Lake Eyre Basin Springs Assessment Lake Eyre Basin (South Australia): mapping and conceptual models of shallow groundwater dependent ecosystems DEWNR Technical note 2015/22 Funding for these projects has been provided by the Australian Government through the Bioregional Assessment Programme. Lake Eyre Basin Springs Assessment Lake Eyre Basin (South Australia): mapping and conceptual models of shallow groundwater dependent ecosystems Catherine Miles1 and Justin F. Costelloe2 Department of Environment, Water and Natural Resources December, 2015 DEWNR Technical note 2015/22 1Miles Environmental Consulting 2Department of Infrastructure Engineering, University of Melbourne Department of Environment, Water and Natural Resources GPO Box 1047, Adelaide SA 5001 Telephone National (08) 8463 6946 International +61 8 8463 6946 Fax National (08) 8463 6999 International +61 8 8463 6999 Website www.environment.sa.gov.au Disclaimer The Department of Environment, Water and Natural Resources and its employees do not warrant or make any representation regarding the use, or results of the use, of the information contained herein as regards to its correctness, accuracy, reliability, currency or otherwise. The Department of Environment, Water and Natural Resources and its employees expressly disclaims all liability or responsibility to any person using the information or advice. Information contained in this document is correct at the time of writing. This work is licensed under the Creative Commons Attribution 4.0 International License. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/. ISBN 978-1-925369-42-7 Preferred way to cite this publication Miles CR and Costelloe JF, 2015, Lake Eyre Basin (South Australia): mapping and conceptual models of shallow groundwater dependent ecosystems, DEWNR Technical note 2015/22, Government of South Australia, through the Department of Environment, Water and Natural Resources, Adelaide Download this document at: http://www.waterconnect.sa.gov.au DEWNR Technical note 2015/22 i Foreword The Department of Environment, Water and Natural Resources (DEWNR) is responsible for the management of the State’s natural resources, ranging from policy leadership to on-ground delivery in consultation with government, industry and communities. High-quality science and effective monitoring provides the foundation for the successful management of our environment and natural resources. This is achieved through undertaking appropriate research, investigations, assessments, monitoring and evaluation. DEWNR’s strong partnerships with educational and research institutions, industries, government agencies, Natural Resources Management Boards and the community ensures that there is continual capacity building across the sector, and that the best skills and expertise are used to inform decision making. Sandy Pitcher CHIEF EXECUTIVE DEPARTMENT OF ENVIRONMENT, WATER AND NATURAL RESOURCES DEWNR Technical note 2015/22 ii Acknowledgements The Lake Eyre Basin Springs Assessment (LEBSA) project received valuable guidance from the project Technical Reference Committee members made up of members from various offices, departments and groups and of diverse backgrounds, including the Department of Environment (DE), Bureau of Meteorology (BoM), Geoscience Australia (GA), Queensland Department of Science, Information Technology, Innovation, and the Arts (DSITIA), the SAAL NRM Board and the South Australian Department of Environment, Water and Natural Resources (DEWNR). The LEBSA project has been delivered concurrently and in-conjunction with an equivalent project run by DSITIA, of which Keryn Oude-egberink (DSITIA LEBSA PM) has been instrumental in providing feedback to the TRC and SA LEBSA project, and guidance to the many DSITIA staff working on the project. Overarching program guidance and coordination of SA and Qld LEBSA projects was provided by the Executive Steering Committee members: Peter Baker (DE), Edwina Johnson (DE), Anisa Coric (DE), Kriton Glenn (GA), Tim Evans (GA), Phil Deamer (BoM), Sarah van Rooyen (BoM), Brendan Moran (BoM), Tom Carrangis (DEWNR), Tim Ryan (DSITIA) and Keryn Oude-egberink (DSITIA). The DEWNR LEBSA project team comprised: Andy Harrison (Project Manager), sub-Project Manager (Danny Brock), Travis Gotch, Ronald Bonifacio, Mel White, Dan Wohling, Mark Keppel, Dave Armstrong, Glen Scholz, Matt Miles, (DEWNR), with Catherine Miles (Miles Environmental Consulting) and Katie Fels (Jacobs ). The authors would like to thank the following people for their contributions to this project: Matt Miles, Lloyd Sampson, Mark Keppel and Daniel Rogers (DEWNR) for technical input and review, Moya Tomlinson (DoE) for review of the draft report; Shelley Fitzgerald (Spatial Ideation) for GIS assistance; Gayle Bruggermann (Jacobs) for conceptual model diagrams; Andy Harrison (DEWNR) for project management; and Katharine Glanville and Don Butler (DSITIA) for sharing the work they are undertaking in Queensland. DEWNR Technical note 2015/22 iii Contents Foreword ii Acknowledgements iii Contents iv Summary 1 1 Introduction 2 1.1 Overview of the Lake Eyre Basin Springs Assessment Project 2 1.2 Scope 2 1.3 Classification and definition of groundwater dependent ecosystems 4 1.4 Overview of aquatic ecosystem mapping, classification and groundwater dependency attribution in the Lake Eyre Basin, South Australia 4 2 Arckaringa alluvial groundwater dependent ecosystems 6 2.1 Conceptual model 6 2.1.1 Geology and soils 6 2.1.1 Geomorphology 8 2.1.2 Depth to groundwater 8 2.1.3 Groundwater quality 10 2.1.4 Recharge 10 2.1.4.1 Regional recharge 10 2.1.4.2 Middle and lower reaches 10 2.1.4.3 Sandy reaches 11 2.2 Mapping 13 2.3 Groundwater dependent ecosystems 16 2.3.1 Waterhole groundwater dependent ecosystems 16 2.3.2 Riparian woodlands 16 3 Cooper (South Australia) groundwater dependent ecosystems 18 3.1 Overview 18 3.2 Riparian woodland groundwater dependent ecosystems 18 3.2.1 Conceptual model 18 3.2.2 Mapping 19 3.3 Waterhole groundwater dependent ecosystems 22 3.3.1 Conceptual model 22 3.3.2 Mapping 22 3.4 Evaporative influence groundwater dependent ecosystems 25 3.4.1 Conceptual model 25 3.4.2 Mapping 27 3.5 Other known and potential groundwater dependent ecosystems 29 3.5.1 Terminal lakes 29 3.5.2 Dune storage groundwater dependent ecosystems 29 DEWNR Technical note 2015/22 iv 4 Conclusions 30 Appendices 32 A. Arckaringa groundwater dependent ecosystem attribute modifications 32 B. Groundwater dependent ecosystem attribute definitions 32 5 References 35 List of figures Figure 1.1 Location of the LEB, coal basins and preliminary assessment extents (PAEs) in South Australia 3 Figure 2.1 Surface geology of the Arckaringa PAE 7 Figure 2.2 Interpreted phreatic groundwater contours for the Arckaringa PAE 9 Figure 2.3 Conceptual model of groundwater–surface water relationships in the Arckaringa sub-region 12 Figure 2.4 Map of aquifer geology and aquifer confinement for potential GDEs in the Arckaringa PAE 14 Figure 2.5 Map of confidence in water source attribution for aquatic ecosystems in the Arckaringa PAE 15 Figure 3.1 Potential woodland GDEs in the Cooper PAE 21 Figure 3.3 Conceptual model of evaporative influence GDEs in wet and dry phase 26 Figure 3.4 Potential evaporative influence GDEs in the Cooper PAE 28 List of tables Table 1.1 Aquatic ecosystem mapping and classification undertaken for the Bioregional Assessment Programme 5 Table 3.1 Attribution of Cooper riparian woodland GDEs 19 Table 3.2 Attribution of waterhole GDEs 23 Table 3.3 Attribution of evaporative discharge GDEs 27 Table 4.1 Alignment of GDE types in the SA LEB with other typologies 31 DEWNR Technical note 2015/22 v Summary This project focusses on two preliminary assessment extents (PAE) (DEWNR 2014) of the Lake Eyre Basin in South Australia, the Arckaringa and the Cooper. The project aims were to 1. Capture the state of knowledge about ecosystems dependent on shallow groundwater through conceptual models and mapping, and 2. Trial the use of the Queensland groundwater dependent ecosystems (GDEs) mapping approach in South Australia. Mapping of GDEs in the Arckaringa PAE was largely undertaken as part of a previous project (Miles and Miles 2015) that built on South Australia’s Water Asset Database (WAD) for the South Australian Arid Lands region (Denny and Berens 2014). Research into water sources accessed by trees and surface water–groundwater interactions in the Neales River catchment has enabled the development of a relatively detailed conceptual model of GDEs for the Arckaringa PAE. Conceptual models for the Cooper PAE are more general, with less supporting evidence. The Cooper GDE mapping aimed, in so far as possible, to apply the Queensland GDE mapping approach, whilst building on prior aquatic ecosystem mapping and classification. The Queensland mapping approach was used with the intent to achieve cross border consistency in mapping, however, application of the Queensland GDE mapping approach to the SA portion of the Cooper PAE was hampered by: 1. Lack of definitive spatial geometries to represent aquatic ecosystems 2. Lack of complementary spatial datasets of other features (such as vegetation, soils, depth to groundwater) necessary to apply the mapping rules approach 3. Very little knowledge about shallow groundwater resources and water sources accessed by vegetation in the Cooper PAE. Therefore the results are considered preliminary. Despite the limitations, this work has demonstrated application of the mapping-rule sets approach used