TECHNICAL REPORT LOWER SOUTH EAST WATER BALANCE PROJECT PHASE 1 – REVIEW OF THE CONCEPTUAL MODEL AND RECOMMENDATIONS FOR A MODELLING APPROACH 2011/12 DISLAIMER The Department for Water and its employees do not warrant or make any representation regarding the use, or results of use of the information contained herein as to its correctness, accuracy, reliability, currency or otherwise. The Department for Water and its employees expressly disclaim all liability or responsibility to any person using the information or advice REPORT LOWER SOUTH EAST WATER BALANCE PROJECT PHASE 1 – REVIEW OF THE CONCEPTUAL MODEL AND RECOMMENDATIONS FOR A MODELLING APPROACH Nikki Harrington, Cameron Wood and Wei Yan Science, Monitoring and Information Division Department for Water February 2011 Technical Report DFW 2011/12 Science, Monitoring and Information Division Department for Water 25 Grenfell Street, Adelaide GPO Box 2834, 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.waterforgood.sa.gov.au Disclaimer The Department for Water 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 for Water 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. © Government of South Australia, through the Department for Water 2010 This work is Copyright. Apart from any use permitted under the Copyright Act 1968 (Cwlth), no part may be reproduced by any process without prior written permission obtained from the Department for Water. Requests and enquiries concerning reproduction and rights should be directed to the Chief Executive, Department for Water, GPO Box 2834, Adelaide SA 5001. ISBN 978-1-921923-02-9 Preferred way to cite this publication Harrington, N, Wood, C. And Yan, W., 2011. Lower South East Water Balance Project Phase 1 – Review of the conceptual model and recommendations for a Modelling Approach. Department for Water. DFW Technical Report 2011/12. Download this document at: http://www.waterconnect.sa.gov.au/TechnicalPublications/Pages/default.aspx Department for Water | Technical Report DFW 2011/12 ii Lower South East Water Balance Project Phase 1 – Review of the conceptual model and recommendations for a Modelling Approach FOREWORD South Australia’s Department for Water leads the management of our most valuable resource—water. Water is fundamental to our health, our way of life and our environment. It underpins growth in population and our economy—and these are critical to South Australia’s future prosperity. High quality science and monitoring of our State’s natural water resources is central to the work that we do. This will ensure we have a better understanding of our surface and groundwater resources so that there is sustainable allocation of water between communities, industry and the environment. Department for Water scientific and technical staff continue to expand their knowledge of our water resources through undertaking investigations, technical reviews and resource modelling. Scott Ashby CHIEF EXECUTIVE DEPARTMENT FOR WATER Department for Water | Technical Report DFW 2011/12 iii Lower South East Water Balance Project Phase 1 – Review of the conceptual model and recommendations for a Modelling Approach Department for Water | Technical Report DFW 2011/12 iv Lower South East Water Balance Project Phase 1 – Review of the conceptual model and recommendations for a Modelling Approach ACKNOWLEDGEMENTS The authors would like to acknowledge the contributions to this study from the following: The Technical Reference Group, whose input was instrumental in shaping the recommendations from Phase 1 - Keith Brown (Parsons Brinckerhoff), Glenn Harrington (CSIRO), Hugh Middlemis and Milo Simonic (Aquaterra). Project Stakeholder and Policy Reference Group Representatives, who were invaluable in clarifying the needs of the Water Allocation Planning Process – David Williamson and Daniela Conesa (South East Natural Resources Management Board), Andrew Johnson, Glyn Ashman, Ann Aldersey, Darryl Harvey, Cathy Cox (Department for Water). Attendees of the Technical Workshop, who made the event a great success, provided valuable feedback on the project approach and highlighted the volume of work that has been done and is underway on water resources in the South East. Department for Water | Technical Report DFW 2011/12 v Lower South East Water Balance Project Phase 1 – Review of the conceptual model and recommendations for a Modelling Approach Department for Water | Technical Report DFW 2011/12 vi Lower South East Water Balance Project Phase 1 – Review of the conceptual model and recommendations for a Modelling Approach CONTENTS FOREWORD ...................................................................................................................................... III ACKNOWLEDGEMENTS ...................................................................................................................... V SUMMARY ........................................................................................................................................ 1 BACKGROUND ..................................................................................................................................... 1 IDENTIFICATION OF SCOPE AND OBJECTIVES FOR WATER BALANCE MODELLING IN THE LOWER SOUTH EAST .............................................................................................................. 2 PROPOSED THREE-STEP MODELLING APPROACH ............................................................................... 3 ADDRESSING SURFACE WATER – GROUNDWATER INTERACTIONS ................................................... 5 LIMITATIONS AND KNOWLEDGE GAPS IN THE CONCEPTUAL MODEL................................................ 5 RECOMMENDATIONS FROM PHASE 1 ................................................................................................ 6 1. INTRODUCTION ....................................................................................................................... 7 1.1. BACKGROUND ........................................................................................................................ 7 1.2. TERMINOLOGY ....................................................................................................................... 8 1.3. OBJECTIVES ............................................................................................................................. 9 1.4. METHODOLOGY ..................................................................................................................... 9 2. PREVIOUS REVIEWS OF THE WATER BALANCE ........................................................................ 11 2.1. SOUTH EAST WATER SCIENCE REVIEW (BROOKES (ED.), 2010) ........................................... 11 2.2. A REVIEW OF SCIENTIFIC ASSESSMENTS UNDERPINNING THE WORK-IN-PROGRESS WATER ALLOCATION PLAN FOR THE LOWER LIMESTONE COAST PRESCRIBED WELLS AREA (SMERDON, 2009). ...................................................................................................... 12 2.3. CURRENT UNDERSTANDING OF THE WATER CYCLE IN THE LIMESTONE COAST REGION (PAYDAR ET AL., 2009) ............................................................................................ 12 3. OBJECTIVES FOR SHORT- AND LONG-TERM GROUNDWATER MODELLING IN THE LOWER SOUTH EAST .......................................................................................................................... 14 3.1. CONSULTATION APPROACH ................................................................................................. 14 3.2. KEY REGIONAL ISSUES .......................................................................................................... 14 3.3. CONSIDERATIONS FOR INTERFACING THE (SHORT- AND LONG-TERM) MODEL APPROACH WITH THE WATER ALLOCATION PLANNING PROCESS ...................................... 15 3.4. OTHER RECOMMENDATIONS FROM THE STAKEHOLDERS .................................................. 15 3.5. GUIDING FUTURE RESEARCH AND DATA COLLECTION EFFORTS ......................................... 15 4. PREVIOUS MODELLING STUDIES IN THE LLC REGION ............................................................... 17 4.1. OVERVIEW ............................................................................................................................ 17 4.2. MODEL SUMMARIES ............................................................................................................ 21 4.2.1. Compartmental Mixing Cell Model ...................................................................................... 21 4.2.2. Tertiary Confined Sand Aquifer (TCSA) Model .................................................................... 22 4.2.3. Wattle Range (Coles-Short) Model ...................................................................................... 26 4.2.4. Coonawarra (Zone 3A) Model ............................................................................................. 28 4.2.5. Zone 1A Model .................................................................................................................... 32 4.2.6. South of Mt Gambier Model ...............................................................................................