An Adaptive Management Framework for Connected Groundwater-Surface Water Resources in Australia

Transcription

1 An Adaptive Management Framework for Connected Groundwater-Surface Water Resources in Australia Ross Brodie, Baskaran Sundaram, Robyn Tottenham, Stephen Hostetler and Tim Ransley 1

2 Commonwealth of Australia 2007 This work is copyright. Apart from any use as permitted under the Copyright Act 1968, no part may be reproduced by any process without prior written permission from the Commonwealth. Requests and inquiries concerning reproduction and rights should be addressed to the Commonwealth Copyright Administration, Attorney General s Department, Robert Garran Offices, National Circuit, Barton ACT 2600 or posted at The Australian Government acting through the Bureau of Rural Sciences has exercised due care and skill in the preparation and compilation of the information and data set out in this publication. Notwithstanding, the Bureau of Rural Sciences, its employees and advisers disclaim all liability, including liability for negligence, for any loss, damage, injury, expense or cost incurred by any person as a result of accessing, using or relying upon any of the information or data set out in this publication to the maximum extent permitted by law. Postal address: Bureau of Rural Sciences GPO Box 858 Canberra, ACT 2601 Internet: Preferred way to cite this publication: Brodie, R, Sundaram, B, Tottenham, R, Hostetler, S, and Ransley, T. (2007) An adaptive management framework for connected groundwater-surface water resources in Australia. Bureau of Rural Sciences, Canberra. Conjunctive Water Management Framework 2

3 Foreword Integrated management of surface water and groundwater is critical in ensuring sustainability of the water resource and for meeting the objectives of the National Water Initiative. Water issues such as over-allocation, environmental flows and river salinity are all influenced by the connectivity between streams and aquifers. This means that groundwater-surface water interactions need to be assessed and incorporated into the management response to a range of water quantity and quality issues. This report describes a framework and toolkit designed to provide a consistent approach to conjunctive water management in Australia. The framework consists of six steps in an adaptive management cycle and provides information and resources to enable water managers and other stakeholders to take a more coordinated approach. The framework aims to deliver the National Water Initiative objective of recognition of the connectivity between surface water and groundwater resources and connected systems managed as a single resource. This framework is the major output of the Managing Connected Water Resources project, a collaboration between Bureau of Rural Sciences (BRS), Australian Bureau of Agricultural and Resource Economics (ABARE), the Australian National University and State agencies. The framework and underlying comprehensive information package on connectivity issues is available at Dr Colin Grant Executive Director Bureau of Rural Sciences April Conjunctive Water Management Framework

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5 Executive Summary Groundwater and surface water are interconnected and interchangeable resources in many regions of Australia. Stream-aquifer interactions can have significant implications for both water quantity and quality. Pumping of fresh groundwater, especially near streams, can reduce the water available to surface water users. This can have significant impacts on users and the environment, especially during times of naturally low stream flow. Aquatic ecosystems such as perennial streams and wetlands can rely on groundwater, especially during the droughts that are common in Australia. Also, land use change can alter groundwater discharge to surface water, which can effect salt loads to rivers. The connectivity between streams and aquifers is presenting major challenges for water managers and policy makers in Australia. Coordinating the management of groundwater and surface water is referred to as conjunctive water management. Historically, surface water and groundwater resources in Australia have not been managed conjunctively. One consequence of the failure to recognise the link between these resources is that some proportion of the water available for consumptive use has been accounted for twice, allocated once as surface water and again as groundwater. Until recently, this over-allocation of water did not emerge as an issue. However, increasing irrigation demand, restrictions on surface water access and drought conditions increases the likelihood of currently unused groundwater allocations being activated, with consequences for surface flows, environmental assets and industry. Table 1 summarises an example of water account in the Murray-Darling Basin (MDB). Surface water allocations have been capped by intergovernmental agreement at 14,419 GL/yr. Groundwater licences have been issued that could allow the extraction of 3,124 GL/yr, a significant volume at around 34% of the surface water allocation. While there are uncertainties with estimating the proportion of groundwater extraction in connected systems that should be accounted for as surface water, stream-flow depletion is projected to be 330 GL/yr in 20 years (MDBC, 2006). Table 1.1: An example of water account in the Murray-Darling Basin Issue Description Gigalitres/year (GL/yr) Average Runoff Average runoff over the MDB catchment area 27,090 (AWR, 2005) Surface water Existing allocation of surface water licences in the 14,419 allocation MDB (AWR, 2005) Groundwater Estimates of the sustainable yields for groundwater 2,356 sustainable yield management areas in the MDB (MDBC, 2006) Groundwater Current allocation of groundwater licences in the MDB 3,124 allocation (AWR, 2005) Double accounting Range of estimates of streamflow depletion in 20 years due to groundwater pumping (MDBC, 2006) Surface water storage capacity Water storage capacity of reservoirs in the MDB (MDBC, 2006) Does not include storage associated with the Snowy Mountains Scheme 25,000 While our understanding of the connection between groundwater and surface water resources has increased significantly in recent times, there remains a concern that many water management plans still do not fully account for stream-aquifer 5 Conjunctive Water Management Framework

6 connectivity. This is particularly the case for the impact on surface water availability of increased groundwater use. In response, a framework for managing connected surface water and groundwater resources has been developed to provide water managers, water authorities, policy makers, catchment groups, industry groups and others with a check list of the main factors to be considered (Figure 1). The framework can be applied at any scale from a project to a catchment through to the national perspective. Many existing water management and planning systems already incorporate elements of this framework, and the aim of this report is to build on the work being done within jurisdictions. The aims of the framework are outlined in Box 1. Box 1: Aims of the framework for conjunctive water management to provide a consistent national approach to conjunctive water management in Australia in line with the principles of the National Water Initiative; to promote decision-making based on an understanding of both the hydrological and hydrogeological characteristics of a catchment; to provide a common understanding of groundwater-surface water connectivity; to catalogue the available tools for assessing connectivity; to raise awareness of the value of numerical models and other predictive tools in setting management targets and options; to promote the coordinated monitoring of groundwater and surface water resources; to identify sources for the key datasets required for management decisions. The framework is underpinned by guiding principles that were developed from a national workshop on managing connected water resources (Fullagar, 2004). The workshop bought together water experts, managers and users from around Australia to identify strategic directions for realising the opportunities and addressing the issues associated with conjunctive water management. These guiding principles are outlined in Box 2. Box 2: General principles of conjunctive water management (Fullagar, 2004) 1. Where physically connected, surface water (including overland flows) and groundwater should be managed as one resource. 2. Water management regimes should assume connectivity between surface water (including overland flows) and groundwater unless proven otherwise. 3. Water users (groundwater and surface water) should be treated equally. 4. Jurisdictional boundaries should not prevent management actions. Some key concepts and definitions central to understanding the connections between surface water and groundwater are defined in Box 3. A lack of agreement around these concepts has been an impediment to developing effective management systems. Conjunctive Water Management Framework 6

7 Identify Management Setting Monitor and Review Performance Assess Water Resources Conjunctive Water Management Framework Develop and Implement Management Options Understand and Predict Set Management Targets Figure 1: A framework for conjunctive water management 7 Conjunctive Water Management Framework

8 Box 3: Some key concepts and definitions There is currently no common or agreed definition for many of the key concepts surrounding stream-aquifer connectivity. A first step in developing a common framework is reaching agreement on what it is we are dealing with. A connected water resource is the combination of surface water feature(s), such as river, estuary or wetland, and the groundwater system(s) that can directly interact in terms of the movement of water. Conjunctive water management is the management of hydraulically connected surface water and groundwater resources in a coordinated way, such that the total benefits of integrated management exceed the sum of the benefits that would result from independent management of the surface water and groundwater components (Sahuquillo and Lluria, 2003). Seepage flux is the magnitude and direction of water movement at the interface between surface water and groundwater systems. A highly connected system is indicated by (1) short-term near-stream response times, with the response in one system (eg stream flow) due to change in the other (eg. watertable decline) occurring over a timeframe of days to months; or (2) seepage flux having a significant (>10%) impact on catchment management targets, particularly over the mediumterm (eg. 1-5 years). A groundwater flow system is defined by a recharge zone and a discharge zone and is separated from other groundwater flow systems by groundwater divides. In recharge zones there is a component of groundwater flow that is downward. In discharge zones, the vertical groundwater flow direction is upward. Baseflow is the longer-term discharge into a stream from natural storages, notably sustaining flow between rainfall events. Recognising that there can be multiple natural storages in a catchment, the discharge of groundwater to the stream is termed the groundwater component of baseflow. The hyporheic zone is the portion of the saturated zone underlying and beside a surface water feature where mixing of surface water and groundwater occurs (after Woessner, 2000). Conjunctive Water Management Framework 8

9 Another important aspect is categorising the connectivity between surface water features and their associated groundwater systems. To this end, a classification scheme based on the position of the watertable, the dominant direction of seepage, the ability of the geological material to transmit water and the impact of connectivity on management targets is proposed (Figure 2). These categories are explained further in Chapter 3. Contiguous Stream is hydraulically linked to the groundwater system by a continuous watersaturated zone Perched Stream is hydraulically separated from the groundwater system by an unsaturated zone Gaining Stream receives water from the groundwater system Fluctuating Seepage direction varies through time Variable Seepage direction varies along stream reach Losing Stream contributes water to the groundwater system High Conductance Highly transmissive geological material Medium Conductance Moderately transmissive geological material Low Conductance Weakly transmissive geological material High Impact >10% impact on long-term management target Medium Impact 1-10% impact on long-term management target Low Impact <1% impact on long-term management target Figure 2: Categorisation of stream-aquifer connectivity Components of the Framework The framework provides a check list of activities. The intent is that the process is iterative, with a feedback loop incorporated into the management process. Not only are there inherent uncertainties in our understanding of catchment processes, but community priorities, perceptions and expectations will change over time and water management will need to evolve in response to these changes. Figure 1 outlines the proposed framework as a general adaptive process than can be followed regardless of the size and nature of a catchment and the water issues that need to be addressed. 9 Conjunctive Water Management Framework

10 Identify Management Setting The first step is an analysis of the key features that define the management of land and water in the catchment. This identifies the setting, scoping out the catchment management problems and the factors that have an impact on their solution. This would include identifying existing: (i.) (ii.) (iii.) Planning and Policy, to outline the existing legislation, policy and rules that define or impact on operational water management. The existing administrative environment can provide opportunities or constraints to implementing conjunctive water management and can involve many government and non-government agencies; Catchment Issues, answering the question of what are the key issues facing the sustainability of land and water resources in the catchment. The nature and scope of conjunctive water management in a catchment can be tailored to address these management issues, whether they are over-extraction of water, river salinity or ecosystem health. The scale of the issues and their overall importance in achieving catchment management objectives must be understood to allow for a prioritised approach. Catchment issues can be perceived differently by different groups of people and there may be different perceptions about their severity; Water use and water resource development, defining the degree of extraction of surface water and groundwater in the catchment and the nature and extent of existing infrastructure. The extent of the use and development of water resources in a catchment dictates how conjunctive management can be applied. This also relates to the extent and nature of land use and development. Water availability is central to economic and social sustainability of many regions, and potential impacts on water users need to be understood and all water users engaged in the planning process. These issues surrounding the identification of the management setting are explored further in Chapter 5. Assess Water Resources The focus of this step is to acquire the baseline information to describe the characteristics of surface water and groundwater systems of the catchment, and their interactions, both spatially and temporally. This can include: (i.) Collation and interpretation of existing catchment datasets that can be used to describe the hydrological and hydrogeological attributes. Catchment-wide datasets such as climate parameters (rainfall, evaporation), topography, surface drainage, geology/geomorphology and land use need to be collected in the first instance; (ii.) Collation and interpretation of existing monitoring that can describe the spatial and temporal variability of groundwater and surface water systems. The key databases are the available time series records of water levels, flow and quality parameters; (iii.) Identification of key information gaps and the initiation of specific studies to clarify key processes. There is a wide range of methods available to assess the nature and degree of the interaction between surface water and groundwater systems. Box 4 summarises the Conjunctive Water Management Framework 10

11 main categories of these assessment tools, with additional details provided in the Appendices section of this report. Chapter 6 provides an overview of the general assessment process and Chapter 7 outlines the key datasets and their principle sources for Australian catchments. Box 4. Tools for assessing connectivity Field Observations, where an initial reconnaissance can highlight hotspots where groundwater is interacting with surface water features. Seepage Measurement, the direct measurement of water flow at the surface watergroundwater interface using seepage meters and similar devices. Ecological Indicators, mapping of specific vegetation communities or biota indicating groundwater discharge to surface water features. Hydrogeological Mapping, to define the geological or geomorphological features such as faults, facies changes or river morphology that can control groundwater flow, and to provide the general hydrogeological setting. Geophysical Survey, the use of geophysical and remote sensing technologies such as airborne electromagnetic (AEM), radiometrics, seismic waves, electrical charge or satellite imagery to map catchment properties. Hydrographic Analysis, the use of techniques such as recession analysis or baseflow separation to analyse the monitoring record of water levels or flows. Hydrometric Analysis, based on Darcy s Law and investigating the hydraulic gradient between the aquifer and surface water feature and the hydraulic conductivity of the intervening aquifer material. Hydrochemical Studies, the interpretation of the chemical constituents of water such as isotopes, radon or chlorofluorocarbon (CFC) involving the application of environmental tracers. Temperature Studies, the use of time series monitoring of temperature in both the surface water and groundwater systems. Artificial Tracers, the monitoring of the movement of an introduced tracer such as fluorescent dye. Water Budgets, such as river reach water balances where the water inputs and outputs are estimated. Understand and Predict The baseline assessment makes it possible to develop a conceptual understanding of connected water resources. The essential function and behaviour of surface water and groundwater systems and the impact of existing developments on the water resource should be able to be described. The conceptual model provides a foundation for further field investigations as well as the development of predictive models. The particular value of these predictive models is that they can be used to obtain an understanding of the impact of different conjunctive water management options. The outcomes of this conceptualisation and predictive modeling process could include: (i.) Classification of stream-aquifer linkages, and indication of the potential impacts on water quantity, quality or beneficial use. This report outlines a simple index model to allow rapid assessment of potential stream-aquifer connectivity, refer Chapter 8; 11 Conjunctive Water Management Framework

12 (ii.) (iii.) (iv.) (v.) (vi.) Depiction of the nature and geometry of groundwater flow systems and their interaction with surface water features. Models can test the existing hydrogeological understanding for a catchment, and are also useful as a visualisation and communications tool; Quantification of the catchment water balance and how it changes through time. The magnitude and dynamics of seepage flux is placed in context with other water balance components (such as rainfall and evapotranspiration); Predictions in terms of how seepage flux may change based on proposed changes to catchment condition (such as climate change, increased groundwater extraction); Estimates of the likely impact of implementing different options of conjunctive water management. Models can be used as optimising tools in the design of both policy and on-ground management options; Identification of key information gaps that need to be addressed. This includes planning of further field investigations or monitoring to quantify connectivity. Models can also be used in the analysis of data sensitivity and uncertainty to help define the priority datasets. Chapter 9 provides further information on the principles and processes underlying the use and development of conceptual and predictive models which are the basis for scenario planning. Set Management Targets An essential step in any planning process is the setting of management targets. Management targets provide the basis for planning and management decisions and a benchmark against which management performance can be assessed. The specific targets for any catchment will depend on the management issues being addressed. Typical catchment targets could include: (i.) (ii.) (iii.) The sustainable yield limit placed on allocation of surface water and groundwater resources; The end-of-valley stream salinity target expressed at a key gauging station; Minimum flows or flow duration curves developed for meeting environmental water requirements. The process and issues surrounding the setting of management targets are discussed in Chapter 10. Develop and Implement Management Actions There is a suite of options available for implementing a conjunctive water management approach. The options adopted will be defined by: (i.) (ii.) (iii.) (iv.) The management issues that have been identified as requiring addressing within the catchment; The current understanding of catchment water processes, as developed through baseline assessment, conceptualisation, field assessment and possible construction of predictive models; The management targets identified for the catchment; Availability of resources in terms of time, budget and expertise. Conjunctive Water Management Framework 12

13 An appropriate mix of both policy and investment options can be implemented. Policy options that recognise or take advantage of the linkages between groundwater and surface water resources can include strategies such as licencing and allocation, water trading or risk management approaches, buffer zones or planning rules. Investment options involve on-ground works such as water banking infrastructure (such as Aquifer Storage and Recovery schemes), groundwater interception schemes, or groundwater pumps to supplement stream flow. These conjunctive water management options are covered in more detail in Chapter 11. Monitor and Review Performance A well-designed, cost-effective and robust monitoring programme is part of a conjunctive water management approach. Monitoring usually involves collecting key indicators that relate to the priority management issues at appropriate spatial and temporal resolutions. Examples include: (i.) (ii.) (iii.) (iv.) (v.) Surface water gauging of flow, level and quality (eg salinity, nutrients); Groundwater levels and quality; Water usage from extraction points; Land use and land use practices; In-stream ecosystem health such as indicator species. Monitoring is the reality check for managers. This requires reviews on a regular basis to: (i.) (ii.) (iii.) (iv.) (v.) (vi.) Evaluate catchment conditions and identify any emerging management issues that may need addressing; Identify information gaps that when addressed would improve assessment of catchment processes; Validate and potentially update the understanding and conceptualisation of key water processes; Help verify or improve the calibration of any predictive models; Evaluate progress towards the management targets identified for the catchment; Test the appropriateness and performance of the conjunctive water management options implemented. Chapter 12 provides further information on the monitoring and review component of the framework. Roles and Responsibilities Effective management depends on each stakeholder having a clear understanding about who does what, where and how. The same participant can have a different role at different levels in the management process. In some cases, stakeholders have complementary roles and will need to work with others at catchment or regional levels, and Commonwealth, State and Territory and local government levels. These roles are not new or constructed, but they are a reflection of existing and emerging arrangements across Australia. Strong and effective partnerships are needed for conjunctive water management to become an effective tool for achieving integrated water management goals and 13 Conjunctive Water Management Framework

14 bringing practical benefits to water users. The roles and responsibilities of various stakeholder groups are examined in Chapter 4. Future Priorities This framework is a work in progress. Development of better tools to assess groundwater-surface water interactions is needed to improve our understanding of the key connectivity processes and how they impact on water quantity and quality. However, such knowledge gaps should not delay responding to the management issues surrounding groundwater-surface water interactions. The key areas where we believe future work could be focussed are: (i.) (ii.) (iii.) In assessing the overall sustainability of water management within each catchment, allocations of groundwater and surface water systems should be considered jointly; Policy instruments that take advantage of the connectivity between groundwater and surface water resources. Many existing instruments such as water trading, tiered access conditions, risk management approaches and management buffer zones can be developed further to improve overall water management efficiency. For example, storage of water in aquifers is typically more efficient technically than in conventional dams, especially farm dams; Improving the communication between stakeholders such as water users, managers, scientists, modellers and policy makers. Communication barriers, including the institutional separation of the assessment and management of surface water and groundwater resources, are a major impediment to implementing a conjunctive approach. Conjunctive Water Management Framework 14

15 Contents Executive Summary... 5 Contents Figures Tables Introduction Connectivity and Water Policy Policy Relevance Key Policy Drivers Impediments and Opportunities General Principles Factors Controlling Connectivity Factors Controlling Connectivity Spatial and Temporal Scales Connectivity Categories An Adaptive Management Framework for Connected Water Resources Aims and Scope Adaptive Management Approach Framework Components Roles and Responsibilities Identifying Management Setting Catchment Issues Water Users Extent of Resource Development Existing Planning and Policy Assessment of Connectivity Available Assessment Methods for Connectivity Comparison of Methods Assessment Strategy Catchment Datasets and Sources Australian Catchment Data Infrastructures Jurisdictional Catchment Data Infrastructures Catchment Mapping Climate Data Hydrogeology Data Conjunctive Water Management Framework

16 7.6 Water Chemistry Data Hydrology Data Water Management Data Aquatic Biota and Ecological Data Mapping groundwater-surface water connectivity Description of connectivity index model Integration of connectivity index model in a GIS environment Conceptualisation and Prediction Conceptual Models Predictive Models Modelling Guidelines Setting Management Targets National Framework for NRM Standards and Targets Integrated Environmental and Economic Accounting Conjunctive Water Management Options Policy Options Investment Options Monitoring and Reviewing Performance National NRM Monitoring and Evaluation Framework Monitoring of Connected Water Resources Acknowledgements References Conjunctive Water Management Framework 16

17 Figures Figure 1: A framework for conjunctive water management... 7 Figure 2: Categorisation of stream-aquifer connectivity... 9 Figure 1.1: The water cycle Figure 2.1: Change in water use in Australia between 1983/84 and 1996/ Figure 2.2: The way we use water Figure 2.3: The extent of high rainfall and flood events Figure 2.4: The extent of drought event Figure 2.5: The extent of temperature anomalies Figure 2.6: Change in groundwater use between 1983/84 and 1996/ Figure 3.1: Vertical directions of seepage flux...43 Figure 3.2: Idealised freshwater/saltwater interface influenced by submarine groundwater discharge Figure 3.3: Components of a typical flood hydrograph Figure 3.4: Different settings for surface water-groundwater connectivity Figure 3.5: Effects of groundwater pumping on river-groundwater interaction Figure 3.6: Groundwater flow systems of varying scale local, Intermediate and regional (Toth, 1963) Figure 3.7: Schematic catchment section showing differences in connectivity for different river reaches in the Murray-Darling Basin Figure 3.8: Surface water-groundwater interaction in the hyporheic zone Figure 3.9: Categorisation of stream-aquifer connectivity Figure 4.1: An Adaptive Management Framework for Conjunctive Water Use Figure 5.1: Components of the Lower Richmond catchment, north coast NSW Figure 6.1: Examples of different methods of assessing stream-aquifer connectivity Figure 6.2: Components of a strategy for investigation and assessment of connectivity Figure 7.1: Summarised Australian groundwater flow systems contributing to salinity Figure 7.2: Extent of traditional published hydrogeological maps at 1:250,000 scale or more detailed Figure 8.1: Flow chart showing structural component of the connectivity index model Figure 8.2: Spreadsheet implementation of the potential connectivity index model Figure 8.3: GIS-based approach for mapping stream-aquifer connectivity applied in the Border Rivers catchment Figure 9.1: Example of a block diagram type conceptual model for a groundwater system Figure 9.2: HarmoniQuA flowchart of the process of modelling river basin processes Figure 9.3: Stream depletion rates for the base scenarios for a bore pumping 1000m3/d for 5 years at varying distances from the river Figure 11.1: Estimated streamflow reduction due to pumping at full allocation levels for the four management areas in the Dumaresq valley, Border Rivers catchment Figure 11.2: Proposed zones for managing new water access entitlements Figure 11.3: Indicative locations of management zones Conjunctive Water Management Framework

18 Figure 11.4: Areas for further water banking investigation based upon the results of the GIS model and model refinement Figure 11.5: Types of water banking Figure 11.6: A schematic cross section of an interception scheme Figure 11.7: Electrical conductivity imaging of Murray River at Waikerie SA showing impact of groundwater interception scheme Figure 11.8: Anaheim Lake is a recharge basin in the OCWD Figure 12.1: Schematic diagram of a suggested approach to monitoring of a connected water resource including integrated in-stream sites (1) and piezometers (2) Figure 12.2: Example of combined monitoring of stream and shallow groundwater systems Conjunctive Water Management Framework 18

19 Tables Table 1.1: Surface water-groundwater connectivity in the Murray-Darling Basin... 5 Table 2.1: Status of jurisdictional policies relevant to conjunctive water management Table 3.1: Spatial scales in stream-aquifer connectivity Table 3.2: Time scales in Stream-Aquifer Connectivity Table 3.3: Impacts of stream-aquifer connectivity Table 3.4: Typical features of various conductance categories for stream-aquifer systems Table 3.5: Development categories for water resource management areas Table 4.1: Conditions for the application of the Precautionary Principle Table 4.2: Five areas in which governments can play a role in conjunctive water management approach Table 5.1: Different levels of stakeholder engagement Table 5.2: Some stakeholder engagement methods and their benefits Table 5.3: Some resources available for stakeholder engagement Table 5.4: Overview of agencies with an interest in water management in the Lower Richmond catchment, New South Wales Table 6.1: Summary of tools to assess stream-aquifer connectivity Table 6.2: Typical catchment hydrology datasets and sources Table 7.1: Key State/Territory Land Mapping Agencies Table 7.2: Nationally available mapping of topography and surface hydrology features Table 7.3: Summary of significant groundwater databases in Australia Table 7.4: Water type categories with the most significant water quality monitoring effort Table 7.5: Organisations undertaking significant water quality monitoring Table 7.6: Significant surface water monitoring databases in Australia Table 7.7: Summary of organisations providing monitoring data on water storages Table 9.1: Examples of modelling code with varying levels of surface water and groundwater capabilities Table 10.1: List of Indicator Headings and Indicators of National Framework for Natural Resource Management Standards and Targets Table 11.1: Modelled impacts of pumping on double accounting in the Border Rivers Catchment Table 11.2: Zonal approach for managing highly connected alluvial systems in NSW Table 11.3: Perspectives on stream-aquifer connectivity across the community Table 11.4: Advantages and disadvantages of different types of water storage Conjunctive Water Management Framework

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21 1. Introduction Effective water management requires an understanding of the components of the hydrological cycle as well as the linkages between these components (Figure 1.1). One important connection that has historically been overlooked in water resource management in Australia is the link between surface water and groundwater resources. Streams and aquifers have historically been managed in isolation. This is due to a number of factors mainly the largely hidden nature of groundwater, the timeframes for groundwater movement and response that can span decades or more, and the institutional separation of expertise and administration. Figure 1.1: The water cycle In many Australian catchments, aquifers and surface water features are hydraulically connected and this movement of water can have significant water management and policy implications. Seepage of fresh groundwater into a stream can maintain flows during extended dry periods. This discharge helps supply the needs of surface water users such as irrigators as well as for aquatic ecosystems during the critical low-flow period. Pumping from an aquifer near a river can dramatically change the amount of this baseflow to the stream. In contrast, if the groundwater is salty or contaminated, increased groundwater discharge can have a negative effect on surface water quality. Hence, effective management of water quantity and quality issues requires an understanding of these surface water-groundwater interactions. Conjunctive water management is the management of hydraulically connected surface water and groundwater resources in a coordinated way. Such an integrated approach is critical in ensuring sustainability of the water resource and will help meet the objectives of the National Water Initiative. Water issues such as over-allocation, environmental flows and river salinity are all influenced by the degree and nature of the connectivity between surface water and groundwater systems. In the forefront is the issue of double accounting where access entitlements have been made to groundwater that previously discharged into streams and become part of the surface water allocation process. Also, the contribution of groundwater to the maintenance of in-stream ecosystems is increasingly being recognised. For many decades, an 21 Conjunctive Water Management Framework

22 understanding of how groundwater discharge delivers salt to streams has been incorporated into catchment-wide salinity mitigation. This report proposes a framework that can be applied in the conjunctive management of groundwater and surface water resources, based on an adaptive approach. Assessing and managing stream-aquifer connectivity is often complex and difficult. To this end, information on the assessment methods that are available is provided as well as a strategy for implementing such methods. Some key definitions and a schema for categorising connectivity have also been drafted. Conjunctive Water Management Framework 22

23 2. Connectivity and Water Policy Surface water features such as streams are located within a landscape defined by catchment topography, geology and climate. There is a wide array of geological settings so there is variability in the nature and degree of connectivity between surface water and groundwater systems. In its upper reaches, a river can gain groundwater from highly dissected fractured rock aquifers, but lose significant water to its alluvial aquifers further downstream. Towards its lower reaches, seepage may be constrained by deposits of clays and silts. Interactions can vary in time as they are defined by the difference in stream and groundwater levels, and these can fluctuate with the season. It is therefore appropriate to perceive a river as not just the river channel and associated surface water features (such as wetlands and lakes) but also the aquifers that the river is located within. A Connected Water Resource is the combination of surface water feature(s), such as river, estuary or wetland, and the groundwater system(s) that can directly interact in terms of movement of water Recognising that surface water and groundwater resources in a catchment are fundamentally linked means that management of these resources needs to be coordinated. Such an integrated approach is called conjunctive water management. This is done to better manage water in terms of economic, environmental or social outcomes. This means understanding surface water-groundwater interactions and incorporating this understanding into management policy and practice. It can also mean investing in on-ground works which allows the different and complimentary characteristics of surface water and groundwater systems to be combined to advantage. Taking a conjunctive approach can benefit how issues such as water security, water use efficiency, dependent ecosystems, stream salinity or nutrient loads are dealt with. Conjunctive Water Management is the management of hydraulically connected surface water and groundwater resources in a coordinated way, such that the total benefits of integrated management exceed the sum of the benefits that would result from independent management of the surface water and groundwater components (from Sahuquillo and Lluria, 2003) As an example water can be stored in the aquifer for use during droughts by increasing recharge during times of above-average water availability. As such, an aquifer can be a water source during dry periods, and a storage reservoir during wet periods. At times when surface water availability is comparatively plentiful (in winter months and during wet years) the direct use of surface supplies is encouraged. Pumping of aquifers is comparatively less during these wet periods, allowing them to refill naturally or through deliberate replenishment efforts such as Aquifer Storage and Recovery (ASR) schemes. When stream flows are less and need to be conserved for ecosystem requirements, stored groundwater can be tapped to meet irrigation or urban demand. Thus, in a given location, the same water uses may be met sometimes 23 Conjunctive Water Management Framework

24 with surface water and other times with groundwater, as part of a deliberate management effort that operates the two resources conjunctively. The potential benefits of this one example of a conjunctive approach include: (i.) (ii.) (iii.) (iv.) (v.) (vi.) Improved security of water access entitlements for landholders; Greater flexibility for producers seeking to ensure access to resources, by allowing switching between more than one water source according to relative availability; Greater average annual water yields by capturing and conserving surplus water supplies when they are available; Producers able to demonstrate due diligence in their management of natural resources; Communities and regions better able to deliver water management and environmental targets; Governments able to achieve better water resource outcomes in the national interest. Conjunctive water management can be seen as one of the methods of addressing sustainable water resource management issues in Australia. It is important to recognise both the strengths and the limitations of conjunctive water management. Adopting a conjunctive approach alone may not necessarily deliver sustainable water resource management outcomes. This is because conjunctive water management is just one component of the concept of Integrated Water Resource Management (IWRM). Integrated Water Resource Management is a process that promotes the coordinated development and management of water, land and related resources, in order to maximise the resultant economic and social welfare in an equitable manner without compromising the sustainability of vital ecosystems (GWP, 2000) In this way, social, economic, environmental and technical dimensions are all taken into account when managing water resources. This involves linking the management of the parts of the natural world that are important for the availability and quality of water. Coordinating the management of surface water and groundwater is just one aspect of this. The other aspects are linking: (i.) (ii.) (iii.) (iv.) Land and water, recognising that land use and vegetation can have an effect on water resources; Water quantity and water quality, so that the usability of water for different purposes is maintained or enhanced; Upstream and downstream interests, as the practices of people high in the catchment can effect the quantity and quality of water for people downstream. To this end, management should encompass the needs of the coastal zone as well as the need for freshwater on the land; Green water and blue water. This recognises that there tends to be a focus on the water flowing down rivers or through aquifers ( blue water ) in catchment management. This is at the expense of the management of the water involved in plant growth such as rainfall, soil moisture and evapotranspiration ( green water ); Conjunctive Water Management Framework 24

25 (v.) Water and waste water, by providing alternative water supplies with the treatment and re-use of water flows traditionally viewed as waste such as saline or brackish sources, storm water or sewage (GWP, 2000). The other critical aspect of IWRM is the linking of the social dimension. This is fundamental, as people and the decisions they make define how water is used or misused. This can be achieved through: (i.) (ii.) (iii.) (iv.) (v.) Coordinating water management and policy-making at all levels from global and national to local and community; Involving all stakeholders in the decision-making process and providing avenues for conflict resolution and mechanisms for evaluating trade-offs. This requires effort in capacity building so that stakeholders have the necessary knowledge and skills for full participation; Making mainstream planning and policy processes assess and account for any impacts on water resources. This acknowledges that decisions made in many sectors (such as food, transport, energy, immigration) need to be water sensitive; Making available adequate information on the biophysical, economic, social and ecological characteristics of a catchment to support appropriate decisionmaking; Influencing water users to make consumptive choices based on the real value of water, and the need for long-term viability of the water resource (GWP, 2000). The concept of IWRM is based on the Dublin Principles, so called as they were adopted from the 1992 International Conference on Water and the Environment in Dublin (Box 2.1). These principles formed the foundation for the freshwater resources component of Agenda 21 Chapter Conjunctive Water Management Framework

26 Box 2.1 The Dublin Principles Principle No. 1 - Fresh water is a finite and vulnerable resource, essential to sustain life, development and the environment. Since water sustains life, effective management of water resources demands a holistic approach, linking social and economic development with protection of natural ecosystems. Effective management links land and water uses across the whole of a catchment area or groundwater aquifer. Principle No. 2 - Water development and management should be based on a participatory approach, involving users, planners and policy-makers at all levels. The participatory approach involves raising awareness of the importance of water among policy-makers and the general public. It means that decisions are taken at the lowest appropriate level, with full public consultation and involvement of users in the planning and implementation of water projects. Principle No. 3 - Women play a central part in the provision, management and safeguarding of water. This pivotal role of women as providers and users of water and guardians of the living environment has seldom been reflected in institutional arrangements for the development and management of water resources. Acceptance and implementation of this principle requires positive policies to address women s specific needs and to equip and empower women to participate at all levels in water resources programmes, including decision-making and implementation, in ways defined by them. Principle No. 4 - Water has an economic value in all its competing uses and should be recognized as an economic good. Within this principle, it is vital to recognize first the basic right of all human beings to have access to clean water and sanitation at an affordable price. Past failure to recognize the economic value of water has led to wasteful and environmentally damaging uses of the resource. Managing water as an economic good is an important way of achieving efficient and equitable use, and of encouraging conservation and protection of water resources. (from Global Water Partnership) Conjunctive Water Management Framework 26

27 2.1 Policy Relevance The implications of stream-aquifer connectivity and the need for a conjunctive management approach have been known in Australia for over forty years. The first national review of water resources (AWRC, 1965) stressed that groundwater should not be regarded as a resource separate from surface water, noting that: In some localities base flows in streams are maintained by drainage into them from underground sources while in other places streams are a source of replenishment for underground supply. Consequently, exploitation of the one can effect the availability of supply from the other. It is desirable, and likely to become increasingly important, that the conservation and utilisation of both resources should be planned jointly. A similar review of water resources in Australia undertaken a decade later (AWRC, 1976) came up with the same conclusions: In the past, groundwater and surface water have tended to be viewed as separate resources, as a result, no doubt, of inherent differences in their modes of occurrence, assessment and development. Yet they are often hydraulically connected, and in any event, are complementary components of a larger single system. Thus, in assessing the water resources of a region, independent measurements of groundwater and surface water yield are not necessarily additive. This was again reiterated in the Water 2000 report of water resource priorities undertaken in 1983 which specified that conjunctive use of surface water and groundwater supplies should be encouraged in present and future water resources planning (DRE, 1983). The report also advocated that analyses of surface watergroundwater relationships are required to provide an appropriate systems approach basis for conjunctive use. The words of the 1965 review and its successors have turned out to be quite prophetic. Over the last decade, the significance of the connectivity between surface water and groundwater systems has come to the fore in Australia. Below is a summary of more recent water policy initiatives and where explicitly mentioned, how these relate to conjunctive water management. COAG Water Reforms In February 1994, all governments across Australia, recognising inefficient and inappropriate use of water, agreed that the management and regulation of water resources required significant policy and institutional change. This agreement resulted in the endorsement of a national policy by the Council of Australian Governments (COAG), known as the COAG Water Reform Framework, to achieve an efficient, economically viable and environmentally sustainable urban and rural water industry. Key policy elements included: (i.) (ii.) (iii.) Water pricing based on full cost recovery and the amount of water used; Establishment of clearly specified water entitlements and the arrangements to enable trade in those entitlements; Allocation to the environment as a legitimate user of water; 27 Conjunctive Water Management Framework

28 (iv.) (v.) (vi.) Adoption of an integrated catchment management approach to water resource management; Establishment of regulatory and water service institutions that have clear roles and responsibilities; Public education and consultation. Although management of groundwater was included in the provisions of the 1994 reforms, the framework had a focus on surface water resources and was not explicit about which aspects applied to surface water and to groundwater. It was not until 1996 that the issues surrounding groundwater management such as trading, pricing, drilling, well construction and institutional arrangements were formally accepted into the reform framework by COAG and thus introduced into national water policy. Also recognised at that time was the notion of considering the linkages between surface water and groundwater. The problems of managing connected water resources through different programmes were acknowledged, noting that: groundwater and surface water resource management should be better integrated, including approaches to pricing (especially adjacent to public surface water regulated schemes), water allocations and trading to ensure consistency (ARMCANZ, 1997: Recommendation 3). According to a policy paper by the Framework Taskforce: In many situations, groundwater and surface water are interconnected and interchangeable resources where decisions made in one area affect the other. Consider, for example, the situation which exists in parts of Australia where no groundwater license is required for a well adjacent to a stream, whereas the stream is fully allocated. Single resource policies embracing conjunctive use and integrated management of groundwater and surface water through allocation and pricing mechanisms need to be more actively pursued by the States (ARMCANZ, 1997:3). In addition, Resolution 6 (ARMCANZ, 1998) states that: Progress has been made in some limited areas in meeting environmental needs of groundwater, but further progress has been constrained by a poor understanding of the location, extent and processes associated with groundwater/surface water interactions and associated ecosystems. National Water Initiative At the August 2003 meeting of COAG, it was agreed that there was a pressing need to consolidate and refresh the 1994 water reform agenda to increase the productivity and efficiency of water use, sustain rural and urban communities and to ensure the health of river and groundwater systems. COAG agreed to develop a National Water Initiative (NWI) to: (i.) (ii.) (iii.) Improve the security of water access entitlements; Ensure ecosystem health by implementing regimes to protect environmental assets at a whole-of-basin, aquifer or catchment scale; Ensure water is put to best use by encouraging the expansion of water markets and trading; Conjunctive Water Management Framework 28

29 (iv.) Encourage water conservation in cities. At its meeting in June 2004, COAG agreed to establish a National Water Commission (NWC) to assess progress in implementing the NWI and advise on actions required to better realise the objectives of the Agreement. There are a number of references to a conjunctive management approach within the intergovernmental agreements relating to the NWI, namely: (i.) (ii.) (iii.) (iv.) One of the primary objectives is to recognise the connectivity between surface and groundwater resources and connected systems managed as a single resource (NWI 2004, clause 23x). With reference to water resource accounting, the key outcome is to ensure that adequate measurement, monitoring and reporting systems are in place to support public and investor confidence in the amount of water being extracted for consumptive use (NWI 2004, clause 80).This outcome is to be achieved, in part, by consolidated water accounts, that can be reconciled annually and aggregated to produce a national water balance (NWI 2004, clause 82 iii). These accounts are to be inclusive of systems to integrate the accounting of groundwater and surface water use where close interaction between aquifers and streamflow exist (NWI 2004, clause 82 iiib). Also States and Territories to immediately establish common arrangements in the case of significantly inter-connected groundwater and surface water systems (NWI clause 79 i(c)). The NWI also stipulates that all states and territories agree to identify by end of 2005 situations where close interaction between groundwater aquifers and streamflow exist and implement by 2008 systems to integrate the accounting of groundwater and surface water use. (NWI 2004, clause 83). Other Australian Water Initiatives This recognition of connectivity has also been supported by other recent water policy discussions. The study, Water and the Australian Economy (ATSE, 1999) concluded that: Policies are needed to ensure the resource is managed in its totality, including groundwater, unregulated rivers and water quality. Water markets must be regulated to ensure individual trades do not impose external effects on third parties. Current regulatory systems do not offer sufficient protection to third party interests or the proper regulation of whole water systems. The National Land and Water Resources Audit (NLWRA) stressed the importance of developing and applying methods to understand and then manage at a basin scale conjunctive use, and to integrate surface water and groundwater management within an overall context of sustainability (NLWRA, 2001). The Audit recommended an Australia-wide initiative in partnership with State and Territory water management authorities that included understanding and managing interactions between surface water and groundwater quality and quantity. In 2002, a series of groundwater policy papers was developed by the High Level Steering Group on Water in conjunction with the National Groundwater Committee (NGC). In particular, one of these papers on groundwater quality protection noted the importance of connectivity. This was followed by a national workshop convened by the NGC to identify research priorities for groundwater management. The workshop 29 Conjunctive Water Management Framework

30 paper Knowledge Gaps for Groundwater Reforms defined the key information gaps of groundwater dependent ecosystems, water level response management, land use change, as well as integration of surface and groundwater management. In July 2003, a Blueprint for a National Water Plan was released by the Wentworth Group of Concerned Scientists. In addition to other aspects of water resource management, the blueprint acknowledged the importance of considering groundwatersurface water interactions: water accounts also need to take into account the interconnected nature of groundwater and surface water systems Entitlements to access water must therefore address run-off, land use, river water and groundwater In the 21 st century we will need systems that recognise hydrological connections. Other Australian Natural Resource Management Programmes An important component of water reform is the management of water quality. In 1992 a National Water Quality Management Strategy (NWQMS) was introduced by the Commonwealth, State and Territory governments. In 1994, the strategy was incorporated into the COAG Water Reform Framework. The main policy objective of the NWQMS is based on the philosophy of ecologically sustainable development to achieve sustainable use of the nation s water resources by protecting and enhancing their quality while maintaining economic and social development. The NWQMS comprises policies, a process and 21 national guidelines for water quality management. The Natural Heritage Trust (NHT) and National Action Plan for Salinity and Water Quality (NAP) are two other major programmes that aim to address environment and natural resource issues in Australia. The NHT was set up by the Australian Government in 1997 and funding has since been extended to 2007 to support the sustainable management of Australia s natural resources, including measures to improve water quality. The NAP was announced in October 2000 to address salinity and water quality in some of Australia s worst affected areas. The NAP is designed to improve land and water management in 21 priority regions. In relation to surface and groundwater management, the Action Plan promotes: (i.) (ii.) Caps to be set for all surface and groundwater systems identified as overallocated or approaching full allocation; Introduction of a new approach to groundwater and surface water administration that recognises their interdependency and the need for their joint management for salinity and water quality outcomes. State and Territory Water Policy Under the Australian constitution, natural resource management is the responsibility of the States and Territories, each of which has adopted water reform processes suitable for their jurisdictions. The National Groundwater Committee has compiled the status of policies, regulations and legislation relevant to conjunctive water management operating under State and Territory jurisdictions (NGC, 2004), as summarised in Table 2.1. Conjunctive Water Management Framework 30

31 International Perspective Water scarcity, allocation, water quality and ecosystem dependencies are global water issues. Many countries and organisations are also dealing with the challenge of integrating the management of surface water and groundwater resources. Some examples are set out below. Global Water Partnership IWRM Toolbox The Global Water Partnership (GWP) has developed a resource relating to integrated water resource management. The IWRM Toolbox contains resources for three key areas of the enabling environment (the overall laws, investments and policies), institution and capacity building, and management tools. International Association of Hydrogeologists (IAH) The IAH maintain a network for promoting and coordinating work on the management and enhancement of aquifer recharge (IAH-MAR). The forum provides access to a reference database, a conference and workshop calendar and publications relating to aquifer recharge management. Hydrology for the Environment, Life and Policy (HELP) UNESCO and the World Meteorological Organization (WMO) is developing the HELP international network as a framework for integrated catchment management. EU Water Initiative (EUWI) The EUWI is designed as a catalyst and a foundation for meeting development goals for drinking water and sanitation, within the context of an integrated approach to water resource management. Integrated water resource management at all levels including natural rivers, lakes or groundwater basins is needed within an overall framework. Table 2.1: Status of jurisdictional policies relevant to conjunctive water management (NGC, 2004) Jurisdiction Details Australian Capital Territory Water Resources Act does not separate surface water and groundwater and is not a constraint to integrated management. One water resources management plan for the ACT that includes both surface water and groundwater. Allocations do not separate surface water and groundwater. Licences to take water may be surface water, groundwater or both. If both, separate limitations on volume may apply to each source. Groundwater and surface water are not traded via a common market. New South Wales Act allows managing surface water and groundwater separately. Water sharing plans may be surface water, groundwater or both. It is state policy to manage water in an integrated way through linkages between the different plans. A policy has been developed for managing unregulated streams that are highly connected to groundwater. Work is continuing on a policy for regulated rivers that are highly connected to groundwater. 31 Conjunctive Water Management Framework

32 Jurisdiction Northern Territory Queensland South Australia Tasmania Victoria Details No trades between surface water and groundwater to date. Trades between the two sources are like to be permitted in the future for highly connected systems. Under the Act water must be allocated within the estimated sustainable yield of both surface water and groundwater to the declared beneficial uses in a water control district. Act treats surface water and groundwater separately from a licensing aspect. Surface water licensing discusses material affects on river flow but not on groundwater. Where a water allocation plan has been declared, the right to take or use water is able to be traded. The different temporal time scales on the impacts of extraction from bore pumps and river pumps on river flow need to be taken into account when determining the sustainable yield of a coupled groundwater / river system. Groundwater and surface water are not traded via a common market. Water Act does not separate surface water and groundwater and is not a constraint to integrated management. One water resource plan for a catchment that includes both surface water and groundwater. Recent changes to the Water Act have split former conjunctive licences (one licence for both surface water and groundwater) into separate surface water and groundwater resources that are being dealt with in the planning process to attribute the take against a particular water resource. Groundwater and surface water are not traded via a common market. Water Act recognises groundwater, water in watercourses and surface water flowing across land able to be captured in dams. The Act recognises the inter-relationship between groundwater and surface water with respect to impacts. Hydraulic connection between surface water and groundwater is implied. Water use may be restricted if taking surface water impacts on groundwater recharge or if taking groundwater impacts on surface water quality. Water allocation plans for prescribed (licensed) areas include surface water, watercourses and groundwater in the one plan. Groundwater and surface water are not traded via a common market. Surface water is piped for aquifer storage and recovery (ASR) scheme. Only surface water licensed and actively managed but may be easier to implement conjunctive use management as could be regarded as extension of surface water management. Water use can be restricted if water quality of either resource is compromised. A water management plan may be prepared for water resources joined naturally and the Act provides for the consideration of the effects of water resource use on other linked water resources. Groundwater not licensed, and therefore cannot be traded. Water Act designed to enable integrated management of surface water and groundwater to provide for the integrated management of all elements of the terrestrial phase of the water cycle and to eliminate inconsistencies in the treatment of surface water and groundwater resources and waterways. Plan may relate to groundwater, surface water or both. Minister may declare a total annual volume of water for an area that may be taken whether surface water, groundwater or both. Limits have not yet been set but the intent is to do so in the future. The current limits have not been set under the new legislative framework. It is likely however that the new limits will relate separately to Conjunctive Water Management Framework 32

33 Jurisdiction Western Australia Details groundwater and to surface water but not to the combined resource. No instances of interchangeable transfers between surface water and groundwater. This will be addressed in the future. Water Act treats surface water and groundwater separately. The Act treats water resources as three entities: water in a watercourse, water in wetlands and groundwater. The Act also differentiates between certain surface waters (water in proclaimed areas) and other surface waters (water in non-proclaimed areas). Separate groundwater and surface water management plans at local and subregional scale but regional plans may combine surface water and groundwater. Highly connected systems in some areas but little opportunity for widespread conjunctive use management because there are few places where fresh surface water/groundwater interact. Where the interactions occur, water quality is poor, quantities are not economical and interactions are intermittent. Groundwater and surface water are not traded via a common market. South Africa South Africa has similar issues to Australia in terms of high variability in rainfall and water availability. In the South African White Paper on Water Policy, all water in the water cycle whether on land, underground or in surface channels, falling on, flowing through or infiltrating between such systems, will be treated as part of the common resource and to the extent required to meet the broad objectives of water resource management, will be subject to common approaches. Nebraska, USA Nebraska Water Law relevant to groundwater-surface water relationships was passed during The Water Law expanded the Ground Water Management and Protection Act to include authorities related to integrated management of hydrologically connected groundwater and surface water. The water law indicated that Hydrologically connected groundwater and surface water may need to be managed differently from unconnected groundwater and surface water in order to permit equity among water users and to optimize the beneficial use of interrelated groundwater and surface water supplies. The act identifies natural resources districts as the preferred entities to regulate groundwater related activities that could contribute to conflicts between ground and surface water users. California, USA The California Department of Water Resources (DWR) is implementing a Conjunctive Water Management Program (CWMP) to increase the state-wide reliability of water supply through planned, coordinated management and use of groundwater and surface water resources. This includes developing a basic understanding of processes in groundwater systems, identifying basin management strategies, and designing and constructing specific projects. Through the coordinated optimisation of surface water and groundwater supplies, California intends to increase water supply reliability, water supply system flexibility and reduce dry year demand deficit, overdraft, and subsidence. 33 Conjunctive Water Management Framework

34 2.2 Key Policy Drivers Although the concepts underlying conjunctive water management have been acknowledged within Australian water policy for over forty years, historically there has been limited implementation. However, the joint management of groundwater and surface water resources has become a greater priority over the last 5-10 years. This is reflected in the greater recognition of connectivity issues within the National Water Initiative when compared with its predecessors in the COAG water reform agenda. The key drivers for this are: (i.) (ii.) (iii.) (iv.) (v.) Water scarcity and demand; Climate variability and water availability; Impacts of groundwater extraction on surface water; Stream salinisation; Environmental water needs and ecosystem health. Water scarcity and demand The mismatch between increasing water demand and decline in water availability is the most critical resource issue in Australia. Population growth, intensive agricultural development, urbanisation, industrial growth and environment requirements are all increasing demand for water. Understanding how we meet this expanding demand in the longer-term is vital. According to the Australian Bureau of Statistics (ABS), Australian households and businesses consumed the equivalent of almost 50 times the volume of Sydney Harbour (24,909 gigalitres GL) of water in (ABS, 2005). Moreover, total water use increased by 9,400 GL/year or 65% between 1983/84 and 1996/97 (NLWRA, 2001). This was mostly due to expansion of irrigated agriculture, while urban centres have shown either low increases or net decreases in water consumption over the same period (Figure 2.1) / /97 59% increase Water usage (GL) % increase 53% increase % decrease 0 Irrigation Urban/industrial Rural (including rural domestic) Total Figure 2.1: Change in water use in Australia between 1983/84 and 1996/97 (NLWRA, 2001) Conjunctive Water Management Framework 34

35 The agriculture industry had the highest water consumption in , accounting for 16,660 GL (or 67%; Figure 2.2). Households were the next highest water consumer, using 2,181 GL (or 9%). The water supply, sewerage and drainage services industry was also a significant consumer of water, with 1,794 GL (or 7.2%), followed by the electricity and gas supply industry with 1,688 GL (or 6.8%) (ABS, 2005). According to the ABS, most water is consumed in NSW/ACT (39%) and Victoria (30%), followed by Queensland (17%), Western Australia (6.4%), South Australia (5.7%), Tasmania (1.4%) and Northern Territory (0.5%) (ABS, 2005). 35 Conjunctive Water Management Framework

36 Manufacturing 4% Electricity & Gas 7% Mining 2% Other 3% Water supply 8% Households 9% Agriculture 67% Figure 2.2: The way we use water (ABS 2005) This recent and rapid expansion of water demand was reported by the Australian Academy of Technological Sciences and Engineering: If recent trends continue, water requirements of the irrigation sector could increase by about 66% by On current growth rates, total national water use could be as much as 33,000 GL by which is clearly unsustainable. (ATSE, 1999). This pressure on water resources is expected to increase with continued economic growth. On the supply side, most climatic models suggest a decline in rainfall over much of the continent. Such reductions in water availability have the potential to magnify the shortages already evident. Declines in water availability will impact on all sectors of the Australian economy, with agriculture being particularly affected. Increased water use is reflected in allocation nearing, and in some cases exceeding, the defined sustainable limits of the resource in parts of Australia. This was summarised in the national perspective of the level of water resource development compiled as part of the National Land and Water Resources Audit (NLWRA, 2001). This means greater pressure to address inefficiencies in water management, such as the existing practices of independently assessing and managing groundwater and surface water resources. Australia is not running out of water, but it is not always available when and where people need it. Climate, normal seasonal variations, droughts and floods can all contribute to local extreme conditions. Climate variability and water availability Climate is the driver of the water cycle. It determines how much water is available (supply) and how much water we need (demand) in the short and long term. Australia is relatively arid, with 80% of the land having <600 mm rainfall per year and 50% of the land area having <300 mm per year. A key feature of Australia's climate is not necessarily the amount of rainfall but the variability in rainfall from year-to-year and season-to-season. The erratic climate is most visible in the cycle of extreme events such as droughts (Figure 2.4) and floods (Figure 2.3). Hence, climate variability and climate change will shape the nature of Australian water availability, in terms of: Conjunctive Water Management Framework 36

37 (i.) Extreme rainfall and flood: The combined impact of rising sea levels and extreme weather events are likely to result in increasing occurrence and severity of high rainfall and flood events in some parts of the country (Figure 2.3). Research shows that with a 20 cm sea level rise, water levels would likely double, and damage costs associated with flooding would increase by up to 50%. Despite forecasts for decreased rainfall in many areas of Australia, research by CSIRO (2004) predicts that by 2040, climate patterns for the eastern coast of Australia are likely to bring about more intense and more frequent extreme rainfall events. The most vulnerable regions for extreme rainfall include Coffs Harbour, Coolangatta, north of Brisbane, and over mountainous terrain (CSIRO, 2004); Figure 2.3: The extent of high rainfall and flood events (Data supplied from the Australian Bureau of Meteorology) (ii.) Drought: Increases in occurrence and severity of drought events are expected across eastern and southern Australia, with the most severe events occurring in northeastern and southeastern Australia (Figure 2.4). Trends in increased drought are already being experienced in southern parts of Australia, with the 2002 drought was recognised as being the most severe drought since This severity of drought has implications on water availability and has resulted in water restrictions across the country in the last 3-4 years; Figure 2.4: The extent of drought event (Data supplied from the Australian Bureau of meteorology) 37 Conjunctive Water Management Framework

38 (iii.) Temperature: Climate change is predicted to make significant changes to daily maximum temperature across Australia. Figure 2.5 shows an annual warming of between 0.5 o C and 2.5 o C during Warm weather occurred mainly in early 2005, with April being the warmest for the past century over much of the country. Figure 2.5: The extent of temperature anomalies (Data supplied from the Australian Bureau of Meteorology) Impacts of groundwater extraction on surface water flow Groundwater use across Australia increased 58% from 2,600 GL to 4,200 GL between 1983/84 and In percentage terms, in some States (such as New South Wales, Victoria and Western Australia) the increase in groundwater use over this time period was over 200% (NLWRA, 2001), refer Figure 2.6. In volume terms, Western Australia increased groundwater use by almost 800 GL followed by New South Wales with a 670 GL increase. In Tasmania and Northern Territory the corresponding increase in groundwater use was about 100%. However, there was a slight reduction in groundwater usage in Queensland (26%) and South Australia (22%). Increase in groundwater use in southeastern Australia has been largely attributed to irrigation in the Murray Darling Basin. From 1 July 1997, the volume of surface water diverted from the Murray Darling river system in New South Wales, Victoria and South Australia was capped by agreement at 1993/94 levels. However, groundwater use in the Basin was not capped and has continued to increase steeply since that time with migration of demand. Low rainfall during the late 1990s has also driven groundwater development. Due to connectivity, this increase in groundwater use will be reflected in reduced surface water flow, although uncertainty surrounds the volume and time of the reduction. Of concern in basin water policy is the extent to which projected increases in groundwater extraction will be reflected in decreased base flows to rivers, so impacting on the integrity of the Cap. It has been estimated that 186 GL/yr of streamflow has been captured due to the growth in groundwater since the introduction of the Cap until (SKM, 2003). This double accounting problem is also predicted to be in the order of 700 GL/year by This prediction makes the assumption that currently over-used groundwater management areas in the basin will have extraction reduced to sustainable yield limits - if existing groundwater Conjunctive Water Management Framework 38

39 overuse is maintained in these areas than the projected streamflow depletion will be 1395 GL/yr by As way of comparison, the recovery target to meet environmental objectives through the Living Murray initiative is 500 ML/yr. Annual groudwater use (GL) % increase 202% increase 26% decrease 205% increase 1983/ /97 22% decrease 122% increase 97% increase 0 New South Wales Victoria Queensland Western Australia South Australia Figure 2.6: Change in groundwater use between 1983/84 and 1996/97 (NLWRA, 2001) Stream Salinisation Tasmania Northern Territory The role of groundwater processes in both dryland and irrigation induced salinity has long been recognised. Across significant areas of Australia, land clearing and cropping have increased groundwater recharge, raised the watertable and driven increased discharge of saline groundwater into nearby streams. The NLWRA estimated that about 25,000 km 2 of salt-affected lands could potentially increase to 170,000 km 2 by The current annual cost in terms of lost agricultural production and infrastructure damage has been estimated at $250m with degradation of ecological assets undefined (NLWRA, 2001). Of concern are increasing trends in stream salinity in the Murray-Darling Basin and the south-west of Western Australia. About a third of divertible surface water in streams in south-west WA is classified as brackish and saline, with only a half of streams classified as potable in terms of salinity (WA Government, 2000). Land and stream salinisation have been key motivators for understanding how groundwater systems respond to changing land use, as well as processes of seepage flux and salt mobilisation to water bodies. Significant investments have been made in engineering solutions such as groundwater interception schemes to reduce salt loads to significant rivers such as the River Murray. Environmental water needs and ecosystem health Pressure to establish and deliver environmental water provisions is another key driver for taking a conjunctive approach. Recognition that the environment is a legitimate user of water requires tradeoffs between competing demands for a limited water resource. As an example, the Murray-Darling Basin Ministerial Council established the Living Murray Programme in 2002 in response to evidence of declines in the health of 39 Conjunctive Water Management Framework

40 aquatic ecosystems. The Living Murray follows on from the Cap on water extractions in the Murray Darling Basin by seeking to provide an additional 500 GL/yr of water to the ecological assets of the River Murray System. The first step of the initiative is to achieve environmental benefits for six icon sites along the river, namely Barmah Millewa Forest, Gunbower Koondrook-Perricoota Forest, Hattah Lakes, Chowilla Floodplain (including Lindsay-Wallpolla), Lower Lakes, Coorong and Murray Mouth and the River Murray Channel. One strategy to provide the additional 500 GL/yr is to identify inefficiencies in water management which can be translated into water savings transferable to the environment. Conjunctive water management is part of this process. In recent years, there has been greater recognition that ecosystems such as particular wetlands, high baseflow streams and vegetation communities can have a dependency on the underlying groundwater system for their long term viability. This means that environmental water provisions should not be assessed and managed from just a surface water perspective, but also includes a groundwater component. 2.3 Impediments and Opportunities In May 2004, a workshop was held focusing on priorities for implementing conjunctive water management in Australia (Fullagar, 2004). The workshop Rivers and Aquifers: Towards Conjunctive Water Management brought together water experts, managers and users to identify strategic directions for realising the opportunities and addressing the issues associated with the coordinated management of surface water and groundwater systems. The workshop found that: (i.) (ii.) (iii.) Traditional institutional separation of surface water from groundwater has created fundamental communication barriers that now extend from technical expertise to policy developers, operational managers and water users. These barriers impede the understanding of the processes and consequences of groundwater-surface water interactions; The sustainable extraction limits for surface water and groundwater resources tend to be estimated in isolation and do not adequately account for connectivity. The activation of groundwater sleeper licences in connected systems is likely to exacerbate over-allocation by reducing base flows to rivers. In particular, increased groundwater extraction from bores adjacent to river systems is having a direct negative impact on river flows, including the River Murray. This has been compounded by the increase in users accessing groundwater in response to surface water restrictions. Better accounting of the combined water resource is required to identify and address over-allocation; Technologies to support coordinated management of surface water and groundwater resources exist, and investment is required for their further development and application. Australia has developed world-renowned expertise in the field of Aquifer Storage and Recovery (ASR). Increasing interest in conjunctive management indicates an international market exists for such technology. Significant efficiencies could be made through improved coordination of relevant expertise, research, policy, management, and technology. Conjunctive Water Management Framework 40

41 The following opportunities for action were defined: 1. Develop comprehensive caps on connected water systems. There is now widespread recognition that groundwater development will increasingly compromise surface water management policies in connected systems until policies are developed and applied across the connected system. Where necessarily separated, surface water and groundwater management plans functioning within a connected system should address the same goals. 2. Adopt a coordinated national approach to assessing the extent of connectivity and significance for maintaining economic, environmental and social assets. This includes: (i.) (ii.) (iii.) (iv.) (v.) (vi.) (vii.) (viii.) (ix.) (x.) Developing a policy definition of connectivity and a standard categorisation system; Developing tools for properly defining the total water balance of connected systems; Improving the understanding of the spatial and temporal aspects of streamaquifer interactions at a range of scales; Applying and improving existing (direct and indirect) methods of obtaining robust estimates of water and solute fluxes; Fostering the development of expertise in groundwater-surface water interactions; Enhancing catchment-scale monitoring including the alignment of surface water and groundwater investigations and data collection. A particular priority is improved collection of water use data; Developing infrastructure to enable coordinated access to existing data sets and encouraging the use of existing data standards; Identifying predictive models that are suitable for supporting decision-making in conjunctive water management. Ensure that the data requirements for these models can be effectively met; Evaluating the impact of floodplain management on connected water resources; Ensuring that assessment techniques are aligned to management needs and are suitable across the range of hydrological systems. 3. Develop a national management toolkit for connected systems. This includes: (i.) (ii.) (iii.) (iv.) Developing a policy for pain sharing in over-allocated connected systems; Developing a zonal approach for managing groundwater input to surface water features; Applying tiered access conditions to groundwater licences that are typically applied to surface water licences; Merging (currently independent) groundwater and surface water licensing arrangements; 41 Conjunctive Water Management Framework

42 (v.) (vi.) (vii.) Providing a framework containing rules for surface water groundwater trading. This includes understanding the potential opportunities, costs and/or impacts of a single water market for surface water and groundwater; Developing guidelines for pumping groundwater into rivers to maintain environmental flows or water quality; Developing guidelines relating to engineering solutions including ownership of water artificially transferred between surface and aquifer storages. 4. Improve communication between water users and other stakeholders to engage their interest and involvement. This involves: (i.) (ii.) (iii.) (iv.) (v.) (vi.) (vii.) (viii.) (ix.) Improving community awareness and understanding of connectivity issues; Explaining the impacts of groundwater use on surface water flows including identifying risks to security of water supply and/or any trade-offs; Outlining the planning process including why a water management plan is necessary, the objectives, process, planning structure and timeframes; Establishing clear rules of community and government engagement within the planning context; Raising awareness of the tools available to assess groundwater-surface water interaction; Providing education on the capabilities and limitations of predictive models; Encouraging the integration of groundwater and surface water research groups at universities and other scientific agencies; Fostering communication between modellers and water managers and users and taking a multi-disciplinary approach in the development of appropriate conceptual and numerical models; Communicating the opportunities and limitations of engineering technologies particularly on the use of aquifers as water storages. 5. Foster the development and application of engineering solutions as part of a conjunctive management strategy. This includes: (i.) (ii.) (iii.) Undertaking economic analysis of engineering options such as water banking or bank filtration; Investing in demonstration sites, by including engineering solutions in catchment management initiatives; Undertaking research to address identified information gaps in the areas of flood water harvesting, subsurface water treatment processes, performance of salt interception schemes, effluent/stormwater storage and evaporative losses. Conjunctive Water Management Framework 42

43 3. General Principles In connected water resources, the flow of water between the surface water feature and the aquifer is termed the seepage flux. The term seepage usually relates to the flow of water through porous medium (such as sediments). The term flux relates to the flow rate of fluid (or particles or energy) through a given surface area. Hence seepage flux relates to the direction and rate of water movement through the stream-aquifer interface (such as the stream bed). This is measured in terms of volume per unit area per unit time. In SI units this translates to m 3 /m 2 /day or alternatively m/d, however other units of measurement reported from studies include m/s, L/m 2 /d, mm/d or cm/d. Flux can also be aggregated over the area of the surface water feature. For example, seepage flux for a stream reach is often expressed in units of m 3 /d/km (or ML/d/km) by incorporating stream channel width. The convention is that positive seepage flux values indicate flow of groundwater to the surface water feature (also referred to as discharge or outflow) and negative flux values indicate flow from the surface water feature to the aquifer (also referred to as recharge, reverse flow or inflow), refer Figure 3.1. Seepage Flux is the magnitude and direction of water movement at the interface between surface water and groundwater systems. Figure 3.1: Vertical directions of seepage flux (from Sebestyen & Schneider, 2001) Seepage flux is an important part of the water budget for all surface water features. The general principles of interaction with groundwater systems hold for streams, estuaries, wetlands, lakes and reservoirs (Box 3.1). However, the emphasis of this report is groundwater interaction with streams due to their importance in the management of water quantity and quality in Australian catchments. Of particular interest in water management is groundwater seepage to streams because such discharge can sustain stream flows over extended periods between rainfalls. This seepage is commonly referred to as baseflow, differentiated from quickflow which is the direct and short-term response to rainfall that includes flow over the land surface 43 Conjunctive Water Management Framework

44 (overland flow or runoff), rapid lateral movement in the soil profile (interflow) and direct precipitation onto the stream surface, refer Box 3.2. Perennial streams that flow continuously throughout the year have a high baseflow component. Box 3.1 Groundwater interactions with estuaries, oceans and wetlands Groundwater can interact with a wide array of surface water features in a variety of catchment settings. Here are some examples: Submarine groundwater discharge (SGD) is groundwater that discharges offshore from either unconfined or confined aquifers (Figure 3.2). In areas where stream flow is low, groundwater can dominate freshwater offshore discharge, largely controlling the distribution of salinity, nutrients and contaminants in the coastal zone. This is of particular importance for coastal geochemical and nutrient budgets. Sites of fresh submarine groundwater discharge can form unique ecosystems on the sea floor. Estuaries can receive groundwater that can be important ecologically due to relatively low salinity as well as transported nutrients. Such seepage can also be a pathway for contaminants to the estuarine environment. For example, the release of shallow acid groundwater generated in areas of acid sulphate soils is a significant coastal management issue. Salt-water intrusion occurs when excessive groundwater extraction causes drawdowns that allow seawater to migrate landwards into the coastal aquifer. This salinises and degrades the groundwater resource, as well as promoting ion exchange and other chemical reactions. Channel dredging, by breaching confining layers, can increase the contact between seawater and groundwater. Sea level rise, waves and tides can also exacerbate this problem. Wetlands can rely on permanent or seasonal groundwater discharge to maintain water levels or moisture conditions. Some wetlands (such as the GAB mound springs) may be wholly reliant on groundwater, and show rapid responses to reductions in groundwater flow such as loss of species diversity and spatial area. Other wetlands may only be partially reliant. Lakes can gain from or lose water to the groundwater system, like streams. Some lakes do both, with one side of the lake receiving groundwater discharge and seepage losses occurring on the other side (Figure 3.4e). Figure 3.2: Idealised freshwater/saltwater interface influenced by submarine groundwater discharge. The discharge may be a composite of recirculated sea water, as well as meteoric and groundwater (Swarzenski et al, 2004) Conjunctive Water Management Framework 44

45 It is important to remember that the assumption that stream baseflow solely equates to groundwater discharge is not always valid. Water can be released into streams over different timeframes from different storages such as connected lakes, wetlands, or from snow. Also, temporary storage within the river bank following the passage of high-flow events (bank storage) can also contribute to the baseflow regime. Also, activities such as stream regulation, discharge or irrigation returns can modify the baseflow signature. Unfortunately, many current definitions assume that baseflow is only derived from groundwater storage. Baseflow is the longer-term discharge into a stream from natural storages, notably sustaining flow between rainfall events. Recognising that there can be multiple natural storages in a catchment, the discharge of groundwater to the stream is termed the groundwater component of baseflow. Box 3.2 The baseflow component of streamflow The relative contribution of quickflow and baseflow components change through the stream hydrographic record. The flood or storm hydrograph is the classic response to a rainfall event and consists of three main stages (Figure 3.3): (i.) Prior low-flow conditions in the stream consisting entirely of baseflow at the end of a dry period; (ii.) With rainfall, an increase in streamflow with input of quickflow dominated by runoff and interflow. This initiates the rising limb towards the crest of the flood hydrograph. The rapid rise of the stream level relative to surrounding groundwater levels reduces or can even reverse the hydraulic gradient towards the stream. This is expressed as a reduction in the baseflow component at this stage; (iii.) The quickflow component passes, expressed by the falling limb of the flood hydrograph. With declining stream levels timed with the delayed response of a rising watertable from infiltrating rainfall, the hydraulic gradient towards the stream increases. At this time, the baseflow component starts to increase. At some point along the falling limb, quickflow ceases and streamflow is again entirely baseflow. Over time, baseflow declines as natural storages are gradually drained during the dry period up until the next significant rainfall event. Figure 3.3: Components of a typical flood hydrograph 45 Conjunctive Water Management Framework

46 a b c d e f Figure 3.4: Different settings for surface water-groundwater connectivity (a) a contiguous losing stream (b) a contiguous gaining stream (c) a perched losing stream (d) a contiguous fluctuating stream, with stream gaining during low-stage period but losing during highstage period (e) a contiguous throughflow lake which both receives groundwater and loses water to the aquifer (f) contiguous gaining lake with preferential groundwater inflow within (after Winter et al, 1998) Conjunctive Water Management Framework 46

47 3.1 Factors Controlling Connectivity The flow of water between a surface water feature and the underlying aquifer is largely controlled by: (i.) (ii.) The difference between the surface water level and the groundwater level. Water moves down gradient from high potential to low. If the stream level is higher than the groundwater level measured within the aquifer, then the stream has the potential to lose water to the aquifer. This is indicated in Figure 3.4a where negative seepage flux occurs because the shallow watertable is lower than the stream stage. Conversely, for groundwater to discharge into a stream channel, the elevation of the groundwater surface near the stream must be higher than the elevation of the river stage, such as in Figure 3.4b; The hydraulic properties and features of the aquifer, as well as the geological material separating the aquifer from the surface water feature. If a river has a coarse gravel bed, this would allow a high degree of interaction between the river and the underlying aquifer, as gravels can transmit water efficiently. If the base of a lake consists of a thick sequence of clay, this is likely to restrict movement of water. This is because the direction and magnitude of seepage flux is based on Darcy s Law: Q dh = K Equation 3.1 A dl where Q is the flow of water (volume per unit time), A is the cross-sectional area of the porous medium through which flow occurs (eg the stream bed), dh/dl is the hydraulic gradient where dh is the change in hydraulic head (or measured water level) along the distance dl of the groundwater flow line, and K is the hydraulic conductivity of the material. Groundwater can move towards the stream if the hydraulic gradient is positive in the sense that the groundwater potential further from the stream is higher than that closer to the stream. The parameter K describes the rate at which water can move through the geological material, and this is largely defined by texture. Coarse grained sediments such as gravel or sand have a high hydraulic conductivity so can readily transmit water, in contrast to much lower flow rates in finer grained material such as silt or clay. Also hydraulic conductivity can vary significantly with the direction of water flow. The hydraulic conductivity in the vertical direction (Kv) in aquifers can be several orders of magnitude lower than that in the horizontal direction (Kh). This is because the interlayering of finer-grained clays and silts impedes vertical water movement, while laterally extensive sand and gravel deposits enable high rates of horizontal flow. Hence, the rate of groundwater movement near the stream is dictated by variations in hydraulic conductivity of the surrounding geological material. This can lead to preferential groundwater flowpaths within more transmissive parts of a sedimentary sequence, as indicated in Figure 3.4f. In alluvial sequences, paleochannels infilled with coarse sediments can provide opportunities for localised enhanced connectivity. In contrast, sequences of low conductivity material such as clays and mudstones can act as barriers for groundwater flow, becoming aquitards or confining beds. These can impede the flow of groundwater from (or to) any deeper confined aquifers. Although, streams are commonly associated with a floodplain of alluvial sediments, in upland 47 Conjunctive Water Management Framework

48 areas there may be direct contact with groundwater systems developed in fractured rock systems. In this setting, preferential flowpaths can be developed in zones of intense fracturing and/or weathering. In karstic terranes, carbonate dissolution can result in extreme interactions of conduit flow where the stream disappears into the aquifer to re-emerge further downstream. Seepage flux can also be controlled by the hydraulic properties of the stream bed as well as the properties of the surrounding aquifer. Deposits on the stream bed such as mud veneers or algal mats can significantly impede the flow of groundwater. As seepage flux depends on the relatioship between stream and groundwater levels, the factors that affect these water levels will also affect connectivity. Groundwatersurface water interactions can change in time and space in response to natural factors such as climate. However, catchment development and management can also significantly change stream-aquifer connectivity over time. Specific activities that can influence connectivity include: (i.) (ii.) (iii.) (iv.) (v.) (vi.) Stream regulation where flow is controlled by infrastructure such as dams, locks or weirs. Releases from surface water storages for downstream users can make up the bulk of streamflow and artificially maintain a high stream stage during dry periods. This can have the effect of reducing inflows in gaining reaches or increasing stream losses in losing reaches. Return flows can artificially maintain stream stage during dry periods. These include direct discharges, such as from sewage treatment plants, industrial outfalls, power generating facilities, mine dewatering activities or seasonal return flows from drainage of irrigation areas; Surface water extraction from the stream for consumptive uses such as irrigation, urban supply or industry can lead to lowering of the stream stage relative to surrounding groundwater levels. This includes artificial diversion of water out of the stream as part of inter-basin transfer schemes; Groundwater extraction can be sufficient to lower the watertable and decrease or reverse the hydraulic gradient towards the stream. Interactions can be altered due to pumping where a gaining stream receives reduced discharge due to interception of groundwater that would have naturally entered the stream (Figure 3.5b). In some cases, groundwater pumping can reverse flowpaths near the stream (Figure 3.5c). This latter scenario is referred to as induced recharge as the stream becomes losing; Land development, such as urbanisation or irrigation development can significantly alter the water budget in the floodplain. Artificial drainage can induce rapid runoff and reduce aquifer recharge. This can lower the watertable and alter the hydraulic gradient with the stream. Irrigation accessions can do the opposite and cause the watertable to rise; Land cover change, such as clearing, reafforestation or replacement of crop type, can significantly alter evapotranspiration rates. For example, broad scale clearing of native vegetation that are efficient interceptors of soil water has resulted in greatly enhanced recharge in parts of Australia. This is reflected in higher water tables and increased influx of groundwater to streams. In areas of shallow saline groundwater this has increased stream salt loads. Conversely, plantation forestry can increase plant water use and reduce the baseflow component of streamflow; Conjunctive Water Management Framework 48

49 (vii.) (viii.) Engineering or mining activities such as straightening and lining the stream can drastically alter connectivity. Such works are commonly undertaken in urban areas and isolate the stream from the aquifer. Levees for flood control can change how and where seepage to the aquifer occurs during high flow events. Also, alluvial mining and dredging activities can alter stream geomorphology by deepening channel incision or removing or mixing bed deposits; Global warming due to increased levels of gases such as carbon dioxide and methane in the atmosphere is projected to change the magnitude and variability of rainfall across Australia. This will have impacts on a range of elements of the water budget for catchments, including surface runoff, groundwater recharge and seepage flux. 49 Conjunctive Water Management Framework

50 Figure 3.5: Effects of groundwater pumping on river-groundwater interaction (a) natural groundwater discharge (b) reduced discharge and (c) induced recharge conditions, after Winter et al, (1998) Conjunctive Water Management Framework 50

51 3.2 Spatial and Temporal Scales Scale issues in time and space are a significant issue in the assessment and management of stream-aquifer connectivity. In a spatial context there are three main scales relating to connectivity (Table 3.1): (i.) (ii.) (iii.) Catchment-scale, where the stream is placed in context with the overall hydrogeological setting of the catchment; Feature-scale, at the level of individual surface water features (eg. a lake or a stream reach); Site-scale, where site-specific studies provide insights into processes particularly at the stream-aquifer interface. There is a need to identify the overall hydrogeological setting for a surface water feature such as a stream. This is because hydrogeology can change across the catchment and there can be many groundwater flow systems developed which have the potential to interact with the stream, either directly or indirectly. A groundwater flow system is defined by a recharge zone and a discharge zone and is separated from other groundwater flow systems by groundwater divides. In recharge zones there is a component of groundwater flow that is downward. In discharge zones, the vertical groundwater flow direction is upward. Groundwater flow systems can operate at different scales and can overly each other (Figure 3.6). In local flow systems, groundwater flow paths are relatively short (say <5 km), where discharge is typically in the lowland adjacent to the more elevated recharge zone. Deeper regional flow systems have much longer flow paths where the recharge and discharge zones can be separated by tens (or hundreds) of kilometres. In addition to geology, topography plays a significant role in the scale of groundwater flow systems. Local flow systems dominate in areas of pronounced topographic relief, whilst regional flow systems develop in flat-lying landscapes. As local flow systems are the shallowest and the most dynamic, they tend to have the greatest interaction with surface water features. However, in the more subdued lowland parts of catchments, discharge from intermediate to regional-scale flow systems can be significant. Figure 3.6: Groundwater flow systems of varying scale local, Intermediate and regional (Toth, 1963) 51 Conjunctive Water Management Framework

52 Also connectivity needs to be viewed at the catchment level as management targets as well as monitoring and reporting operate at this scale. Water management units (both surface water and groundwater) tend to be at this scale, so that connectivity properties need to be aggregated to this level to be incorporated into water management plans. Similarly, water quality targets (such as end-of-valley salinity targets) also operate in the catchment context. Table 3.1: Spatial scales in stream-aquifer connectivity Scale Typical Units Relevance Catchment-scale Regional >100 km 2 Hydrogeological setting Water management areas Catchment management targets Catchment monitoring and reporting Feature-scale Intermediate 1-100km Water management decisions Environmental planning Site-Scale Local <100 m Process studies Ecosystem dependencies Water quality protection Connectivity also needs to be assessed at the feature level, in terms of individual surface water features such as lakes or stream reaches. This is because stream-aquifer connectivity can change significantly from reach to reach. As an example, Figure 3.7 shows the downstream changes in seepage in a typical Murray-Darling Basin catchment. Also, operational decisions are typically made at the reach-scale. For example, licencing and allocation of groundwater entitlements can be based on the likely impacts on the nearest stream reach. Mitigation of salt loads from groundwater discharge can involve mapping management zones on a reach-by-reach basis. Management plans can be developed for individual surface water features such as wetlands or lakes, particularly for the protection of important ecosystems. Hydrogeologists tend to focus at the feature scale, but there is a need to rescale to a finer resolution (Woessner, 2000). Stream-aquifer processes are commonly much more complex than that presented in the schematic cross-sections of Figure 3.4. This complexity can have important consequences. Investigations at the site-scale have historically been undertaken to resolve hydraulic, biological and chemical processes that relate to water quality issues (such as protection from contamination) or aquatic ecology. This involves direct investigation of the hyporheic zone. The hyporheic zone is the portion of the saturated zone underlying and beside a surface water feature where mixing of surface water and groundwater occurs (after Woessner, 2000). Changes in pressure gradients (and thereby seepage flux) can occur at fine scales along the stream bed. Such changes in gradients can occur near areas of positive relief on the stream bed such as point bars, boulders or ripples. In pool and riffle sequences, localised down-welling can occur upstream with up-welling at the riffle base (Figure 3.8a). Also, water flow in the hyporheic zone can be controlled by the geometry and Conjunctive Water Management Framework 52

53 position of the stream channel within the floodplain sequence and the groundwater flow regime (Woessner, 2000). Figure 3.8b shows shallow subsurface flow directions established in such as meandering stream. This shallow mixing of groundwater and surface with complex near-surface flow directions can make the investigation of seepage flux problematic. A particular issue is differentiating between this mixing and the actual groundwater flux in a gaining stream. Coastal Drainage Murray- Darling Basin standing water level Murray/ Barwon Upland streams gaining baseflow from fractured rock aquifer. Gaining Narrow alluvial valleys with high rainfall, shallow groundwater levels and highly-connected river reaches Flux in both directions (Generally net losing) Wide, arid, alluvial plains with deep groundwater levels and disconnected river reaches. Losing Finer alluvial aquifer materials and structural controls lead to shallower groundwater and connected reaches. Flux in both directions (Generally net gaining) Connected Disconnected Connected Figure 3.7: Schematic catchment section showing differences in connectivity for different river reaches in the Murray-Darling Basin (Braaten and Gates, 2002) Figure 3.8: Surface water-groundwater interaction in the hyporheic zone associated with (a) a pool and riffle sequence and (b) stream meanders (Winter et al, 1998) Like the spatial context, variations in time scales relating to connectivity need to be recognised. Surface water groundwater interactions can be viewed over short, medium to long-term time frames (Table 3.2) 53 Conjunctive Water Management Framework

54 A long-term perspective needs to be taken when evaluating stream-aquifer connectivity. This is because groundwater input to streams can be derived from intermediate to regional-scale flow systems (Figure 3.6) where the transit time between recharge and discharge can span decades and longer. The response to changes in catchment management (such as land use change or groundwater development) can also take a long time to manifest as changes to groundwater discharge and stream flow. This is the case if such changes have occurred within the catchment but some distance from the stream. As groundwater-surface water interactions are sensitive to changes in the catchment water balance, long-term trends in climate (such as decreased rainfall reliability or increased evaporation) need to be accounted for. Table 3.2: Time scales in Stream-Aquifer Connectivity Scale Typical Units Relevance Long-term decadescenturies Climate variation Land use change Groundwater extraction Medium-term seasons-years Water management cycle Allocation and planning Water quality protection Short-term days-months Episodic events Evapotranspiration Tidal effects Ecosystem dependencies Processes that effect stream-aquifer connectivity over the medium-term are important as these timeframes coincide with water management and operations. The evaluation of seasonal or annual fluctuations in groundwater inputs to streams is critical in water allocation, environmental water provisions and water quality management (such as salinity mitigation). In certain settings, the understanding of short-term (eg daily) fluctuations in seepage flux is critical. In the arid zone, flooding of ephemeral streams can be an important recharge mechanism for the underlying aquifer that requires understanding of irregular and short-lived processes. Understanding tidal effects is important in assessing groundwater-surface water interactions in coastal areas. Evapotranspiration, particularly by near-stream vegetation that can access shallow groundwater, can cause daily variations in watertable depth expressed as fluctuations in seepage flux. An understanding of these processes is important when evaluating groundwater dependent ecosystems. 3.3 Connectivity Categories There are many different approaches to categorising the connectivity between surface water features and their associated groundwater systems. This is reflected in a wide range of terms currently being used to describe connectivity. In general, surface water-groundwater interactions can be classified on the basis of the four key aspects Conjunctive Water Management Framework 54

55 of contiguity, seepage direction, conductance and impact. Figures 3.4 and 3.9 outline this classification in the case of streams, but this can equally be applied to other surface water features. Contiguity describes whether or not the groundwater system is in direct hydraulic contact with the surface water feature. A stream is contiguous with the groundwater system if the water-saturated zone is continuous between the two. This is consistent with the general use of the term which describes when two entities are in contact and share a common boundary, in this context a hydrological one. Figure 3.4a shows a situation where there is a direct hydraulic connection between the stream and unconfined aquifer via the shallow watertable. This situation is commonly called connected in many classifications (eg Winter et al, 1998). In contrast, a stream is perched if an unsaturated zone separates it from the underlying groundwater system, as indicated by the example of Figure 3.4c. This situation is commonly termed disconnected which is misleading as it suggests that there is no possibility of actual movement of water between stream and aquifer. In Figure 3.4c, this is not the case as downward infiltration from the stream through the unsaturated zone has formed an underlying watertable mound. It can be difficult to explain the concept that a disconnected stream can still lose water to the aquifer. Whether a connected water resource is contiguous or not is significant (Table 3.3). Pumping groundwater from a contiguous stream-aquifer system will impact on the local stream flow hydrology, reducing water availability for surface water users and riverine ecosystems. Pumping of shallow groundwater near a perched stream generally does not affect stream flow, although unsaturated zone storage of water may play a role. 55 Conjunctive Water Management Framework

56 l 1: Contiguity Contiguous Stream is hydraulically linked to the groundwater system by a continuous watersaturated zone Perched Stream is hydraulically separated from the groundwater system by an unsaturated zone Level 2: Seepage Direction Gaining Stream receives water from the groundwater system Fluctuating Seepage direction varies through time Variable Seepage direction varies along stream reach Losing Stream contributes water to the groundwater system Level 3: Conductance High Conductance Highly transmissive geological material Medium Conductance Moderately transmissive geological material Low Conductance Weakly transmissive geological material Level 4: Impact High Impact >10% impact on long-term management target Medium Impact 1-10% impact on longterm management target Low Impact <1% impact on long-term management target Figure 3.9: Categorisation of stream-aquifer connectivity Table 3.3: Impacts of stream-aquifer connectivity (modified from REM, 2002) Contiguity Seepage Direction Synonyms Potential impact of groundwater on surface water Contiguous Gaining Effluent High Upwelling Groundwater-fed Aquifer discharge Contiguous Losing Influent Medium Down-welling Stream-fed Aquifer recharge Contiguous Underflow Low Medium Perched Losing No Impact Medium Contiguous Fluctuating Variable Gaining/Losing Medium Medium Seasonal Contiguous Throughflow Flowthrough Medium Medium Potential impact of surface water on groundwater Low High Conjunctive Water Management Framework 56

57 Connected water resources can also be classified in terms of the direction of seepage. However, this is not straight forward as seepage direction can be variable in both space and time due to changes in the relativity of the stream stage to the shallow watertable. Gaining streams which receive inflows of groundwater and losing streams which leak water to the underlying aquifer are two ends of the spectrum. In many studies, gaining streams are also called effluent and losing streams are influent. Situations intermediate to these end-members are common and include fluctuating seepage streams where the seepage direction changes through time. These are also commonly called variably gaining/losing as they either receive from or lose water to the groundwater system, depending on the time of year. Seasonal effects can alter the type of connection between groundwater and surface water, with streams gaining in summer months and losing in winter in some regions and vice-versa in other regions. Streams are termed variable seepage, if the direction of seepage flux varies, so that one part of the reach loses water and another part gains groundwater. These are called throughflow in the situation where groundwater flow is perpendicular to the stream and groundwater enters the stream on one side but stream leakage occurs on the other. Figure 3.4e shows this setting for a throughflow lake. Underflow streams are a special situation where groundwater flows parallel to, but does not actually discharge into the stream. As we are dealing with a spectrum, rather than distinct independent categories, it is suggested that a nominal threshold of 70% is used (eg. stream reaches are termed gaining if they receive groundwater for more than 70% of the time for more than 70% of their length). Contiguous streams can span the whole spectrum of seepage direction from gaining to losing depending on the relative elevation of the surrounding watertable. Perched streams tend to be losing, as by definition the watertable is deeper than the stream stage. However, it is possible for a perched stream to be gaining over the short-term, due to the release of perched bank storage immediately following a high-stage event. This can occur for ephemeral streams where underlying permeability barriers (such as clay horizons) encourage shallow laterally outward subsurface flow during floods which become return flows during the flood recession. Figure 3.4d shows this bank storage mechanism for the contiguous case. Classification can also be applied on the basis of conductance, which is the ability of the geological material to transmit water. The domain is the material through which groundwater flows through in the groundwater flow system, that directly interacts with the surface water feature. This is inclusive of both the aquifer itself and any intervening geological features, such as stream bed profiles which may impede or encourage interaction. Hence, a systems approach is taken where classification is at the scale of the overall groundwater flow system, accounting for the entire groundwater flow path between aquifer and stream. Simple categories of high, medium and low-conductance can be used to describe the extent of seepage flux (Figure 3.9). Table 3.4 provides some guidance for categorisation. Highly conductive streams are associated with highly permeable lithologies (such as gravels) that allow large seepage fluxes to occur and reflected in rapid hydrological responses. In contrast, weakly conductive streams have very low seepage flux due to the presence of extensive low-permeability material (eg clay). In some studies, this end-member is termed an insulated stream where the reach neither contributes water to, nor receives 57 Conjunctive Water Management Framework

58 water from the saturated zone, due to an intervening impermeable horizon. The seepage flux thresholds defined in terms of m 3 /d/km in Table 3.4 are those suggested in a study of stream-aquifer connectivity in the Murray-Darling Basin (SKM, 2003). This approach requires extrapolating flux rates over the stream reach using known stream dimensions of width and length. When describing seepage flux for other surface water features (such as lakes and wetlands) the units m 3 /d/km 2 would be more appropriate. Also, the potential for flux is assessed, so semi-arid streams can still be deemed to be highly conductive although flux may not exceed 1000 m 3 /d/km. This recognises that the existing seepage flux relates to water availability. In this context, the ratio of seepage to the total flow regime is a better criterion. Table 3.4: Typical features of various conductance categories for stream-aquifer systems Features High Conductance Moderate Conductance Low Conductance Typical lithologies Gravels, coarse sands, karst Fine sands, silts, fractured rock, basalt Clay, shale, fresh unfractured rock Typical hydraulic >10 m/d m/d <0.01 m/d conductivities (K) Typical seepage flux >1000m 3 /d/km m 3 /day/km <10 m 3 /d/km Ratio of seepage to total flow Typical near-stream Response Times > <0.1 Days-Months Years Decades+ Lastly, connectivity can also be classified in terms of the potential impact on the combined water resource and its use and management. In this respect, a relative classification (high, medium, and low-impact) is the simplest approach to describe the significance of stream-aquifer connectivity for water resource management. When assigning an impact category the following aspects need to be considered: (i.) (ii.) (iii.) (iv.) Both the water quantity and water quality issues of the catchment need to be included in the analysis. Accounting for groundwater discharge to streams is important in the water allocation process, to avoid the double accounting of the water resource. Equally, groundwater discharge can also have an impact on stream water quality, in terms of ingress of salt, acid, nutrients or contaminants or changes to the in-stream temperature regime. In this regard, the connectivity for a stream reach may be deemed to be high impact despite having a relatively low seepage flux, because of the input of very poor quality groundwater. Connectivity can have implications for both the surface water resource and the groundwater resource. A stream can be losing water to the underlying aquifer which may be viewed as a minor transmission loss, but such seepage can be providing a valuable mechanism for groundwater recharge. The likely impacts on all users of the resource need to be assessed. This includes environmental needs (the ecosystem dependencies of both surface water and groundwater systems) as well as future consumptive users. A long-term (>50-year) view of the likely impacts should be taken as well as accounting for the effects within a seasonal or annual timeframe. Depending Conjunctive Water Management Framework 58

59 (v.) on the catchment setting, the management impacts associated with changes to connectivity may only manifest themselves after several decades. The significance of connectivity needs to be assessed in terms of the overall objectives of the catchment plan, particularly in terms of management targets. The thresholds demarcating the different impact categories are highly debatable. Nominally, connectivity can be viewed as low-impact if the predicted effect on a long-term (>50 years) target is <1%. Likewise, a highimpact connectivity has a highly significant impact on whether a long-term catchment management target can be met, say >10%. This prioritisation approach (albeit with different thresholds) has been proposed in a national framework for managing the impacts of groundwater and surface water interaction (SKM, 2006). The overall stream-aquifer connectivity can be described on the basis of conductance and impact. Surface water and groundwater systems are highly connected if attributes of high conductance and/or high impact are evident. A highly connected system is indicated by: short-term near-stream response times, with the response in one system (eg stream flow) due to change in the other (eg watertable decline) occurring over a timeframe of days to months; or seepage flux having a significant (>10%) impact on catchment management targets, particularly over the medium-term (eg 1-5 years) This definition is similar to the approach used by the NSW for developing operating rules for highly connected systems, which uses the definition: Highly connected river-aquifer systems are ones where groundwater extraction results in equivalent streamflow depletion within a relatively short time frame of days to weeks Groundwater-surface water interactions need to be assessed and managed for highly connected water resources to protect dependent economic, social, and environmental values. Examples of highly connected water resources include: (i.) (ii.) (iii.) (iv.) Unregulated systems where groundwater seepage defines the low-flow stream conditions; Shallow alluvial systems where groundwater recharge is reliant on leakage from the overlying stream; Where seepage of saline groundwater contributes significantly to in-stream salinity; Lakes (or wetlands) where the input of nutrient-rich groundwater can initiate algal blooms. Surface water and groundwater systems are weakly connected if: (i.) (ii.) Potential movement of water between these systems is limited and the nearstream response times is slow (eg decades); or Seepage flux has no significant impact (say <1%) on water quantity and/or quality over the long-term (>50 year) timeframe. 59 Conjunctive Water Management Framework

60 Examples of weakly connected water resources include where: (i.) (ii.) Stream and aquifer is separated by impermeable layers (such as clay) that impede the movement of water; The hydraulic gradient between stream and aquifer is low. Weekly connected water resources still need to be assessed and monitored in terms of changes in hydraulic conditions. For example, watertable mounding due to land use change (such as irrigation development) can alter hydraulic gradients and induce groundwater discharge to the stream. Also weakly connected water resources can be used to advantage. For example, the aquifer component could be used in water banking without significant losses from storage due to leakage to surface water features. The significance of connectivity is coached in terms of two key questions: (i.) (ii.) Does the seepage flux between stream and aquifer have a role (either positive or negative) in meeting existing management targets that relate to water quality or quantity? This relates how existing flux rates contribute to management goals and a 10% threshold is suggested in terms of defining significance. For example, if there is a 10% variance when seepage flux is included in assessment and when it is not, then the system is deemed to be highly connected; Will changes in seepage flux due to predicted changes in the surface water or groundwater regime have a significant impact on water quality and quantity targets over a long-term (>50 year) timeframe? This looks at the potential status for flux and focuses on the effect of future hydrological stresses such as increased water extraction, irrigation accessions, land use change or climate change. Stream-aquifer connectivity is controlled by the relativity between stream stage and the shallow watertable. Both of these can change due to catchment activities, so that post-development connectivity may be quite different to that operating under prior undeveloped conditions. For example, stream regulation can artificially maintain high stream stages and induce stream losses to the underlying aquifer. Excessive groundwater extraction can deepen the watertable so that a previous contiguous stream becomes perched, due to the development of an underlying unsaturated zone. Hence, the categorisation of stream connectivity should be placed in context of the extent of catchment modifications. This involves the use of descriptors such as: (i.) (ii.) Whether the stream is regulated or unregulated involving the artificial manipulation of stream flow using infrastructure such as dams or weirs; Water development terms based on the percentage ratio of water extraction to defined sustainable yields such as weakly developed (<30%), moderately developed (30-70%), highly developed (70-100%) or overdeveloped (>100%). These are the thresholds used in the National Land and Water Resources Audit (NLWRA, 2001), refer Table 3.5; Conjunctive Water Management Framework 60

61 (iii.) Whether the stream (and near-stream environment) is modified or unmodified in terms of works (such as engineering, drainage or mining) which has altered stream morphology. Table 3.5: Development categories for water resource management areas (NLWRA, 2001) Category Description Extraction /allocation 1 No to low levels of resource use, direct management interventions and information requirement is low. 2 Moderately developed, management and resource information requirement is moderate. 3 Close to, or at, their extractions limit and require a high level of management inputs. Resource information and monitoring is vital for these systems. Development depends on putting in place appropriate water markets to move water to higher value use and to provide surplus for development or the environment through efficiency gains. 4 Over-committed in water allocation and/or use-insufficient provision has been made for environmental and nonconsumptive uses, management intervention and information requirements are substantial. Development Examples Status 1 <30% Low development Victoria River (Northern Territory, SWMA) Burnie (Tasmania, GMU) 30 70% Moderate development Mary River (South Australia, SWMA) Ti Tree (Northern Territory, GMU) % Highly developed Pioneer (Queensland, SWMA) Woongarra (Queensland, GMU) >100% Overdeveloped Wimmera-Avon Rivers (Victoria, SWMA) Neuarpur GSPA (Victoria, GMU) 1 Development status is water use as a percentage of sustainable flow regime (surface water) and sustainable yield (groundwater). 61 Conjunctive Water Management Framework

62 Conjunctive Water Management Framework 62

63 4. An Adaptive Management Framework for Connected Water Resources A simple framework for conjunctive water management has been developed to provide a context within which existing groundwater and surface water management can be integrated to provide social, environmental and economic outcomes across industries and regions. The framework is designed to help water managers, water authorities, policy makers, catchment groups, industry groups and others to learn more about evolving water management priorities and requirements to facilitate coordinated responses. 4.1 Aims and Scope A framework is provided for coordinating groundwater and surface water management from a project to a catchment through to a national scale. It recognises and seeks to add value to existing water management practices that aim to improve sustainability of water resources. The framework for conjunctive water management: (i.) (ii.) (iii.) (iv.) (v.) (vi.) (vii.) (viii.) (ix.) Aims to provide a consistent national approach to conjunctive water management in Australia in line with the principles of the National Water Initiative; Promotes decision-making on the basis of a robust and evolving understanding of catchment processes; Provides information on data sources for the key catchment datasets required for management decisions; Provides an overview of general principles and approaches for categorising connectivity; Facilitates access to tools to assess connectivity as a basis for resource management decisions and to demonstrate the significance of connectivity; Endorses the conceptualisation of key catchment processes and the use of predictive models to support the setting of management targets; Provides options in terms of policies or investments that link the management of groundwater and surface water resources; Allows a coordinated response to changing circumstances through monitoring and review; Identifies the need for governments to coordinate their support roles across jurisdictions and the national level. By defining roles across the board, the framework promotes the coordinating and facilitating of the wide range of voluntary, industry- and community-led approaches to more sustainable integrated water management in rural agricultural and urban settings. It also helps to improve integration of these activities across different scales and across industry sectors. It aims to support individual landholders who wish to make a significant contribution to improving the sustainability of agricultural production and meeting community expectations of environmental, social, and economic outcomes. The framework recognises the diversity in the agriculture sector and provides a means to better integrate industry activities with broader natural resource management processes such as state and regional planning for more integrated water management. 63 Conjunctive Water Management Framework

64 The framework is underpinned by some general principles that were developed from a national workshop on managing connected water resources (Fullagar, 2004). The workshop brought together water experts, managers and users from around Australia to identify strategic directions for realising the opportunities and addressing the issues associated with conjunctive water management. These guiding principles are outlined in Box 4.1. Box 4.1 General Principles of Conjunctive Water Management (Fullagar, 2004) 1. Where physically connected, surface water (including overland flows) and groundwater should be managed as one resource. All surface water and groundwater stores rely (either directly or indirectly) on rainfall for recharge. Identification of new storages within a connected system does not automatically increase the net sustainable yield of that system. 2. Water management regimes should assume connectivity between surface water (including overland flows) and groundwater unless proven otherwise. The Precautionary Principle should apply to protect against potential impacts of surface water-groundwater interactions. For example, a single combined sustainable yield should be used as the basis for the net allocation of surface water and surrounding groundwater resources until: (i) It can be proven they are disconnected; or (ii) Management regimes for those storages are developed to take advantage of respective storage efficiencies and time lags between surface and groundwater flows. 3. Water users (groundwater and surface water) should be treated equally. It is not appropriate to assume a blanket hierarchy between surface water and groundwater licences. Pricing, security, capping, licensing, metering, and defining reliability should be consistent for all water users. 4. Jurisdictional boundaries should not prevent management actions. Discontinuity in government institutional arrangements between (and within) jurisdictions should not be an excuse for failing to identify and address issues associated with connected systems, or for not progressing opportunities associated with conjunctive water management. 4.2 Adaptive Management Approach The framework recognises a need for a simple check list of activities set out in a logical order that provides the opportunity for those involved in water resource management to assess and revise their position within the overall scheme of sustainable water management. The philosophy of adaptive management is followed where policies and practices are continually improved by learning from the outcomes of previous work. The process is iterative and aspects of the management process are revisited and reviewed. Adaptive Management is an approach that involves learning from management actions, and using that learning to improve the next stage of management (Holling, 1978) It is learning to manage by managing to learn (Bormann et al, 1993). A feedback loop is incorporated into the management process. This recognises that there are inherent uncertainties in our understanding of catchment processes Conjunctive Water Management Framework 64

65 (Figure 4.1), the priorities and perspectives of water users, the impact of water management options and future changes and threats. There is constant change in our knowledge about complex natural systems which themselves are dynamic, and community priorities, perceptions and expectations also change (Pagan and Crase, 2004). This means that conjunctive water management needs to be flexible and be able to evolve. Identify Management Setting Monitor and Review Performance Assess Water Resources Conjunctive Water Management Framework Develop and Implement Management Options Understand and Predict Set Management Targets Figure 4.1: An Adaptive Management Framework for Conjunctive Water Use The ideals of adaptive management have recently become popularised in natural resource management. Ludwig et al (1993) provide some practical advice when working towards effective management: (i.) (ii.) 65 Include human motivation and responses as part of the system to be studied and managed; Act before scientific consensus is achieved. Calls for additional research may be delay tactics; Conjunctive Water Management Framework

66 (iii.) (iv.) (v.) Rely on scientists to recognise problems but not to remedy them. The judgement of scientists is often heavily influenced by their training in their respective disciplines, but the most important issues involving resources and the environment involve interactions whose understanding must involve many disciplines; Question claims of sustainability. Claims that basic research will lead to sustainable resource use may lead to false complacency; Confront uncertainty. Effective policies are possible under conditions of uncertainty, but they must take uncertainty into account. Consider a variety of plausible hypotheses about the world; consider a variety of possible strategies; favour actions that are robust to uncertainties; hedge, favour actions that are informative; probe and experiment; update assessments and modify policy accordingly; and favour actions that are reversible. The second point is the premise of the Precautionary Principle: The Precautionary Principle is applied where there are threats of serious or irreversible damage, lack of full scientific certainty shall not be used as a reason for postponing costeffective measures to prevent environmental degradation Rio Declaration on Environment and Development Table 4.1: Conditions for the application of the Precautionary Principle (after Andorno, 2004) Condition Summary Precaution Conjunctive Example Uncertainty of risk Existence of risk cannot be proven Response to situations of potential risk Extent to which near stream groundwater pumping depletes stream flow is not known Scientific assessment of likely harm Serious and irreversible damage (short or long-term) Proportionality of measures Shifting burden of proof Good reason to believe that there might be harmful effects Likelihood of serious or irreversible effects on life and health of individuals, vital natural resources, species preservation, climate, ecosystem balance Measures taken to avoid likely harm should take impact on society into account Those who may cause serious damage show that it is unlikely Definition and evaluation of uncertainties by scientific experts Determination of a threshold of nonnegligible damage Identification of socioeconomic sacrifices required to adapt the precaution, careful evaluation of precautionary measures available and active review Hazard creators assume costs of risk assessment; proof of zero risk is not realistic Quantification of magnitude and timing of stream flow depletion through monitoring, field investigations and predictive models Assessment indicates that groundwater pumping can seriously degrade in-stream aquatic ecosystems particularly during extreme low-flow conditions Consideration of impact of reduced water access by consumptive users during drought period Onus of proof is that aquifer is assumed to be connected to stream, unless proven otherwise Conjunctive Water Management Framework 66

67 4.3 Framework Components Figure 4.1 outlines the framework in terms of a general process that can be followed when taking a conjunctive water management approach regardless of the size and nature of a catchment and the water issues that need to be addressed. These adaptive management processes are well established and have been suggested in other natural resource management arenas, including groundwater (IAH, 2004) and the coastal zone (Bennett and Lawrence, 2002). These steps are outlined below. Identify Management Setting The first step is an analysis of the key features that define the management of land and water in the catchment. This identifies the setting, by scoping out the catchment management problems and the factors that have an impact on their solution. This includes identifying existing: (i.) (ii.) (iii.) (iv.) Catchment Issues, answering the question of what are the key issues facing the sustainability of land and water resources in the catchment. The nature and scope of conjunctive water management in a catchment can be tailored to address these management issues, whether they are over-extraction of water, river salinity or ecosystem health. The scale of the issues must be understood to allow for a prioritised approach; Water Users, as the potential impacts on water users need to be addressed and for water users to be engaged in the planning process. Often catchment issues are perceived differently by different groups of people and different perceptions about their severity are easily formed; Resource Development, defining the degree of extraction of surface water and groundwater in the catchment and the nature and extent of existing infrastructure. The extent of the use and development of water resources in a catchment dictates how conjunctive management can be applied. This also relates to the extent and nature of land use and development; Planning and Policy, to outline the existing legislation, policy and rules that define or impact on operational water management. The existing administrative environment can provide opportunities or constraints to implementing conjunctive water management and can involve many government and non-government agencies. These issues surrounding the identification of the management setting are explored further in Chapter 5. Assess Water Resources The focus of this step is to acquire the baseline information to describe the characteristics of surface water and groundwater systems of the catchment, and their interactions, both spatially and temporally. This can include: (i.) (ii.) Collation and interpretation of existing catchment datasets that can be used to describe the hydrological and hydrogeological attributes. Catchment-wide datasets such as climate parameters (rainfall, evaporation), topography, surface drainage, geology/geomorphology and land use need to be collected in the first instance; Collation and interpretation of existing monitoring that can describe the spatial and temporal variability of groundwater and surface water systems. The key 67 Conjunctive Water Management Framework

68 (iii.) databases are the available time series record of water levels, flow and quality parameters; Identification of key information gaps and the initiation of specific studies to clarify key processes. There is a wide range of methods available to assess the nature and degree of the interaction between surface water and groundwater systems. Box 4.2 summarises the main categories of these assessment tools, with additional details provided in the Appendices section of this report. Chapter 6 provides an overview of the general assessment process. Box 4.2. Summary of tools for assessing connectivity Field Observations, where an initial reconnaissance can highlight hotspots where groundwater is interacting with surface water features. Seepage Measurement, the direct measurement of water flow at the surface watergroundwater interface using seepage meters and similar devices. Ecological Indicators, mapping of specific vegetation communities or biota indicating groundwater discharge to surface water features. Hydrogeological Mapping, to define the geological or geomorphological features such as faults, facies changes or river morphology that can control groundwater flow, and to provide the general hydrogeological setting. Geophysical Survey, the use of geophysical and remote sensing technologies such as airborne electromagnetic (AEM), radiometrics, seismic waves, electrical charge, or satellite imagery to map catchment properties. Hydrographic Analysis, the use of techniques such as recession analysis or baseflow separation to analyse the monitoring record of water levels or flows. Hydrometric Analysis, based on Darcy s Law and investigating the hydraulic gradient between aquifer and surface water feature and the hydraulic conductivity of the intervening aquifer material. Hydrochemical Studies, the interpretation of the chemical constituents of water such as isotopes, radon or chlorofluorocarbon (CFC) involving the application of environmental isotopes. Temperature Studies, the use of time series monitoring of temperature in both the surface water and groundwater systems. Artificial Tracers, the monitoring of the movement of an introduced tracer such as fluorescent dye. Water Budgets, such as river reach water balances where the water inputs and outputs are estimated. Understand and Predict This step follows on from the data collation and interpretation made in the assessment process to develop a conceptual understanding of stream-aquifer interaction. A conceptual model describes the essential function and behaviour of surface water and groundwater systems in a catchment. It summarises the current understanding of the processes, dependencies and impacts on the water resource. The conceptual model forms the foundation for further field investigations as well as the development of predictive models. These are essentially mathematical models that contain equations that represent the physical processes of water movement in a catchment. The value of constructing a predictive model is that it can be used as a tool to quantify the likely impact of different conjunctive water management options. Conjunctive Water Management Framework 68

69 Some outcomes of this conceptualisation and predictive modelling process include: (i.) (ii.) (iii.) (iv.) (v.) (vi.) Classification of stream-aquifer linkages, and indication of the potential impacts on water quantity, quality or beneficial use; Depiction of the nature and geometry of groundwater flow systems and their interaction with surface water features. Models can test the existing hydrogeological understanding for a catchment, and are also useful as a visualisation and communications tool; Quantification of the catchment water balance and how it changes through time. The magnitude and dynamics of seepage flux is placed in context with other water balance components (such as rainfall and evapotranspiration); Predictions in terms of how seepage flux may change based on proposed changes to catchment condition (such as climate change, increased groundwater extraction); Estimates of the likely impact of implementing different options of conjunctive water management. Models can be used as optimising tools in the design of both policy and on-ground management options; Identification of key information gaps that need to be addressed. This includes planning of further field investigations or monitoring to quantify connectivity. Models can also be used in the analysis of data sensitivity and uncertainty to help define the priority datasets. Chapter 9 provides further information on the principles and processes underlying the use and development of conceptual and predictive models. Set Management Targets An essential step in a conjunctive water management approach is the setting of management targets in the catchment. These define the goals towards which management is focussed, and are directed at the management issues defined for the catchment. Quantification of these targets is based on the understanding of catchment processes, developed through baseline assessment that can lead to conceptualisation and construction of predictive models. As targets depend on the management issues being addressed, they can be many and varied. Some typical catchment targets include: (i.) (ii.) (iii.) The sustainable yield limit placed on allocation of surface water and groundwater resources; The end-of-valley stream salinity target expressed at a key gauging station; Minimum flows or flow duration curves developed for meeting environmental water requirements. The process and issues surrounding the setting of management targets are discussed in Chapter 10. Develop and Implement Management Options 69 Conjunctive Water Management Framework

70 There is a suite of options available for implementing a conjunctive water management approach. The options adopted will be defined by: (i.) (ii.) (iii.) (iv.) The management issues that have been identified as requiring addressing within the catchment; The current understanding of catchment water processes, as developed through baseline assessment, conceptualisation, field assessment and possible construction of predictive models; The management targets identified for the catchment; Availability of resources in terms of time, budget and expertise. An appropriate mix of both policy and investment options can be implemented. Policy options that recognise or take advantage of the linkages between groundwater and surface water resources can include strategies such as licencing and allocation, water trading or risk management approaches, buffer zones or planning rules. Investment options involve on-ground works such as water banking infrastructure (such as Aquifer Storage and Recovery schemes), groundwater interception schemes, or groundwater pumps to provide supplementation of stream flow. These conjunctive water management options are covered in more detail in Chapter 11. Monitor and Review Performance A well-designed monitoring programme is part of a conjunctive water management approach. The current understanding of catchment processes, evolved from the processes of assessment, conceptualisation and predictive modelling can be used to design a cost-effective and robust monitoring programme. Monitoring usually involves collecting key indicators that relate to the priority management issues at appropriate spatial and temporal resolutions. Examples include: (i.) (ii.) (iii.) (iv.) (v.) Surface water gauging of flow, level and quality (eg salinity, nutrients); Groundwater levels and quality; Water usage from extraction points; Land use and land use practices; In-stream ecosystem health such as indicator species. Monitoring is the reality check for managers. This requires reviews on a regular basis to: (i.) Evaluate catchment conditions and identify any emerging management issues that may need addressing; (ii.) Identify information gaps that when addressed would improve assessment of catchment processes; (iii.) Validate and potentially update the understanding and conceptualisation of key water processes; (iv.) Help verify or improve the calibration of any predictive models; (v.) Evaluate progress towards the management targets identified for the catchment; (vi.) Test the appropriateness and performance of the conjunctive water management options implemented. Conjunctive Water Management Framework 70

71 Chapter 12 provides further information on the monitoring and review component of the framework. 4.4 Roles and Responsibilities A primary function of the framework is to identify who does what, where and how. It seeks to clarify and recognise the scales of involvement and complementary roles for participants at the levels of catchment and regional, and Commonwealth, State and Territory, and local government. These roles are not new or constructed, but they are a reflection of existing and emerging roles. The framework also promotes strong and effective partnerships between the various stakeholder groups in the catchment. Such partnerships are needed for conjunctive water management to become an effective tool for achieving integrated water management goals and bringing practical benefits to water users. Role of Water Users The framework enables water users to view their activities in a catchment sense. Users can support the progressing of conjunctive water management through: (i.) (ii.) (iii.) (iv.) (v.) Representation of local (community and environmental) needs and objectives; Development of locally applicable conjunctive water management options (eg water trade); Identifying potential trade-offs (eg less water if there are more licence flexibilities) at the regional level; Management options that reflect an understanding of how communities will be affected by different options (local environment and socio-economics); and Local critique and quality assurance to technical outputs (eg identifying where poor reporting/monitoring of water usage may skew resource modelling), (Fullagar, 2004). Role of Catchment and Regional Groups Catchments and regions are increasingly recognised as the most appropriate operational scale for managing natural resource issues. Governments have focused on this scale to achieve tangible environmental improvements over the medium to longer term. Examples include the Murray Darling Basin Commission (MDBC) Integrated Catchment Management Strategy and a range of regional-specific State plans and strategies which have been funded through NAP and NHT. As a result, most efforts at natural resource management priority setting and monitoring are being undertaken at the catchment level. Catchment planning should be based on the best available science and be inclusive of the needs of the community that live within the region or catchment. It should also be responsive to the expectations of the communities that live outside the region. Catchment groups can: (i.) Participate in catchment conjunctive water planning that is cooperative, makes effective use of best science information, is inclusive of all stakeholders, and fully integrates social, economic and environmental objectives; (ii.) Support the delivery of community-agreed objectives for integrated groundwater-surface water management outcomes; 71 Conjunctive Water Management Framework

72 (iii.) (iv.) (v.) (vi.) (vii.) Support capacity building activities and ensure the necessary resources are in place to enable goals to be met; Form strategic partnerships and encourage industry to participate in and deliver on planning processes and outcomes for conjunctive water management; Actively seek information and support from reliable sources (including relevant biophysical and economic expertise) and apply it to the catchment water resources planning and management process; Prepare catchment integrated water management plans in sufficient detail to enable private landholders to link to catchment-scale outcomes; Regularly monitor and publish the progress towards meeting catchment goals and objectives. The framework enables landholders to view their farm-based activities in a catchment sense. It enables communities to have confidence in regional water planning and its ability to address broad national issues of integrated water management and natural resource management outcomes. Role of Governments The conjunctive water management framework is consistent with the objectives of the National Water Initiative (NWI). The NWI was brought about by governments recognising that water availability has always been important in Australian life and management of water resources is extremely challenging. The initiative foreshadows expanded water trading across States borders, increased security of water entitlements for land owners, introduction of new arrangements for environmental flows and greater recognition of the connectivity between surface water and groundwater resources. The framework seeks to build on these existing water resources management initiatives and to facilitate the development and implementation of conjunctive water management. Australia, State and Territory governments share a range of roles that would support conjunctive water management. The role of governments should be consistent with existing legislation and with intergovernmental initiatives, such as the NWI and other water reforms. This is the case even for activities that do not rely on legislation. Assessment against National Competition Policy principles is useful in considering whether government intervention is applied in a consistent manner that does not impinge on private enterprise. Table 4.2 summarises the proposed roles of governments into five main categories: (i.) (ii.) (iii.) (iv.) (v.) Providing and facilitating water user access to education and information on conjunctive water management; Coordination; Developing integrated water management policy; Research and development; Monitoring and evaluation. There are also some roles that are unique to a particular sphere of government depending on the responsibilities and scale at which the action is needed, for example: The Australian Government has a strong role in: Conjunctive Water Management Framework 72

73 (i.) (ii.) (iii.) (iv.) (v.) (vi.) (vii.) (viii.) Providing leadership, coordination and support through a mixture of policies and incentives to drive the widespread adoption of conjunctive water management; Supporting regional bodies to engage water users to contribute to integrated water management that support natural resource and environmental outcomes; Promoting a consistent intergovernmental approach to conjunctive water management in agriculture and that this is consistent with major natural resource policy direction in other sectors such as mining, fisheries, forestry and urban; Assessing and supporting national natural resource management priorities; Promoting a coordinated approach to conjunctive water management across industry sectors; Assessing the impact on water resources and management by decisions in other policy sectors (such as immigration, defence, transport, regional development); Actively participating in water resource issues that cross jurisdictional boundaries; Promoting Australia s approach within the international water arena. State and Territory governments, with constitutional responsibility for water resource management, are in a primary position to influence natural resource management at the catchment level and to support integrated water management by: (i.) Providing leadership and support through a mixture of State water policies and incentives to drive the widespread adoption of conjunctive water management; (ii.) Provide research and development support to primary producers for designing more sustainable production systems and practices; (iii.) Supporting regional bodies to engage water users to contribute to landscape natural resource and environmental outcomes through integrated water management linked to sufficiently detailed natural resource management plans; (iv.) Assessment of, and support for, state and regional natural resource management priorities; (v.) Working across state boundaries where catchments dictate. Local governments are the sphere of government closest to the people and it can facilitate the voluntary adoption of conjunctive water management by: (i.) Acting as local information brokers for community and landholders on conjunctive water management; (ii.) Being a local facilitator and advocate by providing meeting rooms, secretarial support, administrative support, and facilitating negotiations; (iii.) Assessing and supporting local natural resource management priorities and working with regional and catchment bodies to enable them to link conjunctive water management to landscape natural resource and environmental outcomes; (iv.) Where agreed and resourced, providing infrastructure or undertaking capital works to support local actions and changed management practices arising from integrated water management plans. 73 Conjunctive Water Management Framework

74 Table 4.2: Five areas in which governments can play a role in conjunctive water management approach Australian Government State/Territory Governments Local Governments 1. Education and information Provide relevant conjunctive water management supporting information (Connected Water website, National Land and Water Resources Audit, State of the Environment reports, and other data and reports) Collate, disseminate and update conjunctive water management information for all stakeholders Facilitate and coordinate conjunctive water management training opportunities through the existing regional model Inform international water agencies about Australian initiatives on sustainable water management Identify case studies and promote benefits of conjunctive water management to growers and catchment authorities Provide information on environmental risks, standards and best practice for water use Facilitate conjunctive water management training opportunities Provide supporting regional data and reports Use Landcare and catchment networks to promote conjunctive water management 2. Coordination Coordinate establishment of national standards and guidelines in partnership with States, industries, research organisations and communities Provide information on relevant national and international integrated water management developments Undertake national reviews of Australia s water resources 3. Facilitation Support the application of this conjunctive water management framework Establish and maintain institutional arrangements to foster voluntary conjunctive water management adoption Catalyse conjunctive water management development and adoption through expertled workshops with interested stakeholders Contribute to development of integrated water management standards and guidelines Coordinate establishment of local and regional water management objectives and targets in partnership with research organisations and communities Ensure stakeholders are up-to-date with relevant regional and State conjunctive water management developments Support conjunctive water management framework appropriate to all levels of government and industry Establish and maintain institutional arrangements to foster voluntary conjunctive water management adoption Assist incorporation of conjunctive water management with State water planning Participate in the establishment of local and regional integrated water management objectives and targets in partnership with regional and catchment bodies Help coordinate local groups that are addressing issues of sustainable water management in farming Support conjunctive water management framework appropriate to all levels of government and industry Support local establishment of sustainable water management objectives and targets 4. Conjunctive water management policy development Focus conjunctive water management to Develop incentives for voluntary address critical issues of water management conjunctive water management adoption, Lead by example through implementation e.g. reduced water fees of conjunctive water management as a Provide input to conjunctive water policy in all government businesses and management to address critical water properties. planning and management issues Lead by example through implementation of conjunctive water management as a policy in all government businesses and properties Support a community culture of conjunctive water management adoption Lead by example through implementation of conjunctive water management as a policy in all government businesses and properties 5. Research and Development Collate and publicise information on current national research and development projects through Connected Water website Develop a framework for collaborative and integrated national groundwater-surface water interaction research and development between funding agencies Ensure coordination to reduce potential for overlap/duplication between State agencies, CSIRO, universities and industry to maximise research and development benefits Use regional planning frameworks such as catchment water management plans to ensure better strategic focus for conjunctive water management research and development and development of regional conjunctive water management Ensure local coordination of research and development activity to reduce potential for overlap and duplication, and to maximise research and development benefits Conjunctive Water Management Framework 74

75 5. Identifying Management Setting The first step in implementing a conjunctive water management approach is an analysis of the key features that define the management of land and water in the catchment. This identifies the priority catchment management issues and the factors that have an impact on their solution. This includes identifying the issues that impinge on the sustainability of land and water resources, the key water users, the degree of resource development and the existing catchment planning and policy arrangements. 5.1 Catchment Issues The water management issues facing catchment managers can be many and varied, whether they are over-extraction of water, stream salinity, water quality protection or ecosystem health. The nature and scope of conjunctive water management in a catchment can be tailored to address these management issues. The scale of the issues must be understood to allow for a prioritised approach. Identifying and prioritising water issues are key functions of catchment planning and management. Outlined below are some key water issues facing Australian catchments and how conjunctive management can be a useful approach. Water Allocation In connected systems where groundwater and surface water licences have been issued separately, there is risk that the same parcel of water has been allocated twice. This commonly occurs when groundwater that normally discharges to streams becomes allocated in its right. These connected water resources may not be assessed as overallocated (or over-used) in isolation but are in fact when considered jointly. Potentially, the long-term reduction in streamflow in highly connected systems can equate to the volume of groundwater extracted. However, other mechanisms such as evapotranspiration, leakage between aquifers or discharge to the sea can reduce this volumetric relationship. Also, the time lag between groundwater use and the resulting reduced stream flow can vary from only days where the bores are located close to streams to many years or decades for distant bores. These issues of volumetric impact and time lags need to be considered when managing stream flow depletion due to groundwater extraction. In some connected systems, seepage from streams is a significant component of recharge to nearby groundwater systems. In these catchments it is important that stream management and allocation take into account the requirements of groundwater users. Assessment of the sustainable yield for groundwater systems in Australia commonly considers recharge processes, but not necessarily the discharge component. Monitoring of groundwater levels is commonly used to evaluate resource condition, but groundwater flows to streams is not routinely monitored. More focus is required on evaluating and monitoring the discharge of groundwater to surface water resources. 75 Conjunctive Water Management Framework

76 Water Security Australia is well known as the driest inhabited continent, with highly variable rainfall and high rates of evaporation. Rainfall is distributed unevenly, both geographically and seasonally. Overall, only 12% of rainfall enters the rivers; the remainder accounted for by evaporation, vegetation use or storage in lakes, wetlands and aquifers. Australia has only one per cent of global freshwater runoff despite occupying five per cent of the global land area. Almost 50% of Australia s average annual runoff occurs in the northern tropics, which has little irrigation development compared to southern Australia. These factors of high rainfall variability, high evapotranspiration rates and geographic separation of water resources and irrigation development conspire to make the storage and delivery of water an enormous challenge. Historically, water resource development in Australia has taken a surface water focus, with the construction of large dams. The national storage capacity of 79,000 GL in 447 large dams is four times the annual surface water diversions of 19,100 GL (NLWRA, 2001). Water delivery in Australia can involve releases that need to travel many hundreds of kilometres between the reservoir and irrigation area. Stream-aquifer connectivity is a significant factor in terms of defining transmission losses and travel times. These losses may in fact be a significant recharge mechanism for alluvial aquifers as well as have ecosystem dependencies. There are also opportunities for using aquifers as water banks in conjunction with surface water reservoirs to enable greater flexibility and efficiency in water supply and delivery. Enhancing recharge to aquifers during periods of above-average water availability provides a resource for access during drought periods. Such a conjunctive approach has benefits when compared with relying solely on large surface water storages. The infrastructure costs are generally cheaper, it is more common for suitable aquifers rather than dam sites to be co-located in areas of water demand and there is the potential that the aquifer material can filter and improve water quality. Management of local aquifers in irrigation areas and urban areas can overcome some of the inefficiencies inherent in delivering water from distant dams. Aquifer storages tend not to have the issues of large reservoirs in terms of high evaporative losses, estimated by Hostetler (2005) to exceed 2000 GL/yr nationally. Using aquifers as storages is becoming a viable alternative considering the existing constraints to building new dams due to environmental concerns and general lack of suitable sites. Stream Salinity Salt is a natural part of much of the Australian landscape, and catchment changes such as land clearing and irrigation have mobilised salt storages and increased salt loads to river systems. It has been estimated that dryland salinity has degraded 2.5 million hectares, and streams in the Murray-Darling Basin and south-west Western Australia are affected. It has been long recognised that stream-aquifer connectivity has a key role in the issue of stream salinisation. Enhanced recharge brought about by the removal of deep-rooted native vegetation, which is an effective interceptor of soil moisture, or by direct irrigation accessions, has been reflected in rising watertables. Hydraulic gradients within the shallow aquifer towards streams have steepened, increasing groundwater discharge. Conjunctive Water Management Framework 76

77 Conjunctive water management is the logical approach to salinity mitigation. This can mean incorporating groundwater-surface water connectivity in numerical models used to assess the salinity impacts of new developments or to map management zones around river systems. It can also mean investing in on-ground works such as interception schemes, where bores are operated to pump and remove saline groundwater before it reaches the river. Water Quality Protection Stream-aquifer connectivity can also influence the movement of poor-quality water contaminated by acid, nutrients or agricultural or industrial chemicals. In coastal areas, shallow acid groundwater generated by the disturbance and oxidation of pyritic estuarine muds can seep into drains and estuaries causing chronic effects on aquatic life. Discharge of nutrient-rich groundwater into waterbodies can cause eutrophication and initiate algal blooms. Contaminants can migrate from industrial sites, land fills, intensive cropping or septic tanks to reach waterways via the groundwater system. Likewise, leakage from polluted waterways can be a mechanism for contaminating valuable groundwater resources. Again, streams and aquifers need to be managed jointly to protect the beneficial use of water resources. Understanding of the underlying processes of connectivity is needed when monitoring and predicting contamination plumes, establishing buffer zones, defining threshold loads, land-use planning and assessing development applications. On-ground works can also be established to control seepage flux. For example, a key strategy to limit acid export is to maintain high water levels in drains to reduce or even reverse the hydraulic gradient. This can be achieved by installing a retention structure within the drain such as a weir, dropboards or a sluice gate. In certain situations, the physical and chemical properties of aquifers can be used to advantage to reduce the toxicity of a contaminant. Management of Ecosystems Input of groundwater can be important in maintaining aquatic ecosystems. Wetlands, river pools or lagoons may be reliant on a relatively stable inflow of groundwater to maintain water levels, particularly during extended dry periods. Base flow of groundwater to rivers can be a critical component of the environmental flow regime. Groundwater discharge can effect stream chemistry and temperature and have implications on aquatic ecology. Mixing of surface water and shallow groundwater in the stream bed can provide a unique and dynamic habitat in its own right. There is a need to assess the dependency of ecosystems (such as in perennial streams, wetlands or estuaries) to groundwater inputs, as well as surface water. This allows for the recognition of any risks to groundwater quantity and quality, and make appropriate management responses. Assessing connectivity and the ecosystem dependencies is a critical part of the assessment of sustainable yields of water resources. In some situations, it may be appropriate to supplement stream flow using pumped groundwater to meet critical environmental objectives. Management of Natural Hazards Seepage of floodwaters into the underlying or adjacent alluvial sediments can reduce the impact of a major flood event by mitigating peak flood levels. Many inland rivers in Australia have very low gradients with very wide and extensive floodplains. This 77 Conjunctive Water Management Framework

78 results in floods with very slow travel times that can inundate large areas, providing the opportunity for significant infiltration and aquifer recharge. For example, the Diamantina River in southwestern Queensland has a floodplain that varies in width between 5 to 60 kms, with transmission losses amounting to 70-98% of flow for floods discharging up to 2,300 GL (Costelloe et al, 2003). Seepage into aquifers as well as evaporative losses and infilling of in-stream storages effectively reduces the magnitude of the flood as it progresses downstream. Engineering works such as installation of levees are designed to limit the area of inundation resulting from a flood event. However, these works can also reduce the extent of floodplain seepage. As well as providing a mechanism for reducing flood peaks, this seepage can also have major implications for ecosystems by providing opportunities for high biological productivity in the floodplain. Also, episodic flooding is a major recharge mechanism for aquifers in the arid zone. Hence, there are opportunities for engineering works to divert flood flows to identified parts of the floodplain for flood mitigation as well as to help fulfil ecosystem requirements or for groundwater replenishment. Excessive lowering of groundwater levels due to pumping can lead to collapse or compaction of the aquifer material. This in turn can lead to subsidence of the overlying land surface, which can cause significant infrastructure and environmental damage. A conjunctive approach can be taken by using surface water to replenish the aquifer so that groundwater levels are maintained over the long term. Another option is to reduce groundwater water use and switch to surface waters where possible. 5.2 Water Users Identifying water users is part of the process of defining the management setting in a catchment. The potential impacts on water users brought about by changes in water management by taking a conjunctive approach need to be addressed. This requires a clear picture of the water requirements for both consumptive users and the environment. It is also critical that water users be engaged in the planning process from the outset. This is an imperative if trade-offs between impacts across water users need to be negotiated, which tends to be inevitable in catchment management. The definition of water users is broad and assumes that the environment is a legitimate user of water. It includes potential beneficial uses of the water resource that have not as yet been developed in the catchment, inclusive of intergenerational equity. It also assumes that there are social and cultural values to water as well as consumptive use across a range of sectors. It involves the typical stakeholders that participate in catchment management. Stakeholders are those who have an interest in a particular decision, either as individuals or representatives of a group. This includes people who influence a decision, or can influence it, as well as those affected by it. Earth Summit, 2002 The role of water users in the management settings involves clarification of: (i.) The minimum, current and projected water requirements of users, in terms of quantity, timing and quality. This investigates the distribution of water use in the catchment, when water is required through the year and trends in future water demand; Conjunctive Water Management Framework 78

79 (ii.) (iii.) (iv.) (v.) The (social, economic and ecological) consequences if water availability does not meet these defined water demands. In addition, the impacts bought about by water resource development and management to meet these demands also need to be clarified and communicated; The level of acceptability to water users of the risk that these water demands may not be met, and also of the likely impacts bought about by meeting such demands. This includes the level of awareness of water users to the extent of uncertainty associated with hydrological assessment and water management. This uncertainty relates to defining community values to water (and how these priorities can change through time), in developing the conceptual understanding of catchment processes and in quantifying these processes (and their response to change) to develop management options; Perceptions and priorities about management issues, as different stakeholders will have different priorities and motives for engagement; The level of awareness of hydrological processes (such as stream-aquifer connectivity), including the opportunity for incorporating local knowledge and experience in the assessment process. Stakeholder engagement is a well-established plank in the catchment management process. Various government initiatives have embodied a more community-based regional approach to land and water management. This trend towards community participation is reflected in the criteria for the accreditation of regional NRM plans as set out by the NRM Ministerial Council, including: Effective participation by all key stakeholders is required to ensure that plans are based on a community process, are accurate, comprehensive, well coordinated and able to be implemented. Indigenous communities, local government, state agencies, resource managers, industry and communities, academic/scientific community and environmental groups should be involved where relevant. Stakeholder s roles, responsibilities and capacity to implement actions to achieve targets will be identified. There are different levels of stakeholder engagement, including information sharing, consultation and active participation (Table 5.1). This relates to the working relationship between the proponent and the stakeholders that can influence or are impacted by the decisions made. In the a conjunctive water management sense, the proponent is the organisation with the role of planning and implementing a conjunctive policy or investment and can be a State agency, a water authority, a shire council, or a catchment management authority for example. 79 Conjunctive Water Management Framework

80 Table 5.1: Different levels of stakeholder engagement (after Qld DoC, 2005) Level Definition Model Information A one-way relationship in which proponent delivers information to stakeholders Proponent Stakeholder Consultation A two-way relationship in which stakeholders provide feedback on issues defined by the proponent A collaboration in which stakeholders shape policy, but where the proponent retains the responsibility for final decisions Proponent Stakeholder Active Participation Proponent Stakeholder A wide range of methods are used to facilitate stakeholder engagement, and Table 5.2 outlines some of these and their benefits. An overall strategy is required to define the appropriate level and combination of engagement methods used for all the components of the conjunctive water management framework (Figure 4.1). This recognises that different approaches may need to be taken as the management cycle progresses, including aspects of: (i.) (ii.) (iii.) (iv.) (v.) (vi.) (vii.) Raising awareness of connectivity processes in the catchment and implications for water users; Defining appropriate structures for community participation and rules of engagement in the defining of catchment priorities. This can involve capacity building to allow communities to effectively engage; Providing transparency to the assessment of catchment processes, including encouraging pathways to local knowledge and experience; Outlining the strengths and limitations of the predictive models being constructed and expressing the level of uncertainty attached to any predictions. Allowing the opportunity for stakeholders to provide feedback on model predictions and their likely impact; Encouraging community participation in the data collection for key catchment indicators and providing public domain access to existing monitoring; Stakeholder engagement during the selection and implementation of conjunctive management options, as well as definition of management targets. This involves communicating the objectives and scope of implementation and managing expectations relating to potential outcomes; A structured and coordinated approach to the review process. Community consultation is an issue that transects government responsibilities. Table 5.3 summarises some of the on-line resources available, reflecting the significance of community consultation in a range of disciplines, not just natural resource management. As an example, Box 5.1 outlines some principles derived for the Australian mining and petroleum industries that can be readily transferred to the water management arena. Conjunctive Water Management Framework 80

81 Table 5.2: Some stakeholder engagement methods and their benefits (Qld DoC, 2005) Technique Benefits Deliberative Techniques Citizens Jury Policy Roundtable Search Conference Valuable in developing a deep understanding of an issue. Offers an opportunity for non-traditional stakeholders to hear expert testimony on an issue, deliberate together and propose recommendations to inform decision making. A joint planning/decision making forum between government and key stakeholders with expertise about a specific issue. Helps to establish a collaborative process from the outset and most valuable in the planning phase. Research intensive, effective means of creating a partnership with citizens. Can be used for developing and gaining broad commitment to a plan of action. Group Consultation Techniques Focus Group Useful with relatively homogeneous, pre-existing group with interest in issue. Allows for creative thinking if adequately facilitated. Public Meeting Views of community groups can be expressed. Not a strong forum for dialogue, but allows stakeholders to self-identify. Meeting management skills required to channel energy productively. Conference Structured approach useful for education and formal expression of views. Must be well planned and adequately resourced. Workshop Smaller groups selected for skills and interests gathering with objective of producing options or ideas, or structured exploration of issues. Needs skilled facilitation. Online Consultation Can provide opportunities to reach a large audience around a specific policy issue. Inquiry Formal body with terms of reference to inquire and report. May have legal authority. Can be costly. Sometimes chaired by judicial figure. Can be public or focused on identified stakeholders. Consultative Committee Members selected or appointed by range of methods for ongoing advice on particular issues. Policy Council Forum for established stakeholder representatives (eg. peak bodies). Strong tool for on-going dialogue with or without specific issue focus to draw group together. Usually chaired by Minister or chief executive of department. Legitimises formal relationships between government and established policy community. Individual Consultation Techniques Individual Discussions Sometimes useful for rapid data collection. Individuals may also initiate discussions with government. Submission Oral or written. May be unsolicited or in response to invitation. Usually attracts individuals or groups with well-defined position. Little dialogue involved. Survey Research Formal data gathering using objective techniques, often using sample of stakeholders. Sometimes useful to gauge public reaction to proposals. Conflict Resolution and Negotiation Participation Observation Conflict resolution methods usually involve structured exchange of information and views. Used after a dispute or clear differences have been identified. Regional and field staff often gain first hand experience of the impact of issues or proposals. 81 Conjunctive Water Management Framework

82 Information-Sharing Techniques Education and Awareness programmes Displays Media Release or Press Conference Ministerial Statement Discussion Paper Policy Paper Effective education and awareness programmes can raise citizen and community awareness about a policy issue. Information dissemination tool. Mobile or permanent, can be designed for easy change to reflect developments, and to elicit feedback. Generating interest and feedback. Major political and institutional tool for information dissemination. Formal parliamentary statement articulating a position or commitment to addressing an issue. Generates interest and may elicit feedback. Formal means of raising issues and requesting submissions. Formal statement of policy. Means of information dissemination. Not strictly consultative because states outcome. Sometimes is a means of providing feedback following discussion paper Conjunctive Water Management Framework 82

83 Table 5.3: Some resources available for stakeholder engagement Resource Organisation Website International Citizens as Partners Engaging citizens in policy making Capacity Building for IWRM Viewfinder: A policy makers guide to public involvement Focusing on citizens: A guide to approaches and methods Bowling Together: Online public engagement in policy deliberation XPIN Constructive Citizen Participation: a resource book NRM Changelinks Eight learning and democracy methodologies in use in Britain A toolbox of processes for community work Participatory strategies in the poverty reduction strategy Multi-stakeholder processes for governance and sustainability Empowering People: A guide to participation OECD UNDP UK Cabinet Office Scotland Community Planning Taskforce Netherlands Expertise Bureau for Innovative Policy-making Connor Development Services Massey University, NZ University of Essex, UK Co-intelligence Institute, USA World Bank Earth Summit UN Development Programme Community Development Foundation, UK International Association of Public Participation Resource Centres for Participatory Learning and Action National Towards Whole of Community Engagement: A practical toolkit Facing the Future: Engaging stakeholders and citizens in developing public policy Social and Institutional Research Programme Murray Darling Basin Commission Australian Public Policy Research Network Land and Water Australia =science&id=62 83 Conjunctive Water Management Framework

84 Action Learning and Action Research Principles for Engagement with Community and Stakeholders Southern Cross University Ministerial Council on Mineral and Petroleum Resources =1B3956CC-D71C-4C97-B BB230A Citizens Science Toolkit BRS Interactive Social Atlas Coastal CRC Bureau of Rural Sciences Jurisdictional Engaging Queenslanders Community Engagement in the NSW Planning System Qld Department of Communities Planning NSW Office of Citizens and Civics WA Department of the Premier and Cabinet Conjunctive Water Management Framework 84

85 Box 5.1 MCMPR Principles for Engagement with Communities and Stakeholders The Australian Ministerial Council on Mineral and Petroleum Resources (MCMPR) have recently released a framework to guide best practice stakeholder engagement for the resource sector. This recognises that resource development can have impacts that are positive (such as employment creation, regional development, and enhanced community services) as well as negative (such as environmental degradation, social problems and health and safety issues) The key principles are: (i.) Communication, with open and effective engagement that involves both listening and talking. The key questions are: Who do proponents need to talk and listen to? What is communicated? What do communities and stakeholders want to know? When do proponents communicate? (ii.) Transparency, with processes that communicate clear, accurate, technically robust, relevant, timely and culturally appropriate information. The key questions are: How is engagement communicated? What is documented? (iii.) Collaboration, where feasible to work cooperatively to seek mutually beneficial outcomes. The key questions are: What is the capacity of stakeholders to participate in the process? Where can assistance be found to support community groups in the process? (iv.) Inclusiveness, to recognise, understand and involve stakeholders in the overall process. The key questions are: What are the cultural characteristics of communities and stakeholders? Do they have the ability, experience, and/or access to support to deal with this process? (v.) Integrity, where engagement is conducted in a manner that fosters mutual respect and trust. The key question is: What is the ability to build credibility and confidence? 5.3 Extent of Resource Development The nature and extent of resource development in the catchment needs to be defined. This includes aspects of: (i.) (ii.) (iii.) the level of groundwater and surface water extraction and allocation compared to any sustainable limits set for the resource; the infrastructure associated with water storage, delivery, drainage and use; the intensity and nature of land use. The extent of the use and development of water resources dictates how conjunctive management can be applied. There tends to be greater flexibility in changing water management and policy in relatively undeveloped catchments. In catchments with high levels of water extraction, existing property rights and infrastructure can limit management change. Alternatively, there may be opportunities where existing infrastructure can be retrofitted in a cost-effective manner to achieve conjunctive management. Any investment in on-ground conjunctive technologies would need to fit in with existing infrastructure used to manage water quantity and quality. In terms of water quantity, the policy tools to implement conjunctive water management will vary with the degree of water regulation in the catchment. Different 85 Conjunctive Water Management Framework

86 approaches may be taken for regulated catchments where water flow is controlled by infrastructure such as dams, locks or weirs, compared to unregulated catchments where such infrastructure does not exist. The tools applied will also vary on development levels, measured by comparing water allocation (and use) with the defined sustainable extraction limit for surface water and groundwater resources. Socalled greenfield catchments have low levels of water use compared to the resource available for extraction. In brownfield catchments, levels of water allocation (and use) are close to or exceed the defined sustainable limits for either or both of the groundwater and surface water resources. The intensity and value of land use activities in the catchment can be an important factor, particularly in terms of response and take up of conjunctive water policies. For example, conjunctive water trading established in catchments with high-value permanent horticulture will have a different market response to catchments dominated by land uses with lower $/ML returns, such as irrigated pasture. 5.4 Existing Planning and Policy Identifying the existing legislation and policies that control or effect water management is part of the process of defining the management setting in a catchment. The existing administrative, policy and management environment can provide opportunities or constraints to implementing conjunctive water management and can involve agencies at three levels of government in Australia federal, state and local as well as non-government organisations. Depending on the policy instruments or on-ground works envisaged, this can cover aspects of: (i.) (ii.) (iii.) (iv.) (v.) (vi.) (vii.) (viii.) (ix.) Water allocation and licensing; Catchment management and targets; Water pollution and water quality protection; Environmental impact statements; Building and development applications; Regional planning and development; Drainage and flood mitigation; Protection of public health; Occupational Health and Safety. Therefore, an overview of the existing administrative arrangements that relate to water management and use in a catchment is needed to ensure that for any conjunctive water management options there is: (i.) (ii.) (iii.) (iv.) Alignment with the water reform agenda. Inconsistencies or impediments in existing water policy can also be highlighted; Recognition of any potential conflict with policy across other sectors. For example, recharge enhancement for water banking may be in conflict with existing strategies for minimising recharge for salinity control; Identified efficiencies in terms of water savings relative to the defined sustainable yields for the catchment water resources, and can be implemented within the existing water management and planning framework; Satisfactory meeting of existing requirements in terms of protection of water quality, public health or environmental assets; Conjunctive Water Management Framework 86

87 (v.) (vi.) Appropriate development consents for any on-ground works; Analysis that future water requirements and priorities for the catchment are met. Box 5.1 uses the Lower Richmond catchment as an example to show the level of complexity in water management with the interplay of multiple government agencies and policies as well as the involvement of non-government bodies such as industry groups, Landcare groups, and environmental organisations. 87 Conjunctive Water Management Framework

88 Box 5.2: Stakeholders in water resource management in the Lower Richmond catchment The Lower Richmond subcatchment is located in the far North Coast region of New South Wales, about 700 km north of Sydney and about 200 km south of Brisbane. The catchment is small (23,000 ha) but diverse and complex. It consists of three parts: (i) The southern half of the Alstonville Plateau, which is a dissected upland basalt plateau whose streams drain into; (ii) The Tuckean Swamp, a large estuarine back swamp connected to; (iii) the Tuckean Broadwater, which is an arm of the Richmond River estuary (Figure 5.1). Although seemingly in a high rainfall area, water availability is a key issue on the Alstonville Plateau. The highly permeable soils limit dam-building; the shallow and free-draining nature of the watertable aquifer means that it can be unreliable during droughts; and the deeper aquifers tend to be low-yielding. Limited storage is a problem when supplying high security water for users such as town water supply and the high-value horticultural industry. There are also significant ecosystems such as freshwater wetlands, the perennial plateau streams, and rainforest remnants. Protection of water quality on the plateau is also an issue. In particular, faecal contamination of both surface water and groundwater supplies needs to be addressed as a matter of public health (Budd et al, 2000). Streams in the trial catchment are part of the unregulated surface water management area of the Richmond River. In 1995, an embargo was placed on applications for new licences to extract water from these streams. The groundwater resources of the Alstonville Plateau have been formalised in a groundwater management area (GWMA 804), which has been classified as highly stressed due to the risk of over-extraction or contamination (DLWC, 1998). As a consequence a Water Sharing Plan has recently been developed for the basalt aquifers of the plateau (DLWC, 2003). In 2001, an embargo was enacted on new groundwater licence applications. In the Tuckean Swamp, the most significant water management issue is the generation of highly acidic runoff from acid sulfate soils. Following major rainfall events, the store of acid can migrate into the drains and be exported into the Tuckean Broadwater. The consequences of this acidity are fish kills, poor water quality, land degradation, reduced agricultural productivity, loss of estuarine fisheries habitat, and degraded vegetation and wildlife values (Hagley, 1996). The Tuckean contains significant freshwater melaleuca wetlands that host threatened flora and fauna species. Flood mitigation, particularly of agricultural areas, is an issue for landholders in and around the Tuckean. A Land and Water Management Plan has been developed for the Tuckean Swamp, with a primary focus on managing the impacts of acid sulfate soils (Baldwin, 1997). Overall, the management of water resources and acid sulfate soils are key components of the catchment blueprint for the Richmond (NRCMB, 2002). Water management in the catchment spans water allocation, ecosystem requirements, contamination, acidity and flooding. This means there is a wide range of stakeholders, with Table 5.4 a summary of the key participants. Some of these stakeholders focus on a particular issue relating to water management mandated by legislation, while others such as community groups are representative of key community sectors. The table is by no means exhaustive, for example the organisations involved in research (such as Southern Cross University, the Australian National University and the Bureau of Rural Sciences) are not listed. Conjunctive Water Management Framework 88

89 Figure 5.1: Components of the Lower Richmond catchment, north coast NSW 89 Conjunctive Water Management Framework

90 Table 5.4: Overview of agencies with an interest in water management in the Lower Richmond catchment, New South Wales Jurisdiction Agency Role Policy Documents and Legislation Australia Australia NSW NSW NSW NSW NSW NSW NSW NSW NSW NSW NSW NSW National Water Commission ( Wetland Care Australia u NSW Department of Natural Resources ( NSW Department of Planning au NSW Department of Environment and Conservation NSW National Parks and Wildlife Service NSW Department of Primary Industries NSW Department of Health State Water Independent Pricing and Regulatory Tribunal Department of Public Works and Services Aboriginal Land Council NSW Farmers Association Oyster Farmers Association of NSW u Drive national water reform and assist jurisdictions to implement reforms Not-for-profit organisation undertaking active wetland repair projects across regional Australia Natural resource management and managing access to water resources Facilitate development of infrastructure to deliver efficient and secure energy and water services Manage the protection, restoration and enhancement of the quality of the environment Develop and maintain the parks and reserve system, and conserve natural and cultural heritage Foster profitable and sustainable development of primary industries, including agriculture, fisheries, forestry and mining Develop standards for water quality Intergovernmental Agreement on a National Water Initiative, 2004 Water Management Act, 2000 and amendment 2004 State Water Management Outcomes Plan, 2002 State Environmental Planning Policies Regional Environment Plans Protection of the Environment Act, 1991 Forestry and National Park Estate Act, 1998 Agricultural and Veterinary Chemicals Act, 1994 Fisheries Management Act, 1994 Bulk water storage and delivery State Water Corporation Act, 2004 Price regulation and performance monitoring Design and construction of services and infrastructure, including sewage and water Statutory authority responsible for protecting and promoting the rights and interests of the Indigenous people of NSW. Voluntary industry body representative of the whole farming community in NSW Industry body representing NSW oyster farmers and processors Independent Pricing and Regulatory Tribunal Act, 1992 Aboriginal Land Rights Act, 1983 North Coast Region, NSW Northern Rivers Catchment Management Authority Prepare, implement, monitor and provide information on catchment action plans Catchment Management Authorities Act 2003 Conjunctive Water Management Framework 90

91 Richmond River Catchment, NSW Richmond River Catchment, NSW Ballina- Lismore area, NSW Ballina area, NSW Lismore area, NSW Tuckean Swamp, NSW Alstonville area, NSW ov.au/ Richmond River County Council Richmond River Cane Growers Association Rous Water au Ballina Shire Council Lismore City Council Tuckean Landcare Group Marom Creek Landcare Group Floodplain management, management of flood control and drainage infrastructure, water quality monitoring Representative body for the cane growers in the Richmond River Catchment Regional water authority proving bulk water Land use zoning, development consent, stormwater management and control, sewerage and septic works Land use zoning, development consent, stormwater management and control, sewerage and septic works Community based catchment restoration activities Community based catchment restoration activities 91 Conjunctive Water Management Framework

92

93 6. Assessment of Connectivity Traditionally, surface water and groundwater resources have been independently assessed. An important addition in taking an integrated approach is that connectivity is also assessed. The nature and level of this assessment will depend on: (i.) (ii.) (iii.) (iv.) (v.) (vi.) The key water management issues within the catchment; The significance of the water resource in terms of social, economic and environmental values; The relative development of the water resource in terms of the ratio between use (and allocation) and sustainable limits; Any risk assessment of the likely magnitude of impacts associated with the management issue, such as loss of economic productivity, land and water degradation or poor ecosystem health; The availability of resources such as data, budget and expertise; The management and policy timeframes. Hence, water resource assessment includes investigation of: (i.) Surface water features including streams, reservoirs, wetlands and estuaries. This includes such aspects as flow duration and dynamics, water storage capacity, water quality, aquatic ecosystems, land use impacts, climate variability and water extraction regimes; (ii.) Groundwater systems, covering aspects such as aquifer geometry, geological and stratigraphic configurations, hydraulic properties such as transmissivity and storativity, water sources and sinks such as recharge, abstractions and discharge mechanisms, environmental dependencies and the impacts of land use; (iii.) Surface water-groundwater interactions, involving the analysis of the dynamics of water flow between aquifers and surface water features, and the impacts of this interaction in terms of water quantity, quality and ecology. Hence, the focus is to acquire the baseline information to describe the characteristics of surface water and groundwater systems of the catchment, and their interactions, both spatially and temporally. 6.1 Available Assessment Methods for Connectivity A wide range of tools are available to assess the nature and degree of the connectivity (Figure 6.1). A summary of these methods is outlined below, with more detailed information provided in Brodie et al (2007). Seepage Measurement The direct measurement of seepage flux at the stream-aquifer interface can be undertaken using seepage meters and similar devices. The basic concept is to cover and isolate the stream bed with an inverted open chamber and measure the change in volume of water contained in a bag attached to the chamber over a measured time interval. Additional water in the bag over the time of operation indicates gaining 93 Conjunctive Water Management Framework

94 stream conditions. Several modifications have been made to the design and operation of the seepage meter to address potential sources of measurement error and to handle logistical issues. Automated versions using different technologies to enable real-time monitoring of seepage flux have been developed. Field Observations Visual indications of seepage flux can be observed in certain catchments and settings. An initial reconnaissance can highlight hotspots where groundwater is discharging to streams; provide guidance to useful parameters to measure and to identify management issues that are impacted by connectivity. Examples of field indicators include direct observation of water flow from springs at the margins or within the stream bed, water vapour or ice-free conditions around springs during winter, mineral precipitates or iron-bacteria accumulations, or changes in water colour or odour. Ecological Indicators Specific vegetation communities or biota can indicate groundwater discharge to surface water features. Changes in the composition and accumulated biomass of submerged aquatic plants can relate to groundwater seepage. The near-stream presence of phreatophytic plants, which are deep-rooted and can access groundwater, can indicate a shallow watertable. The extent and composition of biota that habitat the hyphoreic zone, can also describe the processes of near-stream groundwater and surface water mixing. Hydrogeological Mapping Knowledge of the hydrogeology surrounding a surface water feature is critical in understanding connectivity. This involves mapping the configuration and characteristics of the groundwater flow systems within the catchment. This covers aspects such as aquifer geometry, host geology and stratigraphy and hydraulic properties (such as transmissivity and storativity). Also included are specific geological features such as faults, facies changes or river geomorphology that can locally control groundwater flow. Geophysics and Remote Sensing Geophysical and remote sensing technologies such as airborne electromagnetics (AEM), radiometrics, seismic waves, electrical charge, or satellite imagery can be used to interpret connectivity. These surveys can map the variation in parameters such as groundwater salinity, vegetation types or soil moisture that can be secondary indicators of groundwater discharge. They can also be used to identify geological features that control seepage flux. Mapping of landscape parameters (such as soil type, land use, vegetation cover) that can have an impact on seepage flux can also be supported by geophysical or remote sensing technologies. Hydrographic Analysis The stream hydrograph can be processed and analysed to characterise the magnitude and timing of groundwater discharge to streams. Baseflow separation techniques use the time-series record of stream flow to derive a baseflow hydrograph. Of these, Conjunctive Water Management Framework 94

95 recursive filters are the most commonly applied. Frequency analysis takes a different approach by deriving the relationship between the magnitude and frequency of stream flows. Recession analysis focuses on recession curves which follow flow peaks. These curves are fitted using storage-outflow models to characterise the natural storages that feed the stream. Hydrometric Analysis Hydrometric methods are based on Darcy s Law so focus on the hydraulic gradient between groundwater and surface water systems and the hydraulic conductivity of the intervening aquifer and bed material. Piezometers are used to measure groundwater levels which are compared with the elevation of the stream stage. Pump (or slug) tests can be undertaken on these piezometers to estimate the transmissivity of the aquifer material. Hydrochemistry Studies Interpretation of the chemical constituents of water can provide insights into streamaquifer connectivity. Dissolved constituents can be used as environmental tracers to track the movement of water. For example, a particular characteristic of the groundwater chemistry (such as high radon levels) can be used as an indicator of groundwater discharge when measured in the surface water. Environmental tracers can occur naturally or have been released into the general landscape by human activities. Some of the commonly used environmental tracers include field parameters such as EC or ph; the major anions and cations such as calcium, magnesium, sodium, chloride and bicarbonate; stable isotopes in the water molecule of oxygen-18 ( 18 O) and deuterium ( 2 H); radioactive isotopes such as tritium ( 3 H) and radon ( 222 Rn); and industrial chemicals such as chlorofluorocarbons (CFC) and sulphur hexafluoride (SF 6 ). Artificial Tracers Artificial tracer tests are used to evaluate the extent to which aquifers interact with streams, providing information on groundwater flow paths, travel times, velocities, dispersion, flow rates and the degree of hydraulic connection. These tests involve the introduction of a tracer material or chemical and subsequent monitoring of its movement. This differs from environmental tracer methods which rely on the measurement and interpretation of background concentrations. Fluorescent dyes (such as Rhodamine WT), conservative major ions (such as chloride or bromide), organic compounds (such as ethanol or fluorinated benzoates), isotopes (such as selenate or deuterium), non-pathogenic micro-organisms or colloidal material (such as club moss spores) have been used in tracer studies. Temperature Studies Heat can also be used as tracer to characterise seepage flux. Time series monitoring of temperature in both the surface water and groundwater systems is used. Stream temperatures have a characteristic diurnal pattern overprinting seasonal trends, whilst regional groundwater temperatures tend to be relatively constant at the daily scale. Temperature monitoring at varying depths in the stream bed can indicate the relative 95 Conjunctive Water Management Framework

96 influence of groundwater and surface water processes. Numerical models of heat flow (such as VS2DH and SUTRA) can be used to quantify seepage flux. Water Budgets A common approach to investigating seepage flux between a stream and underlying aquifer is to measure stream flow at specific points. These measurement sites subdivide the stream into reaches and a water budget is estimated for each reach, accounting for inputs such as tributary flows and outputs such as evaporative losses and diversions. The difference between inflows and outflows is then attributed to the seepage flux. The method relies on accurate measurement of stream flow and appropriate accounting of the other gains and losses. 6.2 Comparison of Methods Table 6.1 presents a summary comparing these different assessment methods. These tools are described in the context of: (i.) (ii.) (iii.) (iv.) (v.) (vi.) (vii.) Spatial Scale, classified in terms of local (ie at a point or site), intermediate (at the scale of a feature such as a stream reach) and regional (at the catchment scale), refer Table 3.1; Temporal Scale, classified in terms of short-term (over the timeframe of days to months such as tidal, evapotranspiration or discrete episodic processes), medium-term (at the seasonal to yearly scale) and long-term (exceeding the decadal timeframe such as influences of climate change), refer Table 3.2; Cost, associated with collection, analysis and interpretation of data; Ease of Use, focusing on the accessibility of technology and the extent of prior expertise required; Advantages, the inherent benefits of applying the methodology; Limitations, the potential constraints and limiting assumptions; Application, outlining the extent that the method has been used in Australia. Conjunctive Water Management Framework 96

97 a c b d Field Assessment Tools for Stream-Aquifer Connectivity f e Figure 6.1: Examples of different methods of assessing stream-aquifer connectivity (a) direct measurement of flux using seepage meters (b) hydrometric studies using minipiezometers in the stream bed (c) monitoring of groundwater levels and stream levels/flows (d) temperature monitoring in the stream and shallow bed sediments (e) run-of-river geophysical survey (f) water sampling for hydrochemistry 97 Conjunctive Water Management Framework

98 Table 6.1: Summary of tools to assess stream-aquifer connectivity Method Spatial Scale Temporal Scale Cost Ease of use Advantages Limitations Application Desktop Tools Hydrographic Analysis Processing of time-series stream flow monitoring to define baseflow (groundwater discharge) component Intermediate to regional Hydrograph represents water balance for subcatchment above gauge Medium to long-term Depends on length of monitoring record Low High Many analysis techniques and software tools available. Stream flow data routinely collected Uses existing flow monitoring data. Can be undertaken as a desktop study prior to detailed field investigations. Provides information of seepage changes through time Applicable to gaining stream conditions only. Assumption that baseflow is groundwater discharge may not be valid. Baseflow effected by water use and management activities (eg regulation) Does not provide spatial distribution of groundwater input along stream Commonly applied method for unregulated Australian catchments Hydrogeological Mapping Mapping of groundwater systems including flowpaths, groundwater quality, aquifer structure and properties and geomorphology Intermediate to regional Typical mapping scales of 1:100,000 to 1:250,000 Short to mediumterm Usually average conditions at time of mapping Some parameters such as aquifer transmissivity or structural contours are time-insensitive Medium to high Depends on data availability. Expensive if drilling required to supplement existing data Low to medium Knowledge of hydrogeological principles required Provides conceptual understanding of groundwater systems around stream and hydrogeological controls on connectivity Compiling and interpreting hydrogeological data can be time consuming and complex. Limited borehole data can lead to misinterpretation Groundwater flow system, surface geological and hydrogeological mapping available at a coarse scale for many groundwater management areas across Australia Modelling Simulate water flow regime around stream using mathematical equations Intermediate to regional Typical models are 2D profiles or 3D grids Medium to long-term Used to predict future events Low to high Depends on data availability and model complexity Low to medium Requires good conceptual understanding of hydrological processes and modelling expertise Useful predictive tool for management and policy. Helps define information gaps. Transient 3-D models can estimate changes in seepage through time and space Oversimplified models may not be adequately robust. Overcomplex models can be data hungry, costly and timeconsuming Commonly, surface water models for a catchment are developed in isolation to groundwater models Conjunctive Water Management Framework 98

99 Method Spatial Scale Temporal Scale Cost Ease of use Advantages Limitations Application Field Tools Field Indicators Visual indications of seepage such as water clarity, springs, aquatic plant species, chemical precipitates etc. Local Site specific observation of seepage indicators Short-term Current at time of observation Low Medium to High Easily incorporated into field work. Depends on familiarity with indicators Can identify seepage hotspots quickly. Return visits can provide information on seasonal changes in seepage flux. Field indicators can form basis for mapping (eg airphoto interpretation) Limited in quantifying seepage flux. Effectiveness varies with observer s knowledge of field indicators (eg plant or aquatic biota) Used in specific settings such as acid groundwater (eg iron precipitates, lilies) and karstic streams (eg travertine deposits). Assessment of groundwaterdependent ecosystems not routine Artificial Tracers Monitoring movement of introduced tracers such as fluorescent dye to track water flow Local to intermediate Short to medium term Typical tracer studies over days to weeks Medium Need to establish monitoring network Medium Conceptually simple but needs expertise in field measurement and data interpretation Can provide direct evidence of water movement between stream and aquifer. Aquifer parameters and fluid transport properties can be quantified Tracer studies require careful planning including meeting environmental regulatory controls. Processes such as degradation, precipitation or sorption can affect tracer performance Not routinely applied in connectivity studies in Australia. Overseas focus on karstic aquifers or investigations of contaminated sites Geophysics and Remote Sensing Use of geophysics (eg resistivity, EM, radiometrics) or remote sensing (eg Landsat) to map landscape features that indicate or control connectivity Local to regional Range from site specific (eg downhole surveys) to intermediate (eg runof-river EC imaging), to catchment scale (eg satellite imagery) Short-term Measures conditions at the time of survey. Multiple surveys can provide trends through time Medium Per hectare cost depends on technology and platform (eg ground, airborne) Low Needs technical expertise in field equipment operation and data interpretation Allows rapid, non-invasive mapping of landscape parameters with good spatial resolution. Some techniques provide information at depth Requires specific equipment, technical expertise and logistical support. Can require complex data processing and calibration with other datasets. Ground surveys can encounter obstacles such as rough terrain, vegetation cover etc. Opportunities exist to use geophysical data collected for other purposes eg. mineral exploration. Satellite imagery commercially available, some free in public domain. Hydrochemistry and Environmental Tracers Use of chemical constituents of water (such as major ions, stable isotopes, radon) to track water flow Local to regional Depends on scope of water sampling survey Short to mediumterm Defines chemistry at time of sampling. Time-series monitoring (eg EC, ph) possible Medium to high Can be expensive due to sampling logistics and cost of analyses Low Requires expertise in appropriate sampling and data interpretation Useful in quantifying seepage flux and defining key hydrological processes (such as groundwater recharge and discharge) Can have long lead times between sample collection and final analytical results Commonly used in Australia to identify hydrogeological processes including groundwater seepage to streams Hydrometrics Measurement of hydraulic Local to regional Can range from in- Short to mediumterm Low to medium Can use existing Medium to high Comparison of Comparison of stream and groundwater levels a simple guide to seepage direction. Relies on reasonable estimate of hydraulic conductivity to quantify seepage Comparison of stream levels with nearby groundwater levels commonly used to define 99 Conjunctive Water Management Framework

100 Method Spatial Scale Temporal Scale Cost Ease of use Advantages Limitations Application gradient between aquifer and stream and the hydraulic conductivity of intervening aquifer material. Based on Darcy s Law stream studies, to borehole transects to regional flow net analysis Possible to compare hydrographs of stream and groundwater levels data but costly if drilling of bores is required groundwater and stream levels simple. Estimation of hydraulic conductivity more difficult Installation of minipiezometers in stream bed allows direct local measurement of potential seepage direction flux.assumption of simple groundwater flow conditions may not be valid. Point measurement. Need to correct for density effects. direction of potential seepage. Seepage Measurement Direct measurement of water flow between stream and aquifer using seepage meters Local Point measurement of seepage. Many measurements required to map spatial variations. Short-term Meters typically installed over days/weeks. Measures aggregate seepage over time of operation Low to medium Can be time consuming if measuring at multiple sites Low Simple concept with meters easy to use and no prior technical knowledge required. Direct measurement of seepage flux. Meters are simple and inexpensive to construct and provide a semiquantitative measurement Potentially significant measurement errors due to meter design and operation. Unsuitable for high stream flow, gravel and heavy clay sediment beds Main application to date in Australia has been investigating leakage from irrigation channels or studying aquatic ecosystems Temperature Monitoring Monitor variations in stream and sediment temperatures to trace seepage Water Budgets Quantification of stream reach water balance to define seepage component Local Multiple measurements required to map spatial variability in seepage Intermediate to regional Does not provide spatial variability of seepage along reach being investigated Short to medium term Temperature can be included in timeseries monitoring Short to medium Term Possible to use timeseries monitoring of stream flow at multiple stations Low Temperature loggers are cheap and widely available Low to medium Can be expensive if data collection required for estimating water balance components Medium to high Temperature simple to measure. Heat transfer modelling to quantify seepage more difficult. Medium to high Conceptually simple using existing monitoring data. Water balance components such as extraction or diversions can be difficult to quantify Temperature loggers are simple, robust and cheap. Heat transfer models that can compliment flow models to quantify seepage are available Simple water balances estimated rapidly using existing stream flow monitoring. Provides estimate of aggregate seepage along reach Only measures at a point. Interpretation of monitoring requires confirmation using other assessment methods Measurement errors in stream flow data can be significant, hence more suited to long reaches. Can be misleading if water balance component (eg extraction) is not adequately accounted for Not specifically applied to study stream-aquifer connectivity in Australia to date. Opportunities to incorporate real-time temperature monitoring into existing hydrographic network Routinely applied, particularly for regulated rivers or irrigation channels Conjunctive Water Management Framework 100

101

102 6.3 Assessment Strategy Table 6.1 highlights the diverse characteristics of the methods available to characterise stream-aquifer connectivity. These variations, particularly in terms of differences in spatial and temporal scale can be used to advantage in an overall assessment strategy. Figure 6.2 outlines such a strategy that fits within the overall conjunctive water management framework, as represented in Figure 4.1. The components of the assessment strategy are data collation, desktop analysis, field survey and site investigations. The understanding of connectivity at different scales both in time and space bought about by this assessment strategy is bundled into the conceptual model developed for the groundwater and surface water systems of the catchment. In turn, this conceptual model can be translated into a predictive model, as detailed in Chapter 7. This process is in fact iterative, as the predictive modelling can highlight information gaps which can spur on additional data collection and assessment. Data Collation Desktop Analysis Field Survey Conceptualisation Prediction Site Investigations Figure 6.2: Components of a strategy for investigation and assessment of connectivity Data Collation The initial step is to collate the existing baseline data useful in characterising the surface water and groundwater systems of the catchment, and their connectivity. This can be time-consuming and resource-intensive as data requirements are comprehensive and need to be sourced from multiple agencies. Table 6.2 summarises the main data themes and their common sources, and includes: (i.) Catchment Properties such as boundaries and topography, remote sensing imagery; (ii.) Hydrogeology such as existing geological, soils, regolith or hydrogeological mapping, or borehole databases, geophysical surveys; (iii.) Surface Water Features, including mapping of drainage and waterways; (iv.) Hydrology, including climate data (rainfall, evaporation), stream gauging, groundwater monitoring and water quality databases; (v.) Ecosystems, such as wetlands mapping, vegetation mapping and rare/endangered species databases; (vi.) Catchment Use and Management, such as land use mapping, water infrastructure, water metering and water allocation. Conjunctive Water Management Framework 102

103 Table 6.2: Typical catchment hydrology datasets and sources Date Type Data Sources Catchment Properties Topography Topographic maps and DEMs Hydrogeology Geology and stratigraphy, aquifer extent and thickness, confining units, bedrock configuration. Aquifer properties (eg hydraulic conductivity, storativity, anisotropy) Geological maps Geological databases Hydrogeological maps Remote sensing State agency groundwater databases Scientific literature (journal and conference papers, student theses) Unpublished reports (eg consultant reports, drilling programmes, geophysical surveys) Surface Water Features Drainage network, lakes, wetlands, estuaries Topographic maps Bathymetric maps Hydrology Rainfall and evapotranspiration Run-off and stream flow Groundwater recharge and discharge Stream-aquifer connectivity Water quality (eg. salinity, acidity) Climate databases Stream gauging data Groundwater monitoring databases Water quality databases Ecosystems Aquatic ecosystems Wetlands Rare/endangered species Vegetation Water management and environmental protection agencies Vegetation mapping Scientific papers Unpublished reports (eg environmental impact statements) Catchment Use and Management Land use Water infrastructure (dams, channels, irrigation, extraction bores, flood mitigation and drainage works, interception or injection schemes) Water allocation and use Community requirements and expectations Legal, regulatory and policy setting Topographic maps Land use mapping Remote sensing State agency databases Catchment authorities (eg CMAs, councils, water authorities) Unpublished reports 103 Conjunctive Water Management Framework

104 Without adequate datasets, analysis of stream-aquifer connectivity cannot be carried out with any degree of confidence. Data needs both spatial and temporal distribution to allow proper interpretation of catchment hydrogeology and hydrology to be made. The quality of data available varies with catchments, and this will reflect the type and accuracy of analysis that can be done. The data required to develop a conceptual understanding of connectivity should be determined as early as possible in the planning process. All data sets should meet agreed quality criteria relating to accuracy and temporal and spatial variability. Chapter 7 provides further information on these key catchment datasets and their data sources in Australia. Desktop Analysis The collation of existing datasets provides an opportunity to undertake an initial desktop analysis of connectivity. Such desktop analysis can provide preliminary insights into seepage flux without any additional investment in data gathering. Depending on budget and time constraints, this may be the extent to which an assessment can be made. Such a desktop analysis can include the approaches of: (i.) (ii.) (iii.) (iv.) (v.) (vi.) (vii.) Hydrogeological Mapping, where available data such as borehole information, pump tests, groundwater monitoring, geophysics and geology or soils mapping are combined to compile maps such as groundwater potentials, flow directions, salinity, aquifer structural contours and hydraulic conductivity distribution. These are necessary in providing the hydrogeological setting for the stream; Hydrographic analysis, where various methods can be applied to the available time-series of stream flow to characterise the baseflow component; Water Balance, where the stream flow record from multiple stream flow gauges can be used to derive the water balance for the intervening stream reaches, or for the overall catchment; Hydrochemistry, where any existing water quality monitoring (such as EC, ph, major ions, nutrients) is used to define variations in surface water and groundwater chemistry that reflects changes in seepage flux in time and space; Geophysics and Remote Sensing, where available imagery and data can be processed to provide information on catchment parameters that either control or indicate connectivity; Hydrometrics, most notably when the available time series of stream water levels are compared with nearby monitoring of watertable elevation, to determine changes in the potential direction of groundwater flow. Historic pump tests can indicate the magnitude of aquifer transmissivity; Temperature Monitoring, acknowledging that stream temperature is commonly monitored (in conjunction with stream level and also for ecological purposes) and can potentially also be used in assessing seepage flux. Conjunctive Water Management Framework 104

105 Field Survey Additional field surveys can be undertaken to support the initial desktop analysis. These surveys are used to provide greater spatial resolution by interpolating along the stream between existing monitoring sites and to infill areas in the catchment with insufficient data. Such surveys are also used to identify key sites that require more intensive investigations. Initial conceptualisation of processes can also be verified. Examples of these survey methods include: (i.) (ii.) (iii.) (iv.) (v.) Hydrochemistry, where water samples are taken along the stream network and analysed for environmental tracers. This is commonly done to highlight trends and hotspots for groundwater discharge to streams. The tracers analysed range from the simple and cheap (such as field EC and ph) to the more sophisticated and expensive (such as stable isotopes and radon); Geophysics, where surveys can be undertaken down the length of the stream or across the extent of the catchment. For example, geo-electric arrays can be towed behind boats to map the electrical conductivity of the water column and underlying sediments. The technique has been particularly effective in mapping seepage of highly saline groundwater. Ground-based seismic traverses can be useful in mapping geological features that constrain or control groundwater flow, such as the geometry and stratigraphy of alluvial aquifers or fault zones; Water Balance, where flow is measured at multiple points along the stream to help target hotspots in terms of gross seepage losses or gains. Simple water balances can be estimated relatively quickly and cheaply to derive an initial rough estimate of the direction and magnitude of seepage on a stream reach basis; Ecological Indicators, involving the reconnaissance survey of indicator species such as specific aquatic plants, phreatophytes or hyporheic biota to map groundwater discharge hotspots. Other field observations (such as precipitates, water colour) can be included in the reconnaissance; Temperature Measurements, where measurements of water temperature along the stream length are used as a screening tool for identifying gaining and losing stream reaches. This is particularly useful if the groundwater discharge has a significantly higher temperature than the ambient stream, either due to geothermal conditions or due to release from deep regional groundwater flow systems. Site Investigations More intensive investigations can be undertaken at key sites in the catchment. This is commonly undertaken to confirm key processes, quantify seepage fluxes or provide more information relating to the hydrological, chemical or ecological aspects of connectivity. Such sites are selected on the basis of the initial desktop analysis and field surveys. Investigations at these specific sites can include: (i.) Seepage Measurement, involving the installation of seepage meters to estimate the direction and magnitude of seepage flux. As it is a direct measurement, seepage meters have the potential to validate indirect methods that involve measuring secondary indicators such as hydraulic head difference, chemical tracers or isotopes; 105 Conjunctive Water Management Framework

106 (ii.) (iii.) (iv.) Hydrometric Analysis, where piezometers and stream gauges are installed to allow local comparison of groundwater and surface water levels and so define hydraulic gradients. Pump tests can be undertaken to estimate shallow aquifer transmissivity; Artificial Tracers, by running a tracer test to quantify aquifer parameters and fluid transport properties, particularly in highly variable aquifers (such as fractured rock or karsts) and in solute transport studies (such as contaminants and nutrients). Specific tracers can be used to track pollutants such as human pathogens, where the movement and fate of these pollutants may not match water flow. Tracers can be used to assess the significance of local geological features (such as faults, clay layers or cave systems) on stream-aquifer connectivity; Temperature Studies, with time-series monitoring of temperature fluctuations for the stream and the sediment profile at varying depths to evaluate seepage flux and hydraulic conductivity. Temperature loggers are robust, simple and relatively inexpensive and available for various scales of measurement. Conjunctive Water Management Framework 106

107 7. Catchment Datasets and Sources Collation and interpretation of catchment datasets is part of the assessment of groundwater and surface water systems, including stream-aquifer connectivity (refer Chapter 6). Outlined below are the key datasets and their principle sources for Australian catchments. 7.1 Australian Catchment Data Infrastructures Over the last decade there have been a number of initiatives at the national level to report or promote coordinated access to catchment mapping and monitoring. Australian Water Data Infrastructure Project An Executive Steering Committee for Australian Water Resources Information (ESCAWRI) has been established to facilitate development of a comprehensive and accessible national water information framework, to support ongoing water reforms and national assessments of water resources. The Australian Water Data Infrastructure Project (AWDIP), under the guidance of ESCAWRI, is developing a distributed database network that will enable on-line access to jurisdictional water resource datasets. The AWDIP is initially focussing on hydrological datasets, including water quality data for reporting on the Resource Condition Indicators under the National Monitoring and Evaluation Framework Matters for Target. A prototype distributed database was available in June 2006, with access to hydrological, water quality and climate data. Additional datasets will be incorporated from Membership of ESCAWRI includes the Department of Agriculture Fisheries and Forestry, the Department of Environment and Heritage, a representative from each State and Territory government and a representative each from the National Water Commission, the Bureau of Rural Sciences, the National Land and Water Resources Audit, the CSIRO, the Australian Bureau of Statistics, the Bureau of Meteorology and the Murray-Darling Basin Commission. National Land and Water Resources Audit (NLWRA) The National Land and Water Resources Audit (NLWRA) is a partnership between all States, Territories and the Commonwealth to facilitate improved decision-making on land, vegetation and water resource management in Australia. Its mission is to provide data, information and nationwide assessments of Australia s land, water and biological resources to support sustainable development. Australian Natural Resource Atlas (ANRA) The Australian Natural Resource Atlas (ANRA, provides access to the data and information prepared by the NLWRA and partners. The functions of the Atlas are to: (i.) Provide ready access to information about the status and trends in Australia's natural resources; 107 Conjunctive Water Management Framework

108 (ii.) (iii.) (iv.) Link and integrate data and information by geography and topics users can navigate through the Audit's data and information by selecting a topic (eg. surface water quantity) and geography (eg. river basin); Provide a dynamic query and mapping facility for the preparation of userconstructed report and map-based products; and Link to data and information services available from other sources to ensure that users have easy access to the most up-to-date information (NLWRA, 2002b). Australian Natural Resource Data Library (ANRDL) The ANRDL provides free access to Audit data. The Data Library allows users to find NLWRA data and information products, and to download data where allowed by the data custodian for use in geographical information systems or spatial modelling tools. State of the Environment (SoE) National reporting of natural resource management and environmental issues every five years is a requirement of the Environmental Protection and Biodiversity Conservation Act 1999 (EPBC), with the latest release being for The 2006 SoE report is currently being prepared. The purpose and objectives of SoE Reporting are to: (i.) (ii.) (iii.) (iv.) (v.) Provide accurate, timely and accessible information on the condition and prospects of the Australian environment; Increase public understanding of these issues; Continue the development of national environmental indicators, and report on these indicators; Provide an early warning of potential problems; and Report on the effectiveness of policies and programmes designed to respond to environmental change, including progress toward achieving environmental standards and targets. Australian Spatial Data Directory (ASDD) The ASDD is an online directory ( launched in 1998 that provides access to descriptions of spatial datasets available from government and commercial organisations across Australia. The resource is used as a tool for finding out about existing spatial data and whether the dataset is useful for particular purposes. Geographic Extent Name Register (GEN) The GEN Register ( provides access to the geographical extents of a range of defined spatial entities such as map sheets, catchments, states, local government areas and statistical local areas. Each of these spatial entities is described in terms of category, name, jurisdiction and bounding geographical coordinates. Conjunctive Water Management Framework 108

109 7.2 Jurisdictional Catchment Data Infrastructures Over recent years, State and Territory governments have moved towards establishing data infrastructures to provide better access to their comprehensive holdings of natural resource data (including water) that may be maintained by multiple agencies within their jurisdiction. This recognises that State governments largely have the constitutional mandate for water resource management in Australia, and that they have had the historic role in collecting and maintaining key water resource data. The degree of integration of water data, both in terms of making water data from different agencies available from one access point and of linking water data with other natural resource datasets, is variable across the jurisdictions. Australian Capital Territory Internet access to various reports on water monitoring within the Australian Capital Territory is available at Environment ACT, Monitoring of dam storage levels and water use for the ACT is available at New South Wales In New South Wales, the Community Access to Natural Resources Information initiative (CANRI, provides integrated access to a range of natural resource datasets held by 16 different agencies in New South Wales. Water resource data such as river height and flow, river health indicators and water quality information have been made available from the site. The NSW Department of Natural Resources (DNR, maintains online access to key water data such as river water levels and flows, storage elevations, volumes and discharges and continuously monitored salinity ( Northern Territory The Northern Territory Department of Natural Resources, Environment and the Arts (NRETA, are responsible for water management in the Northern Territory. Hydrogeological mapping showing aquifer boundaries, typical bore yields and groundwater salinity at the Territory scale is available at Data reports for telemetered stream gauging sites is also available Queensland The Queensland Spatial Information Infrastructure Strategy (QSIIS, aims to provide easy access to integrated spatial information within the state. Online access to natural resource data has not as yet been implemented through the strategy. The Queensland Department of Natural Resources Mines and Water, provides access to gauging station information, stream flow data and water chemical analyses at their Watershed website 109 Conjunctive Water Management Framework

110 ( Annual water statistics are also reported (in pdf format) at South Australia The South Australia Atlas ( provides a common access point to State datasets (including water management areas, catchment boards, wetland and drainage) in an interactive atlas format, as well as a database of spatial products. The SA Department of Water, Land and Biodiversity Conservation (DWLBC, provides online access to groundwater level and salinity data from the State observation bore monitoring network through its Obswell facility The DLWBC also provides access to rainfall, stream water level, reservoir level, storage volume, flow volume, flow rate and salinity data via its Surface Water Archive (SWA, SA Water provides reservoir levels and River Murray flow data at Tasmania The Water Information System of Tasmania initiative (WIST, of the Tasmanian Department of Primary Industries, Water and Environment (DPIWE, provides on-line access to water resource information such as water management policies, current river levels and flows, catchment reports, and data summaries for individual sampling/flow sites. Mineral Resource Tasmania (MRT, is the custodian for groundwater information in the State, and provides on-line access to borehole information (eg depth, standing water level, groundwater salinity). Victoria The Victorian Water Resources Data Warehouse ( is designed to provide access to both raw and summary data on both water quantity and quality throughout the State. Victorian Resources Online (VRO, hosted by the Victorian Department of Primary Industries (DPI, is an access point for a broad range of natural resource information for the State, including information on water resources ( Western Australia The Western Australia Land Information System ( is a partnership of State agencies, local government authorities and private organisations, formed to facilitate the sharing of spatial information across the State. To this end, WALIS has developed the Western Australia Atlas ( as the main integrated web mapping tool, combining administrative, economic, statistical, environmental and social data derived from a range of agencies. Under the Tools, systems and data section, the WA Department of Environment website ( provides access to a range of water resource data and mapping. Conjunctive Water Management Framework 110

111 7.3 Catchment Mapping An overall catchment framework requires mapping of the topography and the drainage network. Australia-wide topographic map series containing mapping of surface water features are publicly available in digital form at different scales ranging between 1:10,000,000 to 1:250,000 (Table 7.2).The available national coverage of digital elevation models (DEM) used for hydrological studies is also indicated in this table. Geoscience Australia (GA, is the principal custodian for these national topographic datasets. In addition, there are State agencies responsible for topographic mapping at finer scales, say at 1:100,000, 1:50,000 or 1:10,000 within their jurisdiction. Table 7.1 provides details on the key land mapping agencies at the State and Territory level, including links to metadata relating to their topographic mapping products. PSMA (Public Sector Mapping Agencies) Australia ( is a government-owned company established to facilitate access to national datasets derived from these multiple government agencies. As well as cadastral and administrative boundaries, this also includes national topographic datasets that contain surface hydrology features, formed by integrating mapping at various scales derived from these agencies. Table 7.1: Key State/Territory Land Mapping Agencies Jurisdiction Agency Topographic Information ACT ACT Land Information Centre ACT Planning and Land Authority NSW NT QLD SA TAS VIC WA Land and Property Information NSW Department of Lands Land Information Division Department of Planning and Infrastructure Land Management and Use Division Department of Natural Resources Mines and Water Division of Environment and Geographic Information Department of Environment and Heritage Information and Land Services Division Department of Primary Industries, Water and Environment Spatial Information Infrastructure Department of Sustainability and Environment Land Information Services Division Department of Land Administration m =Products html Land use mapping is useful in providing a perspective on water use and also for estimating recharge and run-off coefficients across the landscape. The Australian Collaborative Land Use Mapping Programme (ACLUMP) is a partnership of State and Australian government agencies to produce consistent land use information across Australia. Information on ACLUMP and the available land use mapping is available from the Bureau of Rural Sciences ( BA1A-11A1-A B0A06257). The BRS Integrated Vegetation Online site provides mapping of major vegetation cover types. 111 Conjunctive Water Management Framework

112 An overview of geological mapping is provided by Geoscience Australia ( with the Geoscience Portal ( ) facilitating access to data for mapping, geophysics and borehole data across agencies. These include the State geological surveys, namely: (i.) (ii.) (iii.) (iv.) (v.) (vi.) (vii.) NSW Department of Primary Industries Victorian Department of Primary Industries Qld Department of Natural Resources, Mines and Water SA Department of Primary Industries and Resources Geological Survey of Western Australia Mineral Resources Tasmania Northern Territory Geological Survey Climate Data A range of climate databases are available for Australian catchments. The Bureau of Meteorology (BOM, is the national meteorological authority for Australia, providing meteorological, hydrological and oceanographic services. The Bureau maintains the Australian Data Archive for Meteorology (ADAM), with 65 Gb of data derived from about 20,000 rainfall sites, with over 1,000 sites having supplementary data such as temperature, wind or evaporation. Details for these monitoring stations are available ( The BOM regional offices and the National Climate Centre provide a range of custom and pre-packaged climate data products, including compilations on solar radiation, daily, monthly or annual rainfall, extreme design rainfall bursts, daily evaporation, maximum and minimum air temperatures, hourly or daily wind, relative humidity and sunshine duration. Information about the standard products designed to meet common needs is outlined at A subset of these datasets is freely available from the BOM website ( SILO ( provides access to BOM meteorological data in combination with agricultural data, to facilitate adoption of climatic risk management techniques in the agricultural sector. Products include meteograms to provide weather guidance; current weather forecasts, observations, warnings and satellite images; maps, data files or gridded data for daily and monthly rainfall; rainfall deficiency maps; maps, data files or gridded data for temperature; climate reports including air pressure, temperature, dew point temperature and cloud amount; seasonal climate outlooks of temperature and rainfall for periods of 3 months or longer; continuous historical meteorological station data using interpolation to infill missing data values; satellite-derived daily solar radiation data; and weather watch radar imagery. The SILO initiative was part of the Climate Variability in Agriculture R&D Programme (CVAP, Conjunctive Water Management Framework 112

113 Table 7.2: Nationally available mapping of topography and surface hydrology features (Brodie et al, 2004) Dataset Hydrological Features Scale Data Format(s) Custodian Data Access GEODATA TOPO 10M 2002 Drainage watercourses, lakes, reservoirs 1: 10,000,000 ArcInfo Export ArcView Shapefile MapInfo mid/mif Geoscience Australia Derived from GEODATA TOPO Free online: CD-ROM (fee TOPO 2.5M 1998 Global Map Australia 1M 2001 Drainage canals, water courses, lakes, reservoirs, swamps and offshore features Drainage aqueducts, water courses, inland water bodies 1: 2,500,000 ArcInfo Export ArcView Shapefile MapInfo mid/mif 1: 1,000,000 Arc Info Export Arcview Shapefile MapInfo mid/mif Vector Product Format Band Interleaved by Line (BIL) 250K Series 1 Geoscience Australia Derived from GEODATA TOPO 250K Series 1 Geoscience Australia Vector data generalized from GODATA TOPO250K Series 1 United States Geological Survey (USGS) provided raster images applies) Free online: CD-ROM (fee applies) Free online: CD-ROM (fee applies) VMAP Level 0 (Formerly Digital Map of the World) GEODATA TOPO-250K Series 1 Topographic Data GEODATA TOPO-250K Series 2 Topographic Data Drainage 1: 1,000,000 Vector Product Format (VPF) Drainage watercourses, lakes, wetlands Drainage lakes, reservoirs, swamps, streams, canals 250,000 GINA ArcInfo DXF MapInfo AS ,000 ArcInfo DXF MapInfo Geoscience Australia Updated version of National Imagery and Mapping Agency s (NIMA) Digital Chart of the World (DCW). Data derived from 1:1M Operational Navigation Charts Geoscience Australia Sourced from National Topographic Map Series (NTMS) and Royal Australian Survey Corps Joint Operation Graphics (JOG) Geoscience Australia CD-ROM (fee applies) CD-ROM Fee applies CD-ROM Fee applies National coverage in progress NATMAP Raster 250K Mapsheets 2002 ROSD Australia s River Basins 1997 Nested catchments and subcatchments for the Australian continent GEODATA 9 second DEM version 2 Drainage 1:250,000 Enhanced Compressed Wavelet (ECW) Drainage watercourse, lakes, reservoirs, canals, swamps Catchments drainage divisions, regions, basins Geoscience Australia Topographic data integrated from state, territory and commonwealth agencies variable MapInfo mid/mif PSMA Australia Ltd 1:10,000 1:100,000 1:250,000 ArcInfo Export ArcView Shapefile MapInfo mid/mif Geoscience Australia Drainage boundaries as defined by the Australian Water Resources Management Committee (WRMC) Catchments 1:250,000 ArcInfo Grid Geoscience Australia Derived from GEODATA 9 second DEM Version 2 Digital Elevation Model 1:250,000 GRIDASCII ASCII XYZ Geoscience Australia Based on ANUDEM 5.0 elevation gridding programme CD-ROM Fee applies Free online: CD-ROM (fee applies) Free online: au CD-ROM (Fee applies) 113 Conjunctive Water Management Framework

114 3 and 18 second DEM Critical Aeronautical Heights 1997 Digital Elevation Model 1:250,000 ASCII XYZ Geoscience Australia CD-ROM (Fee applies) Part of Australia Spot Heights 1:1,000,000 Formatted ASCII XYZ Geoscience Australia Free online: CD-ROM (fee applies) Conjunctive Water Management Framework 114

115 National compilations of climatic parameters have also been undertaken to support projects under the Audit (NLWRA, Gridded surfaces of annual and monthly means for canopy transpiration, maximum daily temperature, minimum daily temperature, incoming solar radiation, potential evaporation, total evaporation and rainfall have been generated by CSIRO Land and Water ( and are available from the Australian Natural Resource Data Library (ANRDL, The Bureau of Rural Sciences hosts a Rainfall Reliability Wizard ( which analyses the long-term monthly rainfall record. Various State agencies also monitor rainfall, particularly in concert with their stream gauging stations. For example, the Queensland Department of Natural Resources Mines and Water ( provides climate management information, including rainfall data, through its Long Paddock website ( 7.5 Hydrogeology Data At the national scale, the Audit (NLWRA, has mapping with a hydrogeological basis, such as: (i.) The mapping and categorisation of groundwater flow systems, based on recharge and flow behaviour and using attributes such as elevation, landscape form and geology (Coram et al, 2000), refer Figure 7.1; (ii.) Estimates of soil-based parameters such as mean annual deep drainage, soil saturated hydraulic conductivity (A and B horizons) and relative soil water content, that are useful in water balance studies. These national coverages, with similar compilations useful for hydrogeological mapping (such as land use and vegetation) are available from the Australian Natural Resource Data Library (ANRDL, State groundwater agencies have also published hydrogeological maps to support their groundwater management role, particularly since the 1980 s and focusing on priority aquifers in their jurisdiction (Figure 7.2). This mapping has been supplemented by production of small-scale nation-wide or large basin-wide maps coordinated by Australian Government agencies. Published hydrogeological maps across Australia include: (i.) The 1:5 million-scale Hydrogeology of Australia map compiled by Jacobson and Lau (1987), which is still the most current Australian-wide perspective of hydrogeological parameters such as aquifer type, groundwater availability, salinity and regional flow directions. This mapping is available digitally as GIS coverages from the Bureau of Rural Sciences (BRS, (ii.) The 26 maps at 1:250,000-scale of the Murray Basin Hydrogeological Map Series, which have been consolidated as a series of GIS coverages and are publicly available from the Australian Natural Resource Data Library (iii.) (iv.) (v.) (ANRDL, The 1:5 million scale map of the Hydrogeology of the Great Artesian Basin (Habermehl and Lau, 1997), which covers about 20% of the continent and is also available digitally from the BRS; Examples of specialised hydrogeological mapping such as groundwater vulnerability, beneficial use, salinity hazard/risk and groundwater dependent ecosystems; Hydrogeological mapping by State agencies covering their priority groundwater management areas. 115 Conjunctive Water Management Framework

116 Figure 7.1: Summarised Australian groundwater flow systems contributing to salinity (Coram et al 2000) Figure 7.2: Extent of traditional published hydrogeological maps at 1:250,000 scale or more detailed (Brodie, 2002) Conjunctive Water Management Framework 116

117 Borehole data is an important pre-requisite for the compilation of hydrogeological maps across catchments. The borehole databases maintained by the groundwater management agencies in the States and Territories are a critical hydrogeological data resource. These databases store primary data collected from boreholes as part of licencing requirements or from groundwater monitoring programmes. Table 7.3 summarises the status of these largely State-based databases, indicating a national coverage exceeding 500,000 boreholes. These borehole databases can store a broad range of data relating to the borehole itself, the geology and the groundwater but have many common elements, namely: (i.) (ii.) (iii.) (iv.) (v.) (vi.) (vii.) (viii.) (ix.) (x.) (xi.) The geographical position of the borehole site; The elevation of the site, as a reference for measurements of water levels; Drilling details of boreholes eg. method, depth, diameter, time; Construction details, particularly borehole casing and screens; The condition of the bore and the purpose(s) of the groundwater extracted, Downhole lithology and interpreted stratigraphy; Information on the aquifer intervals or water cuts intersected downhole; Water level measurements; Pump test summaries, with actual field measurements not commonly stored; Rates of groundwater extraction/flow; Groundwater chemistry. Table 7.3: Summary of significant groundwater databases in Australia (Brodie et al, 2004) Database Name Area Custodian Database Data Access Sites ACT ACT Environment ACT GDS NSW NSW Department of Natural Resources NT NT NT Dept Natural Resources, Environment and the Arts GWDB Qld Qld Dept Natural Resources, Mines and Water SA_GEODATA SA SA Dept of Water, Land and Biodiversity Conservation TIGER Tas Mineral Resources Tasmania Groundwater Module (previously BORIS) GDB Vic Vic Dept Sustainability & Environment Excel 900 Oracle 93,000 HydSys 30,000 Oracle 80,000 Oracle 140,000 Oracle 9,000 Ingres net 130,000 CLPR Vic Centre for Land Protection Research Access 3,250 WIN, Water Information System and HYDSTRA WA WA Department of Environment Agbores WA WA Department of Agriculture GWATER Aus Bureau of Rural Sciences Oracle (WIN), Hydstra 96,000 Oracle 4,000 Oracle 5, Conjunctive Water Management Framework

118 7.6 Water Chemistry Data It is estimated that about $ M is spent annually in Australia on monitoring water quality (Atech, 2000). This monitoring is undertaken by a range of Commonwealth, State or Local Government agencies, private companies, research groups and community-based groups, and over a range of settings, the most significant being rivers and creeks, industrial effluent and reservoirs and lakes (refer Table 7.4). The most common reasons cited for monitoring water quality are compliance with health or environmental regulations, operational or process control, or for environmental or catchment health, with the most common parameters monitored being general physico-chemical attributes (eg temperature, ph), nutrients, ions and pathogens (Atech, 2000). Table 7.5 outlines the organisations that undertake significant monitoring of water quality. Table 7.4: Water type categories with the most significant water quality monitoring effort (Atech, 2000) Water Type Category Number of Monitoring Programmes % of Programmes Rivers and creeks Industrial effluent Reservoirs and Lakes Drinking water reticulation systems 82 8 Estuaries 83 8 Groundwater 69 7 Domestic wastewater 68 7 Coastal and marine waters 46 5 At a national level, the Australian Water Resources Assessment 2000 (NLWRA, 2001) reported the level of significance of various water quality issues such as nutrients, salinity, turbidity and ph at a river basin scale. The analysis highlighted the catchments where monitoring was insufficient for undertaking exceedance or trend analyses. Other national assessments by the NLWRA associated with water quality and available from the ANRDL ( include: (i.) (ii.) (iii.) Sediment and nutrient source, sink, load and delivery information compiled from the Water-borne Soil Erosion Project; Reporting of the proportion of farms with significant land or water degradation problems at the Statistical Division (SD) level; Mapping of current and future dryland salinity hazard. These assessments were undertaken by State/Territory agencies using a combination of groundwater levels and trends, known salinity incidences, soil properties and topography. At the national level is the Waterwatch initiative ( which is a community-based water monitoring programme designed to encourage local participation in catchment management. Over 300 community groups in 200 catchments are involved in the regular monitoring of about 5,000 sites across Australia, including physical and chemical testing. The programme supports Statebased facilitators and activities: (i.) (ii.) (iii.) (iv.) Waterwatch ACT Waterwatch NSW Waterwatch Queensland Waterwatch South Australia Conjunctive Water Management Framework 118

119 (v.) (vi.) (vii.) Waterwatch Tasmania Waterwatch (Victoria) Ribbons of Blue (Waterwatch WA) Streamwatch ( is a similar public water quality network established around the Sydney metropolitan area and sponsored by Sydney Water ( The National Pollutant Inventory ( provides public access to information on the types and amounts of 90 priority substances being emitted to the environment. The inventory covers pollution emission data for about 3,000 facilities within 29 catchments across Australia. At the State level, a wide range of water management, environmental protection and health agencies maintain water quality databases to service their regulatory, licensing or management activities (refer Table 7.5). The more significant of these databases relate to issues such as rural drinking water, sewage treatment plants, algal blooms, pesticides, agricultural waters, riverine sediment or salinity trends. 119 Conjunctive Water Management Framework

120 Table 7.5: Organisations undertaking significant water quality monitoring (modified from Atech, 2000) Organisation Jurisdiction Web Monitoring Focus Waterwatch AUS River health Murray Darling Basin Commission MDB Salinity Environment ACT ACT Natural resource management ACT Health ACT Recreational waters ACT Department of Urban Services ACT Landfills Sydney Water Corporation NSW Urban water supply Sydney Catchment Authority NSW Urban water supply catchments NSW Department of Natural Resources NSW Natural resources management NSW Environmental and Conservation NSW Environmental regulation and compliance Hunter Water Corporation NSW Urban water supply NT Department of Natural Resources, NT Natural resources management Environment and the Arts NT Department of Primary Industries, Fisheries and Mines NT Environmental compliance of mining industry NT Power and Water Authority NT Urban and regional water supply Qld Department of Natural Resources, Qld Natural resources management Mines and Water Qld Environmental Protection Agency Qld Environmental regulation and compliance South East Queensland Water Corporation Qld Urban water supply Great Barrier Reef Park Authority Qld Impacts on GBR SA Department of Water, Land and SA Natural resource management Biodiversity Environmental Protection Authority SA SA Environmental regulation and compliance SA Water Corporation SA Urban water supply Tas Department of Primary Industries, Tas Natural resource management Water and Environment Hydro Tasmania Tas Power station discharges Mineral Resources Tasmania Tas Groundwater Tasmania Department of Health and Human Tas Health compliance Services Victorian Department of Sustainability and Vic Natural resource management Environment Melbourne Water Corporation Vic Urban water supply Goulburn-Murray Water Vic Irrigation and drainage Rural water supply Environmental Protection Authority Victoria Vic Environmental regulation and compliance WA Department of Environment WA Natural resource management Environment regulation and compliance WA Water Corporation WA Urban water supply Irrigation and drainage Department of Agriculture WA WA Groundwater salinity Nutrients Conjunctive Water Management Framework 120

121 7.7 Hydrology Data In terms of data availability, Table 7.6 outlines the significant surface water monitoring databases in Australia, highlighting the State and Territory agencies involved in water management as the main data custodians. As a guide to the location of existing stream gauging sites, the Water Resources Station Catalogue ( developed by the Bureau of Meteorology provides a national inventory of the river gauging stations, as well as rainfall and evaporation stations, across the country. A summary of the agencies that provide water monitoring data for water storages is provided in Table 7.7. Monitoring of groundwater hydrology (eg. standing water levels, groundwater pressure, and flow) is typically stored in the borehole databases maintained by the State agencies, as outlined in Table 7.3. Table 7.6: Significant surface water monitoring databases in Australia (after Brodie et al, 2004) Database Name Area Custodian Water Features Water Resource ACT Environment ACT Information System ct.gov.au/airandwater/wat er Data Access Data Themes Sites 360 Surface Water Data NSW NSW Dept Natural Streams Resources channels reservoirs es.nsw.gov.au/water/inde x.shtml water flow water level rainfall water quality 1,700 NSW Manly Hydraulics Laboratory au/ streams estuaries ww/dcol.htmlx water level water quality tides rainfall 200 Surface Water and Water Quality NT NT Dept Natural Resources, Environment and the Arts whatwedo/waterresources/index.html streams rainfall wedo/waterresources/surface/telemetered sites/index.html water flow water level Surfacewater Resource Information Qld Qld Dept Natural Resources Mines and Water u/resources/index.html streams atershed/index.html water level water flow temperature conductivity water quality 5,000 State Surface Water Archive SA SA Dept of Water, Land and Biodiversity Conservation au/ streams rainfall ubs/surface_water_archive/a1 pgs/index.htm water flow water level velocity 1,035 Tasmanian Water Information Database Tas Tas Department Primary Industries, Water and Environment streams rainfall wist/ui water level water flow water quality 17,000 Victoria Water Resources Data Warehouse Vic Vic Dept Sustainability streams and Environment /dse/index.htm water flow water levels water quality 90, Conjunctive Water Management Framework

122 Database Name Area Custodian Water Features Data Access Data Themes Sites WIN, Water Information System and HYDSTRA WA WA Department of Environment wa.gov.au streams wetlands rainfall ormation/telem/table.htm water flow water level water quality rainfall 15,000 Water Resources Station Catalogue Aus Bureau of Meteorology ydro/ streams /wrsc Metadata 2,050 Conjunctive Water Management Framework 122

123 Table 7.7: Summary of organisations providing monitoring data on water storages Area Custodian Data Themes Data Access MDB Murray Darling Basin Commission River Murray Water Volume flow, salinity n_centre ACT ActewAGL Volume (%) water/damcapacity.htm NSW NSW Department of Natural Resources Volume NSW Hunter Water NSW Sydney Catchment Authority Volume rainfall Volume rainfall html NT NT Power and Water Corporation Volume rainfall outus/darwin_river_dam.htm#levels Qld Sunwater Volume Blue green algae status Qld SEQWater Volume level sp?name=damoperationsandmaintenance rainfall SA SA Water Volume w/waterdataupdate/reservoir+levels.htm Vic Barwon Water Volume h2o=services.water_levels Vic Central Highlands Water Volume (%) rainfall Vic Coliban Water Volume rainfall voirs.html Vic Gippsland Water Volume erlevel.asp Vic South East Water Volume eservoirs.asp?area=bus Vic Vic Department of Primary Industries Volume ges/water-streports-storage Vic Melbourne Water Volume ter/water_storages/water_storages.asp WA WA Water Volume rainfall s_storage.cfm?rootparent=ourwatersources 123 Conjunctive Water Management Framework

124 7.8 Water Management Data The most recent Australia-wide perspective on water management is the Australian Water Resources Assessment 2000 (NLWRA, 2001), producing national datasets including: Australian Surface Water Management Areas, defining 325 regions used by State/Territory water management agencies for reporting of the status of water management. A linked database contains information on the availability, use, allocation, sustainability and management of water in these defined regions. Data from the 1985 Review of Australia s Water Resources and Water Use (DPIE, 1987) is also available for comparison; Australian Groundwater Management Units, Unincorporated Areas and Provinces, involving the mapping of 538 groundwater management units and unincorporated areas, the former being the groundwater systems that are defined and recognised by State/Territory agencies for management purposes, the latter being residual areas with low levels of groundwater development and corresponding management input. These have been aggregated into 69 groundwater provinces for reporting purposes. Information such as surface area, groundwater allocation and use, average salinity, depth to top of aquifer, and an estimate of sustainable yield has been compiled for each unit where available. This allowed a national analysis of where groundwater resources are over-allocated or over-used relative to sustainable yield estimates; Australian Irrigation Areas (Version 1A), showing designated and actual irrigation areas across Australia. A gridded version indicating the proportion of land area under irrigation for each 0.05-degree land cell is also available; Major Water Resources Infrastructure, containing the location of 1,237 dams and their unique identifiers, names and total capacity for water storage; Surface Water Gauging Stations, with the location of 3,143 significant monitoring stations for surface water management, as well as a range of statistics for flow and rainfall. Metadata and the facility to freely download are available for these datasets from the Australian Natural Resources Data Library (ANRDL, Another national data resource in terms of water management is the Water Account for Australia. This is a compilation of detailed statistics on water supply, consumptive use and management of water, by the Australian Bureau of Statistics (ABS, The data is obtained from government agencies, industry associations, businesses and farmers. The Water Account has been prepared for the periods and as well as for ment. The ABS also provides other water-related statistics including irrigation data in Agricultural Commodities (ABS ), household use of water in Environmental Issues: Peoples Views and Practices 2001 (ABS 4602). Conjunctive Water Management Framework 124

125 As water management in Australia is vested in the States and Territories, agencies in these jurisdictions maintain a range of databases to support their management role. These include details on administrative or management arrangements (eg regions, catchment management boards, prescribed areas, proclaimed catchments etc), water licencing, infrastructure such as irrigation areas, dams and storages, or water usage. 7.9 Aquatic Biota and Ecological Data Some examples of databases that can have relevance to the aquatic ecology of a catchment include: (i.) (ii.) (iii.) 125 Assessment of river condition, such as mapping and data collection under the National River Health Programme ( This includes a database on Australia s Rivers and Catchment Condition ( which maps rivers based on a disturbance index to identify priority undisturbed (wild) rivers. The NLWRA Australian Catchment, River and Estuary Assessment also included assessment of the condition of about 14,000 river reaches across the more intensively used catchments using a national protocol based on an a combined aquatic biota and environment index; Survey of wetlands or other environmental assets, with a focus on wetlands of international, national or regional significance. The Department of Environment and Heritage (DEH, maintains a directory of 63 Ramsar-listed wetlands as well as nationally important wetlands The selection criteria for national importance include being good examples of a wetland type occurring within a biogeographic region, playing an important ecological or hydrological role, importance as the habitat for animal taxa at a vulnerable stage in their life cycles, providing a refuge when adverse conditions such as drought prevails, supporting 1% or more of the national populations of any native plant or animal taxa, supporting native plant or animal taxa or communities which are considered endangered or vulnerable at the national level and/or of outstanding historical or cultural significance. Environment Australia also maintains a database of locations of places such as World Heritage properties, Ramsar wetlands, threatened species or protected areas, which may be relevant in determining obligations under the Environment Protection and Biodiversity Conservation (EPBC) Act, This is called the Protected Matters Search Tool, Collections relating to specific genera, such as the separate databases maintained by the Australian Museum ( on birds, crustacea, aquatic invertebrates and fishes etc. Environment Australia maintains on-line databases such as the Australian Biodiversity Information Facility (ABIF, and the Species Bank ( The Australian Aquatic Invertebrate Web Keys ( compiled by CSIRO Entomology ( provides information on the macroscopic invertebrate taxa occurring in Australian inland waters. Australia s Virtual Herbarium (AVH, is a web-based botanical information resource incorporating 6 million specimen records developed by a consortium of Conjunctive Water Management Framework

126 Australian herbaria. State government agencies also maintain specific databases as part of their regulatory role in environmental protection or fisheries management. For example, NSW Department of Primary Industries ( maintain various databases relating to stocking rates, population studies, kills, protected species sightings and resources of fish. The NSW National Parks and Wildlife Service ( is the custodian for data relating to an annual waterbird survey across eastern Australia. In South Australia, an annual frog census is coordinated by the SA Environmental Protection Agency ( Conjunctive Water Management Framework 126

127 8. Mapping Groundwater-Surface Water Connectivity Development of simple methods that allow a rapid assessment of the potential hydraulic connection between groundwater and surface water systems are of great value to natural resource managers, State and catchment water agencies and in the development of water policy. Such mapping of connectivity potential can be useful in water accounting as well as for conjunctive water management purposes. A simple GIS based method has been developed to map the potential hydraulic connection between groundwater and surface water systems in a catchment, taking into account hydrological and hydrogeological factors. This method can handle spatially distributed catchment-scale data and can be modified depending on data availability. The methodology provides sufficient information for a first-cut prioritisation of stream reaches identifying potential connected and disconnected systems, enabling targeting of further investigations and management development. It is important to remember that this GIS methodology focuses on the conductance of the geological material to derive an indicator for the potential for water movement. This is a precursor to methods such as hydrographic analysis or numerical modelling to derive an understanding of the direction and magnitude of seepage flux. 8.1 Description of Connectivity Index Model Stream-aquifer connectivity potential in a catchment can be determined by means of a rating index approach. To fully describe the catchment processes, many input data and their spatial and temporal variability has to be taken into account. Hydrological and hydrogeological factors mapped at the catchment scale can be combined to obtain a final rating. The general data inputs needed for this method are: (i.) (ii.) (iii.) (iv.) Depth to water table; Stream bed characteristics; Geology; Geomorphology. One of the prime considerations is the conductance of the geological material. As well as the aquifer itself, this also includes the material of the stream bed and banks, being the interface between stream and aquifer. For example, it is assumed that connectivity will be high where stream bed sediments consist of gravel and the aquifer consists of alluvial sands. Alternatively, the connectivity will be low where there is an intervening layer of clay of significant thickness. A numerical rating and ranking system was devised for the four parameters mentioned above. The system contains the three components of ranges, ratings and weights. The dataset representing each parameter is subdivided into meaningful ranges, with a rating assigned to each data range. The rating represents the relative influence on connectivity. The weights determine the relative importance of each parameter. Each parameter is assigned a relative weight ranging from 1 to 5; a weight of 1 is the least significant and a weight of 5 is the most significant. Sensitivity analysis can be undertaken to explore the effects of different weightings placed on the parameters. 127 Conjunctive Water Management Framework

128 The following is an example of the overall additive model where a numerical connectivity index is obtained. Connectivity Index = Potential for groundwater-surface water connectivity = (3 x depth to water table) + (5 x stream bed sediments) + (5 x aquifer material) + (2 x geomorphology) Figure 8.1 outlines a flow chart for this process. The calculated index identifies the stream reaches that will have potential for groundwater-surface water connectivity. The higher the connectivity index, the greater the potential for stream-aquifer connectivity. The rigour in the index model has been achieved without making it a data-hungry model and sacrificing its practicality. The potential connectivity ratings for different river reaches provided by this model can be compared with actual field measurements. Depth to water table Stream sediments characteristics Aquifer material/geology Groundwatersurface water connectivity potential Geomorphology Figure 8.1: Flow chart showing structural component of the connectivity index model In an initial implementation, the methodology used a simple spreadsheet software format (Figure 8.2). The tool allows the user to select appropriate ranges and ratings for each parameter using a drop down menu. The spreadsheet then converts the various input parameters into numerical values using a series of mathematical and logical steps using standard spreadsheet functions. Variables can be changed by the user, and the connectivity indices automatically calculated. The spreadsheet presents indices of groundwater-surface water connectivity as high, moderate and low potential. The spreadsheet can be used as an exploratory tool to determine the relative sensitivity of each parameter, so that data collection and preparation can be focussed on the most critical data sets. Conjunctive Water Management Framework 128

129 Figure 8.2: Spreadsheet implementation of the potential connectivity index model 8.2 Integration of Connectivity Index Model in a GIS Environment The index method was implemented in a GIS environment using ESRI ArcGIS 9.0 to enable the creation of maps of connectivity potential at the catchment scale. The GISbased approach was trialled using datasets for the Border Rivers catchment (Box 8.2). Potential connectivity was mapped spatially by combining four raster datasets into one representing water table depth, stream sediments, aquifer material and geomorphology. Map algebra was used to derive and assign a single numerical index along the river reach of the catchment. The map algebra equation is formulated from the connectivity index model equation based on weighting individual data parameters and combining the results into a single index value. The higher the single index output, the greater the potential for groundwater-surface water connectivity. The final single index value output from the map algebra equation for each grid cell in the raster is further categorised into low, medium and high connectivity potential classes based on the output classification classes in the connectivity model. These categories can then be mapped using a standardised legend to spatially represent the estimated potential connectivity along the river reaches (Figure 8.3). 129 Conjunctive Water Management Framework

130 Box 8.2 Application of a GIS-based index approach for mapping streamaquifer connectivity potential in the Border Rivers catchment The following four catchment datasets for the Border Rivers catchment were rasterised and combined to derive a connectivity index (Figure 8.3): (i) Depth to water table: The depth to groundwater measurements from existing State water agency borehole monitoring were interpolated into a gridded surface (250m cell size) of the depth to the water table. The resulting watertable depth raster was then reclassified into three broad categories according to the weighted value in the connectivity index model. Shallow watertables (<10 m) were assumed to reflect higher connectivity with streams when compared with deeper watertables (>20 m). (ii) Stream/river bed characteristics: The NLWRA soil saturated hydraulic conductivity (permeability) of Layer 2 gridded (1.1 km cell size) national dataset (1999) was used as a surrogate for stream bed characteristics. The dataset was categorised into five permeability classes of very low; low; moderate; high and very high. The permeability classes were then reclassified into a weighted value based on values from the connectivity index model. Finally the raster dataset was re-sampled to 250m cell size for the catchment using the bilinear resampling technique. River beds composed of sand and gravel deposits were assumed to have high connection, any silt and clays a low connection. (iii) Geology: The aquifer material data was sourced from the 1:250,000 scale Geology of the Murray- Darling Basin digital dataset. Lithology units from the dataset were used to identify the type of aquifer material. Where lithology units do not differentiate between sediment types, lithological logs sourced from borehole databases maintained by State agencies can be used as an alternate dataset. Borehole data can provide greater detail in the spatial variability of aquifer lithology. However, using drillers logs to classify the aquifer material distribution in the profile is more time-consuming. It is assumed that aquifers with gravel and sand materials tend to have higher potential for connectivity with streams and are thus rated more highly. Geological units dominated by silt, clay or fractured rocks are assumed to have lower potential for connection and are thus assigned low index values. (iv) Geomorphology: The Multi-resolution Valley Bottom Flatness Index (MrVBF; Gallant and Dowling, 2003) was used to interpret landscape geomorphology. The MrVBF index allows for the delineation of erosional and depositional environments based on an algorithm applied to a DEM at multiple scales. Narrow alluvial valleys with high rainfall and shallow groundwater are assumed to have high connection with streams and are thus assigned higher values compared with lower values assigned to wide, arid alluvial plains with deep groundwater levels. Conjunctive Water Management Framework 130

131 Figure 8.3: GIS-based approach for mapping stream-aquifer connectivity applied in the Border Rivers catchment 131 Conjunctive Water Management Framework

132

133 9. Conceptualisation and Prediction 9.1 Conceptual Models A conceptual model is developed from the collation and interpretation of available datasets. The conceptual model summarises the current understanding of the key catchment processes, dependencies and impacts on the water resource. The essential function and behaviour of surface water and groundwater systems and their interaction in the catchment is described. The conceptual model can be presented graphically, typically in cross-section or block diagram format, with supporting descriptions. An example of such a presentation of the conceptual model for a groundwater flow system is presented in Figure 9.1. The key elements of a conceptual model are: (i) (ii) (iii) (iv) (v) (vi.) The catchment framework, defining the boundaries of the study area, in terms of groundwater and surface water divides; The hydrogeological framework, in terms of the general structure and properties of the aquifers, aquitards and other geological units making up the catchment; The surface water framework, the configuration of streams, lakes, wetlands, reservoirs, estuaries and other surface water features in the catchment landscape; The hydrological framework, the key processes defining the movement of water throughout the landscape such as rainfall, evapotranspiration, run-off, stream flow and groundwater flow; The ecosystem framework, the key environmental assets that have a dependency on the surface water or groundwater features of the catchment such as wetland ecosystems, endangered aquatic species or important vegetation communities; The anthropogenic framework, the human-induced factors that can influence hydrological processes in terms of water quantity and quality, such as pumping, land clearing, intensive agriculture, drainage, flood mitigation works, mining etc. Also included are the social dependencies of the water resource such as heritage and cultural values. Figure 9.1: Example of a block diagram type conceptual model for a groundwater system (Middlemis, 2001) 133 Conjunctive Water Management Framework

134 9.2 Predictive Models The conceptual model forms the foundation for further field investigations as well as the development of predictive models. These are essentially mathematical models or simple tools that contain equations that represent the physical processes of water movement in a catchment. Encapsulating the hydrological processes using governing mathematical equations, boundary conditions and estimates of catchment parameters can provide a powerful predictive tool. The conceptual model outlines the dominant processes and underlying simplifying assumptions to be implemented by the predictive model. It is important to clarify the complexity of the solution required, as an oversimplified model may not be adequately robust and an over-complex model may be costly, time-consuming and have intractable data requirements. The level of conceptualisation and requirements of the predictive model depends on the management objectives, available resources and field data, and the legal and regulatory framework (Bear et al, 1992). Mathematical models can vary in form and complexity and include analytical, analytical element, boundary integral and numerical techniques. Box 9.1 presents one of many alternatives to implement a predictive model for a connected water resource. Box 9.1 An example of a predictive modelling approach of a connected water system The area of the catchment can be represented as an interconnected 3D grid of cells, which can be given a number of different parameters to represent natural variation in hydrogeological properties. Groundwater fluxes into and out of these cells can be simulated using the numerical groundwater flow modelling code MODFLOW (Harbaugh et al, 2000). Once calibrated against empirical data (ie. historical records of groundwater recharge and extraction and water level monitoring) the model can be used to develop predictions of what future groundwater levels will be for any projected changes in groundwater extraction. This response function can be developed for a variety of different projections of what future pumping scenarios may be. An environmental component can be incorporated into the response function that allows for the environmental water requirements of each connected ecosystem. As well as this, a water resource management component can be used to allocate the remaining water between surface water withdrawal and groundwater extraction based on different water property right arrangements and the seasonal stream flows and groundwater recharge. An economic component is incorporated into the model that allocates water extracted on-farm between various cropping enterprises. At the farm level, the decision maker is faced with an intermediate-term decision of allocating land versus short-term decisions of allocating water between crops within the season, as the actual allocation of water may be different from farmers expectation at the beginning of the season. In this manner the impact on farmer s decisions of uncertainty in water supply throughout the season is captured. The farmer is assumed to maximise profits subject to land and water resources available for a given set of prices and production technologies. Analytical Models In analytical models the partial differential equations that govern water flow are directly solved. Analytical models are useful in providing simple, quick and Conjunctive Water Management Framework 134

135 approximate solutions to one- or two-dimensional flow problems, with relatively small data requirements. However, simplifying assumptions such as straight boundaries or homogenous aquifers are required that may not be valid in reality. Analytical models are often used in preliminary investigations and for validating other modelling efforts. Initial development of analytical models focused on stream depletion due to groundwater extraction (Theis, 1941; Glover & Balmer, 1954; Jenkins, 1968). Later refinements include existence of a semipermeable layer (Hantush, 1965), analysis of cyclic pumping wells (Wallace et al, 1999), a stream that only partially penetrates the aquifer (Hunt, 1999) and estimation of the baseflow reduction and stream infiltration components of stream depletion as well as the timing of hydraulic gradient reversal (Chen, 2003). Analytical solutions that represent the hydraulic interaction between streams and a range of different aquifer types (confined, leaky or watertable) are publicly available (Barlow & Moench, 1998). Analytical models can be constrained by assumptions that oversimplify the conceptual model or are invalid for the catchment. In analytical element models, analytical solutions for different processes (such as groundwater pumping, recharge, and seepage boundaries) are spatially combined and superimposed. This allows greater capability in simulating the complexity of hydrological processes in a catchment, and to accommodate layering and heterogenity in aquifer properties. Examples of available analytical element modelling tools include QUICKFLOW, WINFLOW, TWODAN, GFLOW and Visual Bluebird (Table 9.1). Boundary integral equation models involve the combination of analytical and numerical solutions, but are not commonly used. Numerical Models Numerical models use approximation and iterative techniques to solve the governing equations. Gridded methods such as finite difference or finite elements are used to discretise the model region into smaller increments. This allows better handling of complexity in terms of spatial and temporal variability (such as boundary conditions, aquifer structure and hydraulic parameters, recharge and discharge processes) and for three-dimensional solutions to be constructed. As such, numerical models tend to be more complicated and time-consuming, and require a larger array of inputs and careful calibration. There are four possible alternatives in terms of the numerical modelling of connected groundwater-surface water systems (CDM, 2001), refer Table 9.1. These are: (i.) (ii.) Using a developed fully-integrated surface water and groundwater hydrological model. Only a few fully-integrated models that encompasses surface, unsaturated and saturated zone flow have been developed; such as MIKE SHE, IHSim and IWFM; Using or expanding the surface water capabilities of developed groundwater modelling software. Many groundwater numerical models omit or oversimplify surface-groundwater interaction processes. The commonly used groundwater flow model MODFLOW (Harbaugh et al, 2000) does include packages that represent interactions with various surface water features. For 135 Conjunctive Water Management Framework

136 (iii.) (iv.) example, the MODFLOW River package calculates seepage flux using Darcy s Law with estimates of a leakage coefficient as well as the head difference between the groundwater elevation in the model cell and the specified stream elevation; Using or expanding the groundwater capabilities of developed surface water modelling software. Many surface water models combine all unmeasured fluxes (such as evaporation, in-stream use, ungauged tributary inflows, and unlicensed abstractions) into one term, which also includes seepage with the groundwater system. The urban runoff model SWMM (US EPA) and the Integrated Quantity and Quality Model IQQM (NSW DNR) are surface water models with limited representation of groundwater processes. IQQM simulates surface water movement using a series of interconnected nodes to simulate water movement from one point in the river or stream to the next; Using or developing an intermediate modelling package linking established groundwater and surface water models. Models such as MODBRANCH linking MODFLOW and the stream network model BRANCH (Swain & Wexler, 1996) and ISGW linking MODFLOW and HSPF have been designed in this way. Software to link the surface water model IQQM to the MODFLOW groundwater package have recently been developed and trialed (REM, 2002). A properly constructed mathematical model can be a powerful analysis tool for a range of purposes (Middlemis, 2001), including to: (i.) (ii.) (iii.) Improve understanding of the key hydrological processes. The behaviour of groundwater-surface water systems can be evaluated and the water balance components quantified in terms of storage and flux. As an example, Box 9.2 describes the use of MODFLOW to evaluate time lags of stream flow depletion due to groundwater pumping in various aquifer types; Help predict the impact of various water management options or changes to catchment condition, assist in the optimisation of management solutions and provide input to the engineering design of on-ground works. Models have been used to simulate the effect of changes to water allocations, increased groundwater development, water trade, long term climatic trends or land use change, by comparing with a baseline status quo scenario. Developing models that simulate linked physical, biological and economic systems under different scenarios is an invaluable way of understanding catchment processes and their response to change; Help synthesise data and encapsulate the existing understanding of the groundwater and surface water systems. Models are often used to interpolate the available (but limited) data both in space and time, as a cheaper and quicker option than intense data collection. Information gaps can be identified and sensitivity and uncertainty analysis undertaken to guide data gathering and risk management. Models can be used as a visualisation and communication tool. However, mathematical models need a robust understanding of the key hydrological processes. A model can have significant errors because of the need to: Conjunctive Water Management Framework 136

137 (i.) (ii.) (iii.) (iv.) (v.) (vi.) Simplify complex natural systems by making key assumptions. Model results can be called into question if the basic assumptions are not valid; Interpolate between often sparse data points (such as monitoring bores or stream gauges); Integrate hydrological processes that operate at different scales in space and time. Surface water processes tend to occur at much shorter timescales than groundwater processes; Assess the natural variability in fluxes (such as episodic recharge or flood events) often with inadequate time series monitoring; Deal with parameters (such as transmissivity) that can vary significantly over the model area; and Use modelling code that intrinsically does not have a unique solution. 9.3 Modelling Guidelines General guidelines have been developed by the Murray-Darling Basin Commission relating to groundwater flow modelling (Middlemis, 2001). This is a useful resource for the non-specialist client in scoping and developing model project specifications, project management and the model review process. The guidelines also have comprehensive technical information relating to the different stages of the modelling process such as conceptualisation, calibration, prediction, uncertainty analysis and reporting. Although principally designed for groundwater flow models, the guidelines have general principles useful for more integrated modelling initiatives. The guidelines are available from the MDBC website The HarmoniQuA project involves a consortium of European agencies and universities to develop a user-friendly guidance and quality assurance framework for best-practice river basin modelling. This involves: (i.) (ii.) (iii.) (iv.) A harmonised, methodology with associated guidelines (generic, domain specific and integrated) for good modelling practice; A computer based toolbox to provide guidance, monitoring and reporting functionality to the HarmoniQuA knowledge base and support the model user/water manager throughout the QA process; Results of two sets of real life test case studies; and Infrastructure for exploitation and dissemination, including training material. The two main products are the Modelling Support Tool (MoST) and Knowledge Base (KB) which are available as a free download. The overall modelling process has been structured into five key processes (Figure 9.2). The Knowledge Base components relate to various components of catchment water management including groundwater, precipitation-runoff, river hydrodynamics, flood forecasting, water quality, ecology, and socio-economics. The HarmiQuA project aims to support the implementation of the EU Water Framework Directive. 137 Conjunctive Water Management Framework

138 Figure 9.2: HarmoniQuA flowchart of the process of modelling river basin processes Relevant Links CEML Environmental Model Library ECOBAS Geotechnical and Geoenvironmental Software Directory George E Brown Jr Salinity Laboratory Geotechnical and Geoenvironmental Software Directory Hydrology Web Computing Integrated Quantity and Quality Model (IQQM) : International Groundwater Modelling Centre Software for Hydrogeologists USEPA GWERD Software USGS Water Resources Software Conjunctive Water Management Framework 138

139 Table 9.1: Examples of modelling code with varying levels of surface water and groundwater capabilities Model Source Description Analytical Models GWFLOW tware/igwmcsoft/ Suite of 7 analytical solutions for groundwater flow problems including streamflow depletion WALTON35 tware/igwmcsoft/ Series of 35 simple analytical/numerical models for flow, solute and heat transport including streamflow depletion and saltwater intrusion Analytical Element Models GFLOW Models steady state flow in a single heterogenous aquifer. Uses stream networks with calculated streamflow TWODAN Visual Bluebird WINFLOW com/ groundwater/software/softw are.html dels.com/software/software. asp Two-dimensional analytical groundwater flow model Interface for 2-D single-layer analytical element groundwater flow Analytical model for 2-D steady state and transient groundwater flow Integrated Numerical Models IHSim tware.htm Integrated finite element model for 3-D subsurface and 2-D overland/stream flow and transport InHM Integrated Hydrology Model integrates surface and subsurface flow and transport processes using physically-based first-order flux relationships IWFM a.gov/modeling/hydrology/i WFM/index.cfm Integrated Water Flow Model is a water resources management and planning model that simulates groundwater, stream flow and interactions, soil moisture etc. Includes a land use based approach of calculating water demand MIKE BASIN GIS-based water resource modelling framework at river-basin level including surface water, groundwater, rainfall, water quality etc. MIKE-SHE Modelling system with modules for 3-D groundwater flow, overland flow, unsaturated flow, solute transport, water quality, irrigation, particle tracking etc MODHMS WASH123D ZOOMQ3D tware.htm il/chl.aspx?p=s&a=softwa re;1 e/3dmodelling/zoom.html MODFLOW-based groundwater flow integrated with dynamic interactions with overland flow and channel flow analysis Watershed Systems of 1D Stream-River Network, 2D Overland Regime and 3D Subsurface Media. Finite element integrated model supported by GMS graphical environment Saturated groundwater flow model using object oriented programming and able to integrate surface water components Surface Water Focused Numerical Models HSPF re/hspf.html Hydrological Simulation Programme for modelling the hydrologic and water quality processes, including groundwater recharge and baseflow 139 Conjunctive Water Management Framework

140 IQQM SWMM care/water/iqqm/ rl/models/swmm/index.htm Integrated Quantity and Quality Model is a node-based hydrological river simulation package with groundwater-surface water interaction capability Dynamic rainfall-runoff model for water flow and quality in urban areas, included interflow between groundwater and drainage system Groundwater Focused Numerical Models DYNFLOW FESEEP ystem/dynflow.html /cgr/software.shtml 3-D finite element groundwater flow model with stream/river package 2-D finite element steady state seepage analysis FLOWNET Generates 2-D flow net using finite difference approximation GGU-SS FLOW 2D/3D Steady state 2-D or 3-D groundwater flow using finite element analysis MARTHE 3-D multilayer groundwater model with capabilities for salt water interface and coupled river (and drain) network MicroFEM MODFLOW 2000 MODRET PLASM ducts/microfemw.html software/modflow2000/modf low2000.html egroup.com/ c/ Finite element groundwater model with drain, river and wadi top systems 3-D finite difference groundwater flow model with various modules including groundwater-surface water interactions. De facto industry standard Modified version of MODFLOW for calculating infiltration from retention ponds to unconfined shallow aquifers 2-D nonsteady finite difference groundwater flow model including option for stream leakage SefWeir Finite element analysis of groundwater flow beneath a dam or weir SHARP SFWMD re/ground_water.html ld/hsm/modflow/index.htm Finite-difference model to simulate freshwater/salt water flow in layered coastal aquifers South Florida Water Management Model. Development of MODFLOW packages for providing better capability in simulating connectivity Hybrid Numerical Models Ground Water Simulator IFMMike IHM ISGW MODBRNCH produkte/feflow/index.html ology_ihm.php isgw.html re/modbrnch.html Integrates MODFLOW 2000, MODPATH particle tracking and MT3DMs mass transport model Links FeFlow finite element subsurface flow and transport model with Mike11 1-D surface water flow model Integrated Hydrological Model linking HSPF surface water model with MODFLOW groundwater model Integrated Surface and Ground Water Model linking HSPF surface water model with MODFLOW groundwater model Linking of MODFLOW3-D groundwater flow package with BRANCH which models 1-D unsteady flow in open-channel networks MODNET Linking MODFLOW with UNET open-channel flow model (Walton et al, 2000) Conjunctive Water Management Framework 140

141 Box 9.2 Exploring time lags of streamflow depletion using numerical modelling (Braaten and Gates, 2004) Braaten and Gates (2004) used the numerical groundwater flow modelling code MODFLOW (Harbaugh et al, 2000) to explore time lags associated with stream depletion due to groundwater pumping. Representative models of four alluvial stream-aquifer systems were constructed, namely: (i.) (ii.) (iii.) (iv.) A wide valley unconfined aquifer A narrow valley unconfined aquifer A wide valley semi-confined aquifer A narrow valley semi-confined aquifer The streamflow depletion due to pumping at different distances from the stream was explored (Figure 9.3). A sensitivity analysis was also undertaken to determine how streamflow depletion responded to systematic changes to model parameters such as aquifer transmissivity, storativity and pumping distance from the river. Some important management implications were derived from the analysis: (i.) In unconfined systems, time lags became longer with increasing distance of pumping away from the river. However, the time lags for the narrow (5km) valley case were significantly shorter when compared to the wide valley (40km) case due to the closer proximity of the groundwater boundary. The most sensitive parameters for unconfined conditions are the pumping distance and aquifer properties. This analysis supports the use a zonal management approach to unconfined aquifers; (ii.) The time lags for semi-confined aquifers are significantly longer due to the overlying aquitard. In the narrow valley case, distance from the river has little effect on the stream depletion. This is because the lateral transmission of drawdown is rapid within the semi-confined aquifer. The most sensitive parameters for semi-confined conditions are the aquitard leakage and properties of this overlying layer. A categorisation of connected systems was developed based on the modelling. This used the criteria of regulation, aquifer type, stream type and valley type, and management options were described for these categories. Figure 9.3: Stream depletion rates for the base scenarios for a bore pumping 1000 m 3 /d for 5 years at varying distances from the river (Braaten and Gates, 2004) 141 Conjunctive Water Management Framework

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143 10. Setting Management Targets An essential step in a conjunctive water management approach is the setting of management targets in the catchment. These define the goals towards which management is focussed on, and are directed at the management issues defined for the catchment. Quantifying and negotiating these targets by catchment groups and others can be supported by an understanding of catchment processes, developed through baseline assessment, conceptualisation and construction of predictive models. Management targets are typically set within the broader natural resource management structures operating in the catchment. In many cases, there are pre-existing water quality, water quantity or environmental targets established through previous processes of biophysical assessment, economic analysis and catchment consultation. Such targets depend on the specific management issues being addressed, so they can be many and varied. Some typical catchment targets include: (i.) (ii.) (iii.) The sustainable yield limit placed on allocation of surface water and groundwater resources; The end-of-valley stream salinity target expressed at a key gauging station; Minimum flows or flow duration curves developed for meeting environmental water requirements. As the setting of targets is an integral part of catchment management, there are a number of national (and international) initiatives aimed at providing consistency and robustness National Framework for NRM Standards and Targets The Natural Resource Management Ministerial Council (NRMMC), representing governments of all states, territories and the Commonwealth, has been established to develop a coordinated approach to issues affecting natural resource management in Australia. As part of this process, the Council has endorsed the National Framework for Natural Resource Management Standards and Targets This national framework sets out national outcomes that investment in natural resource management (through programmes such as the NAP and the NHT) should work to achieve. The framework also identifies Matters for Target, designed to help focus efforts to achieve the national outcomes, namely: (i.) (ii.) (iii.) (iv.) (v.) (vi.) (vii.) (viii.) Land salinity; Soil condition; Native vegetation communities integrity; Inland aquatic ecosystems integrity (rivers and other wetlands); Estuarine, coastal and marine habitats integrity; Nutrients in aquatic environments; Turbidity/suspended particulate matter in aquatic environments; Surface water salinity in freshwater aquatic environments; 143 Conjunctive Water Management Framework

144 (ix.) Significant native species and ecological communities; (x.) Ecologically significant invasive species; (xi.) Critical assets identified and protected; (xii.) Water allocation plans developed and implemented; (xiii.) Improved land and water management practices adopted (Table 10.1). As part of the regional planning process, regional NRM plans prepared by the regional bodies will need to set regional targets for all relevant 'matters for targets' listed in the framework. To monitor progress against the targets and performance of investments made under programmes such as the NAP and NHT, a suite of related indicators has been developed under the National Monitoring and Evaluation Framework. By promoting consistency in setting and measuring progress towards targets within and across regions, the indicators will contribute to overall assessment of resource condition. The catchment targets can fall into three categories: (i.) (ii.) (iii.) Aspirational targets, that establish the vision for catchment management in terms of the long-term (eg >50 years) goal for improvement in land and water resource condition; Achievable resource condition targets, that is the specific, time-bound and measurable targets for catchment management typically over the year timeframe eg. end-of-valley average stream salinity, percentage sites with particular river condition status; Management action targets, which are short-term (1-5 years) and relate to management actions or capacity building eg. hectares of riparian vegetation fenced Integrated Environmental and Economic Accounting As an international example of NRM target setting, Integrated Environmental and Economic Accounting (SEEA 2003, has been established by the United Nations Statistics Division to combine economic and environmental information into a common framework. Indicators and descriptive statistics are used to monitor how the environment contributes to the economy, and the impact on the environment by the economy. The account consists of four components: (i.) (ii.) (iii.) (iv.) Flow accounts for pollution, energy and materials, which provide information at the industry level about the use of energy and materials as inputs to production and the generation of pollutants and solid waste; Environmental protection and resource management expenditure accounts, which identify expenditures incurred by industry, government and households to protect the environment or to manage natural resources; Natural resource asset accounts, which record stocks and changes in stocks of natural resources such as land, fish, forest, water and minerals; Valuation of non-market flow and environmentally adjusted aggregates, which presents non-market valuation techniques and their applicability for answering specific policy questions. Conjunctive Water Management Framework 144

145 Table 10.1: List of indicator headings and indicators of National Framework for Natural Resource Management Standards and Targets Matter for Target Indicator Heading Recommended Indicators Land Salinity Area of land threatened by shallow or rising water tables Depth to groundwater Groundwater salinity Location and size of salt affected areas Soil Condition Soil condition For regionally significant soil condition issues that are the subject of targets in regional plans: Soil acidification Soil erosion - water Soil erosion - wind Soil carbon content Native Vegetation Native vegetation extent and distribution Native vegetation condition For regionally significant native vegetation that is the subject of targets in regional plans: The extent of native vegetation by IBRA subregion measured in hectares The extent of each present native vegetation type by IBRA subregion measured in hectares The proportion remaining of each native vegetation type by IBRA subregion measured as a percentage of the pre-european extent For regionally significant native vegetation types that are the subject of targets in regional plans: The proportion of each native vegetation type in each IBRA subregion that is estimated to be in specified condition classes based on a selected set of attributes. Inland Aquatic Ecosystems Integrity River condition For regionally significant reach based issues that are the subject of targets in regional plans, the indicators are: Benthic macroinvertebrate community assemblages Fish community assemblages Benthic diatom community assemblages Riparian vegetation community assemblages Riverine physical structure and in-stream habitat Water quality Hydrology If all or most of these indicators are measured, it may be possible to use monitoring data to develop an index of river condition Wetland ecosystem extent and distribution Extent of regionally significant wetlands Wetland ecosystem condition Condition of regionally significant wetlands based on: o waterbirds o macroinvertebrates o diatom communities o vegetation communities o water quality o hydrology. Estuarine, coastal and marine habitat integrity Nutrients in Aquatic Environments Turbidity/suspended particulate matter in aquatic environments Surface Water Salinity in freshwater aquatic environments Significant native species and ecological communities Ecologically significant invasive species Estuarine, coastal and marine habitat extent Area of each estuarine, coastal and marine habitat type measured in and distribution hectares Estuarine, coastal and marine habitat Condition of habitat at significant sites of selected estuarine, coastal and condition marine habitats Nitrogen in aquatic environments Total Nitrogen + flow leaving sub-catchment or whole catchment Phosphorus in aquatic environments Total Phosphorus + flow leaving sub-catchment or whole catchment Turbidity/suspended solids Turbidity OR Total Suspended Solids (TSS) + Flow In-stream salinity Total dissolved solids (TDS) + Flow OR Electrical conductivity (EC) + Flow Selected significant native species and ecological communities extent and conservation status Selected ecologically significant vertebrate invasive species extent and impact Selected ecologically significant invasive vegetation species extent and impact For significant species that are the subject of targets in regional plans: Range area and location of each species: area Area, location and condition of key habitat of each species Relative abundance of each species. For significant ecological communities that are the subject of targets in regional plans: extent of each ecological community: estimated area (in hectares) condition of each ecological community. Reduction in impact of regionally significant invasive vertebrate pests (excluding fish) The areal extent and density of weeds under selected regulatory control that are being addressed by regional bodies or community projects 145 Conjunctive Water Management Framework

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147 11. Conjunctive Water Management Options Implementing conjunctive water management can take the form of either policy instruments or investment that can involve on-ground works. Understanding of surface water-groundwater interactions can be incorporated into different aspects of water management policy and practice in the catchment. Infrastructure works (such as Aquifer Storage and Recovery schemes) can be undertaken to enable the different and complimentary characteristics of surface water and groundwater systems to be combined to advantage Policy Options The concepts and principles of stream-aquifer connectivity can be embedded into a wide range of existing water policy instruments. Outlined below are some policy options that can encourage conjunctive water management. Licencing and Allocation Linking of the licencing and allocation arrangements for the groundwater and surface water resources in a connected system is required. Different approaches are possible to better coordinate regulation. Some examples are: (i.) (ii.) (iii.) (iv.) Total Water Accounting. Taking a catchment-wide approach to the water balance that is inclusive of the inputs and outputs of groundwater and surface water resources is a pre-requisite for conjunctive water management. Estimates of the sustainable limits to water allocation should be based on budgets for the total water resource, or at the very least that there is coordination between groundwater and surface water assessments. Groundwater sustainable yield estimates are typically based on a function of recharge, with evaluation of discharge magnitude and dynamics less of a priority. Equally, surface water resource assessments tend not to directly include a groundwater interaction component. Such explicit accounting of seepage flux is required (refer Box 11.1); Linking of Water Management Plans. Surface water and groundwater management plans for a catchment should address the same goals and their development should be coordinated. Ideally, in a highly connected system a single water plan would combine the management of the two resources, taking advantage of their inherent characteristics; One (or compatible) licensing system to allow tradings. Existing groundwater and surface water licenses are not compatible. Common licensing arrangements across a connected water resource would facilitate consistency of water securities and enable potential trade opportunities. A key issue in developing a single license system is the matching of groundwater and surface water securities (including supply, volumes, quality, access and reliability); Coordinated Embargoes. Recognising that any caps placed on one component of the connected water resource will have an impact on the other. As in the case for the Murray-Darling Basin, the Cap on surface water diversions transferred water demand and stresses to the groundwater resource. When 147 Conjunctive Water Management Framework

148 (v.) (vi.) restricting entitlements, it is assumed that there is no prior hierarchy between groundwater and surface water users (refer to principles in Box 4.1); Tiered access conditions. Consistent with security ratings of surface water allocations, tiered access conditions can also be applied to groundwater licences. Seasonally variable groundwater access could help optimise the timing of extraction of groundwater to minimise impacts on stream flow. Seasonal allocations set by comparing groundwater levels to benchmark conditions are used in some Victorian groundwater management areas; Triggers or Thresholds. Water access may be temporarily restricted (or transferred to the other water source) on the basis of triggers such as using defined thresholds for minimum stream flows or groundwater levels. This requires assessment of the impacts of groundwater use on stream flow (and vice-versa in terms of surface water extraction on groundwater levels). For example, in the case of streamflow depletion a robust and transparent assessment of both the magnitude of the change in groundwater discharge and the time lag for response is required. Conjunctive Water Management Framework 148

149 Box 11.1 Estimating the double accounting component in a connected system The impact of groundwater pumping on streamflow can be estimated using groundwater models. For example, the double accounting component of the water balance was calculated for the stream-aquifer system in part of the Border Rivers catchment. A transient MODFLOW-based groundwater flow model constructed for the Dumaresq River valley was run to compare the seepage flux for various management scenarios. The existing groundwater allocation in the valley is about 30,000 ML/yr with actual groundwater use estimated at 5,200 ML/yr for the year Table 11.1 lists the estimated impact of groundwater pumping on stream flow, assuming average recharge conditions of about 5,000 ML/yr. The table shows the change in seepage flux (compared with the no-pumping scenario) for groundwater use at 50% and 100% of the groundwater allocation. This suggests that groundwater use to the full allocation level would reduce stream flows by about 17,000 ML/year. This streamflow depletion represents the level of double accounting for the system. Results from the transient numerical groundwater model have provided insights into the temporal changes in seepage flux. Figure 11.1 shows the time lag involved for the full impact of ground pumping at existing allocation levels to take effect for the different groundwater management zones in the valley. Table 11.1: Modelled impacts of pumping on double accounting in the Border Rivers Catchment Pumping Rate (% Allocation) Change in Seepage Flux (ML/yr) Change in Seepage Flux (% of Pumping Rate) 15 3, , , Streamflow Depletion (ML/yr) Management Zone 1 Management Zone 2 Management Zone 3 Management Zone 4 Year Figure 11.1: Estimated streamflow reduction due to pumping at full allocation levels for the four management areas in the Dumaresq valley, Border Rivers catchment 149 Conjunctive Water Management Framework

150 Water Trading Water trading across a connected resource would essentially have the capacity to transfer a licence from groundwater to surface water and vice versa, with the aim of increasing the beneficial use of the water. Development and activation of a single water market would require a robust administrative framework. A resource limitation (such as an embargo on new licences) is also required in order to create buying and selling capacity. In the absence of such a framework, trade would tend to activate sleeping licenses and possiblly accelerate over-use. At the broader scale, trading between groundwater and surface water within a framework of total resource sustainable yield (based on a catchment-wide water balance) would expand buying and selling markets. If a trading market was enforced across both over-allocated and developing areas, there is the opportunity to redistribute entitlements to less stressed areas. There are currently a number of issues that impede the development a single water market, even at the local scale. These mostly relate to differences in groundwater and surface water access entitlements and their administration. In particular there are currently frequent incompatibilities in: (i.) Definition and relative securities of surface water and groundwater entitlements; (ii.) Cost structures; (iii.) Ownership of infrastructure; (iv.) Physical capacity of infrastructure to deliver water to where it is to be used; (v.) Reporting and monitoring; (vi.) Management plan objectives (ie between groundwater plans and surface water plans); (vii.) Institutional administrative structures; (viii.) Understanding of flow dynamics and dependent ecosystems (Fullagar, 2004). Risk Management Risk management approaches are commonly used in the management of surface water reservoirs. For example, dams are drawn down during drought periods based on the assessment that there is a high probability that dam levels will recover during the planning timeframe. This acknowledges the high variability of rainfall in Australia. Similar risk management approaches can be taken for connected water resources, to take advantage of the different characteristics of surface and aquifer storages. Taking a risk management approach in conjunctive water management can involve: (i.) (ii.) Using aquifers as a drought reserve by allowing temporary depletion of groundwater storage beyond the rate of recharge, based on the assessment that there is adequate provision for groundwater dependent ecosystems, that groundwater recovery can be achieved over the planning timeframe, that there is no long-term impacts on water quality or no damage to the aquifer matrix (REM, 2002). In many catchments, aquifers can provide greater storage volumes than existing surface water reservoirs; Coordinating the replenishment and withdrawal of both surface water and groundwater storages in the catchment to better management climate Conjunctive Water Management Framework 150

151 (iii.) variability. This can mean switching between these storages depending on catchment conditions. During non-drought periods water is released from surface reservoirs for water users and for aquifer replenishment while groundwater is the dominant water source during drought periods; Using climate predictions or long-term rainfall forecasts, such as correlations between El Nino/Southern Oscillation (ENSO) or Inter-Decadal Pacific Oscillation (IPO) indices and water availability to assess future risk. 151 Conjunctive Water Management Framework

152 Management Zones Defining zones such as stream buffers that have specific management rules is a useful policy tool. In conjunctive management, this approach tends to be used to subdivide the catchment based on the likely impact on stream flow or water quality by changes to groundwater discharge. Management zones can be used to address the effect of groundwater extraction (refer Box 11.2). For example, New South Wales takes a zonal approach for managing alluvial aquifers that are highly connected to streams. Buffer zones around these streams have different management rules (Table 11.2). It should be noted that a zonal approach may not be universally applicable. Numerical modelling scenarios infer that for the case of semi-confined aquifers in narrow (<5km) valleys, varying the distance from the river of the groundwater pumping had no effect on the rate and magnitude of streamflow depletion (Braaten and Gates, 2004), refer Box 8.2. Management zones can also be used to reduce the risk of contamination from industrial spills or septic tank effluent, or manage the salinity impact of rising watertables due to irrigation development. A good example of the latter application is the salinity impact zones (HIZ/LIZ) defined for the Victorian side of the River Murray. There is also the option to subdivide an aquifer (vertically as well as horizontally) as part of managing stream-aquifer connectivity. These zones could then provide a framework for water trade. Table 11.2: Zonal approach for managing highly connected alluvial systems in NSW Distance from High Bank of Stream Management Rule <40 m Surface water works approval and surface water rules apply m Groundwater works approval and surface water rules apply >200 m Groundwater works approval and groundwater rules apply Land Use Planning Changes in land use can have a dramatic impact on seepage flux with outcomes for both water quantity and quality. Knowledge of stream-aquifer interactions is part of the process of using land use planning and policy to meet catchment targets. Some key examples are: (i.) (ii.) Salinity mitigation, with land use policies to protect native vegetation remnants (particularly over groundwater recharge areas), prohibit or limit land clearing, promote revegetation on private lands, joint venturing of agroforestry, promotion and incentives for the use of deep-rooted perennial pastures or crops, advocating good management practice for grazing and cropping, or to set appropriate guidelines for irrigation development. The focus of these policies is to limit or reduce groundwater recharge, hydraulic gradients to streams and discharge of saline groundwater; Water Quality Protection, with land use policies relating to siting of industrial areas and waste disposal sites, guidelines for the design and installation of septic tanks, best management practice for the use of agrichemicals such as pesticides or fertiliser application. The focus of these policy instruments is to minimise the potential for the movement of contaminants into waterways via shallow groundwater movement. Conjunctive Water Management Framework 152

153 Box 11.2 Management Zone Approach The impacts of groundwater extraction from new water entitlements on stream flow can be managed on the basis of zones (Evans et al, 2005). Four management zones surrounding the stream and based on the time lag between groundwater extraction and response in stream flow is proposed (Figure 11.2): (i.) Zone 1 Very Short Time Lag, which applies near-stream where there is major interference and the time lag is short (<1 week). All new entitlements should be managed on the basis of surface water extraction rules. (ii.) Zone 2 Short Time Lag, applying to all groundwater users who could impact stream flow over the critical low flow period of the stream during the planning timeframe. Typically, flow depletion from extraction is detected within three months. Short-term restrictions on groundwater use may be emplaced based on triggers such as minimum groundwater levels. (iii.) Zone 3 Medium to Long Time Lag, applying to groundwater users that have an impact on stream flow over the long term (1-50 years). The focus of management is (iv.) maintaining groundwater allocation and use within the defined sustainable yield. Zone 4 Very Long Time Lag, where there is no discernable impact on stream flow by groundwater use. No active management relating to streamflow depletion is required. Figure 11.3 shows the typical distribution of these zones for a contained alluvial valley. Various methods can be applied to estimate the magnitude of the time lag between groundwater extraction and stream flow depletion. These include field investigations or analytical or numerical modelling (refer Chapter 8). Figure 11.2: Proposed zones for managing new water access entitlements (Evans et al, 2005) Figure 11.3: Indicative locations of management zones (Evans et al, 2005) 153 Conjunctive Water Management Framework

154 Institutional Arrangements It has been recognised that traditional institutional separation of surface water from groundwater has created fundamental communication barriers that severely limit the implementation of a conjunctive approach. These barriers impede the understanding of the processes and consequences of groundwater-surface water interactions on water policy and management. Such separation is evident across policy development, operational management, research and development and even water users. Organisational change such as combining groups that make management decisions on groundwater and surface water resources is necessary. This is because conjunctive water management requires a large amount of joint and coordinated effort among catchment communities and organisations; and institutions are key to such coordination. Even where conjunctive water management is physically possible and economically feasible, whether and how it is pursued depends on the institutional setting. By better understanding, identifying and clarifying the relationship between institutional arrangements and water management outcomes, institutional researchers can help advance the larger goal of improving the sustainable use of water resources. Recently, Blomquist et al (2004) investigated the feasibility of conjunctive water management as a means of improving water management, as well as how institutions affect conjunctive water management. The study compared the institutions and water management experiences in the three American western states of Arizona, California and Colorado and provided insight into the role of institutions in water management in a more general sense. Recently, the NWI also recognises the importance of institutional arrangements to ensure the achievement of the environmental and other public benefit outcomes, including common arrangements in the case of inter-connected groundwater and surface water systems (NWI Clause 79i C). The importance of institutions in terms of water laws, policies and organisational arrangements for water management in Australia, including the definition of water access/property entitlements have been discussed in the Rivers and Aquifers: Towards conjunctive water management workshop held in Adelaide during 2004 (Fullagar 2004). The institutional arrangements for managing water resources differ among the States in Australia (NGC, 2004). The workshop identified and recommended for adoption the following principle. Jurisdictional boundaries should not prevent management actions. Discontinuity in government institutional arrangements between (and within) jurisdictions should not be an excuse for failing to identify and address issues associated with connected systems, or for not progressing opportunities associated with conjunctive water management. Institutional factors such as the rules governing water use and the organisational arrangements for water management are likely to play important roles in determining whether, when, and how conjunctive management programmes develop and perform. Institutions facilitate the ease with which multiple stakeholders interact in complex situations, prescribing what actions are allowed, required, or forbidden in given Conjunctive Water Management Framework 154

155 situations (Crawford and Ostrom, 1995). Thus, institutions are especially significant when a task requires coordination. Given the organisational and physical complexity involved with conjunctive management, it is likely to require considerable amounts of coordinated behavior. For instance: (i.) (ii.) (iii.) (iv.) Surface water facilities, such as dams, reservoirs and water distribution systems, must be operated in coordination with ground water supplies, with underground storage capacity, and with the bores and pipes for groundwater conveyance. Each of these facilities may be owned, operated, or regulated by distinct public or private organisations. Each of those organisations is governed by rules specifying what it may, must, and must not do. Those governing rules may be set at local, state, or national levels; Extensive monitoring of the conjunctive management operations and of water supply and storage conditions, and the exchange of information from that monitoring, are essential to conjunctive management success; Certain environmental and ecological need to be maintained (such as stream flows and surface water quality, flood control needs, riparian and aquatic habitat conditions) which are often governed or monitored by other rules and organisations; Environmental impacts can follow from conjunctive management projects, including land subsidence or seawater intrusion from excessive aquifer drawdown, soil saturation from excessive aquifer replenishment and migration of contaminants. These issues may be within the jurisdiction of the same organisations that operate or oversee these projects, but often they are within the jurisdiction of other (typically public) agencies. In summary, there are institutional issues and effects at every step in even the simplest of conjunctive management projects. Those institutional arrangements can be conducive to success, or they can present substantial barriers. Communication Communication should be a component of any water management strategy. Table 11.3 attempts to map the current status of awareness of connectivity across the community, highlighting the need for improving communication (Fullagar, 2004). Education and extension should attempt to develop a shared understanding of the issues, knowledge gaps, knowledge requirements, and potential opportunities of conjunctive water management. Table 11.3: Perspectives on stream-aquifer connectivity across the community (Fullagar, 2004) Local Science Agencies Indigenous Mine the resource, its infinite Disconnected from overstressed rivers Escape from regulation & strife Control my own future with pumps Not impacting neighbours or the rivers Drives regional catchment bodies Incomplete process understanding Need to connect surface water and groundwater models Need more data Need more research Critical problems being ignored We have enough problems with surface water Hard to understand and connections to surfacewater unclear Coming onto horizon as they start to understand environmental flows especially base flows River channel or floodplain as recharge needs to be understood Unknown, though potentially very valuable 155 Conjunctive Water Management Framework

156 Effective communication involves: (i.) Improving community awareness and understanding of general connectivity principles and issues; (ii.) Explaining the impacts of groundwater use on surface water flows including identifying risks to security of water supply and any trade-offs; (iii.) Outlining the planning process including why water management planning is necessary, including the objectives, process, planning structure and timeframes; (iv.) Establishing clear rules of community and government engagement within the planning context; (v.) Raising awareness of the tools available to assess groundwater-surface water interaction; (vi.) Providing education on the capabilities and limitations of predictive models that are used in decision making; (vii.) Encouraging the integration of groundwater and surface water research groups at universities and other scientific agencies; (viii.) Fostering communication between modellers and water managers and users and taking a multi-disciplinary approach in the development of appropriate conceptual and numerical models; (ix.) Communicating the opportunities and limitations of engineering technologies particularly on the use of aquifers as water storages (Fullagar, 2004) Investment Options A wide range of engineering solutions that take a conjunctive approach is available. Such technologies can play a significant role in meeting the water quality and quantity management targets in a catchment. Some examples are outlined below. Water Banking Water Banking (also called Managed Aquifer Recharge or MAR) is a conjunctive technique that seeks to deliberately increase the amount of water stored in an aquifer, which is then recovered by pumping. By storing water underground, loss of water to evaporation can be drastically reduced and the water savings returned to other users such as the environment, towns or irrigators. Water banking offers several advantages when compared with the more traditional use of surface water reservoirs (Table 11.4). The potential for water banking is enormous as the total volume of water that could be stored in aquifers worldwide is several orders of magnitude greater than that available in surface dams. As well as providing water savings and better water delivery, water banking can also provide water quality outcomes. There are various water banking technologies, and some are specifically used to treat surface water in order to improve water quality (Figure 11.4). Disinfection by-products (trihalomethanes) can be removed as well as iron, manganese, hydrogen sulphide, nitrogen, phosphorous and microorganisms (Pyne, 2002). Water banking can even be used to lower the salinity in an aquifer. Fresh injected water mixes with the saline aquifer and is then removed so that after several cycles, the zone around the bore contains fresh stored water (Pyne, 2002). Conjunctive Water Management Framework 156

157 Water banking has been used successfully in Europe for over 50 years and is increasing in application in the United States. The number and scale of schemes increased by an order of magnitude in the United States since mid 1990s; one scheme in Orange County California now stores about 300 GL per annum (Mills, 2002), refer Box In Australia, most of the focus has been on storing recycled/non-potable water for use in irrigation and municipal use. Currently there are about twenty small-scale (< 1 GL per year) water banking pilot schemes (primarily using ASR) such as Andrews Farm, Greenfield, Parafield Airport, Mawson Lakes, Angas Bremer and Wilunga Basin located mainly in South Australia. The schemes hope to relieve pressure on reticulated water supplies by providing users of large volumes of water, such as market gardens and recreation areas, with a reliable alternative supply of water (Gerges et al., 2002). Investment has been from both the private and public sectors. The oldest water banking scheme in Australia is located in the Burdekin Delta. It is use to replenish aquifers that have been depleted because of long term use for sugarcane irrigation (Charlesworth et al., 2002). In the Northern Territory, pilot schemes are being trialled in remote indigenous communities to provide water security during the seasonal dry periods (Pavelic et al., 2002). Hostetler (2006) investigated the potential for water banking as an option for increased water availability in Murray Basin, refer Box Conjunctive Water Management Framework

158 Box 11.3 Investigation of the feasibility of water banking in the Murray Basin The feasibility of water banking within the Murray Basin was examined by modelling the characteristics needed to successfully carry out such a scheme (Hostetler, 2006). In the study, three classes of information recognised as being needed to assess a site for water banking were collated: (i.) (ii.) (iii.) Presence of a water source (proximity to a river, channel or urban area, climate); Nearness to potential users (proximity of a region to irrigators or towns) and; Aquifer characteristics (depth to water table, salinity, aquifer type and size, and storativity). Preliminary assessment was undertaken at the national scale using a Geographic Information System (GIS) approach. Each dataset was assessed as to its importance for producing a successful water banking scheme, weighted accordingly, and combined to produce an index using the following schema (after Hekmeijer, 2002). Suitability for water banking = 2 * water storage potential + 2 * aquifer yield + 2 * depth to water table * closeness to river + 2 * aquifer salinity * closeness to irrigation area + slope suitability + climatic suitability The total score was then used as a relative measure of the suitability of an area for water banking. This process identified the Murray Geological Basin (Murrumbidgee Valley) as one of the largest and significant of the suitable areas in Australia. A more detailed regional water banking study for the Murray Basin made use of finer-scale information on hydrogeology, water use and climate to further refine the suitability scores. Highly prospective areas were defined as areas with suitability scores greater than two standard deviations from the mean. Four additional sources of information were also used to further refine the model: (i.) (ii.) (iii.) (iv.) Highly Saline Groundwater (>7000 mg/l) - aquifers with salinity greater than 7000 mg/l TDS were eliminated. This cut-off was chosen because water with salinity below this level can be shandied with fresh water, relatively cost effectively, to produce irrigation water. Surface Water/Groundwater Connectivity - Water banking is generally only suitable for unconnected systems or losing streams because, by definition, in a gaining system the banked water will discharge to the river system and will therefore not be available for consumptive use. Availability of Water for Recharge - Rivers are generally the source of recharge water in a water banking scheme. Some potential water banking areas may have a much larger capacity to store water than there is the water available to fill them. Banking areas were eliminated where the potential river flow, calculated from average annual flow past all relevant gauging stations, was an order of magnitude, or more, greater than the storage potential. Recharge Rate - Potential regions needing a large percentage of surface area devoted to infiltration basins (>5%), or needing a large number of bores for recharge, were eliminated. Figure 11.4 shows the end result of the modelling process. The resulting nine most suitable areas can now be the focus of more detailed work. Assuming a management scenario where the water table is allowed to fluctuate by ±5% (of total aquifer thickness), the total potential groundwater storage in these areas was estimated at 4,300 GL. If the area is managed to allow a greater movement of the water table, the volume of water that could be stored will be higher. Conjunctive Water Management Framework 158

159 Figure 11.4: Areas for further water banking investigation based upon the results of the GIS model and model refinement (Hostetler, 2006). Numbers on the map are an estimate of the volume of water that can be stored in each area (± 5% watertable movement x area x storativity) 159 Conjunctive Water Management Framework

160 Table 11.4: Advantages and disadvantages of different types of water storage (Tuinhof and Heederik, 2002) Subsurface storage Small dams and surface reservoirs Large dam reservoirs Advantages Limitations Key issues Little evaporation Widely distributed Operational efficiency Available on demand Water quality treatment Seawater intrusion Slow recharge rate Groundwater contamination Cost of extraction Recoverable fraction Rising water levels Management of access and use Groundwater salinisation Groundwater pollution Ease of operation Response to rainfall Multiple use Groundwater recharge High evaporation rate Relatively high unit cost Absence of over-year storage Removal of water from the river system Sedimentation Adequate design Dam safety Environmental impacts Carryover capacity Low cost per m 3 water stored Multi-purpose (power, recreation, flood control) High evaporation Complexity of operation Siting High initial investment cost Time needed to plan and construct Loss of arable land Loss of habitat Social impacts Environmental impacts Sedimentation Dam safety However, water banking is not without its logistical issues, the main ones being: (i.) (ii.) (iii.) (iv.) Clogging of the aquifer matrix. Decreasing the amount of water that can be recharged and recovered. Clogging can take the form of gravity settling of fine-grained sediments sealing the surface of the aquifer, the straining under pressure of fine-grained sediment into the aquifer matrix, physical-chemical clogging due to reaction of the recharge water with the geological material (such as the deposition of calcite) and bridging where silt grains get wedged across the interstices of the aquifer. Clogging can be alleviated through removal of the suspended material in the water by the use of settling ponds, flocculating chemicals and/or sand filters or to alter the chemistry of the recharge water so that it does not react with the aquifer. Also, the clogging deposits can be removed by mechanical scouring or by flushing aquifers to remove build-up; Aquifer Contamination. Although water banking can be used to remove contaminants such as bacteria and some pesticides, it can be vulnerable to contamination if the water is not suitable or compatible, or it overwhelms the ability of the aquifer to process the waste. This is why water banking schemes need to be strictly monitored; Potential Water Losses. Accumulation of a watertable mound in an aquifer can increase hydraulic gradients either laterally to surface water features or vertically into other aquifers; Water accounting and security. Currently, the water allocation arrangements needed to develop water banking in Australia are not in place. This is the case for clarifying the ownership of water artificially transferred between surface and aquifer storages. For example, a farmer that harvests water during a major flood for storage in a water banking scheme has this water counted against their surface water entitlement despite not directly consuming the water. Furthermore, the irrigator may not be able to withdraw the water from the scheme at a later date because they do not have a groundwater licence or the groundwater cap is exceeded in the catchment. Conjunctive Water Management Framework 160

161 Figure 11.5: Types of water banking (Dillon, 2004) 161 Conjunctive Water Management Framework

162 Outlined below and in Figure 11.4 are various water banking technologies. Aquifer Storage and Recovery (ASR) Aquifer Storage, Treatment and Recovery (ASTR) ASR and ASTR both use bores to inject water into an aquifer. In the case of ASR, the same bore or an adjacent bore is used to recover the water from the aquifer. ASTR uses an adjacent bore to draw the water through the aquifer, which increases the zone of water treatment. Bank Filtration Bank filtration makes use of the connected nature of most stream/aquifer systems. Water levels are kept high in streams that lose water to the aquifer causing an increase in groundwater recharge. The water is then withdrawn from the groundwater system from a bore located near the river system. Bank filtered water makes up a large proportion of groundwater supplies in Europe (Tuinhof and Heederik, 2002). It provides water quality improvements compared with water taken directly from the river due to the absorptive capacity of the aquifer. The other benefit is resource security because the capacity of the system is limited only by the ability of the aquifer to process the water and not by the surface water resource, which is generally much larger. Dune Filtration Dune filtration is used primarily for water treatment. Pre-treated water is pumped into a dune swale and then re-harvested at a lower level after gravity transport through the dune. Biological and chemical processes within the dune remove residual organic material, nitrogen and pathogenic micro-organisms. Infiltration Pond An infiltration pond is one of the simplest and most effective methods of increasing the amount of recharge into an aquifer. Water is pumped into a permeable area above the target aquifer to allow water to infiltrate by gravity into the groundwater system. Leakage is encouraged which is the opposite to a traditional dam, where leakage is kept to a minimum. Soil Aquifer Treatment Soil Aquifer Treatment also makes use of the natural chemical and biological processes within the soil (unsaturated zone) to polish treated wastewater. After conventional wastewater treatment, water is pumped into infiltration ponds and then returned via recovery bores. Soil aquifer treatment is most commonly used to remove residual organic material, nitrogen and pathogenic micro-organisms (NCSWS, 2001). Rainfall Harvesting Rainwater harvesting is a variant to traditional rainwater collection using a tank as storage. Rainfall is collected from a catchment surface and stored in an above ground Conjunctive Water Management Framework 162

163 tank. Instead of wasting excess water as in the case of a typical collection system, overflow is stored in an underground percolation tank where it recharges the groundwater system. The water is then available to be exploited from a nearby bore. Underground Dam Underground dams are a low technology solution to storing water, that is well suited to fractured rock terrain or regions with limited resources. A low permeability barrier is introduced into an aquifer either through injection or excavation, which stops the flow of groundwater until the water level rises above the obstacle. Water that would normally drain away is then available for extraction Recharge Releases Water banking, via recharge releases, makes use of existing (or purpose built) dams that capture surface water during floods and then release for slower infiltration. The water is then harvested down gradient by production bores. It is a useful technique in steep terrains, where water normally flows too quickly to allow significant infiltration to the groundwater system. Water Interception Interception schemes are a series of bores along a stretch of river (or lake or wetland) used to extract near-stream groundwater. Such schemes are a common engineering solution to mitigating stream salinity. By continually pumping from the bores, not only is saline groundwater prevented from entering the river, but the river can become a losing stream with fresh river water drawn into the aquifer. The intercepted groundwater is then generally piped to a site distant from the river where it is evaporated. An example of an interception scheme is presented in Figure To highlight the impact of interception schemes on stream-aquifer connectivity, Figure 11.7 shows the results of a geophysical survey along the River Murray near Waikerie, South Australia (Allen and Merrick, 2004). The colours represent relative electric conductivity (salinity) in a vertical profile along the river. In the zone of the interception scheme the dark blue (fresh) water has been drawn below the river bed (light blue line). This is in contrast with the regional saline groundwater represented by red in the imagery. These interception schemes are a conjunctive technology that is a critical component of meeting salinity targets for the River Murray. 163 Conjunctive Water Management Framework

164 Figure 11.6: A schematic cross section of an interception scheme Figure 11.7: Electrical conductivity imaging of Murray River at Waikerie SA showing impact of groundwater interception scheme (Allen and Merrick, 2004) Water Supplementing The idea of water supplementing is to extract water from one source (groundwater or surface water) and use it to augment the other during critical periods. Because of the cost involved in pumping and delivering water, supplementation can generally only be used for a short period of time depending on the needs of targeted users such as the environment (during spawning season) or irrigators (growing season). Supplementing can take the form of: (i.) Using groundwater to increase stream flows. In areas with a heavy reliance on surface water for consumptive use, it may be necessary to maintain river levels by pumping groundwater and then adding it to the river. It is probably only an option in systems that are weakly connected systems or have a long lag time in terms of response. In a highly connected system, the decline of the water table Conjunctive Water Management Framework 164

165 (ii.) due to pumping would increase stream losses to the groundwater system and so be counterproductive. Because of the cost associated with such a scheme, pumping can only be carried for short periods to maintain water levels during extreme low-flow conditions; Providing water to maintain groundwater dependent ecosystems. In regions of high groundwater extraction, it may be viable to maintain high value groundwater dependent ecosystems (GDEs) by injecting water (from any source) near the ecosystem to artificially maintain a high water table. On a map showing the potentiometric surface of the water table, the area in the vicinity of the GDE would be totally enclosed by contours and look like an island. This technique has been trialled in the Great Artesian Basin near the Bopeechee Springs by Western Mining (Mudd, 2000). While there was some increase in the pressure surface around the injection bore, the number of vents and the size of the wetlands surrounding the springs did not increase (Mudd, 2000). Also, Australia has a rich diversity of cave fauna in Tasmania, Western Australia, and the Nullarbor. Due to the isolated nature of the cave environment they are particularly susceptible to disturbance. Lowering the water table in a karst environment can cause the extinction of rare and vulnerable cave fauna and threaten the stability of the cave system itself. In Western Australia, water supplementing has also been used as a temporary measure to maintain water levels around the Yanchep Caves region. Heavy use of groundwater in the region has lowered the water table threatening vulnerable cave fauna and speleothems. 165 Conjunctive Water Management Framework

166 Box 11.4: Large-scale infiltration basins in Orange County, California An example of the use of infiltration basins for water banking can be found in the Orange County Water District (OCWD) California, USA, which has been experimenting with water banking since The OCWD recharges approximately 300 GL per year from storm flows in the Santa Ana River and imported from the Colorado River (Mills, 2002). After recovery, the water undergoes extensive treatment before becoming the primary source of water for approximately 2 million people. Figure 11.8: Anaheim Lake is a recharge basin in the OCWD. Photo: The OCWD uses 9 infiltration basins ranging from metres deep with some of them used for fishing and water skiing. Like all water banking schemes, clogging of the basins is a problem. As a result the OCWD has developed a range of strategies and machines to remove sedimentation in the lakes. The results of which can be quite dramatic. For example, infiltration rates range from 3 metres/day for a new cleaned basin to virtually zero after 6 to 8 months ( Conjunctive Water Management Framework 166

167 12. Monitoring and Reviewing Performance A well-designed monitoring programme is part of a conjunctive water management approach. The current understanding of catchment processes, evolved from the processes of data collation, assessment, conceptualisation and predictive modelling can be used to design a cost-effective and robust monitoring programme. Catchment monitoring requires the establishment of a set of indicators that are able to show changes in management and in resource condition. Such indicators need to relate to the key management issues (Chapter 5) and the management targets established for the catchment (Chapter 9) at appropriate spatial and temporal resolutions. Such indicators are generally considered to have the properties of being simple, measurable, accessible, relevant and timely. Examples include: (i.) (ii.) (iii.) (iv.) (v.) Surface water gauging of flow, level and quality (eg salinity, nutrients); Groundwater levels and quality; Water usage from extraction points; Land use and land use practices; In-stream ecosystem health such as indicator species. Monitoring is the reality check for managers. This requires reviews on a regular basis to: (i.) (ii.) (iii.) (iv.) (v.) (vi.) (vii.) (viii.) Identify any emerging management issues in the catchment that may need addressing; Identify information gaps that when corrected would improve assessment of catchment processes; Validate and potentially update the understanding and conceptualisation of key water processes; Help verify or improve the calibration of any predictive models; Evaluate progress towards the management targets identified for the catchment; Check that conjunctive water management options were implemented appropriately; Test the appropriateness and effectiveness of these management options; Ensure that there is compliance with established rules and regulations National NRM Monitoring and Evaluation Framework Many catchments already have a monitoring and evaluation framework established related to the key land and water management issues. Over recent years, efforts have been made to better coordinate monitoring and to provide consistency in approaches and standards. To this end, the Natural Resource Management Ministerial Council (NRMMC), has endorsed the National Natural Resource Management Monitoring and Evaluation Framework. The Monitoring and Evaluation (M&E) Framework is aimed at assessing progress related to the: (i.) Health of the nation's land, water, vegetation and biological resources; and 167 Conjunctive Water Management Framework

168 (ii.) performance of programmes, strategies and policies that provide national approaches to the conservation, sustainable use and management of these resources. The M&E Framework ensures processes are useable, cost-effective, accurate, comprehensive and transparent. The arrangements for monitoring and evaluation, outlined in the Natural Heritage Trust (NHT) and National Action Plan for Salinity and Water Quality (NAP) Bilateral Agreements between the Commonwealth and each State/Territory, require each jurisdiction to develop a Monitoring and Evaluation Implementation Plan. Effective monitoring and evaluation arrangements also need to be in place at the regional level, as this is a requirement for the accreditation of regional NRM plans. The M&E Framework requires that data infrastructure to support the framework: (i.) (ii.) (iii.) (iv.) (v.) (vi.) Avoids duplication of effort, and maximises the benefits of earlier investment in data collection, by building on existing State, Territory and Commonwealth initiatives for developing and sharing of data such as the NLWRA and State of the Environment (SoE) reporting; Uses data for multiple purposes, wherever possible. In particular, data are collected so that they can be used for both monitoring resource condition and assessing programme outcomes. This requires data to be collected in such a way as to permit their use at a range of scales and levels (national, state, regional and local); Ensures that users can obtain the data. Data are easily accessible to all sectors of the community in format, location and cost and under conditions that do not inhibit their use; Ensures that users can easily find out whether suitable data already exist. All data are documented in the Australian Spatial Data Directory with sufficient information for users to determine whether the data are suitable for their intended purpose; and Supports meaningful interpretation of data over time by establishing standard national indicators, protocols for their sampling, measurement and interpretation, and data quality and management requirements. Protocols specify the quality of the data to be produced and ensure the data can be used for their intended purposes. To maximise their use and comparability, where required, data are developed and maintained to meet agreed international or national guidelines or standards for the management of spatial information as endorsed by ANZLIC or national coordination arrangements. Quality assurance and control requirements will ensure the consistency of the monitoring process over time and across jurisdictions and may necessitate the accreditation of complying monitoring programmes; and Specifies the assumptions on which monitoring and evaluation activities are undertaken in a consistent manner, which is open to all stakeholders Monitoring of Connected Water Resources In connected groundwater-surface water systems, the need to rigorously account for flows across the two resources adds additional complexity to monitoring requirements. Surface water reporting and monitoring is usually supported by some degree of centralised coordination, validation and management. With some notable Conjunctive Water Management Framework 168

169 exceptions, groundwater reporting and monitoring tends to be a lower priority dataset, resulting in patchy, isolated, lower confidence data. There is a need for greater integration of surface water and groundwater monitoring in a catchment to understand and manage the influence of groundwater-surface water interactions. As well as long-term time-series hydrographic monitoring, water sampling programmes involving analysis of a comprehensive range of parameters are also recommended. These are designed to highlight any emerging management issues that may not have been recognised or anticipated in previous assessments. This acknowledges that management needs to be adaptive and able to respond to changing situations. Figure 12.2 gives an example of an integrated approach to the monitoring of surface water and groundwater systems at a site. Stream water levels are logged using a pressure transducer or other technology (1) and calibrated by manual measurements from the installed gauge plate (2). By establishing a flow rating curve, the stream level data can be converted to a stream flow hydrograph. Such flow data is critical for water resource management and is used for hydrographic analysis of the baseflow component of streamflow. The same water level data can also be compared with the time-series record of groundwater levels measured from piezometers set at different depths within the shallow aquifer (3). This provides information on the changes in near-stream vertical head gradient (hence the potential direction of seepage flux) through time. Temperature loggers can be readily and cheaply installed in both the stream and the shallow piezometers in heat tracer studies to simulate variations in seepage flux. Pump (or slug) tests undertaken on the shallow piezometers can be used to validate the interpretation of aquifer transmissivity. The piezometers can also provide the infrastructure to undertake artificial tracer tests to confirm the responsiveness and direction of seepage. Water quality monitoring (such as EC and ph) can also be incorporated into the site to help monitor catchment condition and provide the opportunity to use environmental tracers to evaluate connectivity. The monitoring data (flow, temperature, water quality) can also be used in ecological studies at the site. Figure 12.1 places these in-stream monitoring sites in a catchment context. Sites similar in concept to Figure 12.2 can be established at key points along the stream. The resulting stream flow data can be incorporated into a water balance analysis for the intervening reach. By accounting for other water budget components (such as tributary flow or water diversions), an estimate of seepage flux can be made on a reach-by-reach basis. A transect of piezometers provides an overview of groundwater conditions away from the monitoring site. These can monitor groundwater levels and changes in the hydraulic gradient through time. These transects may not necessarily be constructed perpendicular to the stream, depending on the geometry of the groundwater flow lines (Woessner, 2000). The actual location of the transects and instream sites will depend on a range of factors such as access, logistics, proximity to surface water and groundwater development, and existing monitoring infrastructure. Survey methods such as geophysics or hydrochemistry can also be used to target suitable sites. At least one of the piezometers should be located in a relatively undeveloped part of the catchment to monitor baseline conditions. 169 Conjunctive Water Management Framework

170 (1) (2) Figure 12.1: Schematic diagram of a suggested approach to monitoring of a connected water resource including integrated in-stream sites (1) and piezometers (2) Conjunctive Water Management Framework 170

171 12.2b (1) (3) (2) 12.2a Figure 12.2: Example of combined monitoring of stream and shallow groundwater systems (a) Design of water level, temperature and water quality monitoring (b) Example in the Lower Richmond catchment (Brodie et al, 2005) 171 Conjunctive Water Management Framework