecosystems, placing additional stress on the the responsibility of the States, but with the demands for scarce water resources and MDBC undertaking a coordinating role. To increasing both the seasonal and territorial enable the setting of consistent sustainable ranges of many pests. While Australia is yield values a strong spirit of cooperation will expected to warm at rates similar to the rest of be required. the world, the impact on rainfall is likely to be more extreme (Whetton, pers. comm. 2001). 9.7 Conclusions

‘All global climate models show increases 1. In regard to over-allocated GMUs good in rainfall, averaged over the globe. But water management would best be served those increases tend to occur in the mid if State jurisdictions: to high latitudes and around the equator • ensured that all large bores were and there’s a tendency for rainfall to metered decrease in most models for the latitudes Australia is in.’ •pro-actively set and publicised future sustainable levels of allocation, and ‘Evaporation will increase over most of the time frame in which this is to be Australia and combined with changes in rainfall, there will be a clear decrease in achieved available moisture across the country.’ • develop with groundwater users appropriate allocations and the In the catchment, for apportionment of the necessary example, stream flows are predicted to fall by reductions across users up to 20% by 2030 while projections for •refrained from holding out the 2070 range from a marginal increase to falls prospect of monetary compensation of as much as 45%. Dr Whetton said for relinquished entitlements Australia’s biggest challenge now was to determine how to respond appropriately to •make sure that allocation reductions the threat of climate change. are not linked to allowing TWE to operate in GMUs ‘There are two responses we can consider. •recognised that a step on the way One is for Australia to play in a global effort towards a permanent reduction in to reduce greenhouse gas emission. The allocations in overused areas could be other is to accept some future change in the imposition of rostering/restrictions climate due to enhanced greenhouse when the watertable appears to be conditions is inevitable and that we should declining below a specified level, look at what those changes are likely to or the setting of annual allocations mean to Australia and take that on board aimed at pushing usage back to as we go into the future.’ sustainable levels Clearly to be forewarned is to be forearmed. • gave priority to GMUs that are over- allocated, overused, and where there This fundamental climate change is predicted is significant groundwater—surface to put significant additional pressure on all water interaction. water resource availability in the Murray-

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2. In regard to ensuring that all other 6. In regard to physical capture of stream GMUs remain within sustainable limits baseflow: a practicable method for good water management would best be estimating the linkage between baseflow served if State jurisdictions: and groundwater extractions might • had a systematic process that GMUs involve multiple transects of piezometers progressed through along the stream in question, and is likely to be expensive. In some cases the • as part of this process, initially set SY baseflow might not be significant enough conservatively i.e. on the low side to warrant the expense of determining it. • had a pre-determined level of allocation, suggested as being 70% of High watertables associated with some SY, at which more intensive Irrigation Areas and Districts (see Figure management, including the installation 4-1) might actually add baseflow to some of meters, is instituted rivers. The most appropriate approach is not to seek to limit groundwater • had a process for equitable allocation development by being too prescriptive on of the remaining sustainable yield baseflow capture, but rather for captured once allocations are ‘within sight’ of baseflow to be reinstated at the full allocation. Auctioning appears to appropriate time by a variety of measures. be the most equitable method, and in addition it would provide funds for Further to the reinstatement of captured groundwater management purposes. baseflow, ‘the appropriate time’ in the case of over-allocated groundwater or 3. In regard to management of UAs good surface systems is after allocations have water management would best be served been brought into line with SY, in both if State jurisdictions: systems. In situations where the • had a systematic approach to allocation and use of the groundwater allocations in UAs, which would has yet to rise to SY, the appropriate time probably be based on a conservative is after use has hovered around SY for a estimate of allocation per unit area period of years, and there is some reliable • monitored development, and as data on the GMU to more confidently appropriate, delineated as GMUs estimate the baseflow owing. areas that were becoming the focus of 7. There is a possible case for the use of development. public funds to purchase entitlements for 4. In regard to possible displacement of reinstatement of baseflows in the case of unsatisfied demand for groundwater over-allocated GMUs. onto surface waters, this is a problem 8. In the case of under-allocated that can be managed—the expected groundwater systems, a prospect of adjustment mechanism is trading of securing acceptance of the need to entitlements such that all water moves to provide for baseflow reinstatement would high value uses. be where an auction system for 5. Because of the fundamental importance groundwater is used to generate funds of trading for providing a ‘safety valve’ for for groundwater management purposes. development after allocations reach SY, 9. The integration of groundwater into the the rules governing the physical spirit of the Cap would be best achieved acceptability of groundwater trading in the short term by keeping the surface should allow as much freedom of water Cap volume separate from the movement as is consistent with the (recalculated) groundwater sustainable sustainable use of the resource. yield volumes.

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10. Conclusions

10.1 Key conclusions 5. Aquifer salinisation has the potential to reduce groundwater sustainable yields 1. The groundwater resources of the by up to 175 GL/yr, assuming Murray-Darling Basin are in many areas salinisation in the 25 GMUs identified. currently highly or over-allocated. Over- 6. ‘Sustainable’ yield estimates by the allocated groundwater management units States have not generally allowed for (GMUs) account for 80% of the total possible impacts on surface waters. allocations in GMUs in the Basin. Considering all GMUs (excluding the Development status Great Artesian Basin (GAB)) 134% of the sustainable yield volume has been 7. 52% of all groundwater use and 41% of allocated. By 2050 the sustainable yield groundwater allocations in GMUs in the levels will be reached by virtually all GMUs Basin occur in only four of the Cap and this will place significant additional regions (Namoi, Murrumbidgee, pressures on the Cap. This is an increase Condamine-Balonne and Goulburn- from the current level of use in the GMUs Broken-Loddon River Valleys). (excluding the GAB) which is at 58% of 8. The majority (54%) of GMU resources the sustainable yield. occur in over-allocated GMUs. 2. Growth of groundwater usage from 9. The only substantial undeveloped 1993-94 to now represents a two per groundwater resources occur in the cent undermining of the Cap by Unincorporated areas (UAs) in most capturing baseflow. parts of the Basin. 10. The GAB is overused and over-allocated 10.2 Current development within the Murray-Darling Basin at status of groundwater present and cannot be developed any in the MDB further. 11. There is little room for further Sustainable yields and sustainability issues development of groundwater resources in GMUs in the Murray-Darling Basin based 3. The sustainable yield methodology used on current allocations. by the States is not consistent across the Basin, with some considering groundwater dependent ecosystems 10.3 Predicted water demands and aquifer salinisation potential, and and groundwater growth others none of these factors at all. The in the MDB sustainable yield values are, using a strict definition, not necessarily 12. The rate of consumption of groundwater in sustainable. the Murray-Darling Basin has grown at an A consistent methodology is needed to average rate of about four per cent per ensure that the assessment of year, over the past two decades. groundwater resource availability is as 13. By far the majority of the growth in use accurate as possible and based on of water resources has been in the reliable estimates. irrigation sector. 4. In general, the potential for aquifer 14. In over developed GMUs to ensure salinisation to reduce the sustainable sustainability of the resource, this growth yield has not been included in the must be curtailed. The demand for water assessment of the current groundwater which will not be met by groundwater will development status or future be transferred to other water sources. development across the Basin.

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15. A ‘cap’, such that groundwater usage 21. There were significant deficiencies in the did not exceed the sustainable yield in analysis due to scale and lack of each GMU, would result in reduced detailed information, but also because it extractions of groundwater for 70% of relied on groundwater use information GMUs. An assessment of the economic by GMU and unincorporated areas impacts of reduced groundwater (UAs). Information in New South Wales extractions suggests an impact between and Queensland within UAs and the $80 million to $800 million, depending GAB was not separated into aquifer on growth scenarios and discount rates systems, and the groundwater used. This estimate does not include resources in these regions were lumped possible responses by stakeholders to together as one reported unit. This lower groundwater availability. meant that the implications of use from those aquifers that have a high level of 10.4 Groundwater/surface water connection with the streams could not be ascertained. interaction 22. The level of ‘double accounting’ of water, Level of interaction as groundwater and surface water 16. Increases in groundwater extraction resources in the Basin is not known. since 1993-94 have reduced the net stream flow and surface water 10.5 Groundwater management extractions allowable under the Cap. and policy 17. An assessment of literature and existing 23. In regard to over-allocated GMUs, the data on aquifer stream interaction in the single most effective thing State Basin has indicated that between ten jurisdictions can do is to set and and 90% of groundwater extraction is publicise future sustainable levels of sourced from stream losses. allocation, and the time frame in which 18. It is estimated that 60% of the the wind-back is to occur. The aims of groundwater extracted represents water the Cap would best be served if which would otherwise be surface water. States gave priority to GMUs that are The rate of growth of groundwater use overused as well as over-allocated, since the Cap was introduced in 1993- and in which the groundwater system 94 represents a two per cent has high interaction with the surface undermining of the Cap, or loss of water system. 186 GL/yr from streams. This is 24. Jurisdictions can make four other expected to grow to seven per cent decisions that will maximise the over the next 50 years unless chances of successful wind-backs. groundwater use is significantly reduced. They are: 19. Current development in the • to ensure all large bore are unincorporated areas in some of the metered fractured rock highlands is low at • to refrain from holding out the present, but if development does occur, prospect of monetary it may have a considerable impact on compensation the Cap in the longer term. • making sure that allocation Data deficiencies reductions are not linked to allowing transferable water 20. The assessment was heavily based on entitlements (TWEs) to operate in qualitative data with little quantitative GMUs information available to assess the level • to use restrictions or annual of dependence of stream flows on allocations as a means of groundwater, or the impact of transitioning back to sustainability. groundwater extractions on stream losses.

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25. The problems currently posed by 31. A variety of options are available to over-allocated GMUs can be avoided incorporate groundwater into the Cap if State jurisdictions have a systematic and hence stop undermining of the Cap. process that all other GMUs progress It is concluded that the most through. The essential elements of this appropriate short term option is to process are: account for groundwater within the spirit • conservatively set initial estimates of the Cap by maintaining separate of sustainable yields groundwater and surface water • an allocation trigger level (e.g. at volumes. In the long-term it is believed 70% of sustainable yield) at which that groundwater should be fully more intensive management is included into an expanded Cap. instituted • an equitable process (suggested to be auctioning) for allocation once the trigger level is reached. 26. UAs also need a systematic approach to allocation, including conservatively set limits on allocation per unit area, and provision to delineate as GMUs areas that become a focus for development. 27. The possible displacement of unsatisfied demand for groundwater onto surface waters is a problem that can be managed. The expected adjustment mechanism is trading of all entitlements such that water moves to high value uses. 28. Streamflow capture is expected to range between the extremes of cases where the capture is too small to warrant the expense of determining it on one hand, to the other extreme where up to 90% of the extracted groundwater is captured streamflow. 29. Except where a significant proportion of the extracted groundwater is captured streamflow, the appropriate approach is not to limit groundwater development by being too prescriptive on baseflow capture, but rather to consider a range of other options for sustainable groundwater management. 30. Groundwater extraction in areas of land salinisation can be beneficial and, where appropriate, should be encouraged. Through salinity/groundwater management plans minimum pumping volume targets are often required.

91 Projections of Groundwater Extraction Rates and Implications for Future Demand and Competition for Surface Water 57548_Book 17/6/03 2:25 AM Page 92

11. Recommendations

11.1 Key recommendations and other factors. Periodic reviews of the sustainable yield values should be 1. The States should reduce groundwater undertaken. allocations (and consequently use) to sustainable yield levels in overallocated 7. GMU boundaries are not static and may groundwater management units (GMUs) change as new areas develop in the as a matter of urgency. Murray-Darling Basin, or as knowledge of aquifers increases allowing further 2. In the short term, groundwater should be definition of aquifer systems and extent accounted for within the spirit of the Cap. of regions with high potential for In the long-term, groundwater should be development. The location and extent of included in an expanded Cap. It is all GMUs in the Basin needs to be proposed that this should be maintained by the Murray-Darling Basin implemented in a different manner to the Commission (MDBC) to ensure way the surface water Cap was adequate accounting of groundwater introduced. This should be implemented resources within the Basin, and to on the basis of revised sustainable yield ensure consistency in reporting of values for each GMU, taking into account groundwater in future years. the known deficiencies in the existing sustainable yield estimates. In the short term the surface water Cap and the 11.3 Predicted water demands groundwater sustainable yield volumes and groundwater growth would be kept separate. Cuts in both in the MDB surface water and groundwater 8. The MDBC conduct a net social allocations would be required to end opportunity cost evaluation of a ‘cap’ on double accounting. The environmental groundwater extraction to quantify the component of the stream flow under the overall impact on society. Cap would not be affected. In the long- term groundwater should be fully 9. The MDBC conduct an evaluation of the integrated into the Cap. wealth and equity impacts of alternative policies to achieve a ‘cap’ on groundwater extraction. 11.2 Current development status of groundwater 11.4 Groundwater/surface in the MDB water interaction 3. Expand metering programs to increase 10. Undertake further investigations and accuracy of use information. assessment on groundwater/surface 4. Ensure all bores are licensed or water interactions to identify more registered. accurately the degree of impact on 5. Develop strategies within each State to streamflow. This is to include the estimate the number of bores not assessment of the likely impact of licensed, and hence the amount of reduction of groundwater inflows to groundwater extracted. streams due to groundwater development. 6. Develop a comparable methodology for States to use in the calculation of 11. Encourage States to appropriately manage groundwater resources in the sustainable yield to ensure that all highlands, which takes into account the States take into consideration the high dependency of streams on potential for aquifer salinisation, groundwater in these areas. groundwater dependent ecosystems, surface water groundwater interaction

92 Projections of Groundwater Extraction Rates and Implications for Future Demand and Competition for Surface Water 57548_Book 17/6/03 2:25 AM Page 93

12. Encourage States to re-assess GMU 17. State jurisdictions have a systematic sustainable yields based on increased process that all other GMUs progress knowledge of stream-aquifer interactions through. The essential elements of this to safeguard the integrity of the Cap. process are: This includes ensuring that no ‘double •set initial estimates of sustainable accounting’ occurs of water, that may yields taking into account the be extracted as groundwater, and has precautionary principal been accounted for in the Cap. • an allocation trigger level (e.g. at 13. The Great Artesian Basin (GAB) and 70% of sustainable yield) at which unincorporated areas (UAs) needs to be more intensive management is split into separate aquifer systems to instituted allow for accounting of surficial aquifers • an equitable process (suggested that have high levels of interaction with to be auctioning) for allocation streams, and deeper aquifers that do once the trigger level is reached. not. Currently information on UAs and 18. States also adopt a systematic GAB GMUs in New South Wales and approach to allocation in UAs, including Queensland are not separated into conservative limits on allocation per unit aquifer systems. area, and provision to delineate as 14. States to endorse a set of river reaches GMUs areas that become a focus for that can be reported on regularly for the development. level of connection and impacts of 19. Jurisdictions recognise that the possible groundwater development on the Cap. displacement of unsatisfied demand for Data set to be maintained by the groundwater onto surface waters is a MDBC. problem that can be managed. The expected adjustment mechanism is 11.5 Groundwater trading of entitlements such that all management and policy water moves to high value uses. 15. In regard to over-allocated GMUs, State 20. Except where a high proportion of the jurisdictions set and publicise future extracted groundwater is captured sustainable levels of allocation, and the baseflow, the State jurisdictions adopt time frame in which the wind-back is to an approach of not limiting groundwater occur. Furthermore, that States give development by being too prescriptive priority to GMUs that are overused as on baseflow capture. well as over-allocated, and in which 21. Groundwater extraction in areas affected there is a high level of surface water by land salinisation should often be groundwater interaction. encouraged and salinity/groundwater 16. Jurisdictions resolve to do four other management plans should include, things that will maximise the chances of where appropriate, provisions for successful wind-backs. They are: minimum pumping volumes.

• to ensure all large bore are Please refer to Appendix F for detailed metered responses by jurisdictions to the above • to refrain from holding out the recommendations. prospect of monetary compensation • make sure that allocation reductions are not linked to allowing transferable water entitlements (TWEs) to operate in GMUs • to use restrictions or annual allocations as a means of transitioning back to sustainability.

93 Projections of Groundwater Extraction Rates and Implications for Future Demand and Competition for Surface Water 57548_Book 17/6/03 2:25 AM Page 94

12. References

ATSE, 1999, Water and the Australian Economy, Australian Academy of Technological Sciences and Engineering and the Institution of Engineers, Melbourne VIC.

ABARE, 2000, Australian Commodity Statistics, Australian Bureau of Agricultural and Resource Economics, Canberra ACT.

ABS, 1996, CData (database), Australian Bureau Statistics, Canberra ACT.

ABS, 2000, Australian National Accounts 5220.0, Australian Bureau Statistics, Canberra ACT.

ARMCANZ, 2000, A National Framework for Managing Over-Allocated Groundwater Systems – Best Management Practice Manual, Agriculture and Resource Management Council of Australia and New Zealand, Canberra ACT.

Armstrong, JS 2001, Principles of Forecasting: A Handbook for Researchers and Practitioners, Kluwer Academic Publishers, New York.

CRCFWE, 2001, Draft Final Report for Sustainable Rivers Audit, Co-operative Research Centre for Freshwater Ecology, Canberra ACT.

CRCFWE, 2001, Ecological Sustainability of the Rivers of the Murray-Darling Basin: CRCFWE Technical Report, Co-operative Research Centre for Freshwater Ecology, Canberra ACT.

Department of Agriculture, Victoria, 1992, The Tongala Groundwater Pumping/Reuse Project: Volume 1—Monitoring and Agronomic Investigations, Department of Agriculture, East Melbourne VIC.

DPW, 1992, Review of the Gumly Gumly Borefield, Southwest Tableland Water Supply Scheme, Department of Public Works Water Resources Technical Services Division.

Evans, R 1987, ‘Current Status of Some Murray River Interception Scheme Investigations’, Papers from the workshop on Recent Advances in the Hydrogeology of the Murray Basin, Rural Water Commission, Victoria, Moama NSW.

GABCC, 1998, Great Artesian Basin Resource Study, Great Artesian Basin Consultative Council, Brisbane QLD.

Harrison, S and Clayton, L 1970, ‘Effects of groundwater seepage on fluvial processes’, Bulletin Geological Society of America, vol. 81, pp.1217-1226.

Hydrotechnology, 1995, Assessment of nutrient loads discharged into the Goulburn, Broken Rivers from groundwater: Hydrotechnology Report No. MC/44242.000/1.

Jolly, P 1990, ‘Investigation into the potential for increased stream salinisation in the Darling Basin’, Proceedings of the Murray-Darling Workshop: Groundwater Research and Management Mildura.

Kalaitzis, P, Brownbill, R and Jamieson, M 1999, ‘Environmental Provisions in Determining Sustainable Yield for Groundwater Management Plans in the Lower Namoi Valley, NSW’, Proceedings of the Murray-Darling Basin Groundwater Workshop Conference, Griffith NSW.

Lawson, S and Kulatunga, N 1998, ‘Sustainable groundwater use in the Eastern Murray Basin, Australia’, Proceedings of the International Groundwater Conference 1998: Groundwater Sustainable Solutions, Melbourne VIC.

Leaney, F 2000, Technical Report 34/00: Groundwater Salinisation in the Tintinara Area of South Australia, CSIRO Land and Water Centre for Groundwater Studies, Adelaide SA.

Linke, G and Kendall, M 1995, ‘Groundwater Interception from a multi well point scheme using air lift pumping’, Proceedings of the Murray-Darling Workshop: Record No. 1995/61 Wagga Wagga.

Linke, G, Seker, M and Livingston, M 1995, ‘Effect of reafforestation on Stream Flows, Salinities and Groundwater levels in the Pine Creek Catchment’, Proceedings of the Murray-Darling Workshop: Record No. 1995/61 Wagga Wagga.

94 Projections of Groundwater Extraction Rates and Implications for Future Demand and Competition for Surface Water 57548_Book 17/6/03 2:25 AM Page 95

McNeil, VH and Horn, AM, 1997, ‘Groundwater Salinity Trends in the Northern Murray-Darling Basin’, Proceedings of the Murray-Darling Workshop ‘Groundwater in the balance’, Department of Natural Resources, Toowoomba QLD.

MDBC, 1997, Murray-Darling Basin Resources, Murray-Darling Basin Commission, Canberra ACT.

MDBC, 2000, Review of the Operation of the Cap—Overview Report of the Murray-Darling Basin Commission, Murray-Darling Basin Commission, Canberra ACT.

NLWRA, 2000, National Land and Water Resources Audit Data, National Land and Water Resources Audit, Canberra ACT.

NLWRA, 2001, Australian Water Resources Assessment 2000, National Land and Water Resources Audit, Canberra ACT.

NRE, 1998, ‘Permissible Annual Volume: Groundwater Management Units in Victoria’, Sinclair Knight Merz, St Leonards NSW.

Prathapar, S, Williams, M, and Punthakey, J 1994, ‘Minimising Land and River Salinisation Consequences of Clearing in the NSW Mallee’, Water Down Under, vol. 1, pp. 61-66.

RBA, 2001, Reserve Bank of Australia (online), http://www.rba.gov.au/.

Schache, M, Cupper, M and Hoxley, G 1995, ‘Minimising Water Transfer Effects on the Murray – A Community Group’s Role’, Proceedings of the Murray-Darling 1995 Workshop, Record No. 1995/61 Wagga Wagga.

Shugg, A 1987, ‘Hydrogeology of the Upper Ovens Valley: Geological Survey 1987/5’, Victoria.

Shugg, A, and Slater, D 1987, ‘Hydrology of the Ovens Valley at Myrtleford: Geological Survey 1987/37’, Victoria.

SKM, 1997, Review of monitoring in the Wemen area: Report for the Department of Natural Resources and Environment, Sinclair Knight Merz, St Leonards NSW.

SKM, 2000a, Environmental Water Requirements for Groundwater Dependent Ecosystems: Report to Environment Australia, Sinclair Knight Merz, St Leonards NSW.

SKM, 2000b, Conjunctive Water Use Options in the Northern Murray-Darling Basin—Upper Condamine River: Report for Murray-Darling Basin Commission, Sinclair Knight Merz, St Leonards NSW.

SKM, 2001, Survey of Baseflow in unregulated catchments in the Murray-Darling Basin: Draft Report for Murray- Darling Basin Commission, Sinclair Knight Merz, St Leonards NSW.

Telfer, A 1987 ‘Interception Schemes along the Murray River in South Australia”, Engineering and Water Supply Department’, SA Papers from the workshop on ‘Recent Advances in the Hydrogeology of the Murray Basin’, Moama NSW.

Walker, G, Nott, R, King, H, Barnett, S and Stadter, F 2001, South Australia/Victoria Border Groundwater Review Committee: Five Year Technical Review 1996-2000, DWR Report 2001/006.

Winter, TC 1999, ‘Relation of streams, lakes, and wetlands to groundwater flow systems’, Journal of Hydrology, vol. 7, pp.28-45.

Winter, TC, Harvey, JW, Franke, OL and Alley, WM 1998, Groundwater and surface water: a single resource, Circular 1139, U.S. Geological Survey, Denver Colorado.

Winter, TC 1995, ‘Recent advances in understanding the interaction of groundwater and surface water’, Reviews of Geophysics, Supplement, U.S. National Report.

Williams, M 1994, ‘Saline Groundwater Inflow to the Darling River near Bourke NSW: Reprints of Groundwater/Surface Hydrology Common Interest Papers’ Water Down Under, vol. 1, p.6259.

Williams, M 2001, Stream Aquifer Interaction in NSW: Draft Maps, DLWC, Sydney NSW.

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Appendix A

Use & allocation volumes per groundwater management unit/ unincorporated area

TABLE A-1 GMU/UA use by use type category

GMU Groundwater State 1999-2000 1999-2000 1999-2000 1999-2000 1999-2000 number management unit/ irrigation urban industrial/ rural total unincorporated area groundwater groundwater commercial groundwater groundwater use volumes use volume groundwater use volume use (ML/yr) (ML/yr) use volume (ML/yr) (ML/yr) (ML/yr)

N50 Great Artesian Basin— NSW - 2,340 - 68,440 70,780 Surat—NSW N51 Great Artesian Basin— NSW 9,090 220 - 2,270 11,580 Southern Recharge—NSW N52 Great Artesian Basin— NSW - 120 - 6,460 6,580 Central N53 Great Artesian Basin—Warrego NSW - 810 - 43,580 44,390 Q78 Great Artesian Basin— QLD 450 3,380 - 40,340 44,170 Barcaldine—Queensland Q80 Great Artesian Basin—Eastern QLD 400 690 - 36,050 37,140 Recharge B—Queensland Q82 Great Artesian Basin—Eastern QLD 190 330 - 17,430 17,950 Recharge C—Queensland Q94 Great Artesian Basin— QLD 210 9,260 - 18,530 28,000 Central—Queensland Q95 Great Artesian Basin— QLD 610 4,390 - 54,400 59,400 Warrego—Queensland Q96 Great Artesian Basin— QLD 890 15,880 - 79,950 96,720 Surat—Queensland GAB Subtotal 11,840 37,420 - 367,450 416,710 A1 Namadgi ACT - - 70 130 200 A2 Murrumbidgee ACT 50 - 490 260 800 A3 Queanbeyan and Molonglo ACT 190 - 2,860 950 4,000 N09 Lower Namoi Alluvium NSW 115,000 3,000 - 849 118,849 N10 Lower Murrumbidgee Alluvium NSW 175,542 2,400 3,368 2,753 184,063 N11 Lower Gwydir Alluvium NSW 37,000 3,000 - 762 40,762 N12 Upper Namoi Alluvium NSW 66,500 13,500 - 1,800 81,800 N13 Peel River Alluvium NSW 6,000 - - 2,000 8,000 N14 Maules Creek Alluvium NSW 500 - - 165 665 N15 Miscellaneous Tributaries of NSW 4,000 - - 321 4,321 the Namoi River (Alluvium) N16 Lower Macquarie Alluvium NSW 29,506 2,000 - 2,500 34,006 N17 Upper Macquarie Alluvium NSW 6,800 3,500 - 700 11,000 N18 Cudgegong Valley Alluvium NSW 1,500 1,500 - 200 3,200 N19 Upper Lachlan Alluvium NSW 40,495 4,688 376 2,000 47,559 N20 Lower Lachlan Alluvium NSW 24,511 2,000 - 1,500 28,011 N21 Mid Murrumbidgee Alluvium NSW 16,034 16,500 680 3,742 36,956

96 Projections of Groundwater Extraction Rates and Implications for Future Demand and Competition for Surface Water 57548_Book 17/6/03 2:26 AM Page 97

GMU Groundwater State 1999-2000 1999-2000 1999-2000 1999-2000 1999-2000 number management unit/ irrigation urban industrial/ rural total unincorporated area groundwater groundwater commercial groundwater groundwater use volumes use volume groundwater use volume use (ML/yr) (ML/yr) use volume (ML/yr) (ML/yr) (ML/yr)

N22 Billabong Creek Alluvium NSW 2,000 30 - 300 2,330 N23 Upper Murray Alluvium NSW 12,140 93 300 710 13,243 N24 Lower Murray Alluvium NSW 100,300 70 1,200 1,600 103,170 N27 Coolaburragundy—Talbragar NSW 1,425 300 - 75 1,800 Valley Alluvium N28 Bell Valley Alluvium NSW 1,000 - - 50 1,050 N29 Alluvium NSW 2,900 - - 100 3,000 N42 Orange Basalt NSW 5,400 - - 1,000 6,400 N43 Young Granite NSW 3,370 - - 3,725 7,095 N44 Inverell Basalt NSW 1,000 - - 549 1,549 N46 Mid and Upper Murrumbidgee NSW 1,723 181 - 100 2,004 Catchment Fractured Rocks N48 Mudgee Limestone NSW 360 - - 150 510 N49 Molong Limestone NSW 600 - - 200 800 Q51 Upper Hodgson Creek QLD 1,059 180 70 630 1,939 Q52 Toowoomba City Basalt QLD 350 1,800 1,300 50 3,500 Q53 Myall/Moola Creek North QLD 2,250 - - 100 2,350 Q54 Myall Creek QLD 2,750 - - - 2,750 Q55 Lower Oakey Creek Alluvium QLD 2800 - - - 2,800 Q56 Oakey Creek Management Area QLD 3,683 - 357 254 4,294 Q57 Condamine—Condamine QLD 723 - - 125 848 Groundwater Management Area Sub-Area 1 Q58 Condamine—Condamine QLD 4,706 1,500 0 272 6,478 Groundwater Management Area Sub-Area 2 Q59 Condamine—Condamine QLD 22,347 856 444 660 24,307 Groundwater Management Area Sub-Area 3 Q60 Condamine—Condamine QLD 1,666 - - 220 1,886 Groundwater Management Area Sub-Area 4 Q61 Condamine—Condamine QLD 289 100 - 136 525 Groundwater Management Area Sub-Area 5 Q62 Condamine River (Down-river QLD 1,650 - - 150 1,800 of Condamine Groundwater Management Area) Q63 Condamine River Alluvium QLD 1,600 - - 100 1,700 (Killarney to Murrays Bridge) Q64 Condamine River Alluvium QLD 3,990 - - 110 4,100 (Murrays Bridge to Cunningham) Q65 Condamine River Alluvium QLD 6,405 - - 95 6,500 (Cunningham to Ellangowan) Q66 Glengallan Creek QLD 7,885 - - 205 8,090 Q67 Dalrymple Creek Alluvium QLD 2,700 295 - 55 3,050

97 Projections of Groundwater Extraction Rates and Implications for Future Demand and Competition for Surface Water 57548_Book 17/6/03 2:26 AM Page 98

GMU Groundwater State 1999-2000 1999-2000 1999-2000 1999-2000 1999-2000 number management unit/ irrigation urban industrial/ rural total unincorporated area groundwater groundwater commercial groundwater groundwater use volumes use volume groundwater use volume use (ML/yr) (ML/yr) use volume (ML/yr) (ML/yr) (ML/yr) Q68 King's Creek Alluvium QLD 1,135 390 0 255 1,780 Q69 Swan Creek Alluvium QLD 885 45 0 435 1,365 Q70 Nobby Basalts QLD 2,320 0 0 455 2,775 Q71 St. George Alluvium QLD 2,200 - - - 2,200 Q73 Border Rivers QLD 6,400 170 - 450 7,020 S18 Angas Bremer SA 1,690 45 15 20 1,770 S19 Mallee—2 SA - - - - - S20 Mallee—1 SA 20,000 460 350 500 21,310 S23 Marne SA 5,000 20 10 30 5,060 S24 Tatiara—1 SA 63,500 700 450 2,300 66,950 S25 Tatiara—2 SA 25,000 10 65 500 25,575 S26 Padthaway—1 SA 24,200 - - - 24,200 S27 Padthaway—2 SA - - - - - S28 Naracoorte Ranges—1 SA 39,000 60 - 2,000 41,060 S29 Naracoorte Ranges—2 SA - - - - - S30 Tintinara—1 SA 18,000 - - 1,000 18,500 S31 Tintinara—2 SA 2,250 10 15 500 2,775 V11 Alexandra VIC 620 - 50 50 720 V12 King Lake VIC 503 - 60 380 943 V35 Mullindolingong VIC 450 - 50 260 760 V36 Barnawartha VIC 23 - 0 60 83 V37 Murmungee VIC 4,540 130 70 2,760 7,500 V38 Goorambat VIC 604 - 1 50 655 V39 Katunga VIC 26,859 400 191 1,290 28,740 V40 Kialla VIC 1,325 - - 110 1,435 V41 Nagambie VIC 1,250 - 33 110 1,393 V42 Campaspe VIC 21,722 400 580 22,702 V43 Shepparton VIC 117,850 740 4,470 4,820 127,880 V44 Ellesmere VIC 305 - 91 40 436 V45 Mid Loddon VIC 13,283 - 71 120 13,474 V47 Balrootan (Nhill) VIC 120 660 20 110 910 V49 Murrayville VIC 2,100 275 125 450 2,950 V50 Telopea Downs VIC 340 - - 150 490 V51 Lillimur (Kaniva) VIC 840 430 - 240 1,510 V52 Neuarpur VIC 18,950 - - 160 19,110 V53 Boikerbert (Apsley) VIC 690 20 - 280 990 V54 Moolort VIC 2,310 - - 250 2,560 V55 Ascot VIC 2,755 75 1,870 890 5,590 V56 Spring Hill VIC - - 280 330 610 V57 Bungaree VIC 3,325 115 150 747 4,337 V58 Glengower VIC - - - - - V59 Bullarook VIC - - - - - V60 Tourello VIC - - - - - GMU Subtotal (excluding GAB) 1,132,073 61,843 20,352 54,240 1,268,508 GMU Total 1,143,913 99,263 20,352 421,690 1,685,218

98 Projections of Groundwater Extraction Rates and Implications for Future Demand and Competition for Surface Water 57548_Book 17/6/03 2:26 AM Page 99

GMU Groundwater State 1999-2000 1999-2000 1999-2000 1999-2000 1999-2000 number management unit/ irrigation urban industrial/ rural total unincorporated area groundwater groundwater commercial groundwater groundwater use volumes use volume groundwater use volume use (ML/yr) (ML/yr) use volume (ML/yr) (ML/yr) (ML/yr)

N01 Unincorporated Area— NSW 3,000 818 - 3,000 6,818 Oxley Basin N03 Unincorporated Area— NSW 294 - 753 6,000 7,047 N04 Unincorporated Area— NSW 69 - - 4,000 4,069 Gunnedah Basin N05 Unincorporated Area— NSW 11,,000 18,907 399 1,889 32,195 New England Province N06 Unincorporated Area— NSW - - - 23,552 23,552 Lachlan Fold Belt Province N07 Unincorporated Area— NSW 200 - - 2,100 2,300 Murray Basin N08 Unincorporated Area— NSW - - 29 236 265 Olary Province Q101 Unincorporated Area— QLD 50,000 - 25,000 25,000 100,000 Yarraman S14 Unincorporated Area— SA 25,000 - - - 25,000 Mt Lofty Ranges S32 Unincorporated Area—1— SA 5,000 - - 500 11,000 Murray Group Limestone S33 Unincorporated Area—2— SA - - - 1,000 2,000 Renmark Group S8 Unincorporated Area— SA - - - - - Flinders Ranges V66 Unincorporated Area— VIC 6,380 144 976 1,612 9,112 Lachlan V77 Unincorporated Area— VIC 14,760 290 2,150 3,250 20,450 Murray (Watertable Aquifer) V78 Unincorporated Area— VIC 2,210 440 320 2,100 5,070 Murray (Middle Tertiary Aquifer) V79 Unincorporated Area— VIC - - - - - Murray (Lower Tertiary Aquifer) Unincorporated Area Total 117,913 20,599 29,627 74,239 242,378 Total Murray-Darling Basin Use 1,261,826 119,862 49,979 495,929 1,927,596

99 Projections of Groundwater Extraction Rates and Implications for Future Demand and Competition for Surface Water 57548_Book 17/6/03 2:26 AM Page 100

TABLE A-2 GMU/UA allocation by use type category

GMU Groundwater State 1999-2000 1999-2000 1999-2000 1999-2000 1999-2000 number management unit/ irrigation urban industrial/ rural total unincorporated area groundwater groundwater commercial groundwater groundwater allocation allocation groundwater allocation allocation volumes volume allocation volume (ML/yr) (ML/yr) (ML/yr) volume (ML/yr) (ML/yr)

N50 Great Artesian Basin— NSW 68,440 0 0 2,340 70,780 Surat—NSW N51 Great Artesian Basin— NSW 34,000 0 220 2,360 36,580 Southern Recharge—NSW N52 Great Artesian Basin—Central NSW 6,460 0 0 120 6,580 N53 Great Artesian Basin—Warrego NSW 43,580 0 0 810 44,390 Q78 Great Artesian Basin— QLD 450 0 3,380 40,340 44,170 Barcaldine—Queensland Q80 Great Artesian Basin—Eastern QLD 400 0 690 36,050 37,140 Recharge B—Queensland Q82 Great Artesian Basin—Eastern QLD 190 0 330 17,430 17,950 Recharge C—Queensland Q94 Great Artesian Basin— QLD 210 0 9,260 18,530 28,000 Central—Queensland Q95 Great Artesian Basin— QLD 610 0 4,390 54,400 59,400 Warrego—Queensland Q96 Great Artesian Basin— QLD 890 0 15,880 79,950 96,720 Surat—Queensland GAB Subtotal 155,230 0 34,150 252,330 441,710 A1 Namadgi ACT 200 0 0 250 450 A2 Murrumbidgee ACT 1,250 0 300 2,000 3,550 A3 Queanbeyan and Molonglo ACT 1,100 0 200 2,000 3,300 N09 Lower Namoi Alluvium NSW 206,600 4,400 0 2,264 213,264 N10 Lower Murrumbidgee Alluvium NSW 361,148 3,665 8,549 11,014 384,376 N11 Lower Gwydir Alluvium NSW 93,500 3,500 0 2,032 99,032 N12 Upper Namoi Alluvium NSW 270,000 5,600 0 3,576 279,176 N13 Peel River Alluvium NSW 30,000 0 0 3,000 33,000 N14 Maules Creek Alluvium NSW 8,393 0 0 440 8,833 N15 Miscellaneous Tributaries of NSW 14,050 0 0 856 14,906 the Namoi River (Alluvium) N16 Lower Macquarie Alluvium NSW 145,831 3,090 0 5,100 154,021 N17 Upper Macquarie Alluvium NSW 37,070 4,753 0 1,304 43,127 N18 Cudgegong Valley Alluvium NSW 12,194 3,199 0 376 15,769 N19 Upper Lachlan Alluvium NSW 164,302 5,860 376 3,936 174,474 N20 Lower Lachlan Alluvium NSW 232,380 2,000 0 3,072 237,452 N21 Mid Murrumbidgee Alluvium NSW 30,893 15,128 1,060 3,742 50,823 N22 Billabong Creek Alluvium NSW 6,825 100 0 536 7,461 N23 Upper Murray Alluvium NSW 37,225 93 910 1,248 39,476 N24 Lower Murray Alluvium NSW 324,000 70 4,400 3,176 331,646 N27 Coolaburragundy—Talbragar NSW 6,528 445 0 216 7,189 Valley Alluvium

100 Projections of Groundwater Extraction Rates and Implications for Future Demand and Competition for Surface Water 57548_Book 17/6/03 2:26 AM Page 101

GMU Groundwater State 1999-2000 1999-2000 1999-2000 1999-2000 1999-2000 number management unit/ irrigation urban industrial/ rural total unincorporated area groundwater groundwater commercial groundwater groundwater allocation allocation groundwater allocation allocation volumes volume allocation volume (ML/yr) (ML/yr) (ML/yr) volume (ML/yr) (ML/yr)

N28 Bell Valley Alluvium NSW 5,870 0 0 48 5,918 N29 Belubula River Alluvium NSW 19,000 0 0 152 19,152 N42 Orange Basalt NSW 5,572 0 0 2,112 7,684 N43 Young Granite NSW 4,815 0 0 13,195 18,010 N44 Inverell Basalt NSW 1,551 0 0 1,464 3,015 N46 Mid and Upper Murrumbidgee NSW 1,284 181 0 112 1,577 Catchment Fractured Rocks N48 Mudgee Limestone NSW 1,787 0 0 672 2,459 N49 Molong Limestone NSW 3,000 0 0 1,000 4,000 Q51 Upper Hodgson Creek QLD 2,843 367 393 1,564 5,167 Q52 Toowoomba City Basalt QLD 769 0 4,682 93 5,544 Q53 Myall/Moola Creek North QLD 2,126 0 25 190 2,341 Q54 Myall Creek QLD 582 0 121 393 1,096 Q55 Lower Oakey Creek Alluvium QLD 5,586 0 386 41 6,013 Q56 Oakey Creek Management Area QLD 7,228 174 526 1,735 9,663 Q57 Condamine—Condamine QLD 1,885 0 38 1,637 3,560 Groundwater Management Area Sub-Area 1 Q58 Condamine—Condamine QLD 7,380 2,700 0 643 10,723 Groundwater Management Area Sub-Area 2 Q59 Condamine—Condamine QLD 48,890 450 64 158 49,562 Groundwater Management Area Sub-Area 3 Q60 Condamine—Condamine QLD 3,082 0 350 262 3,694 Groundwater Management Area Sub-Area 4 Q61 Condamine—Condamine QLD 542 0 479 105 1,126 Groundwater Management Area Sub-Area 5 Q62 Condamine River (Down-river QLD 1,267 10 621 0 1,898 of Condamine Groundwater Management Area) Q63 Condamine River Alluvium QLD 1,100 0 665 296 2,061 (Killarney to Murrays Bridge) Q64 Condamine River Alluvium QLD 3,185 0 350 630 4,165 (Murrays Bridge to Cunningham) Q65 Condamine River Alluvium QLD 6,485 195 500 900 8,080 (Cunningham to Ellangowan) Q66 Glengallan Creek QLD 6,335 0 440 0 6,775 Q67 Dalrymple Creek Alluvium QLD 3,755 560 0 0 4,315 Q68 King's Creek Alluvium QLD 1,135 390 0 255 1,780 Q69 Swan Creek Alluvium QLD 885 45 0 435 1,365 Q70 Nobby Basalts QLD 2,320 0 0 455 2,775

101 Projections of Groundwater Extraction Rates and Implications for Future Demand and Competition for Surface Water 57548_Book 17/6/03 2:26 AM Page 102

GMU Groundwater State 1999-2000 1999-2000 1999-2000 1999-2000 1999-2000 number management unit/ irrigation urban industrial/ rural total unincorporated area groundwater groundwater commercial groundwater groundwater allocation allocation groundwater allocation allocation volumes volume allocation volume (ML/yr) (ML/yr) (ML/yr) volume (ML/yr) (ML/yr)

Q71 St. George Alluvium QLD 6,300 0 0 40 6,340 Q73 Border Rivers QLD 26,080 555 3,235 1,020 30,890 S18 Angas Bremer SA 6,532 0 0 0 6,532 S19 Mallee—2 SA 0 0 0 0 0 S20 Mallee—1 SA 51,635 0 0 0 51,635 S23 Marne SA 0 0 0 0 0 S24 Tatiara—1 SA 90,500 0 0 0 90,500 S25 Tatiara—2 SA 0 0 0 0 0 S26 Padthaway—1 SA 35,100 0 0 0 35,100 S27 Padthaway—2 SA 0 0 0 0 0 S28 Naracoorte Ranges—1 SA 78,700 0 0 0 78,700 S29 Naracoorte Ranges—2 SA 0 0 0 0 0 S30 Tintinara—1 SA 17,500 0 0 0 17,500 S31 Tintinara—2 SA 8,000 0 0 0 8,000 V11 Alexandra VIC 601 0 130 951 1,682 V12 King Lake VIC 1,152 0 80 826 2,058 V35 Mullindolingong VIC 950 0 103 280 1,333 V36 Barnawartha VIC 184 0 0 309 493 V37 Murmungee VIC 10,960 260 146 3,300 14,666 V38 Goorambat VIC 1,400 0 2 50 1,452 V39 Katunga VIC 58,750 760 400 1,590 61,500 V40 Kialla VIC 2,081 0 0 150 2,231 V41 Nagambie VIC 7,292 0 1,522 190 9,004 V42 Campaspe VIC 45,972 0 600 680 47,252 V43 Shepparton VIC 1,590 1,050 6,430 4,828 13,898 V44 Ellesmere VIC 1,140 0 171 46 1,357 V45 Mid Loddon VIC 26,785 0 345 170 27,300 V47 Balrootan (Nhill) VIC 200 1,090 40 220 1,550 V49 Murrayville VIC 3,400 520 80 500 4,500 V50 Telopea Downs VIC 340 0 10 290 640 V51 Lillimur (Kaniva) VIC 590 690 0 480 1,760 V52 Neuarpur VIC 24,250 0 0 500 24,750 V53 Boikerbert (Apsley) VIC 780 40 0 560 1,380 V54 Moolort VIC 4,842 0 0 500 5,342 V55 Ascot VIC 4,150 100 1,336 390 5,976 V56 Spring Hill VIC 4,000 0 598 680 5,278 V57 Bungaree VIC 4,400 145 190 1,135 5,870 V58 Glengower VIC 0 0 0 0 0 V59 Bullarook VIC 0 0 0 0 0 V60 Tourello VIC 0 0 0 0 0 GMU Subtotal (excluding GAB) 2,659,904 62,185 40,853 98,370 2,861,312 GMU Total 2,815,134 62,185 75,003 350,700 3,303,022

102 Projections of Groundwater Extraction Rates and Implications for Future Demand and Competition for Surface Water 57548_Book 17/6/03 2:26 AM Page 103

GMU Groundwater State 1999-2000 1999-2000 1999-2000 1999-2000 1999-2000 number management unit/ irrigation urban industrial/ rural total unincorporated area groundwater groundwater commercial groundwater groundwater use volumes use volume groundwater use volume use (ML/yr) (ML/yr) use volume (ML/yr) (ML/yr) (ML/yr)

N01 Unincorporated Area— NSW 6,084 818 0 5,448 12,350 Oxley Basin N03 Unincorporated Area— NSW 3,754 0 1515 588 5,857 Sydney Basin N04 Unincorporated Area— NSW 69 0 0 7,224 7,293 Gunnedah Basin N05 Unincorporated Area— NSW 21,842 18,907 895 3,778 45,422 New England Province N06 Unincorporated Area— NSW 0 0 47,104 47,104 Lachlan Fold Belt Province N07 Unincorporated Area— NSW 200 0 1,900 2,100 Murray Basin N08 Unincorporated Area— NSW 0 0 472 472 Olary Province Q101 Unincorporated Area— QLD 0 0 0 0 0 Yarraman S14 Unincorporated Area— SA 0 0 0 0 0 Mt Lofty Ranges S32 Unincorporated Area—1— SA 0 0 0 0 0 Murray Group Limestone S33 Unincorporated Area—2— SA 0 0 0 0 0 Renmark Group S8 Unincorporated Area— SA 0 0 0 0 0 Flinders Ranges V66 Unincorporated Area— VIC 15,950 0 3,160 4,030 23,140 Lachlan V77 Unincorporated Area— VIC 14,760 0 2,440 3,250 20,450 Murray (Watertable Aquifer) V78 Unincorporated Area— VIC 1,230 0 760 2,100 4,090 Murray (Middle Tertiary Aquifer) V79 Unincorporated Area— VIC 0 0 0 0 0 Murray (Lower Tertiary Aquifer) Unincorporated Area Total 63,889 19,725 8,770 75,894 168,278 Total Murray-Darling Basin Use 2,879,023 81,910 83,773 426,594 3,471,300

103 Projections of Groundwater Extraction Rates and Implications for Future Demand and Competition for Surface Water 57548_Book 17/6/03 2:26 AM Page 104

Table A-3 Groundwater use and level of development within surface water Cap regions

Cap Surface water Cap region GMU type Groundwater Groundwater Groundwater % gw % gw region use* in allocations sustainable use in alloc. in number 1999-2000 in 1999-2000 yields in 1999- 1999- 1999-2000 2000 2000 1 Border Rivers (NSW) GAB 8,236 10,736 6,374 129% 168% GMU 5,059 18,460 23,600 21% 78% UA 6,439 9,084 372,909 2% 2% Total 19,734 38,280 402,883 5% 10% 2 Moonie (NSW) GAB Total 54,107 54,107 45,621 119% 119% 3 Gwydir River Valley (NSW) GAB 11,775 14,275 9,056 130% 158% GMU 52,647 120,358 44,500 118% 270% UA 6,439 9,084 372,909 2% 2% Total 70,860 143,718 426,465 17% 34% 4 Namoi River Valley (NSW) GAB 9,973 16,223 7,889 126% 206% GMU 201,750 527,853 225,500 89% 234% UA 173,728 27,429 835,109 20% 3% Total 229,095 571,504 1,068,498 21% 53% 5 Macquarie-Castlereagh-Bogan GAB 27,603 41,353 21,647 128% 191% water supply system (NSW) GMU 55,366 235,325 119,950 46% 196% UA 6,779 12,476 177,080 3% 7% Total 89,748 289,154 318,677 28% 91% 6 Barwon-Upper Darling water GAB 15,056 15,056 11,923 126% 126% supply system (NSW) UA 5,625 10,452 359,830 1% 2% Total 20,681 25,508 371,753 6% 7% 7 Lachlan River Valley (NSW) GMU 96,849 469,547 338,950 29% 139% UA 5,170 9,841 181,780 1% 3% Total 102,020 479,388 520,730 20% 92% 8 Murrumbidgee River Valley (NSW) GMU Total 226,064 442,061 524,150 43% 84% 9 Lower Darling from the UA Total 385 386 94,950 1% 1% Menindee Lakes to Wentworth Weir Pool (NSW) 10 Murray Valley (NSW) including GMU 116,413 371,122 166,300 70% 223% portion of Lower Darling UA 2,815 5,130 158,092 2% 3% influenced by the Wentworth Weir Pool Total 119,228 376,252 305,190 39% 123%

11 Condamine-Balonne water GAB 103,424 103,424 80,517 128% 128% supply system (QLD) GMU 84,192 136,657 113,765 74% 120% UA 65,000 0 25,200 258% 0% Total 252,616 240,081 219,482 115% 109% 12 Border Rivers (QLD) GAB 15,057 15,057 11,903 126% 126% GMU 3,510 15,445 15,000 23% 103% UA 80,000 0 31,016 257% 0% Total 98,567 30,502 57,919 170% 53% 13 Moonie River Valley (QLD) GAB Total 15,405 15,405 11,579 133% 133% 14 Warrego River Valley (QLD) GAB Total 20,693 20,693 17,325 119% 119% 15 Paroo River Valley (QLD) GAB Total 11,880 11,880 9,792 121% 121% 16 Goulburn-Broken-Loddon GMU 146,918 79,040 185,640 79% 42% water supply system (VIC) UA 13,032 19,002 491,830 3% 4% Total 159,950 98,042 677,470 24% 14%

104 Projections of Groundwater Extraction Rates and Implications for Future Demand and Competition for Surface Water 57548_Book 17/6/03 2:26 AM Page 105

Cap Surface water Cap region GMU type Groundwater Groundwater Groundwater % gw % gw region use* in allocations sustainable use in alloc. in number 1999-2000 in 1999-2000 yields in 1999- 1999- 1999-2000 2000 2000

17 Campaspe river valley (VIC) GMU 35,817 49,659 32,650 109% 152% UA 2,187 3541 85,990 3% 4% Total 38,004 53,200 118,640 32% 45% 18 Wimmera-Mallee water GMU 910 1,550 1,000 91% 155% supply system (VIC) UA 8,567 9,676 295,740 3% 3% Total 9,477 11,226 296,740 3% 4% 19 Victorian portion of the Murray GMU 40,523 83,132 50,475 80% 164% Valley including Kiewa and UA 10,845 15,461 405,840 3% 4% Ovens River Valleys Total 51,368 98,593 456,315 11% 22% 20 River Murray (SA) GMU 44,395 83,667 65,300 57% 128% UA 17,750 0 61,150 29% 0% Total 62,145 83,667 126,450 49% 66% 21 Australian Capital Territory (ACT) GMU Total 1,560 3,595 69,180 2% 5% 22 Reclaimed swamps (SA) GMU Total 5060 0 0 0% 0% 23 SE Murray Province (SA) GMU 133,630 204,300 203,300 62% 100% UA 0 0 0 0% 0% Total 133,630 204,300 203,300 66% 100% 24 SW Murray Province (VIC) GMU 21,610 27,890 41,557 52% 67% UA 0 0 0 0% 0% Total 21,610 27,890 41,557 52% 67% Total Murray-Darling Basin 1,813,887 3,319,434 6,384,665 28% 52%

105 Projections of Groundwater Extraction Rates and Implications for Future Demand and Competition for Surface Water 57548_Book 17/6/03 2:26 AM Page 106

Appendix B

Forecast demands for Murray-Darling Basin

Year Total sustainable Unrestricted demand Restricted demand Unmet demand yield in MDB (low growth scenario) (low growth scenario) (low growth scenario)

1 7,471,709 1,874,466 1,868,642 9,876 2 7,471,709 1,880,420 1,878,172 11,636 3 7,471,709 1,886,505 1,887,833 11,759 4 7,471,709 1,892,723 1,869,516 32,863 5 7,471,709 1,899,075 1,851,267 55,462 6 7,471,709 1,905,561 1,833,065 78,148 7 7,471,709 1,912,184 1,814,945 100,905 8 7,471,709 1,918,943 1,796,908 123,717 9 7,471,709 1,925,842 1,778,953 146,585 10 7,471,709 1,932,880 1,761,083 171,947 11 7,471,709 1,944,107 1,743,298 200,960 12 7,471,709 1,955,476 1,725,599 230,029 13 7,471,709 1,966,989 1,707,986 259,156 14 7,471,709 1,978,646 1,713,865 264,935 15 7,471,709 1,990,450 1,722,157 268,447 16 7,471,709 2,002,401 1,730,511 272,045 17 7,471,709 2,014,501 1,738,986 275,685 18 7,471,709 2,026,750 1,747,519 279,368 19 7,471,709 2,039,152 1,756,131 283,111 20 7,471,709 2,051,706 1,764,834 286,964 21 7,471,709 2,064,414 1,773,630 290,878 22 7,471,709 2,077,278 1,782,520 294,854 23 7,471,709 2,090,298 1,791,506 298,892 24 7,471,709 2,103,478 1,800,586 302,993 25 7,471,709 2,116,817 1,807,496 309,424 26 7,471,709 2,130,317 1,814,481 315,942 27 7,471,709 2,143,980 1,821,542 322,546 28 7,471,709 2,157,808 1,828,680 329,340 29 7,471,709 2,171,801 1,835,896 336,425 30 7,471,709 2,185,962 1,842,686 343,776 31 7,471,709 2,200,291 1,848,728 351,169 32 7,471,709 2,214,791 1,854,836 360,045 33 7,471,709 2,229,463 1,861,012 369,023 34 7,471,709 2,244,308 1,867,228 378,105 35 7,471,709 2,259,329 1,871,366 389,391 36 7,471,709 2,274,526 1,877,744 398,688 37 7,471,709 2,289,901 1,884,192 408,092 38 7,471,709 2,305,457 1,890,709 417,604 39 7,471,709 2,321,195 1,897,296 427,226 40 7,471,709 2,337,116 1,903,955 436,958 41 7,471,709 2,352,678 1,910,513 446,257 42 7,471,709 2,368,321 1,916,117 456,844 43 7,471,709 2,384,144 1,921,713 467,137 44 7,471,709 2,400,150 1,926,910 478,401 45 7,471,709 2,416,339 1,932,165 490,023 46 7,471,709 2,432,714 1,936,481 501,971 47 7,471,709 2,449,277 1,940,818 513,970 48 7,471,709 2,466,028 1,945,203 527,239 49 7,471,709 2,482,971 1,949,636 540,635 50 7,471,709 2,499,932 1,954,119 554,017

106 Projections of Groundwater Extraction Rates and Implications for Future Demand and Competition for Surface Water 57548_Book 17/6/03 2:27 AM Page 107

Year Total sustainable Unrestricted demand Restricted demand Unmet demand yield in MDB (medium growth (medium growth (medium growth scenario) scenario) scenario)

1 7,471,709 1,902,316 1,868,642 37,722 2 7,471,709 1,937,086 1,905,659 38,818 3 7,471,709 1,972,984 1,943,915 39,946 4 7,471,709 2,010,043 1,942,545 76,425 5 7,471,709 2,048,298 1,941,917 113,359 6 7,471,709 2,087,785 1,942,052 150,762 7 7,471,709 2,128,540 1,942,875 188,647 8 7,471,709 2,170,601 1,944,450 227,167 9 7,471,709 2,214,006 1,941,486 266,213 10 7,471,709 2,258,795 1,938,002 314,371 11 7,471,709 2,306,955 1,933,333 365,290 12 7,471,709 2,356,331 1,926,924 420,572 13 7,471,709 2,407,153 1,919,702 476,958 14 7,471,709 2,459,466 1,929,133 521,497 15 7,471,709 2,513,312 1,947,989 552,808 16 7,471,709 2,568,682 1,962,444 590,049 17 7,471,709 2,625,285 1,977,313 631,273 18 7,471,709 2,683,414 1,992,610 673,738 19 7,471,709 2,743,250 2,008,346 717,340 20 7,471,709 2,804,844 2,024,392 768,894 21 7,471,709 2,868,249 2,040,710 815,459 22 7,471,709 2,932,850 2,057,438 867,060 23 7,471,709 2,998,739 2,073,737 915,798 24 7,471,709 3,066,565 2,089,871 967,124 25 7,471,709 3,136,388 2,106,437 1,020,138 26 7,471,709 3,208,203 2,123,308 1,079,911 27 7,471,709 3,282,001 2,138,440 1,139,468 28 7,471,709 3,357,973 2,153,639 1,200,144 29 7,471,709 3,436,185 2,169,274 1,262,623 30 7,471,709 3,516,702 2,185,259 1,326,960 31 7,471,709 3,592,152 2,201,146 1,386,154 32 7,471,709 3,668,824 2,216,862 1,446,923 33 7,471,709 3,747,755 2,232,898 1,509,574 34 7,471,709 3,823,879 2,248,335 1,570,385 35 7,471,709 3,894,727 2,264,153 1,625,494 36 7,471,709 3,967,660 2,280,324 1,682,078 37 7,471,709 4,042,741 2,296,867 1,740,707 38 7,471,709 4,114,480 2,313,764 1,797,953 39 7,471,709 4,187,807 2,330,397 1,853,724 40 7,471,709 4,263,292 2,347,391 1,912,071 41 7,471,709 4,341,000 2,364,875 1,972,456 42 7,471,709 4,420,873 2,382,667 2,035,219 43 7,471,709 4,503,058 2,400,961 2,099,279 44 7,471,709 4,587,502 2,419,175 2,164,926 45 7,471,709 4,673,787 2,436,442 2,234,318 46 7,471,709 4,745,012 2,450,286 2,286,876 47 7,471,709 4,815,868 2,464,531 2,343,706 48 7,471,709 4,878,694 2,478,630 2,391,904 49 7,471,709 4,941,323 2,493,112 2,440,079 50 7,471,709 5,005,788 2,508,014 2,490,561

107 Projections of Groundwater Extraction Rates and Implications for Future Demand and Competition for Surface Water 57548_Book 17/6/03 2:27 AM Page 108

Year Total sustainable Unrestricted demand Restricted demand Unmet demand yield in MDB (high growth scenario) (high growth scenario) (high growth scenario)

1 7,471,709 1,930,167 1,868,642 65,573 2 7,471,709 1,994,767 1,934,491 68,648 3 7,471,709 2,062,594 2,003,348 71,875 4 7,471,709 2,133,807 2,020,252 123,930 5 7,471,709 2,208,572 2,038,992 177,737 6 7,471,709 2,286,145 2,059,923 232,344 7 7,471,709 2,364,505 2,070,632 296,380 8 7,471,709 2,446,789 2,077,677 369,066 9 7,471,709 2,533,190 2,086,035 444,214 10 7,471,709 2,623,644 2,091,047 523,167 11 7,471,709 2,721,959 2,088,941 622,912 12 7,471,709 2,824,983 2,088,022 726,167 13 7,471,709 2,932,854 2,087,786 833,011 14 7,471,709 3,043,862 2,090,589 940,334 15 7,471,709 3,160,206 2,118,386 1,025,694 16 7,471,709 3,281,950 2,147,214 1,118,042 17 7,471,709 3,409,436 2,166,025 1,226,009 18 7,471,709 3,543,074 2,192,649 1,339,677 19 7,471,709 3,672,266 2,220,021 1,440,828 20 7,471,709 3,804,516 2,246,981 1,544,062 21 7,471,709 3,928,101 2,267,335 1,653,222 22 7,471,709 4,051,585 2,294,397 1,749,468 23 7,471,709 4,175,321 2,322,463 1,844,762 24 7,471,709 4,300,583 2,350,495 1,941,207 25 7,471,709 4,431,839 2,379,710 2,043,256 26 7,471,709 4,569,185 2,409,922 2,152,569 27 7,471,709 4,712,341 2,439,143 2,264,230 28 7,471,709 4,838,540 2,459,741 2,366,912 29 7,471,709 4,951,752 2,483,587 2,455,460 30 7,471,709 5,059,088 2,507,768 2,537,457 31 7,471,709 5,165,164 2,533,101 2,619,497 32 7,471,709 5,260,064 2,559,321 2,689,639 33 7,471,709 5,347,930 2,584,759 2,749,917 34 7,471,709 5,429,900 2,601,497 2,805,277 35 7,471,709 5,515,401 2,618,757 2,874,400 36 7,471,709 5,600,416 2,636,763 2,940,835 37 7,471,709 5,685,226 2,653,442 3,006,581 38 7,471,709 5,770,189 2,669,680 3,079,587 39 7,471,709 5,849,171 2,686,451 3,146,130 40 7,471,709 5,931,163 2,703,844 3,210,605 41 7,471,709 6,014,623 2,721,744 3,276,722 42 7,471,709 6,097,091 2,740,029 3,340,644 43 7,471,709 6,178,335 2,759,171 3,403,213 44 7,471,709 6,262,601 2,778,640 3,469,287 45 7,471,709 6,349,961 2,797,890 3,546,302 46 7,471,709 6,440,217 2,817,971 3,616,445 47 7,471,709 6,533,371 2,838,998 3,688,515 48 7,471,709 6,629,234 2,860,749 3,764,797 49 7,471,709 6,727,380 2,882,815 3,841,803 50 7,471,709 6,823,003 2,905,923 3,914,180

108 Projections of Groundwater Extraction Rates and Implications for Future Demand and Competition for Surface Water 57548_Book 17/6/03 2:27 AM Page 109

Appendix C

Groundwater cost model

A spreadsheet model has been developed for estimating the cost to an irrigated agricultural enterprise of using groundwater for irrigation water supplies. The required inputs to the model are: • Cost of capital (%) •Crop—total irrigation requirement (mm/season) •Crop—peak irrigation requirement (mm/day) •Crop—duration of irrigation season (months) •Crop—maximum salinity of irrigation water for zero production loss (g/L) • Surface water quality (g/L) •Well—water quality (g/L) •Well—pumping head (m) •Well—average yield (ML/day) •Well—pump efficiency (%) •Well—unit energy cost ($/MWh) • Installation cost—Bore ($) • Installation cost—Pump ($) • Installation cost—Electricity connection ($) • Service life—bore (yrs) • Service life—pump (yrs) • Service life—electricity connection (yrs) • Maintenance cost ($/yr)

The model assumes that groundwater will be diluted with surface water to ensure a zero crop loss due to salinity in the irrigation water. The cost of groundwater is adjusted for the salinity level of the groundwater relative to the crop requirement and the salinity of surface water. The cost estimate also includes the capital installation costs and the operating cost based on an electrical power supply.

The model is useful for comparing the costs of groundwater development in particular area against the potential gross margin from an irrigated crop. If the cost of groundwater is less than the gross margin then it would be economically optimal to use groundwater if surface water supplies became limited. An example of a model application is shown in Figure C-1.

The cost of groundwater is calculated for different groundwater salinities and three different bore configurations—shallow, medium depth and deep bores. If the crop gross margin (less water costs) is $100 per ML then it would be profitable to use groundwater up to the point where the groundwater costs exceeds the gross margin. For the bore configurations considered in this example it is profitable to use the shallow bore at all salinity levels, the medium depth bore up to 1.9 g/L and the deep bore up to 1.3 g/L.

A typical set of input data and result calculations are illustrated in Table C-1.

109 Projections of Groundwater Extraction Rates and Implications for Future Demand and Competition for Surface Water 57548_Book 17/6/03 2:27 AM Page 110

TABLE C-1 Groundwater cost model—illustrative example

Groundwater cost calculator

Input data

Cost of capital % 12% Crop—total irrigation requirement mm/season 950 Crop—peak irrigation requirement mm/day 2 Crop—duration of irrigation season months 6 Crop—maximum salinity of irrigation water for zero production loss g/L 1 Surface water quality g/L 0.5 Well—water quality g/L 1.1 Well—pumping head m 60 Well—average yield ML/day 4 Well—pump efficiency % 60% Well—unit energy cost $/MWh 70 Installation cost—Bore $ 5,000 Installation cost—Pump $ 22,000 Installation cost—Electricity connection $ 10,000 Service life—bore yrs 30 Service life—pump life yrs 10 Service life—electricity connection yrs 30 Maintenance cost $/yr 2,000

Results

Dilution ratio ratio 0.8333333 Effective area irrigated ha. 64.04 Effective irrigation applied ML 608.33333 Peak power KW 45 Seasonal power use MWh 517 Power cost $/yr 36,206 Capital cost $/yr 5,139 Total cost $/yr 43,345 Cost per ML $/ML 71 Cost per ha $/ha 677

Figure C-1. Cost of Groundwater—Shallow, Medium Depth and Deep Bores—Illustrative Example.

110 Projections of Groundwater Extraction Rates and Implications for Future Demand and Competition for Surface Water 57548_Book 17/6/03 2:27 AM Page 111

Appendix D

River reaches

TABLE D-1 Adjusted river reaches used in analysis

GMU GMU name Name Length Cap number (km) region number A1 Namadgi Murrumbidgee River & Tributaries 73.0 22 A2 Murrumbidgee Murrumbidgee River & Tributaries 64.8 22 A3 Queanbeyan and Molonglo Murrumbidgee River & Tributaries 217.7 22 N01 Unincorporated Area—Oxley Basin 135.8 5 Coxs Creek 76.8 4 N03 Unincorporated Area—Sydney Basin 10.5 5 N04 Unincorporated Area—Gunnedah Basin Cudgegong River 55.7 5 Mooki River 10.2 4 Namoi River 4.4 4 Warrah Creek 24.8 4 N05 Unincorporated Area—New England Province 12.5 4 58.5 12 Frazers Creek 77.2 1 Gwydir River 278.2 3 Macdonald Creek 4.5 4 Macdonald River 158.8 4 Macintyre River 228.3 1 Namoi River 114.5 4 Peel River 75.5 4 Severn River 196.4 1 N06 Unincorporated Area—Lachlan Fold Barwon River 38.7 6 Belt Province Boomi Creek 355.4 5 Cudgegong River 142.1 5 2.2 6 Darling River 754.5 6 Kiewa River 0.1 10 Lachlan River 455.0 7 Macquarie River 547.0 5 Murray River 195.6 19 Murrumbidgee River 29.0 8 Murrumbidgee River And Tributaries 1,196.3 8 Paroo River 31.1 6 Warrego River 19.3 6 N07 Unincorporated Area—Murray Basin Murrumbidgee River 84.3 8 Darling River 787.2 10 54.0 10 493.7 10 Murray River 871.7 19 266.8 10 Willandra Creek 16.0 10

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GMU GMU name Name Length Cap number (km) region number N08 Unincorporated Area—Olary Province Darling River 10.8 6 N09 Lower Namoi Alluvium Namoi River 116.1 4 Pian Creek 158.2 4 N10 Lower Murrumbidgee Alluvium Murrumbidgee River 583.4 8 Lachlan River 253.3 7 Edward River 66.4 10 N11 Lower Gwydir Alluvium Gwydir River 142.0 3 Gwydir Anabranch 22.0 3 Gwydir River 141.5 3 185.0 3 Moomin Creek 24.7 3 N12 Upper Namoi Alluvium Coxs Creek 156.4 4 Mooki River 89.5 4 Namoi River 187.0 4 Turrabeile (Coxs) Creek 52.0 4 Warrah Creek 35.7 4 N13 Peel River Alluvium Cockburn River 21.1 4 Peel River 116.7 4 N15 Miscellaneous Tributaries of the Namoi River Namoi River 30.9 4 (Alluvium) N16 Lower Macquarie Alluvium Macquarie River 106.9 5 N17 Upper Macquarie Alluvium Macquarie River 155.3 5 N18 Cudgegong Valley Alluvium Cudgegong River 48.1 5 N19 Upper Lachlan Alluvium Lachlan River 504.1 7 N20 Lower Lachlan Alluvium Lachlan River 386.0 7 Middle Creek 177.8 7 N20 Lower Lachlan Alluvium Willandra Creek 415.6 7 N21 Mid Murrumbidgee Alluvium Murrumbidgee River 302.6 8 N23 Upper Murray Alluvium Murray River 104.4 19 N24 Lower Murray Alluvium Edward River 255.3 10 Murray River 323.9 19 Wakool River 93.3 10 N28 Bell Valley Alluvium Macquarie River 30.8 5 N44 Inverell Basalt Macintyre River 22.6 1 N46 Mid and Upper Murrumbidgee Catchment Murrumbidgee River & Tributaries 15.4 8 Fractured N48 Mudgee Limestone Cudgegong River 43.8 5 N49 Molong Limestone Macquarie River 151.6 5 Q106 Unincorporated Area—New England Dumaresq River 63.9 12 Macintyre Brook 83.9 12 100.3 12 Severn River 86.9 12 Q107 Unincorporated Area—Clarence Moreton Condamine River 67.9 11 Condamine River (North Branch) 60.2 11 Q57 Condamine—Condamine Groundwater Condamine River 33.0 11 Management Area Sub-Area 1 Q58 Condamine—Condamine Groundwater Condamine River 19.0 11 Management Area Sub-Area 2

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GMU GMU name Name Length Cap number (km) region number Q59 Condamine—Condamine Groundwater Condamine River 102.9 11 Management Area Sub-Area 3 Condamine River (North Branch) 83.2 11 Q60 Condamine—Condamine Groundwater Condamine River 23.0 11 Management Area Sub-Area 4 Condamine River (North Branch) 25.5 11 Q61 Condamine—Condamine Groundwater Condamine River 7.3 11 Management Area Sub-Area 5 Q62 Condamine River (down-river of Condamine Condamine River 78.8 11 Groundwater Management Area) Q65 Condamine River Alluvium (Cunningham Condamine River 38.0 11 to Ellangowan) Condamine River (North Branch) 3.9 11 Q67 Dalrymple Creek Alluvium Condamine River 3.7 11 Q68 Kings Creek Alluvium Condamine River 0.2 11 Q71 St. George Alluvium Balonne River 289.0 11 Ballandool River 62.8 11 78.1 11 Culgoa River 160.1 11 151.5 11 65.6 11 Q73 Border Rivers Dumaresq River 165.5 12 Macintyre Brook 3.4 12 S32 Unincorporated Area 1—Murray River Murray 667.0 21 Group Limestone V11 Alexandra Goulburn River 21.0 16 V12 King Lake Yea River 0.2 16 V35 Mullindolingong Kiewa River 96.3 19 Kiewa River West Branch 3.8 19 Kinchington 2.3 19 Murray River 2.9 19 V37 Murmungee Buckland River 7.0 19 Buffalo River 23.1 19 King River 14.2 19 Ovens River + East & West Branches 138.0 19 V38 Goorambat Broken Creek 28.3 16 Broken River 7.2 16 V40 Kialla Broken River 15.3 16 Goulburn River 73.7 16 V41 Nagambie Goulburn River 57.8 16 V43 Shepparton Groundwater Supply Broken Creek 127.3 19 Protection Area Broken River 18.6 16 Campaspe River 39.0 17 Goulburn River 199.3 16 Murray River 37.9 19 V44 Ellesmere Campaspe River 2.8 17 V45 Bridgewater (Loddon) Loddon River 68.2 16 Serpentine Creek 36.5 16 V54 Moolort Loddon River 65.9 16

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GMU GMU name Name Length Cap number (km) region number V66 Unincorporated Area—Lachlan Acheron River 57.0 19 Avoca River 128.9 16 Big River 111.5 19 Broken River 74.3 19 Buckland River 8.9 19 Buckland River East Branch 23.7 19 Buffalo River 37.1 19 Buffalo River West Branch 36.1 19 Campaspe River 112.2 17 Dandongadale River 3.7 19 Delatite River 84.7 16 Goulburn River 222.4 16 Kiewa River 5.7 19 Kiewa River West Branch 18.0 19 Kinchington 18.8 19 Kinchington Creek 15.0 19 King River 27.9 19 Loddon River 63.8 16 Mcivor Creek 32.7 17 Mitta Mitta River 198.8 19 Mount Ida Creek 22.3 17 Murray River 111.4 19 Ovens River East Branch 3.6 19 Ovens River West Branch 7.3 19 Pretty Valley Creek 12.9 19 Rocky Valley 12.3 19 Rose River 40.0 19 Tallangatta Creek 60.8 19 Wimmera River 36.6 18 Yea River 72.8 16 V77 Unincorporated Area—Murray Avoca River 152.2 16 (Watertable Aquifer) Broken Creek 37.6 16 Broken River 71.5 16 Buckland River 8.0 19 Buffalo River 4.2 19 Campaspe River 76.8 17 Goulburn River 80.9 16 Kiewa River 6.2 19 Kiewa River West Branch 7.5 19 Kinchington 3.0 19 King River 83.4 19 Little Murray River 45.7 19 Loddon River 307.0 19 Mitta Mitta River 5.7 19 Murray River 129.1 20

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GMU GMU name Name Length Cap number (km) region number Ovens River 52.8 19 Ovens River East Branch 4.0 19 Ovens River West Branch 3.2 19 Serpentine Creek 47.3 16 Wimmera River 273.5 16 Yarriambiack Creek 141.0 18

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TABLE D-2 Physical connection between surface and ground water resources (watertable aquifers only)

GMU GMU name Name Length Type of Level of Likely Source number (km) connection connection Impact of of gw data pumping A1 Namadgi Murrumbidgee 73.0 Gaining Low Low Williams, River & Tributaries 2001 A2 Murrumbidgee Murrumbidgee 64.8 Gaining Low Low Williams, River & Tributaries DLWC 2001 A3 Queanbeyan Murrumbidgee River 217.7 Gaining Low Low Williams, and Molonglo & Tributaries DLWC 2001 N01 Unincorporated Castlereagh River 135.8 Losing Low Low Williams, Area—Oxley Basin DLWC 2001 Coxs Creek 76.8 Losing Moderate Low D Woolley N03 Unincorporated Cudgegong River 10.5 Gaining Low Low Estimate Area—Sydney Basin N04 Unincorporated Cudgegong River 55.7 Gaining Low Low Estimate Area—Gunnedah Basin Mooki River 10.2 Losing Low Low Williams, DLWC 2001 Namoi River 4.4 Gaining Low Low Williams, Dlwc 2001 Warrah Creek 24.8 Gaining Low Low Williams, DLWC 2001 N05 Unincorporated Cockburn River 12.5 Seasonal High Moderate Estimate Area—New England Dumaresq River 58.5 Seasonal Medium Low Estimate Province Frazers Creek 77.2 Gaining Low Low Estimate Gwydir River 278.2 Gaining Low Moderate Williams, DLWC 2001 Macdonald Creek 4.5 Gaining Medium Low Estimate Macdonald River 158.8 Gaining Low Low Estimate Macintyre River 228.3 Gaining Low Low Estimate Namoi River 114.5 Gaining Low Low Williams, DLWC 2001 Peel River 75.5 Gaining Medium Low Williams, DLWC 2001 Severn River 196.4 Gaining Low Low Estimate N06 Unincorporated Area Barwon River 38.7 Gaining Low Low Estimate Area—Lachlan Fold Boomi Creek 355.4 Gaining Low Low Estimate Belt Province Cudgegong River 142.1 Gaining Medium Low Estimate Darling River 754.5 Gaining Low Low Literature Lachlan River 455.0 Gaining Low Low Williams, DLWC 2001 Macquarie River 547.0 Gaining Low Low Williams, DLWC 2001 Murray River 195.6 Gaining Low Low Estimate Murrumbidgee River 29.0 Losing Low to Medium Williams, Medium DLWC 2001

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GMU GMU name Name Length Type of Level of Likely Source number (km) connection connection Impact of of gw data pumping Murrumbidgee River 1196.3 Losing Low Low Williams and Tributaries DLWC 2001 Paroo River 31.1 Gaining Low Low Estimate Warrego River 19.3 Gaining Low Low Estimate N07 Unincorporated Murrumbidgee River 84.3 Gaining Low Reduce in Williams, Area—Murray Basin Stream DLWC Salinity 2001 Darling River 787.2 Gaining Low Low Estimate Edward River 54.0 Gaining Medium Low Williams, DLWC 2001 Great Darling Anabranch 493.7 Gaining Low Low Estimate Murray River 871.7 Gaining U/S Low to Low Williams Albury, Medium DLWC Losing to 2001 Barnham, Gaining to SA border Wakool River 266.8 Gaining Medium Low Williams, DLWC 2001 Willandra Creek 16.0 Losing Low Low Williams, DLWC 2001 N08 Unincorporated Darling River 10.8 Nil Nil Nil Estimate Area—Olary Province N09 Lower Namoi Namoi River 116.1 Losing Low due to High D Woolley, Alluvium during floods clay liner pers. and from under comm. pumping river bed 27/07/01 Pian Creek 158.2 Losing Low High Estimate N10 Lower Edward River 66.4 Gaining Medium Low Williams, Murrumbidgee DLWC Alluvium 2001 Lachlan River 253.3 Losing Low To Low Williams, Medium DLWC 2001 Murrumbidgee River 583.4 Losing High High Literature, M Williams DLWC, 2001 N11 Lower Gwydir Gwydir Anabranch 22.0 Losing Low Moderate Williams, Alluvium DLWC 2001 & D Woolley pers. comm. 2001 Gwydir River 141.5 Losing Low Moderate D Woolley Mehi River 185.0 Losing Low Moderate Williams, DLWC 2001 Moomin Creek 24.7 Losing Low Moderate Williams, DLWC 2001

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GMU GMU name Name Length Type of Level of Likely Source number (km) connection connection Impact of of gw data pumping N12 Upper Namoi Coxs Creek 156.4 Losing Medium Low D Woolley Alluvium Mooki River 89.5 Losing Medium Low Williams, DLWC 2001 & D Woolley pers. comm. 2001 Namoi River 187.0 Losing Low Nil D Woolley Turrabeile (Coxs) Creek 52.0 Losing Medium Low D Woolley Warrah Creek 35.7 Losing Medium Low Williams, DLWC 2001 N13 Peel River Alluvium Cockburn River 21.1 Seasonal High Moderate Estimate Peel River 116.7 Seasonal High Moderate D Woolley N15 Miscellaneous Namoi River 30.9 Losing Low Nil D Woolley Tributaries ofthe Namoi River (Alluvium) N16 Lower Macquarie Macquarie River 106.9 Seasonal High High D Woolley Alluvium N17 Upper Macquarie Macquarie River 155.3 Seasonal High High D Woolley Alluvium N18 Cudgegong Valley Cudgegong River 48.1 Gaining Low Low Estimate Alluvium N19 Upper Lachlan Lachlan River 504.1 Losing & Medium High D Woolley Alluvium Gaining & MWilliams, DLWC N20 Lower Lachlan Lachlan River 386.0 Losing Low High D Woolley Alluvium & M Williams Middle Creek 177.8 Losing High High Estimate Willandra Creek 415.6 Losing Low High Williams, DLWC 2001 N21 Mid Murrumbidgee Murrumbidgee River 302.6 Losing Medium High Williams, Alluvium DLWC 2001 N23 Upper Murray Murray River 104.4 Losing and Low Low Williams, Alluvium Gaining DLWC 2001 N24 Lower Murray Edward River 255.3 Gaining Moderate Low Williams, Alluvium DLWC 2001 Murray River 323.9 Losing Low Medium Williams, DLWC 2001 Wakool River 93.3 Gaining Medium Low Williams, DLWC 2001 N28 Bell Valley Alluvium Macquarie River 30.8 Gaining Low Low Williams, DLWC 2001 N44 Inverell Basalt Macintyre River 22.6 Gaining Low Low Estimate N46 Mid and Upper Murrumbidgee River 15.4 Gaining Low Low Williams, Murrumbidgee & Tributaries DLWC, Catchment 2001 Fractured

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GMU GMU name Name Length Type of Level of Likely Source number (km) connection connection Impact of of gw data pumping Q106 Unincorporated Area Dumaresq River 63.9 Seasonal Medium Low Estimate —New England Macintyre Brook 83.9 Seasonal Medium Low Estimate Pike Creek 100.3 Seasonal Medium Low Estimate Severn River 86.9 Seasonal Medium Low Estimate Q107 Unincorporated Area Condamine River 67.9 Losing High Medium Estimate —Clarence Moreton Condamine River 60.2 Losing High Low Estimate (North Branch) Q57 Condamine— Condamine River 33.0 Losing Low Low D Woolley Condamine Groundwater Management Area Sub-Area 1 Q58 Condamine— Condamine River 19.0 Losing Low Low D Woolley Condamine Groundwater Management Area Sub-Area 2 Q59 Condamine— Condamine River 102.9 Losing Low Low D Woolley Condamine Groundwater Condamine River 83.2 Losing Low Low Estimate Management Area (North Branch) Sub-Area 3 Q60 Condamine— 23.0 Losing Low Low D Woolley Condamine Groundwater Condamine River 25.5 Losing Low Low Estimate Management Area (North Branch) Sub-Area 4 Q61 Condamine— Condamine River 7.3 Losing Low Low D Woolley Condamine Groundwater Management Area Sub-Area 5 Q62 Condamine River Condamine River 78.8 Losing Low Low D Woolley (Down-River of Condamine Groundwater Management Area) Q65 Condamine River Condamine River 38.0 Losing Low Low D Woolley Alluvium (Cunningham Condamine River 3.9 Losing Low Low Estimate To Ellangowan) (North Branch) Q67 Dalrymple Creek Condamine River 3.7 Losing Low Low Estimate Alluvium Q71 St. George Alluvium Balonne River 289.0 Losing Medium Low Estimate Ballandool River 62.8 Losing Medium Low Estimate Bokhara River 78.1 Losing Medium Low Estimate Culgoa River 160.1 Losing Medium Low Estimate Maranoa River 151.5 Losing Medium Low Estimate Narran River 65.6 Losing Medium Low Estimate Q73 Border Rivers Dumaresq River 165.5 Seasonal Medium Low Estimate Macintyre Brook 3.4 Seasonal Low Low Estimate S32 Unincorporated Area River Murray 667.0 Gaining Low Reduce in Literature Area–1—Murray Stream Limestone Salinity V11 Alexandra Goulburn River 21.0 Gaining Medium Medium NRE, 1998 V12 King Lake Yea River 0.2 Gaining Low Medium NRE, 1998

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GMU GMU name Name Length Type of Level of Likely Source number (km) connection connection Impact of of gw data pumping V35 Mullindolingong Kiewa River 96.3 Gaining High High NRE, 1998 Kiewa River West 3.8 Gaining High High Estimate Branch Only Kinchington 2.3 Gaining Medium Low Estimate Only Murray River 2.9 Gaining Low Low Williams, DLWC, Murray Region Aquifer— Stream Interaction V37 Murmungee Buckland River 7.0 Gaining High High NRE, 1998 Buffalo River 23.1 Gaining High High Literature King River 14.2 Gaining Low Low Estimate Ovens River + East 138.0 Gaining Medium High Literature & West Branches V38 Goorambat Broken Creek 28.3 Losing Low Seasonal NRE, 1998 Broken River 7.2 Losing Low Seasonal NRE, 1998 V39 Katunga Gspa Broken Creek Losing Medium High NRE, 1998 physical connection, High impact despite medium volumes/ km given in SY estimates Goulburn River Losing Low Low Estimate Murray River Losing High High Estimate V40 Kialla Broken River 15.3 Losing Low High NRE, 1998 connection, Lower instream flows Goulburn River 73.7 Losing Low Low NRE, 1998 V41 Nagambie Goulburn River 57.8 Losing Low Low NRE, 1998 V42 Campaspe Campaspe River Gaining and Medium High NRE, 1998 Losing physical connection, High impact despite low volumes given In SY estimates V43 Shepparton Broken Creek 127.3 Gaining Medium Low Estimate Groundwater Supply Broken River 18.6 Gaining Medium Low Estimate Protection Area Campaspe River 39.0 Losing Medium Low Estimate Goulburn River 199.3 Losing Low Low Estimate Murray River 37.9 Losing Medium Low Williams, DLWC V44 Ellesmere Campaspe River 2.8 Losing Medium Increased NRE, 1998 Discharge to Aquifer V45 Bridgewater (Loddon) Loddon River 68.2 Losing Low Low NRE, 1998 Serpentine Creek 36.5 Gaining High Low NRE, 1998

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GMU GMU name Name Length Type of Level of Likely Source number (km) connection connection Impact of of gw data pumping V54 Moolort Loddon River 65.9 Losing from Medium Reduced NRE, 1998 storages, baseflows Gaining in to Loddon Loddon River River V66 Unincorporated Acheron River 57.0 Gaining Low Low Estimate Area—Lachlan Avoca River 128.9 Gaining Medium Reduce Estimate in Stream Salinity Big River 111.5 Gaining Low Low Estimate Broken River 74.3 Gaining Medium Low Estimate Buckland River 8.9 Gaining High High Literature Buckland River East 23.7 Gaining High High Literature Branch Buffalo River 37.1 Gaining High High Literature Buffalo River West 36.1 Gaining High High Literature Branch Campaspe River 112.2 Losing Medium Low Literature Dandongadale River 3.7 Gaining Low Low Estimate Delatite River 84.7 Gaining Low Low Estimate Goulburn River 222.4 Gaining Low Low Estimate Kiewa River 5.7 Gaining High High Estimate Kiewa River West 18.0 Gaining High High Estimate Branch Kinchington 18.8 Gaining Medium Low Estimate Kinchington Creek 15.0 Gaining Medium Low Estimate King River 27.9 Gaining Low Low Estimate Loddon River 63.8 Gaining Low Low Estimate Mcivor Creek 32.7 Gaining Low Low Estimate Mitta Mitta River 198.8 Gaining Low Low Estimate Mount Ida Creek 22.3 Gaining Low Low Estimate Murray River 111.4 Gaining Low Low Estimate Ovens River East 3.6 Gaining Low Low Estimate Branch Ovens River West Branch 7.3 Gaining Low Low Estimate Pretty Valley Creek 12.9 Gaining Low Low Estimate Rocky Valley 12.3 Gaining Low Low Estimate Rose River 40.0 Gaining Low Low Estimate Tallangatta Creek 60.8 Gaining Low Low Estimate Wimmera River 36.6 Losing Low Low Estimate Yea River 72.8 Gaining Low Low Estimate

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GMU GMU name Name Length Type of Level of Likely Source number (km) connection connection Impact of of gw data pumping V77 Unincorporated Avoca River 152.2 Gaining Medium Reduce Estimate Area—Murray in Stream (Watertable Aquifer) Salinity Broken Creek 37.6 Gaining Medium Low Estimate Broken River 71.5 Gaining Medium Low Estimate Buckland River 8.0 Gaining High High Literature Buffalo River 4.2 Gaining High High Literature Campaspe River 76.8 Losing Medium Low Estimate Goulburn River 80.9 Losing Low Low Estimate Kiewa River 6.2 Losing Low Low Estimate Kiewa River West 7.5 Gaining High High Estimate Branch Kinchington 3.0 Gaining High High Estimate King River 83.4 Gaining Medium Low Estimate Little Murray River 45.7 Gaining Low Low Estimate Loddon River 307.0 Gaining Low Low Estimate Mitta Mitta River 5.7 Gaining Low Low Estimate Murray River 129.1 Gaining Low Low Estimate only Ovens River 52.8 Gaining Low Low Estimate only Ovens River East 4.0 Gaining Low Low Estimate Branch only Ovens River West 3.2 Gaining Low Low Estimate Branch only Serpentine Creek 47.3 Gaining Low Low Estimate only Stuart Murray Canal 1.3 Gaining Low Low Estimate only Wimmera River 273.5 Losing Low Low Estimate only Yarriambiack Creek 141.0 Gaining Low Low Estimate only GAB GAB areas not Paroo River - Gaining Low Low Estimate included in specific only GMUs or WT UAs Warrego River - Losing Low Low Estimate only Maranoa River - Seasonal Low Low Estimate only Warrego River - Seasonal Low Low Estimate Tributaries only Barwon River - Gaining Low Low Estimate only Gwydir River - Gaining Low Low Estimate only Condamine River - Losing Low Low Estimate (downstream Of CGMA) only

122 Projections of Groundwater Extraction Rates and Implications for Future Demand and Competition for Surface Water 57548_Book 17/6/03 2:28 AM Page 123

Appendix E

Jurisdictions' responses to the recommendations of the Report

(Some jurisdictions have responded to the summary recommendations given in the Executive Summary, while others have responded to the recommendations given in the body of the report. Some have responded to both.)

Commonwealth

(Response to the recommendations in the executive summary)

Mr Scott Keyworth Director Natural Resources Projects Murray-Darling Basin Commission GPO Box 409 CANBERRA ACT 2601

Dear Mr Keyworth

I refer to your memorandum of 30 November 2001 to Contact Officers regarding the report on “Groundwater Use in the Murray-Darling Basin – Implications for the Integrity of the Cap”.

The Commonwealth is generally comfortable with the findings and recommendations of the Report, but is concerned that the roles and responsibilities of the MDBC and the jurisdictions be clearly understood and delineated.

The Commonwealth supports the concept of groundwater being managed on an integrated basis with surface water within the spirit of the Cap for those areas where there is a high degree of interconnectivity between surface water and groundwater, particularly as surface water base flow reduction caused by groundwater extractions has the potential to impact on the integrity of the Cap. The Commonwealth is also supportive of such a Cap being based on sustainable yield values.

However, there is a particular need to ensure there is a consistent and robust framework for the establishment of sustainable yields, as this is a prerequisite for such a Cap. The National Land and Water Resources Audit highlighted the wide variances in approach taken by the States in approving their upper limits of extraction, including omitting consideration of environmental water requirements and surface water interactions.

As such, the Commonwealth supports in-principle the recommendations relating to the incorporation of groundwater into the Cap. The process through which this is to be achieved will need to reflect the economic, social and environmental costs and benefits, and provide for stakeholder participation in the process.

The Commonwealth also supports further investigations and assessments on groundwater/surface water interactions to better enable the development and operation of appropriate Caps.

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The Commonwealth supports the incorporation of an appropriate groundwater trading regime into the water trading framework to facilitate the use of water for the highest net community benefit. Where a groundwater management unit crosses jurisdictional boundaries, the Commonwealth considers there may be a role for the MDBC to facilitate trade through an expanded interstate water trading project.

However, those recommendations dealing with the broader management of groundwater and issues such as compensation for relinquished entitlements are beyond the Commission’s responsibility. Ultimate responsibility for the management of groundwater rests with the jurisdictions, but the Commonwealth supports the general principles behind recommendations aimed at improving groundwater management. The Commonwealth is pursuing these objectives through the CoAG Water Reform Framework and through bilateral processes such as the National Action Plan for Salinity and Water Quality. In relation to your question on the public release of the Report, the factual elements of the Report could provide a useful platform for public discussion by bringing out into the open the issues surrounding groundwater management and the setting of a Cap. Nevertheless, the Commonwealth considers that the repercussions of the Report should be discussed within the Commission and Ministerial Council before it is publicly released.

Yours sincerely

Ross Dalton General Manager Natural Resource Management Policy

December 2001

CC Mr Bernie Prendergast BRS

Mr Theo Hooy Environment Australia

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Australian Capital Territory

(Response to the recommendations in the body of the report)

Mr Scott Keyworth Director, Landscapes and Industries Murray-Darling Basin Commission PO Box 409 CANBERRA ACT 2601

Dear Mr Keyworth

I refer to your letter of 1 March 2002 seeking a formal response to the 21 recommendations made by the report “Projection of Groundwater Extraction Rates and Implications for Future Demand and Competition for Surface Water”. Unlike some areas of the Murray-Darling Basin, groundwater has not been over allocated in the ACT so some of the recommendation are not relevant.

All water resource within the ACT are controlled by the Water Resources Act 1998 (ACT) (the Act). The Act is administered through a statutory Water Resources Management Plan which embodies the requirements of the ACT Environmental Flow Guidelines. The Environmental Flow Guidelines partition low flows from extraction and limit the volume that can be extracted from higher flows. Allocations for consumptive use are only made after allocations to environmental flows. Overall just over 60% of the total water resource is reserved as environmental flows.

Both the Environmental Flow Guidelines and the Water Resources Management Plan recognise and account for the relationship between groundwater and surface water in the ACT region. Almost all groundwater extraction in the ACT is from shallow fractured aquifers which generally align with surface topography and sub-catchments. Water resources are managed by sub- catchments with recognition of the input of higher catchments to those downstream. Overall extraction limits set for sub-catchments include groundwater extraction. Groundwater extraction is further limited to a very conservative 10% of the assessed recharge rate.

The Act requires that all extraction, for other than stock and domestic use, is licensed. All licences require the metering of extraction. The system of allocation to the environment first, ensures that no sub-catchment can be over allocated and the conservative limit on groundwater extraction ensures that aquifers are not over used. As surface and groundwater are treated in the same manner, the ACT will be able to include groundwater extraction in Cap reporting when required.

Yours sincerely

Gary Croston Manager Environment Protection April 2002

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Community Advisory Committee

(Response to the recommendations in the executive summary)

COMMUNITY ADVISORY COMMITTEE OF THE MURRAY-DARLING BASIN MINISTERIAL COUNCIL

c/- The Secretariat GPO Box 409 CANBERRA ACT 2601 Telephone: (02) 6279 0131 Facsimile: (02) 6248 8424 E-Mail: [email protected]

Minute

CAC: J:\DOCS\CAC\REPORTS\WKGPS-RP\GroundwaterReport_CAC response Dec01.doc

To: Scott Keyworth From: Community Advisory Committee CC: Water Policy Committee Subject: Groundwater Project Report – CAC response Date: 22 January 2002

Preamble: Mrs Leith Boully, in her capacity as CAC Chairman, was invited by you to respond to the Sinclair Knight Merz report. Unfortunately, the expiry of Leith’s term of appointment as Chairman at the end of 2001 has intervened with timely delivery of comments. The following is a compilation of Leith Boully’s comments, as conveyed to the Secretariat just prior to her departure, and with input from Peter Milliken, the CAC ‘expert’ though his involvement with the Groundwater Technical Reference Group. We hope that the comments may still be noted.

Thank you for providing us with the opportunity to respond to the report Projections of Groundwater Extraction Rates and Implications for Future Demand and Competition for Surface Water. In its response to the review of operation of the Cap — report to Ministerial Council Meeting 29 — 25 August 2000 — the CAC highlighted groundwater issues and the importance of taking an integrated approach to management of the total water resource. So we certainly support the report when it states “…sustainable total water resource management is absolutely crucial to the future of the Basin.” However, there is a need to understand the implications of groundwater level changes — decline or rise — on groundwater dependent ecosystems. We feel this aspect is not adequately dealt with either in this report or in the Basin Salinity Management Strategy. In addition, there are some specific issues that the CAC has with the recommendations made in the Report, as follows — the numbers refer to the recommendation numbers used in the Executive Report: 1. Agree in principle but the social and economic ramifications in some areas are huge. The sheer size of many groundwater systems provides for some buffering capacity and allows some time to reach sustainable yields. Transparency about knowledge or lack of it is vital, and the CAC feels that this time should be used to create inclusive processes for equitable and lasting outcomes. "The matter of urgency" decision often results in political backlash. 2. Agree

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3. Agree except for the area of compensation. The issue of compensation or other adjustment mechanism needs to be dealt with in a manner that is consistent with surface water approaches. The CAC is of the view that there definitely needs to be a public debate on the issue. There was bipartisan political support for a COAG debate especially since the COAG principles have failed to guide investment by the jurisdictions. Note that we find it strange that a technical brief should lead to a consultant conjecturing on an essentially social issue requiring political commitment and decision. 4. The CAC feels that further discussion is required. Our comments made under Recommendation 1 are relevant here too. Also, it is important to be precautionary in approach, but care needs to be taken to not lock in decisions ahead of the knowledge base for fear of alienating the community. In addition, we note that actions under this recommendation present a great opportunity for the use of inclusive processes. 5. The CAC feels that further discussion is required. 6. This assumes connectedness and unrestrained market – a perfect situation which won’t always occur and which is often physically impossible. 7. We wonder what the implications of this recommendation might be. 8. Agree – we need to be particularly active in supporting investigation and assessment of groundwater/surface water interactions. 9. Agree – this is important and needs to be raised in early recommendations as well to provide a balanced view to those that may implement recommendations in isolation. With regard to the potential for undermining of the Cap through groundwater use, we believe that peer review through the jurisdictions is necessary to establish the truth. The CAC supports public release of the report as it is of the view that further discussion involving the community is warranted in several areas and that ready availability of the report would assist such discussion.

CAC Executive Officer on behalf of the Community Advisory Committee

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New South Wales

(Response to the recommendations in the executive summary)

Mr Don Blackmore Ref: Y02/108 Chief Executive Murray-Darling Basin Commission PO Box 409 CANBERRA ACT 2601

Dear Mr Blackmore

I refer to your letter of 30 November 2001 (your reference: MDBC:AP:122) forwarding for comment to the Department of Land and Water Conservation (DLWC) a document entitled “Projection Of Groundwater Extraction Rates and Implications For Future Demand And Competition For Surface Water”.

The DLWC has considered the report and generally agrees with its findings. However, the issues raised in the report are complex and require sophisticated modelling to understand where and when the effects on the various stakeholders would be observed.

In regard to the specific recommendations, please see the attached notes.

In regard to the public release of the document, I am in favour of its release provided the Commission clearly presents the report as the initial step of a wider process of examining the location and timing of potential effects as well as evaluating the magnitude of the effects and the stakeholders affected.

Yours sincerely

Bob Smith Director-General

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NSW COMMENTS ON RECOMMENDATIONS OF A REPORT ENTITLED PROJECTION OF GROUNDWATER EXTRACTION RATES AND IMPLICATIONS FOR FUTURE DEMAND AND COMPETITION FOR SURFACE WATER

1. Agreed – NSW is currently preparing water sharing plans for its groundwater management areas. Each plan contains a strategy to reduce groundwater allocations to a level necessary to control usage to sustainable yields.

2. Not Agreed – The words “in the spirit of the Cap” needs to be better defined before commitment can be given to its implementation either in the short or long-term. The definition of Cap in the surface water refers to “93/94 level of development”. The arguments raised in the report target “sustainable yield”. There is a vast difference between these two definitions. For example, the statement could imply: a) wind use back to 93/94 levels; b) targeting sustainable yield as currently calculated; or c) targeting a different figure, taking into account the interaction with surface water. It is wise to first understand the location and timing of potential effects of managing to the current sustainable yield estimates as opposed to the new estimates before cutting allocations to either surface or groundwater (as recommended by the consultant). More studies are required to investigate where and when these effects will be observed and the effectiveness of different management options.

3. Agreed – With regard to NSW response to the detailed recommendations:

• The Department of Land and Water Conservation is in the process of expanding the metering to cover all large bores; • The water sharing plans, shortly to be publicly exhibited, deals with sustainable levels of allocation and the time frame of adjustment; • There is no intention to pay compensation for relinquished licences, but structural adjustment measures will be put in place to assist those most affected. NSW plans to clearly articulate both the rules for allocation reduction as well as rules for trade. • It is NSW intention not to permit transfers of any entitlements that are beyond those required to ensure usage does not rise above sustainable yield. • NSW has developed a ‘hotspots’ program that identifies the local restrictions required to address local draw-downs of watertable or pressure; and • NSW is focussing on the groundwater systems with high levels of surface/ground interaction.

4. Agreed – With regard to the detailed recommendations:

• Agreed – The NSW Water Sharing Plan process through which GMUs progress is systematic; • Agreed in part – NSW is committed to using the best scientifically supported estimate of sustainable yield that is available at the time of development of the plan; • Agreed – Each plan identifies the monitoring required to manage the resource; and • Agreed – The NSW Water Management Act 2000 requires a plan, where there are un- allocated resources available, to determine the method of assignment.

5. Agreed – However, in regard to NSW, the systematic approach does not include a “per unit area” allocation since such areas tend not to be homogeneous in resources. NSW does intend to monitor development in the unincorporated areas.

6. Agreed – NSW is currently exploring the possibility of trade between the groundwater and surface water in closely connected systems.

7. Agreed.

8. Agreed.

9. Agreed.

129 Projections of Groundwater Extraction Rates and Implications for Future Demand and Competition for Surface Water 57548_Book 17/6/03 2:29 AM Page 130

Queensland

(Response to the recommendations in the executive summary)

Scott Keyworth Director, Natural Resources Projects Murray Darling Basin Commission GPO Box 409 CANBERRA ACT 2601.

Dear Scott

Reference is made to your letter dated 30/11/01 (reference MDBC:AP:122) requesting a Queensland response to the findings of the recently completed investigation project entitled “Projection of Groundwater Extraction Rates and Implications for Future Demand and Competition for Surface Water”.

Queensland has noted the contents of the report and does not recognise a need for specific action beyond what Queensland is already doing in relation to the recommendations at this point in time. The report concedes that the collation of data for the analysis was a difficult task due to inconsistent methodologies employed by the States. The report also recognises the poor level of understanding in relation to groundwater /surface water interaction in the majority of systems. In Queensland the degree of connectivity between an aquifer system tens of metres below the river bed is very small and considered most unlikely to significantly impact on our proposed Cap management arrangements.

From a Queensland perspective the issues raised and the predicted outcomes suggested are more relevant to the southern part of the Basin where significant interaction between groundwater and surface water is well documented. Queensland will satisfactorily deal with and manage the issues raised in the report through our Water Resource Planning processes which are applicable to both surface water and groundwater systems.

In terms of public release of the report Queensland would hold the view that although the information collated in the report is ‘best available at the time’ it is not necessarily correct or complete and therefore could be misquoted and misinterpreted in the public arena. For this reason the report should be held as a technical working document in the records of the jurisdictions and the MDBC until further work overcomes some of the technical issues highlighted in the report.

Yours sincerely

Greg Claydon Queensland Contact Officer

Cc Chris Robson

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Mr Scott Keyworth Director, Landscapes and Industries Murray Darling Basin Commission GPO Box 409 Canberra Act 2601

Dear Scott

Project Report “Projection of Groundwater Extraction Rates and Implications for Future Demand and Competition for Surface Water”

I refer to your letter dated 11 March 2002 (reference MDBC:AP:122) requesting a Queensland response to the individual recommendations contained in the abovementioned report.

Many of the groundwater management issues raised in this report are currently being addressed in Queensland through our Water Resource Planning process. The main purposes of a Water Resource Plan (WRP) being; • Defining the availability of water for any purpose, •Providing a framework for sustainably managing water and the taking of water, • Identifying priorities and mechanisms for dealing with future water requirements, •Providing a framework for establishing water entitlements, and •Providing a framework for reversing, where practicable, degradation that has occurred in natural ecosystems.

Although Queensland is already on record as not recognising a need for specific action beyond what our WRP process is delivering I will provide specific comments in relation to each of the 21 recommendations contained in the report.

Recommendation 1. a) Qld Agrees in Principle b) For many years Qld has been working with groundwater user groups to deliver sustainable natural resource outcomes in terms of aquifer system management. These approaches have resulted in community endorsed groundwater management plans which contained strategies to address over allocation and use. Our current approach involves the WRP process which defines a volume of water to be allocated as opposed to a sustainable yield concept. Timeframes for dealing with these issues will be set in a State wide context.

Recommendation 2. a) Qld Agrees in Principle b) The WRP will define allocatable volumes for surface water and groundwater as separate entities. Once defined in a plan these volumes can be accounted for within the spirit of the Cap. The WRP process will account for potential double dipping of allocation and consider all environmental needs. Qld does not recognise a need to revise sustainable yields as our current WRP process is not based on sustainable yield values.

Recommendation 3. a) Qld Agrees b) Qld has been metering high yielding bores in the QMDB since the late 1970’s. Several GMUs have since been fully metered. The mandatory metering of all high yielding bores (bores with allocation) commenced in the QMDB in the early 1990’s.

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Recommendation 4. a) Qld Disagrees. b) Qld does not require domestic bores to be licenced. The National Water Bore Licensing System has been adopted in Qld requiring drillers to provide details and locations for all water bores drilled.

Recommendation 5. a) Qld Disagrees b) The development of strategies is seen as unnecessary. There are existing methodologies that have been applied successfully in the past and would be utilised again as required.

Recommendation 6. a) Qld Disagrees b) This is seen as impractical. Methodologies already differ within Qld depending on the specific situation. How are States going to agree on a comparable methodology when levels of data and resourcing available will reducing the outcome to the lowest common denominator. In Qld a WRP is a statutory plan which must be reviewed every 10 years.

Recommendations 7, 8 & 9. a) Qld Agrees b) Qld is happy for the MDBC to progress these issues.

Recommendation 10. a) Qld Agrees b) Qld views the further investigation and assessment of groundwater/ surface water interaction as a necessary part of including groundwater in the WRP’s.

Recommendation 11. a) Qld Agrees b) Qld has imposed administrative holds on many of the highland fractured rock aquifer systems in the QMDB until the level and extent of groundwater/ surface water interaction is better known.

Recommendation 12. a) Qld Agrees in Principle b) Qld will be reassessing the amount of water that can be allocated (not sustainable yield) based on stream/aquifer interactions as part of the WRP process.

Recommendation 13 a) Qld Agrees b) However this has not been recognised as a priority activity at this point in time.

Recommendation 14. a) Qld Agrees in Principle b) However Qld has not assessed the level of connection and the impacts of groundwater development at this point in time. Timeframes would depend on priorities in a State wide context.

Recommendation 15. a) Qld Agrees in Principle b) Qld will address this recommendation through the WRP process. The plans will define the amount of water that can be allocated and provide the operational rules to achieve required outcomes. Qld has already assessed all GMUs to determine a priority ranking on a State wide basis.

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Recommendation 16. a) Qld Agrees b) The four parts of this recommendation are endorsed subject to a WRP being in place.

Recommendation 17. a) Qld Agrees in Principle b) Qld has assessed all GMU’s and ranked them on a State wide basis. Resultant WRP’s will deliver the required outcomes. Timeframes for WRP’s will depend on GMU priority ranking and resources.

Recommendation 18. a) Qld Agrees in Principle b) Qld has assessed the major UA’s and ranked them on a State wide basis. Resultant WRP’s will deliver the required outcomes. Timeframes for WRP’s will depend on GMU priority ranking and resources.

Recommendation 19. a) Qld Agrees b) Trading rules are part of the WRP process.

Recommendation 20. a) Qld Agrees in Principle b) Qld approach to future assessment of groundwater yield will take into account the level and extent of groundwater/ surface water interaction.

Recommendation 21. a) Qld Agrees in Principle b) Groundwater extraction in areas affected by land salinisation is normally encouraged as long as groundwater quality is not an issue. The mechanism to facilitate this action may not be through a WRP or groundwater management plan.

As mentioned in previous correspondence the issues raised and the predicted outcomes suggested in this report are viewed as being more relevant to the southern part of the MDB where significant interaction between groundwater and surface water is well documented. Queensland will satisfactorily deal with and manage the issues raised in the report through our Water Resource Planning processes which are applicable to both Surface water and groundwater systems.

A major concern with the release of this report into the public domain relates to the fact that much of the collated data contained in the tables is not necessarily correct or complete and will be misquoted and misinterpreted into the future.

Yours sincerely

Greg Claydon General Manager (Water Planning)

Cc Chris Robson, ED(NRS), Block A, 80 Meiers Road, Indooroopilly Q 4068

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South Australia

(Response to the recommendations in the body of the report)

Mr Don Blackmore Chief Executive Murray-Darling Basin Commission GPO Box 409 CANBERRA ACT 2601

(Attention Awadhesh Prasad)

Dear Don

I refer to the report “Projections of Groundwater Extraction Rates and Implications for Future Demand and Competition for Surface Water” prepared for the Commission by Sinclair Knight Merz. The formulation of robust policies for the conjunctive management of ground and surface waters is seen as an important next step in comprehensive water resources management for social, economic and environmental outcomes throughout the Murray-Darling Basin. The study commissioned by the Commission should form the basis for future work and negotiations to assist in the formulation of these policies. As such it is important that all relevant information, including this report, be made public as soon as possible.

Senior hydrogeological and policy staff from the Department of Water, Land and Biodiversity Conservation have reviewed the report. Overall it is considered that the report is well written and presents a complex synthesis of data in an informative style. The methods used and the caveats on the accuracy of information are well documented throughout the report. It is recognised that there are shortcomings in some of the data used and different methods have been used to calculate water use, irrigation requirements and other parameters intrinsic to the basic calculations in the report. However provided the caveats are recognised and the information is used within the limits of its accuracy, the report should be released for consultation.

In relation to the specific recommendations in the report the South Australian Government strongly supports all the Key Recommendations and those relating to Current Development Status of Groundwater and Predicted Water Demands and Groundwater Growth.

The recommendations relating to Groundwater / Surface Water Interactions are supported as are the majority of those relating to Groundwater Management and Policy. However it is considered that recommendations 20 and 21 require further consideration in relation to the precautionary principal.

In summary, it is strongly recommended that this report be released for public consultation in order to stimulate the debate on this important issue which has the potential to off-set many of the gains made through the environmental flows program. In addition it is recommended that the Commission begin immediate consideration to the implementation of the Key Recommendation contained in the report relating to accounting for groundwater use in the spirit of the Cap on surface water extractions.

Yours Sincerely

Peter Hoey A/Commissioner

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Victoria

(Response to the recommendations in the executive summary)

Ref: TF050

6 February 2002

Mr Scott Keyworth Director, Natural Resource Projects Murray Darling Basin Commission GPO Box 409 Canberra ACT 2601

Dear Scott,

REPORT ON IMPACT OF GROUNDWATER USE ON THE MDBC CAP

I refer to your letter dated 30 November 2001 where you requested a formal response to recommendations contained in an MDBC investigation report “ Projection of Groundwater Extraction Rates and Implications for Future Demand and Competition for Surface Water”, and Victoria’s view regarding its public release.

The report highlights the important issue of the potential for increased groundwater use to erode the Murray-Darling Basin Cap by reducing groundwater discharge to streams. This issue has been largely neglected to date and the report is a timely and valuable contribution to water management.

The report is wide-ranging in that it includes an assessment of the impact of groundwater on the Cap, and recommendations regarding a management approach to the problem as well as other groundwater management issues. The conclusion that the increase in use of groundwater since 1993/94 has undermined the Cap by 2% and that there is potential to increase this to 7% over the next 50 years, has far reaching implications for surface water allocation. As yet these implications have not been able to be fully explored. I also understand the figure of 60% adopted in the report to represent the proportion of groundwater extraction that does not ultimately reach streams, has had to be largely assumed.

In relation to the recommendations in the report, recommendations 3 to 6, and 8 and 9 are generally consistent with the current Victorian policy position on groundwater management. With respect to recommendation 1, I would endorse the reduction of use to the sustainable yield as a matter of urgency, but not necessarily allocation. Where use is below the sustainable yield and there is over-allocation, the wind back of over-allocation may be a longer term objective.

With recommendation 7, it is appreciated that an adaptive approach is needed towards managing baseflow capture due to the difficulty in reliably quantifying capture, and also that some reasonable allowance for baseflow reduction needs to be made to permit the groundwater resource to be utilised. I would therefore generally agree with recommendation 7.

Recommendation 2 relates to the management of groundwater allocation in conjunction with the Cap. At this stage I believe it is premature to be able to endorse any particular management prescription before the findings of this report have been released and examined more fully. From

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this perspective it is important that the report is made available to the public, so the issue of the impact of groundwater on the Cap can be subjected to community debate.

The MDBC however needs to have a clear understanding about it’s policy before releasing the report. A first step in this process should be a discussion at the next water policy meeting.

I would like to thank you for your role in developing this report, and I look forward to further developments.

Yours Sincerely

Campbell Fitzpatrick Director Water Resources Management

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Victoria

(Response to the recommendations in the body of the report- communicated by Mr Gordon Walker, Victoria's representative on the Groundwater Technical Reference Group)

Awadhesh,

Further to your request to respond to the 21 recommendations at the back of the report, I consider that the letter we have sent previously that responded to the recommendations in the Executive Summary provides a formal response to the main issues.

In relation to the 21 recommendations at the back of the report we would agree with all of them and we are actively implementing those recommendations that relate to juristictions, with the exception of:

Recommendation 13, that is not relevant to Victoria Recommendation 15, where as indicated in our previous letter we do not see that it is essential to wind back allocation to the level of sustainable yield as a matter of urgency. Recommendation 18, where we are not adopting a uniform approach of limiting allocation in UAs on an allocation per unit area formula. Rather in these areas interference criteria are used to achieve a reasonable bore spacing and as allocation increases, areas are incorporated as GMUs with a defined Permissible Annual Volume to limit allocation.

Regards Gordon

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138 Projections of Groundwater Extraction Rates and Implications for Future Demand and Competition for Surface Water _g

Integrated catchment management in the Murray-Darling Basin A process through which people can develop a vision, agree on shared values and behaviours, make informed decisions and act together to manage the natural resources of their catchment: their decisions on the use of land, water and other environmental resources are made by considering the effect of that use on all those resources and on all people within the catchment.

Our values Our principles We agree to work together, and ensure that our We agree, in a spirit of partnership, to use the following behaviour reflects that following values. principles to guide our actions.

Courage Integration •We will take a visionary approach, provide leadership •We will manage catchments holistically; that is, and be prepared to make difficult decisions. decisions on the use of land, water and other environmental resources are made by considering Inclusiveness the effect of that use on all those resources and on •We will build relationships based on trust and all people within the catchment. sharing, considering the needs of future generations, and working together in a true Accountability partnership. •We will assign responsibilities and accountabilities. •We will engage all partners, including Indigenous •We will manage resources wisely, being communities, and ensure that partners have the accountable and reporting to our partners. capacity to be fully engaged. Transparency Commitment •We will clarify the outcomes sought. •We will act with passion and decisiveness, taking •We will be open about how to achieve outcomes the long-term view and aiming for stability in and what is expected from each partner. decision-making. Effectiveness •We will take a Basin perspective and a non- partisan approach to Basin management. •We will act to achieve agreed outcomes. •We will learn from our successes and failures and Respect and honesty continuously improve our actions. •We will respect different views, respect each other and acknowledge the reality of each other’s situation. Efficiency •We will act with integrity, openness and honesty, be fair •We will maximise the benefits and minimise the and credible and share knowledge and information. cost of actions. •We will use resources equitably and respect the Full accounting environment. •We will take account of the full range of costs and Flexibility benefits, including economic, environmental, social and off-site costs and benefits. •We will accept reform where it is needed, be willing to change, and continuously improve our actions Informed decision-making through a learning approach. •We will make decisions at the most appropriate scale. Practicability •We will make decisions on the best available •We will choose practicable, long-term outcomes information, and continuously improve knowledge. and select viable solutions to achieve these •We will support the involvement of Indigenous outcomes. people in decision-making, understanding the value of this involvement and respecting the living Mutual obligation knowledge of Indigenous people. •We will share responsibility and accountability, and act responsibly, with fairness and justice. Learning approach •We will support each other through the necessary •We will learn from our failures and successes. change. •We will learn from each other. 57548_Book 17/6/03 2:30 AM Page bc1