Upper Barwon River Seasonal Watering Proposal 2021-22 FINAL Version 2, June 2021 Upper Barwon River Seasonal Watering Proposal 2021-22 Contents Tables ........................................................................................................................................ ii Figures ....................................................................................................................................... ii Acknowledgement of Country ..................................................................................................... iii Preface for Version 2 ................................................................................................................. iv Executive Summary ................................................................................................................... v 1. Introduction ............................................................................................................................ 1 1.1 System overview ............................................................................................................... 1 1.2 Environmental entitlement ................................................................................................. 2 2. Engagement ........................................................................................................................... 6 2.1 Notable feedback ............................................................................................................ 10 3. Values and uses of waterways ............................................................................................. 11 3.1 Aboriginal cultural values and uses of waterways ........................................................... 12 3.2 Social, recreational and economic values and uses of waterways .................................. 16 4. Seasonal review 2020-21 ..................................................................................................... 18 4.1 Climate ........................................................................................................................... 18 4.2 Environmental water delivery 2020-21 ............................................................................ 20 4.3 Hydrological achievement ............................................................................................... 24 4.4 Key ecological observations ............................................................................................ 28 4.5 Shared benefit review ..................................................................................................... 29 5. Environmental objectives and scope of environmental watering ........................................... 31 5.1 Water delivery objectives ................................................................................................ 32 5.2 Flow recommendations and potential watering actions ................................................... 33 6. Scenario Planning ................................................................................................................ 41 6.1 Outlook for 2021-22 ........................................................................................................ 41 6.2 Scenario planning ........................................................................................................... 41 7. Delivery constraints .............................................................................................................. 46 7.1 Temporary constraints .................................................................................................... 46 7.2 Systemic constraints ....................................................................................................... 46 8. Confounding factors ............................................................................................................. 48 8.1 Flow constrictions ........................................................................................................... 48 8.2 Riparian rehabilitation ..................................................................................................... 48 8.3 Fish barriers .................................................................................................................... 48 9. Increasing knowledge ........................................................................................................... 49 9.1 Knowledge gaps ............................................................................................................. 49 10. Risk management .............................................................................................................. 51 Corangamite Catchment Management Authority i Upper Barwon River Seasonal Watering Proposal 2021-22 11. Approval and endorsement ................................................................................................. 55 Appendix 1. Abbreviations ........................................................................................................ 56 Appendix 2. References ........................................................................................................... 57 Appendix 3. IAP2 spectrum of public participation .................................................................... 58 Appendix 4. VEHW Risk matrix ................................................................................................ 59 Tables Table 1. A summary of the priority watering actions for 2021-22 ............................................... vii Table 2. Passing flow rules for the Upper Barwon ...................................................................... 3 Table 3. Stakeholder engagement for the Upper Barwon River SWP 2021-22 ........................... 8 Table 4. Traditional Owner values and uses ............................................................................. 14 Table 5. Social, recreational, and economic shared benefits for the Upper Barwon River for 2021-22 ............................................................................................................................. 17 Table 6. Hydrological achievement of flow compliance over time at Ricketts Marsh (Conns Lane, Birregurra): 2009-2021 ............................................................................................. 26 Table 7. Hydrological achievement of flows 2020-21 at the east branch (East Barwon River at Flume) ............................................................................................................................... 27 Table 8. Identified emerging patterns in environmental watering in Victoria and their relation to the Upper Barwon .............................................................................................................. 28 Table 9. Shared benefits review ............................................................................................... 30 Table 10. Environmental watering priorities and the Upper Barwon entitlement beneficiaries ... 32 Table 11. Potential watering actions for 2021-22 ...................................................................... 35 Table 12. Planning of environmental watering under different climate scenarios ...................... 43 Table 13. Risk assessment for 2021-22 ................................................................................... 52 Table 14. VEWH risk rating matrix ............................................................................................ 59 Table 15. VEWH risk likelihood legend ..................................................................................... 59 Table 16. VEWH risk consequence matrix................................................................................ 60 Figures Figure 1. The Upper Barwon River System showing adopted study reaches and locations ........ 4 Figure 2. A typical section of the Upper Barwon east branch constrained by willows .................. 5 Figure 3. Red gums on the Upper Barwon ............................................................................... 11 Figure 4. River Blackfish (Gadopsis marmoratus) found in the Upper Barwon .......................... 16 Figure 5. A comparison of monthly average rainfall at Mount Sabine 2000-2019, 2020 & 2021 19 Figure 6. Daily average stream flow at Ricketts Marsh and Winchelsea, 2020-21 .................... 19 Corangamite Catchment Management Authority ii Upper Barwon River Seasonal Watering Proposal 2021-22 Figure 7. East branch flow against reach 4 flow recommendations in 2020-21 ......................... 21 Figure 8. Dry period east branch flow against reach 4 flow recommendations in 2020-21 ........ 22 Figure 9. Daily average stream flow at Ricketts Marsh and flow recommendations achieved ... 23 Figure 10. Flow recommendations for the Barwon River .......................................................... 31 Figure 11. IAP2 spectrum of public participation ....................................................................... 58 Acknowledgement of Country The Corangamite Catchment Management Authority (CCMA) wishes to acknowledge the Eastern Maar and Wadawurrung, Traditional Owners of the land of the Barwon River. We pay our respects to their Elders past, present and emerging. We commit to continuing to work with all Traditional Owners to ensure their knowledge and culture is included and valued in CCMA planning and delivery. Corangamite Catchment Management Authority iii Upper Barwon River Seasonal Watering Proposal 2021-22