MURRAY-DARLING BASIN AUTHORITY Pipeline to the Sea Feasibility Study — Phase 1 Prepared October 2008 by Tonkin Science Engineering Published May 2011 Pipeline to the Sea: Feasibility Study - Phase 1 Prepared for the former Murray-Darling Basin Commission by Tonkin Science Engineering Published by Murray-Darling Basin Authority Postal Address GPO Box 1801, Canberra ACT 2601 Office location Level 4, 51 Allara Street, Canberra City Australian Capital Territory Telephone (02) 6279 0100 international + 61 2 6279 0100 Facsimile (02) 6248 8053 international + 61 2 6248 8053 E-Mail [email protected] Internet http://www.mdba.gov.au For further information contact the Murray-Darling Basin Authority office on (02) 6279 0100 This report may be cited as: Pipeline to the Sea: Feasibility Study – Phase 1 MDBA Publication No. 148/11 ISBN (on-line) 978-1-921914-11-9 © Copyright Murray-Darling Basin Authority (MDBA), on behalf of the Commonwealth of Australia 2011. This work is copyright. 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To the extent permitted by law, the MDBA and the Commonwealth excludes all liability to any person for any consequences, including but not limited to all losses, damages, costs, expenses and any other compensation, arising directly or indirectly from using this report (in part or in whole) and any information or material contained within it. Australian Government Departments and Agencies are required by the Disability Discrimination Act 1992 (Cth) to ensure that information and services can be accessed by people with disabilities. If you encounter accessibility difficulties or the information you require is in a format that you cannot access, please contact us. Cover image: “Salinity Interception infastructure at Bookpurnong SA. Main line for salinity water to evaporation ponds” Arthur Mostead Pipeline to the Sea: Feasibility Study - Phase 1 Preface The Basin Salinity Management Strategy 2001–2015 is the Murray-Darling Basin Ministerial Council’s response to the threat of salinity to water quality, the riverine environment, regional infrastructure and productive agricultural land. A key element of this Strategy was the implementation of a joint program to construct new salt interception schemes to offset a predicted 61EC future increase in average salinity at Morgan. With an increase in the number of operating salt interception schemes came the need to assess options for disposal of saline groundwater generated by these schemes. Due to the controversial nature of disposal basins from a social and environmental perspective, more detailed assessments of a number of alternate disposal options have been carried out or are under way. One alternative for the Riverland is a pipeline to transfer saline water to the sea. The Murray-Darling Basin Commission first assessed a pipeline to the sea to transfer saline water generated by salt interception schemes in the Murray-Darling Basin in 1990 (GHD et al, 1990). That assessment considered a combined pipeline to transfer water from the Sunraysia and Riverland areas (‘the Mallee Zone’) as well as a separate pipeline to transfer saline water east/upstream of Swan Hill (‘the Riverine Plains Zone’). The objective of this latest feasibility report was to establish the feasibility of a pipeline/channel delivery system that would efficiently and effectively dispose of saline groundwater from the Stockyard Plain Disposal Basin in the Riverland Region of South Australia to the sea. The key conclusion of this feasibility study is that a pipeline to the sea may have some promise in the longer term when or if the capacity of the existing basins is exceeded. This report has only been prepared to inform discussion around possible disposal alternatives. Any decision to build such a pipeline at some point in the future would require more detailed engineering and ecological assessments followed by an extensive consultation and approval process. Pipeline to the Sea: Feasibility Study - Phase 1 Table of Contents Pipeline to the Sea Feasibility Study – Phase 1 Executive Summary i 1. Introduction 1 1.1 Project Objective 1 1.2 Stockyard Plain Disposal Basin 2 2. Outline of Scheme 3 2.1 Outline of Infrastructure 3 2.2 Range of options considered 4 3. Other Options 5 3.1 General 5 3.2 Disposal to Existing Salt Fields 5 3.3 Disposal of Salt 6 3.4 Discharge to Morella Basin or Southern Lagoon of the Coorong 6 4. Pipeline Routes 7 4.1 Alternative Routes 7 4.2 Alternative Disposal Locations 7 4.3 Options Assessed 8 5. Pipeline and Pumping Infrastructure 12 5.1 System Description and Operating Philosophy 12 5.2 Pipeline 12 5.2.1 Pipe Size 12 5.2.2 Pipe Material 16 5.2.3 Pipeline Cost 16 5.3 Pump Stations 19 5.3.1 Number of Pump Stations 19 5.3.2 Pump Station Cost 23 5.4 Discussion 27 5.5 Off Peak Pumping 27 5.6 Energy Recovery 28 5.7 Open Channels 28 5.8 ETSA Upgrade 29 6. Marine Outfalls 32 6.1 General 32 6.2 Ecosystems at Outfall Locations 33 6.2.1 Port Wakefield 33 6.2.2 Port Gawler 35 6.2.3 Middleton 37 6.2.4 Murray Mouth 40 Pipeline to the Sea: Feasibility Study - Phase 1 6.2.5 Coorong Crossings (Hells Gate, Tea Tree Crossing, 42 Mile Crossing & South of Coorong) 42 6.3 Impact of Discharge on Receiving Environments 44 6.3.1 General 44 6.3.2 Water Quality Policy 44 6.3.3 Discharge Water Quality 45 6.3.4 Required Dilution for Compliance 46 6.3.5 Modelling of Discharge Mixing 47 6.3.6 Risk Assessment 50 6.3.7 Summary 56 7. Outfall Infrastructure 58 7.1 Description of outfalls 58 7.2 Outfall construction 59 7.3 Pipeline to the Sea Outfalls 59 7.3.1 Length of Outfalls 59 7.3.2 Cost of Outfalls 60 8. Concentration Techniques 64 8.1 Introduction 64 8.2 Concentration via solar evaporation 64 8.3 Climate Change 65 8.4 Opportunistic production of other products 65 8.5 Evaporation Basin Model 67 8.5.1 General 67 8.5.2 Model Methodology 67 8.5.3 Model Inputs and Assumptions 68 8.6 Area of Evaporation Basins Required 69 8.7 Cost of Evaporation Basins 70 8.7.1 Capital Cost 70 8.7.2 Operation and Maintenance Cost 72 8.8 Issues Associated with Evaporation Basins 72 8.9 Concentration by Desalination 73 9. Ecological Issues 75 9.1 Desktop Study 75 9.2 Stockyard Plain Basin 75 9.3 Pipeline Alignments 76 9.3.1 Methodology 76 9.3.2 Vegetation Types and Significance 78 9.3.3 Summary of Vegetation Assessment 79 9.3.4 Other Vegetation Issues 80 10. Aboriginal Heritage 82 10.1 Desktop Study 82 10.2 Aboriginal Heritage Sites 82 10.3 Native Title 85 10.4 Consultation with Aboriginal Groups 85 10.5 Summary 86 Pipeline to the Sea: Feasibility Study - Phase 1 11. Social Impacts 87 12. Comparison of Options 88 12.1 General 88 12.2 Total Cost 88 12.3 Present Value Cost 89 12.4 Cost per Tonne of Salt Removed 96 12.5 Cost of Removing Salt by Truck 98 12.6 Overall Comparison of Alternative Pipeline Alignments 99 12.7 Comparison of Pipeline and Trucking 100 13. Technical Review Workshop 101 13.1 Workshop Purpose, Attendees and Outcomes 101 13.2 Phase 2 102 14. Conclusions 104 14.1 Individual Conclusions 104 14.2 Overall Conclusions 106 15. References 107 Tables Table 4.1 – Alternative Pipeline Routes 9 Table 5.1 - Pipe Sizes Assessed for Different Velocities 13 Table 5.2 – Optimum Pipe Sizes 13 Table 5.3 – Pipe Details 14 Table 5.4 - Optimisation of Pipeline Size 15 Table 5.5 – Pipeline Capital Costs 18 Table 5.6 – Pipeline Friction (m/km) for Different Pipeline Capacities and Velocities 19 Table 5.7 – Number of Pump Stations for Each Pipeline Option (50 L/s) 20 Table 5.8 – Number of Pump Stations for Each Pipeline Option (100 L/s) 21 Table 5.9 – Number of Pump Stations for Each Pipeline Option (250 L/s) 21 Table 5.10 – Number of Pump Stations for Each Pipeline Option (375 L/s) 22 Table 5.11 – Number of Pump Stations for Each Pipeline Option (500 L/s) 22 Table 5.12 – Unit Cost for each Different Pump Station 23 Table 5.13 – Pump Station Capital Costs 24 Table 5.14 – Density of Pumped Water 25 Table 5.15 – Annual Pump Station Operational Cost ($ million) 26 Table 5.16 - Power Upgrade Costs 29 Table 5.17 - Costs to Upgrade Electricity Network 31 Table 6.1 – Water Quality Data for Stockyard Plain Basin 46 Table 6.2 – CORMIX Model Input Data for Receiving Waters 48 Table 6.3 – CORMIX Model Input Data for Outfall Discharge 48 Table 6.4 – Results of Initial CORMIX Model Runs 48 Table 6.5 – Results of CORMIX Model Runs for Different Outfall Pipe Sizes 49 Table 6.6 – Impact Assessment Matrix 50 Table 6.7 – Summary Risk Matrix 55 Table 6.8 – Summary Risk Assessment for Habitat and Species 56 Pipeline to the Sea: Feasibility Study - Phase 1 Table 6.9 – Summary of Marine Outfalls 57 Table 7.1 – Outfall Lengths for Port Gawler Pipeline Options 60 Table 7.2 – Cost of Outfall Structures 62 Table 8.1 – Weather Data Used in Evaporation Basin Model 68 Table 8.2 – Area of Evaporation