Managing extreme water shortage in Victoria Lessons from the Millennium Drought © The State of Victoria Department of Environment, Land, Water and Planning 2016 This work is licensed under a Creative Commons Attribution 4.0 Australia licence. You are free to re-use the work under that licence, on the condition that you credit the State of Victoria as author. The licence does not apply to any images, photographs or branding, including the Victorian Coat of Arms, the Victorian Government logo and the Department of Environment, Land, Water and Planning logo. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/au/deed.en ISBN 978-1-76047-046-3 (pdf) Accessibility If you would like to receive this publication in an alternative format, please telephone DELWP Customer Service Centre 136186, email [email protected], via the National Relay Service on 133 677 www.relayservice.com.au. This document is also available on the internet at www.delwp.vic.gov.au Disclaimer This publication may be of assistance to you but the State of Victoria and its employees do not guarantee that the publication is without flaw of any kind or is wholly appropriate for your particular purposes and therefore disclaims all liability for any error, loss or other consequence which may arise from you relying on any information in this publication. Contents Executive summary v Victoria’s water entitlement and planning frameworks vi Victoria’s water resources 1996–2010 vi Managing Victoria’s large regulated systems vii Securing urban water supplies vii Small rural water supply systems viii Qualification of rights ix Beyond 2010 ix 1. Victorian water entitlement and planning frameworks 1 1.1 Supply sources and systems 1 1.2 Victoria’s Water Entitlement Framework 1 1.3 Victoria’s Water Planning Framework 6 1.4 Emergency measures – qualification of rights 10 1.5 Summary 11 2. Victoria’s water resources 1996–2010 12 3. Managing water scarcity in Victoria’s rural regulated systems 18 3.1 How Victoria’s rural regulated systems operate 18 3.2 Sharing available water resources 20 3.3 Maximising water available through system operations and infrastructure modifications 29 3.4 Supplying essential needs on regulated systems 34 3.5 Increasing options for entitlement holders in the medium to long term 40 3.6 Summary 47 4. Securing urban water supplies 49 4.1 Urban supply systems 49 4.2 Performance of urban bulk entitlements 49 4.3 Performance of drought response plans 52 4.4 Demand management 53 4.5 Supply augmentation measures (short and long term) 56 4.6 Summary 64 5. Small rural supply systems 66 5.1 Licences on unregulated streams 66 5.2 Section 8 private rights (unregulated domestic and stock supply) 68 5.3 Groundwater supplies and use during drought 70 5.4 Managing environmental water on unregulated systems 73 5.5 Summary 74 6. Qualifying rights to water 75 6.1 Translating legislation into practice – key principles 75 6.2 Implementation of qualifications since 2006 77 6.3 Managing the impact of qualification of rights 82 6.4 Reviewing and refining the qualification process 85 6.5 Reducing the need to qualify rights in future 88 6.6 Summary 89 Managing extreme water shortage in Victoria Lessons from the Millennium Drought i 7. Beyond 2010 90 7.1 The floods – 2010/11 90 7.2 Statewide streamflow and reservoir levels since 2010 91 7.3 State-wide water resources available since 2010 97 7.4 Reforms coming out of the drought 97 7.5 Planning for future water shortages 101 7.6 The future 103 8. Glossary 104 9. Acronyms 108 10. References and further resources 109 List of tables Table 1.1 Types of entitlements in regulated and unregulated systems 2 Table 2.1 Rainfall reductions across Victoria in 1997–2009 compared with 1900–1996 13 Table 2.2 South-Eastern Australian rainfall anomalies in percentage terms relative to the 1872–2009 long-term mean 14 Table 2.3 Reduction in inflows to water storages July 1997–August 2009 compared to the long-term average 16 Table 3.1 Historical seasonal allocations to high-reliability water shares and low-reliability water shares (LRWS) in northern Victorian systems 21 Table 3.2 Measures undertaken by rural water corporations to reduce system operating losses and increase supply to rural users in declared irrigation systems 29 Table 3.3 Volumes of water carried over across all systems with carryover between 2007 and 2015 41 Table 3.4 Summary of annual allocation trade in Northern Victoria 2007/08 to 2014/15 45 Table 5.1 Total estimated annual groundwater use in Victoria 71 Table 7.1 Total Victorian streamflow compared with long-term average, 2003–04 to 2013–14 92 ii Managing extreme water shortage in Victoria Lessons from the Millennium Drought List of figures Figure 1.1 Victorian Water Entitlement Framework 3 Figure 1.2 EWR –management flexibility and certainty of supply 5 Figure 1.3 Timeframes of the Victorian Water Planning Framework 7 Figure 1.4 Relationship between short and long-term urban supply planning 8 Figure 2.1 Australian rainfall deciles from 1 October 1996 to 31 January 2010 12 Figure 2.2 Annual rainfall across Victoria – droughts compared to long-term average 13 Figure 2.3 Difference in annual mean temperature from long-term average in Victoria (1910–2009) 14 Figure 2.4 Severity of Millennium Drought compared to World War II and Federation droughts 15 Figure 2.5 Number of months per year with rainfall above the 90th percentile 15 Figure 3.1 Victoria’s regulated water supply systems 19 Figure 3.2 Historic allocation hierarchy for historic system operations and reserve rules 23 Figure 3.3 Progression of irrigation allocations in northern Victoria 2007/08 23 Figure 3.4 Allocation hierarchy for systems with new reserve rules 25 Figure 3.5 Options for using consumptive water en route in the lower Broken Creek 39 Figure 3.6 Volume of water carried over on Murray and Goulburn systems between 2007 and 2015 41 Figure 3.7 Timeline of carryover reform 43 Figure 3.8 High-reliability water share transfers in northern Victoria 2008/09 to 2014/15 44 Figure 3.9 Change in high-reliability water shares linked to land, by area, 2001 to 2015 45 Figure 4.1 Number of Victorian towns on water restrictions and the severity of restrictions 53 Figure 4.2 Water restriction levels (post uniform drought restriction guidelines) 54 Figure 5.1 Total number of streams on restrictions or bans (2003–2015) 67 Figure 5.2 Section 8 private rights for domestic and stock water use 68 Figure 5.3 Emergency water supply point network (2007/08) 69 Figure 6.1 Rivers subject to qualification of rights, overlaid with rainfall deciles 77 Figure 7.1 Volume of water in Victoria’s major storages 91 Figure 7.2 Levels in major Victorian water supply systems, December 2015 92 Figure 7.3 Annual streamflow in the Wimmera River at Glynwylln 93 Figure 7.4 Volume in Glenelg-Wimmera major storages 93 Figure 7.5 Annual streamflow in the Campaspe River at Rochester 94 Figure 7.6 Volume in Lake Eppalock 94 Figure 7.7 Annual streamflow in the Goulburn River at Dohertys 95 Figure 7.8 Annual inflows to Melbourne’s main harvesting reservoirs 95 Figure 7.9 Volume in Melbourne Water Corporation storages 96 Figure 7.10 Annual streamflow in the Mitchell River at Glenaladale 96 Figure 7.11 Victoria’s framework for planning for future water shortages 102 Managing extreme water shortage in Victoria Lessons from the Millennium Drought iii List of case studies Case study 3.1: Collaborative contingency planning in northern Victoria 24 Case study 3.2: Water to operate the Goulburn system 26 Case study 3.3: Thomson drought reserve 28 Case study 3.4: Pumping dead storage at Waranga Basin 31 Case study 3.5: Modernising the Goulburn-Murray Irrigation District – the Goulburn-Murray Water Connections Project 33 Case study 3.6: Emergency supply to Wimmera-Mallee domestic and stock customers 35 Case study 3.7: Drought refuge and environmental watering in the Boort Wetlands 37 Case study 3.8: Murray hardyhead 38 Case study 3.9: Unprecedented low inflows drive trade in the Latrobe Valley 46 Case study 4.1: Maintaining supplies to South Gippsland towns 50 Case study 4.2: Buying time for Wangaratta 56 Case study 4.3: Water carting for Broadford, Sunday Creek system 57 Case study 4.4: Alternative supplies and interconnections for greater Geelong 58 Case study 4.5: Bushfires and floods create Emergency in Mitchell basin 58 Case study 4.6: Recycled water in Campaspe basin 59 Case study 4.7: How recreation returned to Lake Wendouree 60 Case study 4.8: Winter diversions to meet east Gippsland demand 62 Case study 4.9: Connections work for north-east towns 62 Case study 4.10: Superpipe delivers a more reliable water supply to Ballarat and Bendigo 63 Case study 6.1: Qualification of rights in the Goulburn system 2009/10 79 Case study 6.2: Different access for Coliban customers 80 Case study 6.3: Moving water between systems 81 Case study 6.4: Beneficiary pays on the Thomson 84 Case study 6.5: Yarra River – environmental risk assessment 85 Case study 6.6: Special rules protect Loddon environment 87 Case study 6.7: Withholding passing flows in the Campaspe system 87 Case study 6.8: Emergency plan for towns on the Maribyrnong 88 iv Managing extreme water shortage in Victoria Lessons from the Millennium Drought Executive summary Australia is renowned for its highly variable climate and this is demonstrated in the rainfall records for Australia that go back more than 100 years.