Amendment date: 1 December 2017
1. Title of measure Menindee Lakes Water Saving Project 2. Proponent undertaking the measure NSW 3. Type of measure Supply (with a constraint measure submitted as supply for the Lower Darling) 4. Requirements for notification a) Date by which the measure entered into or The measure will be operational by 30 June 2024. will enter into operation Must be before 30 June 2024 b) Confirmation that the measure is not an Yes ‘anticipated measure’ It is a new measure (not already included in the benchmark ‘Anticipated measure’ is defined in section 7.02 of conditions). the Basin Plan to mean ‘a measure that is part of the benchmark conditions of development’. c) NSW agrees with the notification Yes 5. Surface water SDL resource units affected by the measure
This measure identifies all surface water resource units in the Southern Basin region as affected units for the purposes of notifying supply measures. The identification of affected units does not constitute an agreement between jurisdictions on apportioning the supply contribution, which will be required in coming months. 6. Details of relevant constraint measures
The measure includes the concept proposal for the Lower Darling constraints area. This will complement the implementation of the three Murray constraints concept proposals for the Murray River (see separate supply measure notifications).
7. Date on which the measure will enter into operation
The date by which the measure will enter into operation is 30 June 2024. 8. Details of the measure a) Description of the works or measures that The Menindee Water Saving Project seeks to make constitute this measure evaporative water savings at Menindee Lakes via: Works to improve discharge from the Menindee Lakes system Works to facilitate management of Lake Cawndilla, independent of Menindee Lake Works to control losses and facilitate higher flows in the Darling below Menindee Operating changes that complement the above works Rule changes and structural adjustment measures which lift constraints and maximise the potential for the suite of works to deliver larger environmental benefits provision of Broken Hill’s Town Water Supply from Murray River resources via a direct pipeline from Wentworth Interrelated works and measures to mitigate local environmental impacts as a result the proposed core works and measures Structural adjustment and strategic purchase for water users on the Lower Darling
See the description of the project and location of the proposed works in sections 5 and 6 and Figure 17 of Attachment A and the summary of infrastructure changes in Table 1 of Attachment A. b) Capacity of the measure to operate as a Yes supply measure ‘Supply measure’ is defined in section 7.03 of the Basin Plan to mean ‘a measure that operates to increase the quantity of water available to be taken in a set of surface water SDL resource units compared with the quantity available under the benchmark conditions of development’. c) Geographical location of the measure The Lower Darling River System is located in south-western New South Wales extending along the Darling River from the Menindee lakes storages to the upstream limit of the Wentworth Weir pool near Burtundy. The Menindee Lakes system are key storages in the Lower Darling system, supplying towns and irrigation along the Murray and Lower Darling rivers. The proposed works are primarily located around the Menindee Lakes, with some works distributed along the Lower Darling river. See Sections 2 and 5 and Figure 5 in Attachment A. d) Spatial data describing the inundation The proposed increase in the rate of releases from Menindee extent associated with the operation of the Lakes will provide additional inundation of the floodplain of measure the Lower Darling River. This is described in Section 6, 7 and Figures 8 and 9 of Attachment A. e) Representation of the measure in the The main elements of the proposal have been included in the MDBA modelling framework Murray Simulation Model by the MDBA, as described in Attachment B and in Amendment 1 (Attachment C). Modelling of the measure by the MDBA will be based on this work. f) Representation of each operating strategy The proposed operating strategy is to: in the MDBA modelling framework. a) reduce the use of Lake Cawndilla, so that it is only filled during large inflow events, and is subsequently drained after a short period; b) increase outflows from Lake Menindee up to 14,000 ML/day to meet peak demands in the Murray River; c) amend shared management arrangements and operational rules to complement the structural works; and d) recognise additional inflows that are expected to flow into Menindee Lakes under the operation of the Basin Plan. The proposed operations are described in Section 8 of Attachment A, noting that further investigation of some elements will be undertaken.
Attachments: A NSW DPI Water, June 2017 Business Case: Menindee Lakes Water Saving Project B NSW DPI Water, May 2017 Menindee Lakes Interim Project Proposal C NSW DPI Water Amendment 1 to Menindee Lakes Water Saving Project (NSW) D MDBA and NSW DPI Water Menindee Lakes Water Saving Project (NSW) Accounting for evaporative savings
Menindee Lakes Notification - Attachment A
Menindee Lakes Water Savings Project
Phase 2 Business Case J une 2017
Menindee Lakes Notification - Attachment A
Menindee Lakes Water Savings Project
LIST OF FIGURES ...... 5 LIST OF TABLES ...... 6 GLOSSARY OF TERMS AND ACRONYMS ...... 7
1 PROJECT SYNOPSIS ...... 8 1.1 Key Features of this Proposal ...... 8 1.2 Project Purpose ...... 8 1.3 Project Background ...... 9 1.4 Proposed Works Measures ...... 10 1.5 Preliminary Project Costs and Benefits ...... 14 1.6 Stakeholder and Community Consultation ...... 15 1.7 Project Delivery ...... 16 1.8 Legislative and Regulatory Frameworks ...... 18 1.9 Next steps ...... 18 2 BACKGROUND - MENINDEE LAKES & THE LOWER DARLING RIVER ...... 19 2.1 Lower Darling & Menindee Lakes ...... 19 2.2 Development of a regulated river system ...... 20 2.3 Storage Capacities ...... 23 2.4 The Lower Darling Regulated River System ...... 24 2.5 The Great Darling Anabranch ...... 24 3 MENINDEE LAKES AND LOWER DARLING SYSTEM ECOLOGY ...... 27 3.1 Menindee Lakes ...... 27 3.2 Lower Darling and Great Darling Anabranch ...... 30 4 MENINDEE LAKES OPERATIONAL ARRANGEMENTS ...... 31 4.1 Operating Objectives ...... 31 4.2 Current Operating Strategy...... 31 4.3 Drought Operations ...... 32 4.4 Flood Operations ...... 32 4.5 “Harmony Operation” with Lake Victoria ...... 33 5 OVERVIEW OF PROPOSED WORKS AND MEASURES ...... 34 6 PROPOSED INFRASTRUCTURE MEASURES ...... 36 6.1 Measure 1 – Enlarged Menindee Regulator Outlet ...... 37 6.2 Measure 2 – Lake Menindee Drainage Channel ...... 39 6.3 Measure 3 – Morton-Boolka Regulator ...... 41 6.4 Measure 4 – Old Menindee Town Weir removal ...... 43 6.5 Measure 5&6 – Lower Darling Channel Capacity (Yartla & Emu Lakes) ...... 44 6.6 Measure 7 – Cawndilla Creek Regulator ...... 46 6.7 Measure 8,9&11 – Anabranch Offtake Regulators, Dam 183 regulator ...... 48 6.8 Measure 10 – Menindee Main Weir Fish Passage ...... 52 6.9 Measure 12 – Flood Protection - Menindee residents ...... 53 6.10 Measure 13 – Lower Darling Constraints Mitigation Works ...... 55 7 PROPOSED STRUCTURAL ADJUSTMENT MEASURES ...... 57 7.1 Measure 14 – Acquisition of Lower Darling & Webster Ltd. (Tandou) entitlements ...... 57 8 PROPOSED INSTITUTIONAL ARRANGEMENTS / OPERATING RULES ...... 59 8.1 Measure 15 - Menindee System Control Transfer & Storage Drawdown ...... 59 8.2 Measure 16 - Broken Hill Entitlement...... 60 8.3 Measure 17 - Cawndilla Additional E-flows ...... 61 8.4 Measure 18 - River Murray Improved Operations ...... 63 8.5 Measure 19 - Lake Wetherell (floodplain) drying cycle ...... 63
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Menindee Lakes Notification - Attachment A
Menindee Lakes Water Savings Project
9 CONCURRENT MEASURES ...... 64 9.1 Measure 20 - Broken Hill TWS Alternate Supply ...... 64 10 OTHER MEASURES ...... 66 10.1 Measure 21 - Northern Basin Inflows ...... 66 10.2 Measure 22 - Lower Darling Temporary Trade ...... 66 11 KEY STAKEHOLDERS AND THE BROADER COMMUNITY ...... 67 12 ENVIRONMENT AND HERITAGE ...... 71 12.1 Environmental Impacts ...... 71 12.2 Cultural Heritage ...... 73 13 RISKS AND ISSUES ...... 76 13.1 Assessment Process ...... 76 13.2 Risk and Issues – Inherent Heat Map (before mitigation) ...... 79 13.3 Risk and Issues – Residual Heat Map (after mitigation) ...... 81 14 PROJECT COSTS ...... 83 14.1 Infrastructure Costs ...... 83 14.2 Non-Construction Project Costs ...... 84 14.3 Contingencies ...... 87 14.4 Structural Adjustment Costs ...... 88 14.5 Funding Requirements - Timings ...... 89 14.6 Price Escalation ...... 89 14.7 Operating and Maintenance Costs ...... 89 15 PROJECT DELIVERY...... 92 15.1 Project Management Plan ...... 92 15.2 Project Schedule ...... 93 15.3 Procurement Strategy ...... 95 15.4 Quality Assurance ...... 95 16 PROJECT GOVERNANCE ...... 96 16.1 Governance Overview ...... 96 17 LEGISLATIVE AND REGULATORY FRAMEWORK FOR MENINDEE LAKES ...... 98 REFERENCES ...... 102 APPENDIX 1 – MENINDEE LAKES INTER-JURISDICTIONAL WORKING GROUP ...... 103 APPENDIX 2 – MENINDEE LAKES INTER-AGENCY WORKING GROUP ...... 105 APPENDIX 3 – RISKS AND ISSUES – RISK REGISTER ...... 107 APPENDIX 4 – EIS REQUEST FOR TENDER – (DRAFT REQUIREMENTS) ...... 115 APPENDIX 5 – MENINDEE PROJECT COSTINGS ...... 128 APPENDIX 6 – ENGINEERING CONCEPT DESIGN DRAWINGS AND SPECIFICATIONS ...... 141 APPENDIX 7 – ENVIRONMENTAL WATER NEEDS AND WATER MGMT ARRANGEMENTS ...... 147 APPENDIX 8 – DETAILED PROJECT SCHEDULE ...... 148 APPENDIX 9 – PROCUREMENT PLAN ...... 149 APPENDIX 10 – INTERIM PROJECT PROPOSAL – APRIL 2017 ...... 151
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Menindee Lakes Notification - Attachment A
Menindee Lakes Water Savings Project
LIST OF FIGURES
Figure 1: Menindee Lakes and Lower Darling Catchment (Green et al. 2012) ...... 19 Figure 2: Average Monthly Rainfall (Menindee) and Evaporation (Broken Hill) ...... 20 Figure 3: Schematic diagram showing regulating structures in Menindee Lakes system ...... 21 Figure 4: Location Map Darling Anabranch (Source Earth Tech 2004) ...... 25 Figure 5: Proposed Location of Infrastructure Works in Scope ...... 35 Figure 6: Measure 1 - Enlarged Menindee Regulator ...... 38 Figure 7: Measure 7 - Cawndilla Creek inundation mapping ...... 47 Figure 8: Measure 8 – Approximate Locality of anabranch regulator ...... 50 Figure 9: Measure 8 – Proposed anabranch offtake regulator ...... 51 Figure 10: Menindee Township Inundation Map at 25,000ML/day ...... 54 Figure 11: Licence Entitlements – High Security ...... 58 Figure 12: Broken Hill Water Supply - Schematic ...... 65 Figure 13: Project Cost Breakdown ...... 83 Figure 14: Projected Project Expenditure by Year ...... 89 Figure 15: Key Milestones for Project ...... 93 Figure 16: Early Estimates of FTE requirements ...... 94 Figure 17: Overview of Proposed works ...... 116 Figure 18: Measure 1 – Menindee Regulator – Aerial View ...... 141 Figure 19: Measure 1 – Menindee Regulator – Side View ...... 142 Figure 20: Measure 2 – Menindee Channel – Cross Sections 1 ...... 143 Figure 21: Measure 2 – Menindee Channel – Cross Sections 2 ...... 144 Figure 22: Measure 3 – Morton-Boolka Regulator ...... 145 Figure 23: Measure 8 – Darling Anabranch Offtake regulator ...... 146
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Menindee Lakes Notification - Attachment A
Menindee Lakes Water Savings Project
LIST OF TABLES
Table 1: Summary of Works and Measures ...... 11 Table 2: Project capital costs (draft) ...... 14 Table 3: Operating & maintenance costs (draft) ...... 14 Table 4: Phased Delivery of Menindee Water Savings project ...... 17 Table 5: Maximum Release Rates of main regulating structures in the Menindee Lakes system ...... 23 Table 6: Storage Capacities ...... 23 Table 7: Vegetation Communities Identified ...... 28 Table 8: Listed wetland flora species from the Menindee Lakes ...... 29 Table 9: Licence numbers by category in lower darling ...... 55 Table 10: Licences ...... 58 Table 11: Licence Entitlements (Volumes) ...... 58 Table 12: Stakeholder Matrix ...... 68 Table 13: Likely approvals process for the Menindee Lakes project ...... 72 Table 14: Registered aboriginal sites within the study area ...... 74 Table 15: Issues Summary...... 75 Table 16: Risk Matrix ...... 76 Table 17: Consequence Matrix...... 77 Table 18: Inherent Risk Heat MAp...... 79 Table 19: Residual Risk Heatmap ...... 81 Table 20: Infrastructure Costs (Total Prime Costs) ...... 84 Table 21: Non-Construction project costs ...... 85 Table 22: Structural adjustment provisions ...... 88 Table 23: Operating and Maintenance Costs ...... 91 Table 24: Estimated project milestones ...... 93 Table 26: Comparison of the current prosed Menindee project with the 2013 proposal ...... 117 Table 27: Measure 1 – Enlarged Menindee regulator (prime costs) ...... 128 Table 28: Measure 2 – Menindee Drainage Channel (prime costs) ...... 129 Table 29: Measure 3 – Morton-Boolka Regulator (prime costs) ...... 130 Table 30: Measure 4 – Old Menindee town weir removal (prime costs) ...... 131 Table 31: Measure 5 – Emu Lake offtake regulator (prime costs) ...... 132 Table 32: Measure 6 – Yartla Lake offtake regulator ...... 133 Table 33: Measure 7 – Cawndilla creek regulator (prime costs) ...... 134 Table 34: Measure 8 – Darling anabranch offtake regulator (prime costs) ...... 135 Table 35: Measure 9 – Darling anabranch e-flow regulator (prime costs) ...... 136 Table 36: Measure 10 – main weir fishway (prime costs) ...... 137 Table 37: Measure 11 – 183 Dam Regulator, Road Bridge & Fishway (prime costs) ...... 138 Table 38: Measure 12 – Menindee Town Flood Protection works (prime costs) ...... 139 Table 39: Measure 13 – Lower Darling constraints mitigation works (prime costs) ...... 140
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Menindee Lakes Notification - Attachment A
Menindee Lakes Water Savings Project
GLOSSARY OF TERMS AND ACRONYMS
ANZECC Australian and New Zealand Environment and Conservation Council. AHD Australian Height Datum AHIP Aboriginal Heritage Impact Permit BOC Basin Officials Committee BSMS Basin Salinity Management Strategy DOC Dissolved Organic Carbon DN Diameter Nominal (internal diameter of a pipe) EC Electrical Conductivity – a measure of salinity EIS Environmental Impact Statement Environmental Provision of water, authorised by an access entitlement, to a location for the watering achievement of ecological targets and objectives. EP&A Act Environmental Planning and Assessment Act 1979 (NSW) IAWG Interagency Working Group IJWG Interjurisdictional Working Group. GL Gigalitres mg/L Milligram per Litre MinCo Ministerial Council ML Megalitres ML/day Megalitres per Day Comprises the catchment of the Murray and Darling Rivers and their many Murray Darling Basin tributaries, extending from north of Roma in Queensland to Goolwa in South (MDB) Australia. Murray Darling Basin Commonwealth Water Act (2007) : Schedule 1 Murray Darling Basin Agreement Agreement The authority responsible for managing the Basin’s water resources in the national Murray Darling Basin interest, in cooperation with state authorities, with the aim of ensuring reliable water Authority (MDBA) supplies for all users. (Formerly Murray Darling Basin Commission – MDBC) NOW NSW DPI Water OEH Office of Environment & Heritage (NSW). ppm Parts per Million RL Reference Level SDL Sustainable Diversion Limits SDLAM Sustainable Diversion Limits Adjustment Mechanism TWS Town Water Supply An accounting period from 1 July to 30 June, seasonally aligned and corresponding Water Year to water allocation policy in the River Murray system.
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Menindee Lakes Notification - Attachment A
Menindee Lakes Water Savings Project
1 PROJECT SYNOPSIS
The Menindee Lakes Water Savings Project Business Case is submitted as part of Phase 2 requirements for proposed Supply Measures under the Murray Darling Basin Plan.
The Business Case confirms that Menindee is capable of making a valuable contribution to Basin Plan outcomes. It draws upon the current state of knowledge and issues, which in some cases has evolved over many years of investigations and consultation in a highly variable and sometimes controversial operating environment.
Where insufficient information is currently available the Business Case provides details of work underway to fill knowledge gaps, ahead of the final Phase 3 submission in November 2017.
The NSW Government is pleased to have reached this important milestone for such an important project.
1.1 1 Key Featu res of thi s Pro posal
The Menindee Project (the Menindee Project) plan, costings and schedule have been completed in concept form and the MDBA modelling of expected water savings is underway as part of the Sustainable Diversion Limit Adjustment Mechanism. The project includes five key categories of co-dependent works and measures, including infrastructure works estimated to cost approximately $152 million. The schedule indicates that the works and measures can be completed before the 2024 target date with a modest margin, provided: o that there are no undue delays from the approvals process or significant inundation of the Lakes. o that some activities are undertaken in parallel with the approvals process. The project risk analysis indicates that all identified inherent risks can be reduced to manageable levels with the right controls in place.
Commercial discussions have commenced with landholders in relation to structural adjustment, for which a successful outcome is critical to the Project’s success. The Project will create environmental and socio-economic benefits at the local level as well making significant contributions to Basin Plan outcomes.
1.2 2 Project Pu rp o se
The Menindee Project is a multi-faceted suite of works and measures contributing to water savings, improved river operations, and environmental improvements, both locally and across the Murray Darling Basin.
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Menindee Lakes Notification - Attachment A
Menindee Lakes Water Savings Project
1.3 3 Pr oject Ba ckgr ound
The Menindee Project is being developed as part of the Murray Darling Basin Plan (the Plan). The Basin Plan sets out Sustainable Diversion Limits (SDL) across the Basin that represent an overall reduction of 2,750 GL in extractions, based on existing permitted use, as at June 2009. The SDL Adjustment Mechanism (SDLAM) provides an opportunity to account for the equivalent environmental outcomes achieved from the improved management of the Lake system and more efficient use of water by environmental water holders.
Projects to be considered under the SDLAM for this purpose are referred to as supply measures (which enable equivalent environmental outcomes to be achieved with less water); the SDLAM also allows for efficiency measures (which increase the volume of water available for environmental use by improving the efficiency with which water is used for consumptive purposes). In addition, a suite of works and measures are being developed to overcome known system constraints which limit the potential for higher river flows and environmental benefits.
Detailed studies between 2006 and 2013 considered a range of potential schemes to provide water savings at Menindee. In 2013, the Commonwealth and NSW governments agreed to further investigate a scope of infrastructure works and potential changes to the Murray-Darling Basin Agreement aimed at realising evaporative water savings, whilst recognising the water supply benefits to Basin States, the natural environmental values of the Lakes, and the recreational and social amenity the Lakes provide for the region.
The Commonwealth has reserved funding of $156 million for a Menindee water savings project. The NSW Government has also committed to a solution for water security for Broken Hill, with $500 million available for this purpose. Together these commitments recognise the ongoing importance of improving water management of Menindee Lakes for the Basin and the local region.
The Menindee Project seeks to achieve significant evaporative water savings by:
a. allowing operation of Lake Menindee independently of Lake Cawndilla, and decommissioning Lake Cawndilla for the purposes of water storage in all but the wettest years; b. removing high security irrigation and town water supply demands from the Lakes through a combination of infrastructure works and structural adjustment mechanisms; c. allowing faster drawdown of water in Lake Menindee, including access to residual water; d. by enlarging the outlet structure and constructing a drainage feeder channel in the bed of the Lake; and e. accommodating higher managed flows in the Lower Darling through works which aim to: o limit breakouts onto the floodplain and into dry Lakes and anabranches, and o protect private infrastructure from being impacted by higher flows, including changed operational rules to complement the structural works.
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Menindee Lakes Notification - Attachment A
Menindee Lakes Water Savings Project
As a consequence of the proposed works and measures, the project will also make significant contributions to overcoming system constraints and improve the ability for operators to achieve higher flow events in the Lower Murray.
1.4 4 Pr opose d Works Me asures
The package includes five categories of works and measures: -
1. Infrastructure works 2. Structural Adjustment measures 3. Changes to institutional arrangements and operating rules 4. Concurrent measures 5. Other measures
Section 6 details the objectives of each measure in the package. Whilst individual elements each bring their own specific benefits and costs to the project, there are critical dependencies between the elements of the package which may in some cases render the project unviable if one or more elements are not pursued as part of the package.
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Menindee Lakes Notification - Attachment A Menindee Lakes Water Savings Project
TABLE 1: SUMMARY OF WORKS AND MEASURES
Measure 1 Menindee outlet regulator capacity increased Works to increase up to 14,000ML/day SDL supply measure, and from 5,000ML/day. Constraints Management Measure 2 Lake Menindee drainage channel to feed Drainage channel up to 14,000ML/day SDLsupply measure outlet and improve discharge Morton-Boolka transfer regulator to control Up to 14,000ML/day regulator SDLsupply measure
Measure 3 releases to and from Menindee and Cawndilla Measure 4 Old Menindee Town Weir removal Removal of redundant Menindee town weir to improve Constraints Management Menindee outlet regulator flows by reducing downstream head
Measure 5, 6 & Increased Lower Darling channel capacity to Two regulators to prevent escape flows into Yartla Lake SDL supply measure, and 11 take higher Menindee discharge – offtake and Emu Lake + bridge at Charlie Stone Crossing Constraints Management regulators at Emu Lake and Yarta Lake
Measure 7 Cawndilla Creek Regulator Up to 14,000ML/day regulator Environmental mitigation
Measure 8 & 9 Anabranch offtake regulators constructed New Anabranch diversion regulator #1 to control up to SDL supply measure, and 14,000ML/day Constraints Management
New Anabranch environmental Regulator #2 to control up Environmental mitigation to 1,000ML/day, and Dam183 road bridge, regulator, and Lake Nearie Nature Reserve fishway Measure 10 Works to facilitate fish passage at Menindee No change to hydrology but fishway on Main Weir included Main Weir in costings
Measure 12 Flood protection measures for Menindee Construction of Menindee town high flow levee bank Constraints Management residents
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1.5 P rel imina ry Pro jec t Costs a n d Benef i ts
1.5.1 Costs
The total cost of works and measures, excluding the structural adjustment package, is estimated at approximately $152 million, based on preliminary concept designs by NSW Public Works. Table 2 summarises the estimated capital costs based on construction in the “dry”. Further discussion and detail of capital costs is provided in Section 14.
The 30% allowance for contingency at this preliminary stage reflects the uncertainty in project scope ahead of field investigations, approvals and detailed design.
TABLE 2: PROJECT CAPITAL COSTS (DRAFT)
NSW Public Works has also provided an initial estimate of the on-going operations and maintenance costs of the works. These estimates have not yet been peer reviewed and as such are considered preliminary in nature. Further consultation and refinement will take place over coming months in preparation of the Phase 3 submission.
TABLE 3: OPERATING & MAINTENANCE COSTS (DRAFT)
1.5.2 Benefits
Previous modelling of earlier versions of the Menindee Project indicated average annual water savings in the order of 72GL. Whilst the expectation is that this enhanced proposal will increase the level of water savings, detailed hydrologic modelling is not yet complete following submission of the final modelling brief to the MDBA in April 2017. The results of the SDLAM modelling will be provided to Ministerial Council as part of the SDL Adjustment process.
In addition, the Lower Darling has been identified by the MDBA as one of seven priority areas where relaxation of physical flow constraints will provide significant environmental benefits. The primary constraint to targeting higher river flows in the Lower Darling is the discharge capacity at Menindee Lakes, and particularly the Lake Menindee Outlet.
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Flood Mitigation will also be improved through works around Menindee township to protect residences close to the Darling River. This will also deliver the added benefit of providing some level of protection from natural flood events, reducing the need to evacuate these residences during times of flooding, and provide greater flexibility in managing flood events as they pass through the Menindee Lakes system.
Besides fish passage the benefits to the local environment will revolve around the greater flexibility provided to the management of the Lakes, the Lower Darling and the Darling Anabranch supply pathways. Under existing arrangements, reserves must be set aside to provide for Stock and Domestic and Local Water Utility in a repeat of the worst drought, but this is not required for the High Security or recommended minimum flows. In practice, the reserve volume required to ensure supply to Broken Hill is around 200GL and most of this is lost to evaporation. In dry years NSW typically allows continued access by High Security water users around the Lakes due to the small volumes involved, and meets downstream demands for riparian, High Security and Pooncarrie with a reduced minimum flow target.
Existing water management decisions at Menindee Lakes are dominated by the need to provide for high reliability supply to a volumetrically small amount of end user demand. The original selection of a NSW control threshold at 640/480GL was made on the basis of providing a reliable supply to NSW water users, in essence, a 480GL reserve was created to support a total of 51GL of regulated delivery entitlement. This is clearly inefficient in the current context.
NSW has been working with the Commonwealth Government to develop opportunities for amending system management requirements, to avoid the continuation of the need for a large operational reserve, for the purpose of delivering a small volume. The Commonwealth investment in the Menindee Lakes project is not simply the purchase of water entitlements, but rather enabling the reserve reduction from 275GL to around 80GL. The economic value of the purchase should be determined against the increased yield from the Menindee proposal compared to the intermediate “Run 35”, which would become the default option if the strategic purchase does not proceed. NSW has in place an Aboriginal Participation In Construction (APIC) policy, to support greater participation by Aboriginal people in government construction projects across NSW. Obligations under this policy are determined by the total construction costs of the project. With this project falling with Category 2 (project value exceeds $10million), at least 1.5% of the total estimated value of the contract must support direct and indirect Aboriginal participation.
As part of a package of concurrent measures, NSW has committed significant funding towards the construction of an alternate town water supply for Broken Hill. This project is currently in mid-stages of tendering for construction.
1.6 S ta k eh ol der a n d Com mun ity Co nsul tati on
Community consultation in regards to the Menindee Lakes project has been hampered over the past five years due to the complexity of issues involved, including extreme and prolonged periods of drought and Broken Hill water security issues.
Consultation was undertaken during the development of the options analysis by the NSW Government between 2006 and 2013. During this process, and in the early stages of business case investigations, key stakeholders indicated concerns regarding:
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security of supply being further impacted and made worse;
loss of amenity at the Lakes, which are a key asset for the regional community;
the environmental values that have developed around current Lakes operations being negatively impacted through the proposed changes;
evaporation occurring elsewhere in the basin is not being addressed, and that Menindee Lakes is being unfairly targeted;
the perception that more water in the Lakes means more employment potential locally whether tourism, fishing, or irrigation, which will be impacted under the proposed changes;
impacts on Broken Hill’s other recreation areas, which may potentially be drier – Copi Hollow, Sunset Strip Kinchega National Park – under the proposed management arrangements;
Menindee town and economy of the region will be permanently depressed due to the proposed changes; and
Concern that the environment of the Lower Darling, the Lakes and the Darling Anabranch will be less valued than downstream environments.
Additionally, local Indigenous people and Traditional Owners expressed concern that the environment upon which their culture is based will be impacted for the worse, with concerns that irrevocable damage will occur to special areas and cultural heritage.
The reinvigoration of this project provides an opportunity to re-engage with the key stakeholders to ensure issues are brought to the table and appropriately addressed.
At the time of preparation of this draft Business Case, stakeholder and community consultation is focused on commercial negotiations with directly affected parties, as a precursor to the development of a structural adjustment package. Broader community consultation is expected to commence in the last quarter of 2017 when commercial discussions are more advanced. This Business Case also outlines proposed arrangements for Inter-Agency and Inter-Jurisdictional engagement, which have already commenced informally and will be more formally established from July 2017.
1.7 P r oje ct D el i ve r y
The Lake Menindee project will be delivered over a six year time frame, with an expectation that scheduled works will be completed in 2023 prior to commissioning in the same year. Some parallel activities are required to achieve completion in the time available. This has implications for project costs and in particular the risk of rework and/or “regrets” expenditure.
Timeframes are highly dependent on the two key schedule risks, namely delays associated with environment and heritage approvals and construction risks associated with lake inundation. In regard to the latter, wet weather delivery options have been separately scoped and costed by NSW Public Works.
A project schedule has been prepared for the entire project and included at Appendix 8. The schedule decreases in detail at the point of transition to the Execution phase, in consideration of increased uncertainty over scope pending the outcomes of the EIS process. Section 15 provides detail around this schedule.
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1.8 L e gi sl a ti ve an d R eg ul a tor y F r a m ew or k s
The ownership, operations and maintenance of the Menindee Lakes sits within a complex suite of independent but interrelated legislative, regulatory and commercial instruments and agreements. The changes contemplated in this Business Case will necessitate changes to these guiding documents. Whilst a detailed legal review is yet to be undertaken, provision has been made in both time and cost to undertake such a review as part of the Phase 3 final submission.
Section 17 provides further details in regard to institutional arrangements.
1.9 Nex t steps
On the basis that the Phase 2 Preliminary Business Case is accepted and notified as part of the SDLAM package by the Basin Officials Committee, the next steps to progressing the business case to Phase 3 Final Submission will focus on further developing stakeholder engagement and communications plans as well as confirming, updating and coordinating matters identified in the Phase 2 preliminary business case prior to the submission of the Phase 3 documentation to MinCo for final approval.
The specific Phase 3 activity currently identified includes;
Stakeholder Engagement / Communications
o Developing stakeholder engagement strategy; o Developing communications strategy / plan; o Coordinating and supporting to IAWG; o Coordinating and supporting to IJWG; and o Re-engaging with Community representatives.
Confirming, Updating and Coordinating
o Governance arrangements; o Funding needs and peer review of costs undertaken; o SDL modelling; o Links to supply measures; o Final Advice on E-water delivery; o Final Advice on risks & 3rd Party Impacts; o Legal & legislative changes required; and o All approvals in train. Preparing and submitting updated Phase 3 business case to Basins Officials Committee for confirmation.
Additionally, to meet the timelines currently proposed there are additional Phase 4 activities that will need to be undertaken in parallel with the submission of the Final Phase 3 business case. These activities include;
Confirming Phase 4 Project Plan & Procurement Strategy,
Commencing procurement of EIS scoping study.
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2 BACKGROUND - MENINDEE LAKES & THE LOWER DARLING RIVER
2.1 1 L ow er D arl i n g & M eni nd ee L ak es
The Lower Darling River System is located in South-Western New South Wales and comprises the portion of the Darling River that is regulated by releases from the Menindee Lakes System. The three main features of the study area are:
The Menindee Lakes - a series of once intermittent, shallow wetlands that have been formally used for water storage since the 1960s. The Lower Darling River - 530 km of main channel from the Menindee Lakes to the confluence with the Murray River at Wentworth. The Great Darling Anabranch - a former channel of the Darling River and associated floodplain wetlands.
FIGURE 1: MENINDEE LAKES AND LOWER DARLING CATCHMENT (GREEN ET AL. 2012)
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Table 5 for Lakes Wetherell, Pamamaroo and Menindee are available when storage levels are high and the Darling River level is low. At other times, the available release rates are lower.
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Each lake contains a percentage of “dead storage” that is unable to be accessed for consumptive use and is referred to as the “residual pool”. The estimated size of the residual pools for each lake is summarised in Table 6. Regulation of the Lakes has increased the rate of sedimentation, particularly in key lake channels, such as Menindee Creek (within the lake). This has reduced the ability of water to drain from the Lakes, particularly at lower lake levels. Although some of this water may still be accessible through the existing gravity channels and regulators, the volume and quality of water able to be accessed at low levels is generally only suitable for drought emergency measures.
2.4 4 The Lo w er D ar l i ng R egul ate d R i ve r S yste m
The characteristics of overbank flow events in this region have been greatly altered through the development of the Menindee Lakes as storage capacity for the Murray-Darling system, and the frequency of freshes has significantly decreased. Furthermore, the frequency and volume of inundation events in the Great Darling Anabranch have both reduced as a result of upstream regulation and extraction (MDBA 2012). A number of ecological targets relating to flow regime for the Lower Darling Floodplain have been established for sustaining native vegetation, supporting habitat of water birds and supporting ecosystem functions. Some targets are limited by existing operational constraints – including regulator capacities, channel capacity, inundation of private land creating access issues, operational policy and ensuring reliability of water supply to Broken Hill and Menindee townships. The issues relating to Broken Hill are currently being addressed by WaterNSW with the development of the replacement pipeline and supply being sourced from the Murray.
2.5 The G rea t D arli ng A na bra nch
The Great Darling Anabranch (Anabranch) is a high level effluent stream that receives flows whenever flows in the Darling River exceed approximately 9,000ML/day. The Anabranch extends approximately 460 km from its difluence with the Darling River, South of Menindee Lakes, to its confluence with the Murray River, approximately 20 km downstream of Wentworth.
There are 11 large lakes and several lesser lakes and wetlands which are connected at various levels of flow to the Anabranch, and these have varying natural flooding patterns. Under natural conditions, the Anabranch flowed about every two years out of three in the upper reaches and less frequently downstream (Irish 1992). About every two and a half years flows reached half way down the system (Withers 1994; GHD 2013)
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FIGURE 4: LOCATION MAP DARLING ANABRANCH (SOURCE EARTH TECH 2004)
Following construction of the Menindee Lakes scheme, an annual replenishment flow for stock and domestic purposes of 50GL was provided if there were no natural high flows. The replenishments were provided from an outlet at the southern end of Lake Cawndilla, which also supplies irrigation water to Lake Tandou.
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Over time, a large number of block banks were constructed to create pools of water that would extend access to water after flows had ceased. The block banks have now been removed as part of the stock and domestic project finalised in 2006. The long-standing practice to limit regulated releases from Menindee Lakes to 9,000ML/day to the Lower Darling River when possible is based on the commence-to-flow threshold for the natural offtake point to the Anabranch, a flow greater than this rate would result in water passing into the Anabranch. Therefore, increasing the release rate would not produce a proportional increase in flows to the Murray River. Due to the commence-to-flow levels, only a small fraction of the increased water entering the anabranch would reach the Lower Murray system until the anabranch has been wetted up.
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3 MENINDEE LAKES AND LOWER DARLING SYSTEM ECOLOGY
3.1 1 M eni n dee Lak es
3.1.1 Flora
The Menindee Lakes system contains a broad diversity of both terrestrial and aquatic habitats. The vegetation / habitat types present within the Menindee Lakes system at any given time are a product of current and antecedent conditions, with water levels being the dominant influencing factor. Typically the Lakes are surrounded by a low woodland, with the lake bed and littoral zone comprising emergent macrophytes or herb / grass lands dependent on water levels. Several of the wetlands contain standing dead trees, which have drowned as a result of prolonged inundation. Five broad categories of inundation dependent vegetation/habitat types have been described in the Menindee Lakes system (Biosis 2001):
1. Floodplain woodland - dominated by Black Box (Eucalyptus largiflorens) and / or River Red Gum (E. camaldulensis) with or without Tangled Lignum (Dura florulenta) and variable understories. 2. Shrubland - chenopod shrubland dominated by Nitre Goosefoot (Chenopodium nitrariaceum) with scattered Black Box. 3. Herb/grass/sedge - occurs on dried out lake beds with vegetation (native and introduced) colonizing exposed sediments. 4. Wetlands - shallow freshwater marsh with emergent and floating vegetation, often with a canopy of dead trees. 5. Unvegetated - open water with or without dead trees, exposed unvegetated sediments.
These were divided into 24 separate inundation dependent vegetation communities based on conditions observed in 2014 (GHD 2015; Table 7).
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Common Carp (Cyprinus carpio) Eastern Gambusia (Gambusia holbrooki)
The site is especially important for waterbirds, with over 70 species recorded in the Lakes. There are 37 waterbirds listed under the EPBC Act, which includes birds listed under international migratory bird agreements. Of these, however, only nine species could be considered international migrants. Six species, the Brolga (Grus rubicunda), the Freckled Duck (Stictonetta naevosa); Blue-Billed Duck (Oxyura australis); Double Banded Plover (Charadrius bicinctus); Lesser Sand Plover (Charadrius mongolus) and the Australian Painted Snipe (Rostratula benghalensis) are also listed under the NSW Threatened Species Conservation (TSC) Act (1995). Large numbers of waterbirds are known to congregate on the Lakes with maximum counts exceeding 200,000. The Lakes have been known to support more than one per cent of the world populations of the Freckled Duck (Stictonetta naevosa), Grey Teal (Anas gracilis), Pink-eared Duck (Malacorhynchus membranaceus), Red-necked Avocet (Recurvirostra novaehollandiae), Sharp- tailed Sandpiper (Calidris acuminata) and Red-capped Plover (Charadrius ruficapillus) (Lau 2014). The site also supports waterbird breeding, particularly of colonial nesting species (URS 2005).
3. 2 L o w er D ar l in g a nd G rea t Dar l i ng A n ab ranch
The Lower Darling River and Great Darling Anabranch (an ancestral channel of the Darling River) support significant ecological values. The Anabranch has a complex geomorphology characterised by extensive meanders, deep riverine pools, riverine benches, adjoining saline Lakes, lignum swamps, channel complexes, backwaters, and billabongs. These wetlands are listed as a nationally important wetland complex in the Directory of Important Wetlands in Australia.
The Lower Darling River supports extensive areas of riparian vegetation dominated by river red gum woodland on the channel banks and the immediate floodplain, and large areas of black box on the outer floodplain. Lignum and nitre goosefoot are common understorey species on the floodplain.
The Lower Darling catchment provides terrestrial, floodplain and aquatic habitat for a range of significant plant and animal species. There are 46 threatened animal species and 14 threatened plant species within the region that are protected under the NSW Threatened Species Conservation Act 1995 (Green et al. 2012).
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4 MENINDEE LAKES OPERATIONAL ARRANGEMENTS
4.1 1 O p e r ati ng O bj ec tive s
General operations of the Lakes are currently divided into two sets of objectives that are related to consumptive water use and environmental benefits. The priority for operations is to maximise the potential supply of the water resources for all users, ensure that the operations provide long term ecological sustainability, and to maximise water quality within the Lakes and the Lower Darling River. To achieve these objectives, the Lakes have generally been operated to:
a. minimise evaporation; b. maximise storage volumes where they are most useful; c. maximise water quality (in terms of salinity); d. maximise ability to supply users; and e. mitigate floods where possible.
Since the 1990s, the operating strategies have been modified to address a range of new objectives including:
a. providing ecological benefits, including fish and wildlife habitat; b. improving water quality (in terms of mitigating blue-green algal bloom risks); c. managing flood mitigation for the lower Darling River to provide environmental benefits; d. controlling foreshore erosion; and e. minimising erosion of cultural heritage sites.
4.2 2 C ur re nt O pe ra ti ng S tr a teg y
The general operating strategy in each season, where Menindee Lakes are holding water in excess of agreed control thresholds, is for the Lakes to preferentially supply demands for water in the Murray River. This draws down water levels in Menindee Lakes ahead of other key storages in the Murray system, in order to reduce annual operating losses. The shared management mode of operation is managed by the MDBA on behalf of NSW and other jurisdictions, under the MDB Agreement.
Under current operating and water supply arrangements, to ensure ongoing supply of water to Broken Hill and surrounds and the Lower Darling River, supply of water to meet Murray demands is reduced to minimal levels when the total storage at Menindee Lakes reduces 480 GL. Additionally, to ensure critical water supply needs are able to be met during periods of low inflows, the current operating strategy also preferences water storage in Lakes Wetherell and Pamamaroo over Lakes Menindee and Cawndilla. This also minimises evaporation loss.
The Lakes filling strategy is therefore as follows:
a. Fill Lake Wetherell to 59.8 m AHD (top of the old river channel) b. Fill Lake Pamamaroo to full supply level (60.45 m AHD) (filling Lakes Pamamaroo and Wetherell simultaneously above 59.8 m AHD c. Fill Lake Menindee/Cawndilla to full supply level (59.94 m AHD) d. Fill Lake Wetherell to full supply level (61.67 m AHD) and e. If required fill Lake Pamamaroo (61.5 m AHD) and Lake Wetherell (62.3 m AHD) to full operating level and then Lakes Menindee and Cawndilla (60.45 m AHD)
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In most instances, the procedures for releasing water from the Lakes are generally the reverse of this, with all immediate consumptive demands being firstly met from Lake Menindee then Lake Cawndilla and Lake Wetherell above 59.8 m AHD.
4.3 3 Dr ou gh t O perati o n s
In a continuing drought where the availability of water for licensed consumptive use on the Lower Darling River is reduced, and where restrictions may become necessary, water is supplied according to the following order of priority:
a. Town and village water supply and riparian entitlement for domestic supply;
b. Riparian and licensed entitlement for stock supply, some of which provides water a considerable distance from the Lower Darling River;
c. Irrigation supply;
i. High security for permanent plantings (horticulture and vines); and
ii. General security for non-permanent plantings (pasture and cereal crops)
As water storage reduces due to evaporation, water salinity increases and in an extended drought it may be unsuitable for some irrigation, and town water supply irrespective of availability of supply. During times of drought the water remaining in the Lakes becomes an important refuge habitat that is necessary to sustain fish populations and other aquatic and terrestrial fauna until the arrival of the next significant inflow.
4.4 4 F l o od O peratio n s
The severity of floods in the Menindee Lakes and the Lower Darling River is dependent on:
a. The volumes, peak and duration of floods upstream;
b. The prior storage volume in the Lakes;
c. The level of surcharge adopted during a flood event; and
d. The rate and duration of release from storage.
The primary objectives of flood operations is to ensure that the integrity of the structures is maintained; to maintain security of future supply of entitlements by limiting pre-releases to levels below expected inflows, and where possible to minimise damage to downstream property. Management of inflows requires consideration of various factors including water quality and levee bank stability. While the scheme was not constructed to provide flood mitigation, some flood mitigation capacity may be achieved by pre-releasing before the peak inflow reaches the Lakes. Airspace in the Lakes up to the selected surcharge volume may then be used to store inflows and mitigate the peak flow.
Pre-releasing is considered when projected release requirements would otherwise cause the storage to exceed the capacity of the Lakes when filled to their maximum surcharge levels. Pre-releasing has the potential to reduce downstream flood peaks, but may cause increased flood duration downstream. Flood releases are currently managed where possible to mimic a more natural flow pattern.
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4.5 “ Harm on y O pe ra tion” w i th La k e V ic tor ia
Under the process of 'Harmony Operation' water can be transferred from Menindee Lakes to Lake Victoria (located in the Lower Murray), if flows in the River Murray are insufficient to satisfy consumptive and environmental demands for water. This process requires shared management of Menindee Lakes, coordinated by the MDBA, to balance the advantages of operational flexibility and reduced evaporation against the increased risk of loss of water as a result of spill from Lake Victoria, should conditions turn wet. These transfers are typically made in late Spring or Summer.
Additional Dilution Flow (ADF) requirements also influence the operation of Menindee Lakes. The ADF procedure aims to reduce river salinities further downstream, without impacting on water availability, and occurs when the storage in Menindee Lakes exceeds agreed target storage volumes (generally between 1,300 to 1,650GL depending on the month) and the combined storage in Hume and Dartmouth Reservoirs exceeds 2,000GL.
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5 OVERVIEW OF PROPOSED WORKS AND MEASURES
The initial modelling undertaken by the MDBA in 2013, based on works and measures proposed by NSW at that time, indicated water savings of only 72GL for the Menindee project. The collective view of the jurisdictions at that time was that more needed to be done to capture a greater share of the well documented system losses at Menindee. In response, the NSW Government developed a proposal, which was submitted in August 2016, this was further revised and expanded into a package of integrated works and measures. NSW submitted this as an Interim Business Case and modelling advice in April 2017.
The package includes five categories of works and measures: -
1. Infrastructureworks
2. Structural Adjustment measures
3. Proposed Institutional Arrangements / Operating Rules
4. Concurrent Measures
5. Other Measures
Whilst individual elements each bring their own specific benefits and costs to the project, there are critical dependencies between the elements of the package, which may in some cases render the project unviable if one or more elements are not pursued as part of the package.
For example, the proposed structural adjustment package represents a potentially large cost to the project; however, its inclusion is critical to decommissioning Lake Cawndilla and avoids much greater costs in providing alternate supply infrastructure to service Webster Ltd (Tandou) operations.
Likewise, the removal of Lower Darling high security entitlement avoids the need to continue providing a large operational reserve, enabling the reserve reduction from 275GL to around 80GL. Similarly, the Broken Hill pipeline project, separately funded by NSW and currently in procurement phase, is critical to the Menindee Project in that it removes high security demands on the Lakes, enabling them to be evacuated more rapidly and in turn reducing evaporative losses.
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Menindee Lakes Notification - Attachment A Menindee Lakes Water Savings Project
FIGURE 5: PROPOSED LOCATION OF INFRASTRUCTURE WORKS IN SCOPE
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Menindee Lakes Notification - Attachment A Menindee Lakes Water Savings Project
6.1 Measure 1 – En larg e d Menin dee Re gu l a tor Outle t
6.1.1 Objectives
The purpose of the new Menindee Outlet Regulator, inlet and outlet channels is to increase outlet capacity to enable faster drawdown of the level of Lake Menindee. This will: -
improve the efficiency of sequential storage drawdowns enable operators to minimise residual surface area quickly address existing issues with piping failures and downstream channel erosion, and address a major operational constraint in relation to lower Murray Basin Plan flow targets.
6.1.2 Description
The proposal is to replace the existing limited capacity pipe outlet of approximately 4,000ML/day maximum flow with a more substantial gated structure capable of passing flows of up to 14,000ML/day under low driving head conditions. Scope includes a new 14,000ML/day structure (incl. outlet channel sections and downstream creek widening) with 5 dual-leaf gates, 3m wide x 8.15m high. The new regulator will target the following outlet objectives:
a. 14,000ML/day flow at upstream lake level of 57.5 m AHD b. 2,000ML/day flow at upstream lake level of 56.0 m AHD.
To achieve this, it is proposed that the outlet regulator will have a sill level of RL 52.85 m AHD, to match the crest of Weir 32 crest. The sill level would be able to be raised or lowered depending on the targeted functionality and relationship with the Lake Menindee residual pool drainage channel. The structure will accommodate a maximum surcharge level (MSL) in the lake of 60.45m AHD. Gate operation will be undertaken locally through a portable actuator and power supply.
Overshot gates that can be lifted clear of the water will provide for downstream fish passage. Provision has been made for installation of fish passage infrastructure in the costings, however due to the height of the upstream storage level range (around 7.65m) the final design has not yet been determined.
The location has been selected to minimise impact to cultural heritage and dewatering requirements, as well as minimising the footprint of the structure. The existing regulator will be required for continued operation throughout construction, and will be retained to augment the new regulator capacity.
The Menindee Creek downstream of the proposed new regulator will be widened to convey the design flow. Widening works will be constrained to the right (western bank) to minimise disturbance of the more sensitive left bank areas. Rock erosion protection works in combination with limiting maximum channel velocities is required to control channel scour.
Connecting channels upstream and downstream of the new regulator will be constructed and optimized to limit scouring impacts, particularly in Menindee Creek. In addition, de-silting of the existing inlet channel may be necessary to improve flow capacity.
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Menindee Lakes Notification - Attachment A Menindee Lakes Water Savings Project
FIGURE 6: MEASURE 1 - ENLARGED MENINDEE REGULATOR
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Menindee Lakes Notification - Attachment A Menindee Lakes Water Savings Project
6. 2 M ea sur e 2 – La k e M enind e e D rai na g e C h an nel
6.2.1 Objectives
The inclusion of these works improves the upstream head conditions for the Lake Menindee Outlet It will address the issue of stored water pulling away from the outlet wall relatively early in the drawdown sequence which currently reduces outlet capacity. It is expected that maximum flows can be extended by at least two weeks as a result of these works, helping to capture the full benefits of related increases in outlet capacity.
These works will also enable operators to access the residual pool of water otherwise considered to be “dead storage” in Lake Menindee – the Menindee outlet is on the high side of the bed of Lake Menindee with a substantial residual pool of approximately 60GL.
6.2.2 Description
The proposed scope involves construction of a channel bed of varying width approximately 9km long and up to 9m in depth.
Currently at lower lake levels, flow control recedes upstream away from the existing Menindee Outlet Regulator and therefore the residual pool becomes isolated from the Regulator. A new internal lake drainage channel will provide access to the full depth of the residual pool and at higher flow rates.
The new channel will make use of a portion of the existing creek system, however, avoids the most downstream reach of the original creek length, within the lake, due to a high concentration of cultural heritage items.
The channel is also expected to potentially reduce fish mortality by allowing fish to move downstream to the Darling River and escape the residual pool. To maximise residual pool drainage rates, the regulator gates would be raised clear of the flow. The avoidance of high energy undershot gate flows is a key component for safe downstream fish passage.
The location of the channel has aimed to minimise channel length, with satisfactory hydraulic performance, as well as minimising the risk of scouring.
The aim of the project is to undertake the works to the drainage channel in the ‘dry’ due to the high additional cost of constructing in the ‘wet’ (not currently included in base costs) and to address potential environmental and heritage concerns.
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Menindee Lakes Notification - Attachment A Menindee Lakes Water Savings Project
FIGURE 8: MEASURE 2 - LAKE MENINDEE DRAINAGE CHANNEL (CONCEPT PLAN)
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Menindee Lakes Notification - Attachment A Menindee Lakes Water Savings Project
6. 3 M ea sur e 3 – M or ton- B o ol ka Re gul a tor
6.3.1 Objectives
Construction of a new regulator at Morton-Boolka allows Lake Menindee to be operated independently of Lake Cawndilla and for the lake levels to be equalised as Darling River floods approach, so that floodwaters can be captured within either or both Lakes.
The volume of water released into Cawndilla will be the amount required to periodically maintain environmental values. These works are central to achieving the water savings for the Menindee Project and therefore critical to project success.
6.3.2 Description
A new regulator capable passing flows of at least half the peak inflows from Copi Hollow is proposed – notionally 14,000ML/day. The concept design includes adjacent abutment banks and 8 dual-leaf gates, 3m wide by 4.95m high.
Historical records of lake operations in conjunction with hydraulic modelling will be utilised to assess past demands placed on Cawndilla Creek during transfer flows for the purpose of determining initial limiting creek velocity values. Subsequent later geomorphology considerations would add further guidance for the establishment of acceptable operating rules.
Rock protection of large sections of the creek is not considered practical, cost effective or permissible given the location within Kinchega National Park and construction access requirements and the number of identified cultural heritage sites.
The structure has a sill level closely matching the existing natural commence-to-flow level at the Morton- Boolka site to maintain the natural channel control conditions and ability for lake equalisation.
Provision for fish passage in both directions is almost certain to be a requirement of the approvals process and has been provided for in the cost estimates. From Menindee to Cawndilla downstream passage is anticipated via overshot gates that can also be lifted clear of the water. During reverse flow conditions from Cawndilla to Menindee downstream fish passage will be able to be achieved through an open structure with gates fully raised.
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Menindee Lakes Notification - Attachment A Menindee Lakes Water Savings Project
FIGURE 9: MEASURE 3 - MORTON BOOLKA REGULATOR (SHOWN SOUTH TO TOP OF PLAN)
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6. 4 M ea sure 4 – O l d M eni nde e To wn We i r re m o va l
6.4.1 Objectives
The objective of this measure is to remove the existing weir and allow operators to extend the duration of peak flows emanating from Lake Menindee outlet by up to 1 week.
An additional benefit of removing the weir will be an improvement in fish passage in the Darling River.
6.4.2 Description
Menindee town weir on the Darling River serves no operational purpose. Town water supplies are being drawn from Weir 32 and from a dedicated groundwater bore, following recent works by Water NSW. The existence of this redundant fixed crest weir does however lift the height of the pool downstream of the Menindee Lake outlet during low-mid Darling River flows, thereby reducing head differential and limiting flows through the Lake Menindee outlet.
Menindee town weir is assumed to comprise a 2.44m high U/S steel sheet pile, D/S timber crib structure with rockfill infill.
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6. 5 Mea sure 5 &6 – Low er D ar l ing C ha nn el Ca p ac i ty ( Yar tl a & Em u L a k es )
6.5.1 Objectives
These works will allow increased flows of up to 14,000ML/day in the Darling River channel downstream of Menindee by controlling water at key points of escape from the main channel, vis a vis Yartla Lake and Emu Lake offtakes. The works will also enable public access to be maintained during managed high flow events.
Increased flows in the Lower Darling, coupled with reduced losses, will assist with Murray River environmental watering requirements; maximise SDL offsets from this project, and help restore some seasonality to the flows in the Lower Darling.
6.5.2 Description
Before regulation, the Lower Darling was subject to highly variable flow conditions (Green et al. 2012). Since the completion of the Menindee Lakes storage scheme in the 1960s, flow in the Lower Darling has been highly regulated and the majority of flows are captured in the 1,700GL storage. The seasonality of flows has also changed, with the largest volumes of water now flowing throughout summer, rather than autumn or spring. Winter flows are also less variable and bank full flows occur less frequently (Gippel & Blackham 2002).
MDBA modelling undertaken for the Basin Plan shows that, without development of storages and weirs, flows in the Lower Darling would have played a key role in contributing to large overbank events in the lower River Murray.
Currently, higher flows down the Lower Darling primarily exceed the low commence-to-flow threshold for a few creeks and anabranches, including the Great Darling Anabranch, Yartla Lake and Emu Lake.
Inundation modelling using CSIRO’s RiMFIM software has been used below Weir 32 to assess likely areas of inundation, and indicates approximately 7,500 ha of additional inundation as flows increase from 9,000 to 14,000ML/day. The majority of the additional inundation occurs at two small Lakes – Yartla Lake and Emu Lake, with some creeks inundated near the Talyawalka area.
The Constraints Management Strategy includes the Lower Darling River as one of seven priority areas of physical flow constraints to be addressed to improve environmental outcomes under the Basin Plan. The principal constraint to release of higher flows is the physical and operational issues at Menindee Lakes, which have been addressed in this draft Business Case – Options Report for the purpose of achieving water savings. Addressing constraints will increase the potential for the Lower Darling to contribute to higher flows in the lower River Murray, delivering benefits to key environmental assets. The increased operating releases to the Darling River below Menindee potentially allow for the Darling Anabranch to be provided with flows as well as increased flows to be available to downstream environments.
There is not expected to be any significant impact on public infrastructure in addition to the levees near Menindee town described in Measure 12.
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The scope of works includes:
a regulator with 3 vertical lift gates, 3.5m wide x 1.5m high; and
a regulator with 1 vertical lift gate, 2.1m wide x 1.0m high; and
a road bridge over Charlie Stone Creek in the Talyawalka floodplain.
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6. 6 M ea sur e 7 – C aw ndil l a Cr ee k Re gu l a tor
6.6.1 Objectives
Cawndilla Creek links Lake Menindee and Lake Cawndilla, and the area between the two lakes supports important ecological and cultural heritage values. The proposed new operating regime for the Lakes will substantially decrease inundation of areas downstream of the Morton-Boolka regulator, including Cawndilla Creek, Lake Eurobilli and Lake Cawndilla.
Construction of a new regulator at the offtake to Cawndilla Creek will enable operators to isolate these areas when Menindee is draining. Additionally, if necessary it will facilitate environmental flows to the higher value assets, using held entitlement in between events which would otherwise fill the Menindee system (typically flow events greater than 600GL/mth at Bourke).
6.6.2 Description
The need to consider the “wetted” ecology of Cawndilla and Menindee Lakes was identified by NSW National Parks and Wildlife Service (NPWS) and within the report for Stages A1 and A2 on Environmental Water Needs and Water Management Arrangements (GHD, Mar. 2015). The works are likely to provide offset and mitigation to potential changes to the wetting and drying of Lake Cawndilla..
Scope of works includes a regulator (incl. adjacent levee/abutment, 6 dual-leaf gates) 3m wide by 4.61m high near the entrance to Lake Cawndilla to allow upstream inundation of Morton-Boolka, Lake Eurobilli and Cawndilla Creek for the benefit of vegetation communities in the area between Lake Menindee and Lake Cawndilla.
The site selection for this regulator is aimed at mitigating the impacts of lower Lake Cawndilla storage levels on River Red Gum and Black Box communities along the fringes of Lake Cawndilla, Morton- Boolka, Lake Eurobilli and Cawndilla Creek Figure 7 shows inundation mapping of Cawndilla Creek.
The structure is to be located on Cawndilla Creek and incorporate provisions to allow flow in either direction. Reverse flow from Lake Cawndilla to Lake Menindee is needed to ensure that the residual storage level of Lake Cawndilla is not raised when Lake Menindee is being drawn down. Fish passage will be facilitated through the gated section of the regulator structure up to a maximum flow of 6,000ML/day.
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Menindee Lakes Notification - Attachment A Menindee Lakes Water Savings Project
FIGURE 7: MEASURE 7 - CAWNDILLA CREEK INUNDATION MAPPING
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6. 7 M ea sur e 8, 9 & 11 – A n a br anch O ffta k e R egu lat ors, Da m 18 3 reg ula to r
6.7.1 Objectives
Existing Menindee releases to the Lower Darling are limited to 9,000ML/day to prevent excessive losses into the Great Darling Anabranch and to other areas along the Lower Darling River. These works will enable operators to exclude higher flows from entering the Anabranch system to take advantage of increased Menindee discharge capacity. Natural high flows will not be excluded, and the regulator will also be opened for environmental water and potentially transmission delivery to the Anabranch which can be piggybacked onto Murray releases.
These works provide water savings, address the Constraints Management Strategy and facilitate more efficient delivery of environmental account water to the Darling Anabranch and the nature reserve at Nearie Lake.
6.7.2 Description
The Anabranch works are made up of three components:
Works at the existing Anabranch regulated offtake o a regulator with 7 dual-leaf gates, 3.65m wide by 2.4m high. Works at the Anabranch environmental offtake. (Offtake regulator to replace current Darling Anabranch offtake) o a regulator with 3 dual leaf gates, 2.05m wide by 3.5m high; o a channel bed of width 6.5m and length approximately 800m; and o a road bridge of 4m width, dual carriage approach and giveway bay. Works at Dam 183 o a regulator with 4 dual leaf gates, 2.1m wide by 2.5m vertical height; o a road bridge of 4m width single span; and o a vertical slot fishway of height 2.24m
The proposed Darling Anabranch twin regulators will enable either the complete exclusion of higher Darling River flows, or the diversion of a proportion of flows to the Anabranch during higher managed releases from Menindee Lakes.
The upstream regulator design will allow for the exclusion of a higher Darling River is a gated sheet pile construction with a height in the order of 1.5m tying into the top of bank levels. The structure will provide a nominal waterway area equivalent to 100% of the natural channel waterway. The downstream regulator and associated cutting will allow diversions into the Anabranch, when required for environmental needs, during high flows in the Darling River. This will provide a replacement for the current diversion point into the Anabranch via Lake Cawndilla.
The twin regulator proposal has been supported to minimise engineering complexity, as the natural offtake sill (the site of the upstream regulator), initially leads to a broad area of inundation that would significantly add to the volume of water required to provide an environmental flow along the Anabranch.
COMMERICAL IN CONFIDENCE PAGE 48
The upstream structure is proposed to operate for the most part in the “fully open” default position, unless environmental flows are released down the Darling River, in which case the structure can be “fully closed” to contain flows within the Darling River.
The downstream Anabranch environmental regulator will be designed to minimise the disturbance foot print during operation. The regulator would only need to be opened at those times when an environmental flow would need to be delivered to the Anabranch, at all other times the regulator would remain closed.
Fish passage structures are not considered necessary since the structures would be normally fully open with a waterway area, matching 100 per cent of the natural cross-section of the stream. The structure is to be located on the choke point in the Anabranch offtake approximately 100 metres downstream of the existing road bridge.
COMMERICAL IN CONFIDENCE PAGE 49
FIGURE 8: MEASURE 8 – APPROXIMATE LOCALITY OF ANABRANCH REGULATOR
COMMERICAL IN CONFIDENCE PAGE 50
Menindee Lakes Notification - Attachment A Menindee Lakes Water Savings Project
FIGURE 9: MEASURE 8 – PROPOSED ANABRANCH OFFTAKE REGULATOR
COMMERICAL IN CONFIDENCE PAGE 51
6. 8 Mea su re 1 0 – Meni n de e Mai n We i r Fi sh Passa ge
6.8.1 Objectives
The objective of these works is to improve fish passage in the Darling River in anticipation of likely regulatory approvals requirements.
6.8.2 Description
Section 218 of the NSW Fisheries Management Act requires fish passage to be provided in the construction and/or augmentation of dams and weirs.
Specifically, the Minister may, by order in writing, require a person (other than a public authority) who constructs, alters or modifies a dam, weir or reservoir on a waterway to carry out works “to enable fish to pass through or over the dam, weir or reservoir”. The Minister may also, by order in writing, require a person responsible for the management or control of a dam, weir or reservoir to carry out repairs to a fishway or fish by-pass.
In addition, a public authority that “proposes to construct, alter or modify a dam, weir or reservoir on a waterway” must “notify the Minister of the proposal, and must, if the Minister so requests, include as part of the works for the dam, weir or reservoir, or for its alteration or modification, a suitable fishway or fish by-pass”.
Whilst works on Menindee Main Weir are not proposed, almost certainly the requirement for fish passage at this weir will be assessed as part of the Environmental approvals under the State Significant Projects process.
COMMERICAL IN CONFIDENCE PAGE 52
6. 9 Mea sure 1 2 – Fl ood P rotecti o n - Meni n de e residents
6.9.1 Objectives
The intention to pass regulated high flows past Menindee to achieve Lower-Darling flows of up to 14,000ML/day will likely result in some localised flooding of Menindee residential properties. The objective with this component of the package is to construct a levee of sufficient height and length to protect riparian residential properties from these managed events.
6.9.2 Description
Flood protection for at least ten properties and access roads is proposed. The scope of works includes levees and access road raisings for a design flood level at a flow of 25,900ML/day (moderate flood level). Figure 10 provides an aerial view of the estimated inundation at 25,000ML/day.
A number of property boundary levees and raised access roads will be required to protect residents from inundation impacts (below floor levels) due to potentially more frequent flooding under modified lake operation and release conditions.
The level of flood protection is to be increased from the current minor flood level at about 17,000ML/day up to a moderate flood level of at least 25,900ML/day. This will provide residents with at least the same or better flood protection as existing compared to the level of protection proposed under modified lake operating conditions.
The proposed works are within the vicinity of the Menindee township, adjacent either side of the river.
COMMERICAL IN CONFIDENCE PAGE 53
FIGURE 10: MENINDEE TOWNSHIP INUNDATION MAP AT 25,000ML/DAY
COMMERICAL IN CONFIDENCE PAGE 54
Before works were commenced, an agreement would be required with each of the licence holders to confirm the scope to modify the equipment and to ensure that no ongoing obligations are incurred to maintain any of the equipment.
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7 PROPOSED STRUCTURAL ADJUSTMENT MEASURES
7.1 1 M ea sure 1 4 – Ac qui si tion of L o w er Dar li ng & We bster L td. (Ta nd ou) en ti tl e m en t s
7.1.1 Objectives
There are a number of entitlement holders of various categories in the Lower Darling Water Source who will need to be considered in the changes to the management of the Lakes with the primary objective being to remove High Security irrigation demand from the Darling downstream of Menindee.
This in turn will reduce NSW commitment to holding upstream water reserves in the system and therefore maximise potential water savings from the project.
Reduced use of Lake Cawndilla impacts on the gravity supply frequency to Lake Tandou. The infrastructure cost of providing alternate pumping and channel infrastructure to supply 80 GL annually to Lake Tandou is significant. It is better value to facilitate a cessation of irrigation on the property.
Additionally, Lower Darling irrigation creates system commitments which when removed will enable quicker and more extensive evacuation of the Lakes.
7.1.2 Description
The Lower Darling is the section of the Darling River between Menindee Lakes and the confluence of the Darling with the River Murray at Wentworth in south-western New South Wales. The townships of Menindee, Broken Hill and Pooncarie are all supplied with water from the Lower Darling system. There are also a number of private irrigators located near Menindee town, and south of Menindee Lakes who extract water directly from the river.
The Lower Darling Water users; particularly the high security entitlement holders, have long expressed concerns that releasing additional, larger flows from the Menindee Lakes storage system, and having shared control (administered by the MDBA) extend to a lower storage volume, will negatively affect the reliability of their water entitlement supplies.
It is proposed to assist water users’ transition from permanent plantings to annual cropping, and to provide increased resilience to sustained periods of no or low flows in the Lower Darling river. A group of vineyard and orchardists below Pooncarie, representing the majority of permanent plantings in the Lower Darling, have brought forward a proposal to the NSW and Commonwealth Governments, which is currently under consideration.
Prior submissions assumed a reduction (but continuance) of demand consistent with Basin Plan recovery targets.
The enhanced Menindee Project is predicated on reducing or removing high security licence obligations and some targeted general security entitlements in the Lower Darling. This component of the package is therefore fundamental to the success of the overall package.
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8 PROPOSED INSTITUTIONAL ARRANGEMENTS / OPERATING RULES
8.1 1 Measure 1 5 - Men in de e Syste m Co ntro l Transfer & Stora g e D rawd own
8.1.1 Objectives
The removal of thresholds which determine “decision control” for Menindee releases provides MDBA with increased flexibility, helping to increase drawdown rates, reduce evaporation, increase the overall regulated supply to the Murray and harmonise operations with Lake Victoria. These measures enable the value of proposed infrastructure works and therefore potential SDL offsets to be maximised.
8.1.2 Description
Current operating rules assume control triggers at 480GL (below which NSW resumes management of the Lakes) and 640GL (above which MDBA assumes management of the Lakes). The intent of the thresholds has been to ensure NSW retains control of the storage volumes to meet residual demands of high security water users’ dependent on the Lakes as the Lakes dry out.
Previous modelling of Menindee options assumed a continuance of (reduced) Broken Hill, Tandou and Lower Darling demand, thereby constraining operating flexibility and NSW ability to handover control. Partial relaxation of the thresholds was possible, to 275GL and 615GL. It was assumed the residual 275GL in dry years would be held in Pamamaroo and Wetherell.
The current proposal effectively removes the thresholds altogether. To enable this, it is essential to remove all TWS and high security irrigation demands from the Menindee system via the provision of an alternate Broken Hill supply from the Murray and the Lower Darling/Tandou structural adjustment package.
However, in order to protect basic landholder rights in the Lower Darling, it is proposed that operators retain approximately 80GL of water for riparian demands until the end of the year following evacuation of the other Lakes, with this volume able to be held in the Lake Wetherell old channel. Sufficient water will be retained to supply any remaining account volumes through ongoing resource assessment processes.
Earlier modelling of the impact of system control and drawdown changes, for model run 35, indicated nil to slightly positive impact on the supply to Murray River entitlement holders (Turner, 2016). However, the latest changes to the proposal have not yet been tested and there have also been concurrent changes to the model in so far as the operating loss regression function, both of which will potentially alter the outcome. Whilst not expected to have a material adverse consequence, this will need to be confirmed prior to the submission of a Phase 3 Business Case.
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8. 2 Mea sure 1 6 - B r ok en H il l E nti tl e m e n t
8.2.1 Objectives
With interrelated works underway to construct a pipeline supply from the Murray River for Broken Hill, agreement will also be required in respect of shifting Broken Hill TWS entitlements. This component of the package will establish and model the likely operating conditions attached to the new licence.
8.2.2 Description
Previous options and modelling assumed that Broken Hill TWS continued from the Darling via Menindee with access to groundwater during times of surface water restriction / shortage. The current proposal assumes the entire demand is shifted to the Murray River.
The model needs to remove Broken Hill demand from the Darling and create a new demand node connected to the Murray near Sunraysia. The pipeline design capacity will be up to 37ML/day.
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8. 3 Mea sure 1 7 - Cawndil l a A dditi onal E -f lo w s
8.3.1 Objectives
Lake Cawndilla incorporates parts of Kinchega National Park and notwithstanding the impact of historical works and operations, the lake is a culturally and environmentally significant area.
This project proposes the decommissioning of Cawndilla for the purposes of regulated water supplies, with future filling only occurring during natural events that would otherwise fill the Lakes. This component of the package provides the capacity to manage and protect Cawndilla’s cultural and environmental values by developing a regime of managed, periodic inundation of the Lake using held entitlement.
8.3.2 Description of works
The proposal to reduce use of Lake Cawndilla as a water conservation storage may have impacts on the environmental values that have developed around Lake Cawndilla during regulation. As described in Section 3, fringing vegetation is now higher up the banks of the Lake, and is dependent on the Lake filling with more frequently (and at higher levels) than under natural conditions.
The SDLAM environmental equivalence scoring framework does not directly recognise environmental values at Menindee Lakes, and a separate assessment of the local environmental needs has been commenced to support this business case. Further work will be necessary as part of the formal EIS process.
To support the existing environmental values of Lake Cawndilla, the proposed operational regime has been adjusted to include periodic filling during natural high flow events for a short period of time. However, increasing the provision of water to Lake Cawndilla reduces evaporative water savings, and there is a trade-off between local environmental values and the benefits of evaporative savings for the environment more generally.
There is also the potential for changed operation at Lake Cawndilla to adversely impact on nationally and NSW State listed threatened flora species including the Menindee Nightshade which is endemic to the Lakes.
Taking into account the water needs of the existing environmental values around Lake Cawndilla, a practical set of triggers has been proposed for the periodic environmental filling and subsequent release from the Lake. This trigger for a filling event at Lake Cawndilla is that it has been more than 36 months since the last successful filling event, and more than 600GL has passed Wilcannia. Whilst these criteria have been designed to minimise failed filling events given the highly variable nature of flows in the Darling, modelling indicates that the period between events to fill Lake Cawndilla may be up to 10 years in some cases. This longest period between events also occurs in the modelled without development scenario.
Reducing the dry period trigger from 36 months would increase the frequency of watering events and reduce the likelihood of adverse impacts on the current ecological values, in particular the River Red- Gum and Black Box woodlands that fringe the Lake. This would also enable more frequent releases
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from Lake Cawndilla to the Great Darling Anabranch. However, this operation would substantially reduce the evaporation savings.
The request for modelling assumes the above arrangements for filling of Cawndilla when Darling River flows at Bourke exceed 600GL per month and it has been three years since the previous fill event. The change with this current proposal is to provide for watering between events using held environmental entitlement.
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8. 4 M ea sure 1 8 - R i ver M urr a y I mpr o ve d O p erati ons
8.4.1 Objectives
Although not a direct component of this Menindee package, changes to the MDBA Monthly Simulation Model (MSM) to reflect contemporary operations and water sharing arrangements are essential in order to capture the full extent of SDL supply benefits from the Menindee project.
8.4.2 Description
Model Run 35 included estimates of River Murray operating losses (OPLOSS) based on a regression equation assuming practices and seasonal conditions pre-2000. Extrapolating forward to post- drought/post-Plan conditions, it appears that the model is overestimating OPLOSS, which manifests as higher averaging storage levels in Lake Victoria despite actual river operations data to the contrary. The capacity to re-regulate additional water emanating from this Menindee project is intrinsically linked to the ability of operators to re-regulate flows in Lake Victoria.
NSW DPI proposes that the OPLOSS regression equation be recalibrated in order to more accurately capture the new operating paradigm and the full extent of benefits from SDL projects such as Menindee.
8. 5 M ea sure 1 9 - La k e W e ther ell (f l oo dpl ai n) d r ying cyc l e
8.5.1 Objectives
The objective of this change in operations of Lake Wetherell is to improve local environmental outcomes by restoring some of the region’s natural hydrologic profile. The Wetherell floodplain environment has deteriorated as a result of conditions being too wet over extended periods and the situation will further decline as a result of this project unless measures are taken. This initiative will reinstate some drying cycles more typical of natural ephemeral conditions.
8.5.2 Description
Previous modelling made no provision for Wetherell drying cycles, however it is an existing practice in operating protocols to allow drawdown of water on the Wetherell floodplain back to the confines of the Old Channel. In light of the issues raised during stakeholder engagement to date, the project team is anticipating that consent conditions may require formalisation of the wetting and drying cycles for Lake Wetherell.
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9 CONCURRENT MEASURES
9.1 1 Mea sure 2 0 - B r ok en H il l T W S Alter na te S uppl y
9.1.1 Objectives
The objective of this concurrent (but separate) project is to eliminate the need to hold a substantial volume of water (200-250GL) in the Menindee Lakes System in order to ensure a minimum of 18 months security of supply for Broken Hill TWS.
9.1.2 Description
Critical to the management of Menindee Lakes in drought periods is the security of water supply for Broken Hill. Development of an alternate supply to Broken Hill is a core component of the overall scheme, as an enabling measure to allow changes to shared management arrangements.
The Darling River off-take at the Menindee Lakes Scheme is the main source of water for Essential Water’s supply of Broken Hill. Essential Water uses an intake structure in the river at Menindee and a pump station to pump water to Broken Hill. The licensed entitlement is 9.975GL per year. The water for Broken Hill has to be pumped a height of 287 metres over a distance of 116 kilometres from its source at the Darling River to the Stephens Creek reservoir. Essential Energy also has a licence for 25ML per year for raw water for Menindee.
The current decision to pump from Menindee is based on a broad range of factors, including, but not limitedto:
Water demand in Broken Hill;
The time of year (summer versus winter);
Efficiency gains and reduction of costs of pumping in off-peak times;
Overall efficient balance of supply between Broken Hill and Stephens Creek; Maintenance of pumping stations and the pipeline;
Responding to supply outages and the need to catch-up supply in local storages;
Refreshing the pipeline to maintain water quality in the pipeline; and
Maintaining supply to pipeline customers, including those at Sunset Strip.
This matrix of issues impacts on the quantity of water required from Menindee and the rate at which the supply is moved between Menindee and Stephens Creek and then on to Broken Hill. Eight in every ten years water supply to Broken Hill is reliant on pumping from the Darling River. Essential Water’s service area is the most arid in the state and experiences extreme conditions including low rainfall, long distances to transport water, ageing infrastructure and high evaporation. The unique operational circumstances combined with dry conditions cause salinity and other water quality problems in the raw water.
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10 OTHER MEASURES
10.1 1 M ea sure 2 1 - N orthern Ba si n Infl o w s
10.1.1 Objectives
The primary objective is to provide formal recognition of additional Menindee inflows related to Basin Plan environmental recovery in the Northern portion of the Basin. Formally recognised additional inflow would be made callable for environmental purposes in the Lower Murray and Lower Darling systems.
10.1.2 Description
Additional inflows may be the result of upstream environmental water recovery actions upstream, or deliberate transfers from Northern systems to the Murray and Lower Darling and are at the discretion of future environmental water managers.
It is expected that formally recognising the additional inflow and making it callable will improve environmental outcomes by giving Murray environmental managers control over timing of delivery for the additional water.
10.2 2 M ea sure 2 2 - Lo w er D ar l ing Tem p orar y Trad e
10.2.1 Objectives
Allowing temporary trade of water allocation into the Lower Darling system when there are sufficient reserves to supply water orders is consistent with the Basin Plan dealing rules and broader National Water Initiative agreements relating to water trading.
Whilst water will only be suitable to support opportunistic cropping, these dealing rules will enable limited economic returns to landholders who remain in the Lower Darling without undermining the structural adjustment activities.
10.2.2 Description
Lower Darling water entitlement holders will be allowed to trade allocation down to the Murray at any time. This enhances the value to holders by increasing the size of the market for their account water, and will also provide increased management options for the holders of the TLM environmental entitlement.
Allowing upstream allocation trade is required by Basin Plan dealing rules and can only be restricted for physical limitations. In this case, the relevant physical limit is the volume remaining in the Lakes available to meet the new delivery during the current water year.
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11 KEY STAKEHOLDERS AND THE BROADER COMMUNITY
Community consultation surrounding Menindee over the last decade has experienced difficulties because of the complexity of issues involved, including extreme and prolonged periods of drought, flooding, water sharing conflicts, environmental and heritage issues and Broken Hill water security issues.
Extensive consultation took place during the development of the options analysis by the NSW Government between 2006 and 2012. During this process, and in the early stages of business case investigations, key stakeholders indicated concerns regarding:
a. entitlement holders are concerned about security of supply being impacted by the proposal, particularly during dry periods;
b. Lower Darling irrigators:
i. suggest that flows of 14,000–17,000ML/day are “probably manageable”, but were concerned that releasing such additional, larger flows from the Menindee Lakes storage system will negatively affect the reliability of their water entitlement supplies, and
ii. are also concerned that higher flows may adversely affect the ecology of the Lower Darling, and feel that additional work should be done to understand and protect this unique environment;
iii. are concerned that rates of rise and fall do not consider the wetting and drying needs of the banks of the river - causing increased tree fall.
c. landholders on the Great Darling Anabranch are concerned that installation of a Regulator on the Anabranch offtake could lead to poorer ecological outcomes in the Anabranch, and fear that rules could change after a regulator is installed, and it will be used to stop flows to the Anabranch more frequently,
d. concern that the environment of the Lower Darling, the Lakes and the Darling Anabranch will be less valued than downstream environments;
e. there is general concern about the environmental values that have developed around current Lakes operations, and whether they will be protected;
f. there is a perception that evaporation occurring elsewhere in the basin is not being addressed, and that Menindee Lakes is being unfairly targeted;
g. local Indigenous people and Traditional Owners are highly concerned that the environment upon which their culture is based will be changed for the worse.
h. local Indigenous people are also concerned that irrevocable damage will occur to special areas and their cultural heritage;
i. Menindee Town and the economy of the area will be permanently depressed; and
j. communities in Broken Hill and Menindee rely on the Lakes for amenity, and a number of community groups have strongly objected to any diminution of water levels in the Lakes, which are a key asset for the regional community.
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12 ENVIRONMENT AND HERITAGE
12.1 1 E n vi r o n m en t al Im p ac t s
12.1.1 Current State of Activities and Investigations
There have been several large-scale investigations into the Menindee Lakes system, including assessments of potential impacts of proposed water savings measures. This includes:
The Ecologically Sustainable Development Project, 2000
An Environmental Impact Statement, 2005
The Menindee Water Savings Project, Ecological Status and Scoping, 2014
These investigations summarised existing information and augmented this with on ground field assessments of water quality, fluvial geomorphology, vegetation, fish, waterbirds, amphibians and terrestrial fauna. They assessed the likely impacts of the former works and measures proposed for the Menindee Lakes system including effects to the Lower Darling River and Great Darling Anabranch.
There have been several environmental watering and water resource plans developed for the Lower Darling and Great Darling Anabranch. The Water Sharing Plan for the New South Wales Murray and Lower Darling Regulated Rivers Water Sources commenced on 1 July 2004 and applied until 30 June 2014. It was suspended during the drought and a new Water Resource Plan is being developed by DPI Water for the NSW Murray and Lower Darling, consistent with the Basin Plan and SDLs. This plan will include mechanisms to manage environmental risks.
Darling Anabranch Adaptive Management and Monitoring Plan (MDFRC 2013) is a program to monitor the ecological effects of changed hydrology in the Darling Anabranch. The program commenced in 2010 and is expected to continue until 2020. It provides additional information on the ecology of the study area, particularly in the Great Darling Anabranch.
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13 RISKSAND ISSUES
A risk assessment was carried out to identify the likelihood and severity of major risks present in the project. The primary focus was largely on the risks associated with the development stages of the project and less on specific construction risks.
As the project progresses it is expected that the risk register would be updated and evolve to identify any significant risks associated with construction and the chosen construction processes to be employed.
13.1 1 Assess me n t Pr ocess
To meet the requirements of ISO 31000:2009 a 5 by 5 risk matrix and supporting consequence matrix were adapted for use in the assessment of risk for the Menindee Water Savings project.
The preliminary analysis shows that there are no intolerable residual risks remaining after the application of controls. This of course has the potential to change as the project unfolds and for this reason the Risk Matrix and Heat Maps should remain live documents for continuous monitoring by the project working groups and project steering committee.
13.1.1 Risk Register
Risks were identified and recorded in the risk register attached in Appendix 3. In total 60 risks were identified as impacting on the project based on currently available information. It is expected that the risk register will be updated and maintained throughout the life of the project.
Due to the early phase of the project, detailed construction risks were not included in the current register.
13.1.2 Risk Matrix
Once risks were identified, each risk was assessed for likelihood and consequence. The definitions used to assess consequence follow in Table 17.
This combination of likelihood and consequence then provides the basis for risks to be classified as either extreme, high, medium or low.
TABLE 16: RISK MATRIX
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Menindee Lakes Notification - Attachment A Menindee Lakes Water Savings Project
13.1.4 Risk Analysis – Heat Maps
The two Heat Maps in Table 18 and 19 provide a before and after visual of the currently identified project risks.
It is to be expected that the inherent risks in Map 1 are predominantly Red, Amber and Yellow, there being little benefit in mapping risks with minimal likelihood and consequence.
What is more important to the success of the project is that all residual risks are reduced to be no greater than amber and that stakeholders have confidence in the proposed control measures to achieve these revised ratings.
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Menindee Lakes Notification - Attachment A Menindee Lakes Water Savings Project
13.3 R i sk a nd I ssue s – R e si du a l H e a t M a p ( a f te r m i ti g a ti o n )
TABLE 19: RESIDUAL RISK HEATMAP
GOVERNANCE, LEGAL & BUDGET (10) COMMUNICATION (4) DEPENDENCY (4) ENVIRONMENT (16) HERITAGE (4) OPERATIONS (2) POLITICAL (7) PROJECT MANAGEMENT (4) STAKEHOLDER (3) REGULATORY (6)
Scope changes increase cost of Perception of waste, due to EIS consent conditions recommend Reductions in bankful and overbank 3rd parties raise injuction against Project is unable to meet all of the Potential for interested stakeholder The assumed impacts of the changes Increased noise & traffic during Menindee Township & Sunset Strip project significantly beyond the duplication of previous work already works and/or operating rules that flows decrease stream metabolism any or all of the project procesing. aspirations of Native Title Owners / groups to require excessive works to licence entitlements is broader constru ction phases. concerned about future water
2
0 contingecy allowance. carried out and representations reduce the overall water saving and affect primary productivity in local / wider aboriginal interests. and operations that impose costs on than expected and the planned quality and supply. 0
K made. benefits. the Lower Darling River and Great the project. structural adjustment package is S R
Darling Anabranch insufficient to address all impacts.
5
0 4 8 9 8 1 2 9 1 6 1 1 0 3 4 0 6 4 0 Y 0 0 0 0 0 0 0 0 K K K K K K K K K S
S S S S S S S S R
R R R R R R R R
9 9 6 9 6 9 9 9 12 Y Y Y Y Y Y Y Y A
Potential to undersize or oversize Key stakeholders are not clearly Third party approval process have Impacts to threatened species during Landowners are reluctant / unwilling Heritage concerns and located Modelled outcomes from the Removal of Old Menindee Town Risk of flooding or inundation during Total compensation paid for design elements. identified and re-engaged at an early significant potential to delay project construction activities to permit easements on title for artifacts providing potential to delay inclusions of SDL package are Weir is resisted by community. constru ction. structural adjustments distorts
3 1 program. 0 1 enough stage in the process and levee construction. or require major scope changes to insufficient to justify the Water Licence markets and sets 0 0
K K actively campaign against the the project or program. expenditure. unwanted precedents. S S R R
project.
7 0 2 3 9 9 16 45 1 4 5 6 051 066 Y Y 0 0 0 0 0 0 K 7 K K K K K K K S 6 S S S S S S S R R R R R R R R
K
S
2 2 4 R 9 9 9 9 12 Y Y Y Y G G A A 9
Y
Potential to exceed construction Perceptions that evaporation Clash between stucture of State Operation changes create negative Change of ownership of properties in Concerns that the Morton Boolka Property values in Menindee and Significant weather event delays Landholders on the Anabranch are
budget, if construction constraints occurring elsewhere in the basin is Significant Project framework and impacts on Kinchega National Park Lower Darling occurs and new regulator would attract vistors who other related townships decrease due planning activities in project (geo, concerned that installation of
1 4 4 46 18 21 4 6 0 are not managed. not being addressed, and that timelines vs stakeholder processes owners do not honour option for would collect artefacts in the area. loss of amenity and/or economic survey) regulators could lead to poorer 012 053 0 0 0 0 0 0 K K K K K
K K K activity from buy-back of Lower ecological & socio-economic
S Menindee Lakes is being unfairly licence buy-back & impairment of S S S S S S S R R R R R
R R R
targeted. works approvals. Darling licences and changes to outcomes in the Anabranch, & fear
4 4 6 6 9 9
12 12 operations. that the Anabranch regulators will Y Y Y G G G
A A
be used to stop flows to the
Anabranch more frequently, Project currently assumes sequential The benefits arising from estimated Without parallel scheduling, Operation changes impacts on Intra state institutional Increased frequency of drying could Community feels previously raised Project works are completed during
program to reduce regret cost. SDL offsets, environmental benefits program has no capacity to slip due Wetting & Dying cycles of the arrangements pose constraints on lead to increased erosion risks concerns/issues have been ignored. dry spell in lakes and works can't be
3 2 7 5
Pressure to bring program forward 1 and basin plan objectives have not to extreme weather conditions and Menindee Lakes the project that threaten the 4 potentially exposing and damaging 5 6 adequately tested and 005 019 022 047 0 0 0 0 K K K K
will increase the likelihood of regret K still meet 2024 deadline. projects viability K cultural heritage items. K K commissioned.
S been clearly articulated to all S S S S S S S R R R R
R R R R
costs and need to re-do some stakeholders.
9 9 9 9
12 activity if scope changes. 12 12 12 Y Y Y Y A A A A
0
5 58 0 0 K Budget has been constructed in real Fish management act will trigger K Interstate institutional arrangements Upstream communities try to link S S R R
dollars. Final nominal project costing requirement for fish passage pose constraints on the project that otherwise unrelated issues to the
6 9
06 will be significantly higher and is structures at each of the new works threaten the projects viability project and threaten its viability. Y G 0
K largely subject to agreement on and potentially the existing main S R
timeline & inclusions. weir.
4 23 G 0 K
S R
4 G
8
6 0
A significant body of work has Death of trees due to lack of K Concerns that inter-jurisdictional Potential action by residents of S R
already been undertaken flooding. stakeholders aren't adequately Sunset Strip & Copi Hollow based on
7 4 9 9
0 (particularly environment). Budget 2 consulted and engaged during the 5 the perceived reduction in Y 0 0 0 K assumes that some benefit will be K project leading to delays during final K availability of water for water sports S S S R R R
derived in time/cost from u se. approval processes. and other recreational activity.
6 Budget will be negatively impacted if 6 9 Y Y Y
prior body of work is not used or no
longer relevant. Risks associated with wet Risk to Black Box-Coolabah as listed Interest groups use project to construction costs will be high. Endangered Ecological Community. increase pressure to have Lake
9 5 1
0 Contractual risk sharing will need to 2 6 system listed with Ramsar and 0 0 0 K be considered carefully to avoid K K potentially delays project. S S S R R R
having the full cost embedded in the
9 base price 6 9 Y Y Y
7
2 supplementary licence from Tandou. 0
Websters Limited (Tandou) currently K S R
have a zero value supplementary
licence available. Government have 6 Y
previously purchased a
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Menindee Lakes Notification - Attachment A Menindee Lakes Water Savings Project R s. a p i d r i s e s d u r i n g f i l l i n g e v e n t s m a y d r o w n e m e r g e n t s p e c i e s & r a p i d r a t e o f d r a i n i n g m a y e x p o s e a q u a t i c s p e c i e Page 82
Menindee Lakes Notification - Attachment A Menindee Lakes Water Savings Project
14 PROJECT COSTS
The overall Menindee Water Savings Project is effectively a construct of multiple measures as sub- projects. Given the nature of the sub-projects and the interdependencies between each, the cost of the projects must be considered as a single project and have been costed on that basis. Removal or alterations to some of the measures within the project will require subsequent changes to other elements of the project and may result in a material changes to the overall project cost estimate. In total, the cost of the project (excluding structural adjustments) is currently estimated to be $151.8m and it is constructed with the main components being direct infrastructure costs, non-construction project costs & contingencies.
FIGURE 13: PROJECT COST BREAKDOWN
14.1 1 I nf ra structure Costs
A significant amount of work has been carried out by NSW Public Works to provide concept designs for the structures proposed and associated non-construction costs.
The detailed costings for the Total Prime Costs (PC) of each of the measures is included in Appendix 1. The estimates have been broken down into the following main components for each measure:
Prime Cost Items – Estimated quantities, construction rates or construction item costs that would be submitted by a contractor to construct the works now, including the contractor’s direct (labour, equipment, materials, etc.) and indirect (overheads, insurance, profit margin, etc.) costs. Preliminaries, Diversion and Water Management - includes establishment, disestablishment, the contractor’s management plans and the contractor’s costs in diversion/coffer dam systems and dewatering systems, landscaping and site rehabilitation,
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haul road rehabilitation, contractor’s traffic and safety management, plus O & M Manuals and Commissioning. Total Prime Cost – PC - This is the total estimated construction cost by the contractor for the works as developed at this stage and includes Prime Cost Items and Preliminaries, Diversion and Water Management.
Table 20 summarises the expected Total Prime Cost for each of the measures included in the Menindee Water Savings project:
TABLE 20: INFRASTRUCTURE COSTS (TOTAL PRIME COSTS)
Overall the estimates are considered to be at a reasonable feasibility level, however current constraints include a lack of geotechnical investigation, associated final engineering design assessments and changes required due to EIS approval constraints.
14.2 2 N on-C o nstructio n Pr oject C ost s
In addition to the direct infrastructure costs there are a number of non-construction intangibles that cut across the project. The inclusions provided in each category are as follows:
Non-Construction Intangibles – NCI - These are the estimated cost required outside of the contractor’s construction costs and include Geotechnical Investigations, Site Surveys, Concept and Detailed Design, Environmental Studies, Social and Community Studies, Contract Administration, Project Management and Client Internal Costs.
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The following table provides a summary of the allowances made in each of the categories within non- construction project costs.
TABLE 21: NON-CONSTRUCTION PROJECT COSTS
14.2.1 Surveys / Easements
Allowance provided
Survey
Extensive surveys are required for the measures proposed.
The surveys are scheduled to be undertaken early in the project and are proposed to occur in parallel with the EIS assessment. This has been recommended to shorten the overall length of the project delivery time frame. A risk with this approach is the potential to have to redo some survey work due to changes required by the final findings of the EIS approvals and thereby incur regret costs from the accelerated plan.
The alternate approach is to delay most survey and geo-technical works until after the final EIS approvals are granted. This would add between 6 -12 months to the overall length of the project.
In addition to land surveys, a bathymetric survey has been recommended to confirm the lake bed profiles and lake volumes and to provide accurate data to model the water savings benefits on.
Easements
To facilitate some of the works and in particular the Menindee flood protection works, it is anticipated that a number of easements will be required to be negotiated with landholders and registered on title.
Allowances have been provided for the cost of negotiating, acquiring and registering of these easements.
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14.2.2 Geo-tech
Allowance provided
As per surveys, it is anticipated that geo-technical assessments will take place early in the project and are also proposed to occur in parallel with the EIS assessment. Consistent with the approach to survey work, this has been recommended to shorten the overall length of the project delivery time frame.
The risk with this approach as per the survey work is the potential to have to redo some geo-tech work due to changes required by the final findings of the EIS approvals and incur some regret costs.
14.2.3 EIS (EIS/ AHIP)
Allowance provided
The project plan provides for a 2 stage EIS process. This process has been recommended to reduce the overall cost for EIS activity and potentially provide additional time savings over a greenfield approach to developing the EIS.
14.2.3.1 Stage 1 – EIS Scoping Study
The first stage is proposed to provide a scoping study.
The intent of this stage is to review the large body of work that has already been undertaken for environmental and heritage purposes in the Menindee region and to instruct the stage 2 consultant to use this body of work.
The expectation is this will reduce the likelihood of reproducing studies already in existence thereby reducing both the time and cost to deliver the overall EIS/AHIP process.
14.2.3.2 Stage 2 – Formal EIS Process
Stage 2 will be the formal EIS/AHIP processes. It has been assumed that the process will be abridged as a result of the Stage 1 scoping study and the reduction in the workload due to the earlier identification and utilisation of existing information and studies.
14.2.4 Design & Documentation
Allowance provided
The allowance for design and documentation provides for 4 phases of work:
Completion of basis of design; Cost estimation for the designs proposed; Detailed engineering design; Final documentation of structures as built.
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14.2.5 Probity / Legal / Professional Fees
Allowance provided
Probity / Legal / Professional Fees covers a range of activities including but not limited to:
Professional advice and drafting associated with changes required to legislation, works approvals, water licences, MDBA agreements etc.; Development of construction contracts; Development of significant consultancy agreements (ie EIS); Agreements associated with land-holder works for mitigation measure; Agreements for easements associated with flood protection levies; Probity processes including probity officer.
14.2.6 Project Management
Allowance provide
Client oversight of the project and the provision of project assurance services includes the following components:
'Owners Engineer' to provide quality assurance services during Planning & Approvals and Executions phases of the project. Client project team(s) to manage stakeholder involvement, environmental, technical and operational oversight, commercial mgt.
An estimate of project resourcing (full time equivalent) over the life of the project is outlined in Section 15.2.1
14.2.7 Client Costs & Business Case Development
Allowance provided .
An allowance has been provided to fund necessary external professional services to assist in developing the final business case as well as a contribution towards funding necessary additional resources within the department
Given the length of the project at over 7 years and removing business case development costs, it is estimated that the allowance amounts to approx. 1 to 1.5 FTE’s for the life of the project.
14.3 3 Co ntin gencies
Allowance provided .
Contingencies are reflective of the considered robustness of the engineering and other assessments at the current phase of the project intended to cover all unknown risks that may occur to successfully complete the works.
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14.5 Fu nding Re qu ire ments - Timi ngs
Due to construction not taking place until the back half of the project, it is expected that the major expenditure will not be required until 2021/22, with $20.8m (real terms) required prior to that date.
$120
s
on $100 i l l i M $80
$60
$40
$20
$0 2016/17 2017/18 2018/19 2019/20 2020/21 2021/22 2022/23 2023/24 2024/25
FIGURE 14: PROJECTED PROJECT EXPENDITURE BY YEAR
14.6 P ri c e Escala tio n
All project costs have been provided in “real” 2017 value and exclude GST.
Given the long lead time of this project, it is expected that construction and other costs will increase in nominal terms. Based on current projected cashflow and an annual 2.5% escalation, it could be expected that final project cost to increase a further $17.6m.
14.7 O p e ratin g an d Main tena nc e Costs
Estimated operation and maintenance (O & M) costs4 have been assessed for the various structures proposed in this study. These operating costs need to be peered reviewed before the final phase 3 submission and post any final design changes.
4 Provided by DPI Water and NSW Public Works
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Costs have been assessed in 3 categories, operating costs, routine maintenance and periodic maintenance. The annualised expenditure is currently estimated to be or approximately of the total estimated capital value of the structures as proposed.
The most significant expense is the estimated required every 2nd year to dredge or remove silt from the proposed Menindee drainage channel. Without regular maintenance, it is expected that silt will reduce the capacity of the channel and impact the overall water savings achieved as a result of slower drawdown rates and the ability to access the entire pool. Annual Operating Costs
Operating costs allowances have been made for the operational management of the structures. The cost relates largely to provision of manpower to manage and operate the new structures and associated mainly with the opening, closing and manipulation of the gates on all of the gated control structures. Operating costs have been based on a 10 year operating cycle. All gated control structures are proposed to be operated by a portable actuator and power supply.
Operating costs include personnel resource costs for remote operation and monitoring, scheduled and unscheduled visits by operating personnel to the pump station and operating personnel involvement in regular clearing of the trash screens. Maintenance – Routine
Routine maintenance allowance is for the provision of materials or 3rd party services related to regularly maintaining the structures and repair of vandalised plant and equipment covering the civil, mechanical and electrical works as appropriate. Maintenance – Periodic
Periodic maintenance costs cover the same item costs as routine maintenance and would typically be larger maintenance items carried out at regular intervals including 2-yearly, 5-yearly, 10-yearly, 15-yearly and 30-yearly.
The estimate has been based on maintenance being required every 2nd year after construction to maintain the structures in good working order for the first 10 years. Beyond this time the allowance would need to increase to allow for major refurbishment works such as replacement regulator gates, control systems as required and repair of erosion downstream of dissipaters.
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The estimated O & M costs for individual structures are summarised in the table below.
TABLE 23: OPERATING AND MAINTENANCE COSTS
5 Indicative only. Capitalisation rate will require professional advice at the time of capitalising assets.
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15 PROJECT DELIVERY
15.1 1 P r oj e ct M a na g e me nt P l a n
The delivery Proponent will be expected to arrange for the construction, operation and maintenance of the required infrastructure and overall Menindee Lakes scheme. The delivery of works is to be undertaken based on a traditional project model split into two key phases being;
a) Planning and Approvals b) Execution
15.1.1 Phase 4a – Planning and Approvals
The objectives of this phase are to:
Minimise and project delivery/construction risks by undertaking necessary onsite technical studies/activities (such as geotechnical, survey and environmental) and optimization of risk allocation and mitigation Minimize cost to the Proponent through scope design requirement optimization Gain relevant planning approvals (IES, land access etc) that facilitate an uninterrupted construction program Facilitate the consultation and community communication of the proposed works and seek feedback on specific infrastructure and operational measures to be implemented Development of a robust tender document and competitive procurement process for the detailed design and construction activities.
15.1.2 Phase 4b – Execution
The objectives of this phase are to:
Undertake detailed design and construction activities to agreed timeframes, cost and quality requirements across the key elements of: - o Infrastructure works; o Structural Adjustment measures; and o Facilitate the changes to institutional arrangements and operating rules.
Figure 15 provides the key milestones for the Menindee Water Savings across the phases of the project plan. The detailed project plan is attached in Appendix 8.
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15.3 3 Pr ocur e men t S trategy
Phase 4a will deliver a concept design, technical specification, environmental approval (EIS) and land access approvals that will facilitate the development of a Design and Construction tender(s).
Infrastructure works will be developed in packages of works and tendered either as a whole or in components, if required.
Structural Adjustment works will be procured independently from Infrastructure works due to the early commencement on these activities and relative unique work required to be implemented.
The Planning and Procurement Strategy has four key objectives:
Minimise the risk cost to Government from potential costly reworks during the detailed design & construction phase Remove and/or minimise construction risk that would otherwise translated to increased cost with a price premium by tenderers Ensure value for money for the Government Maximise allowable construction time (to ensure works are completed late 2024) by running an EOI and ECI process in parallel to the concept design and Environmental Assessment activities.
The details of the procurement strategy are provided in Appendix 9.
15.4 4 Q u a li t y A ssur an c e
Quality assurance processes will largely be dependent on the proposed Proponents corporate policies and processes. The project will, as a minimum, need to implement a range of quality assurance processes and procedures practices including:
Adoption of relevant Australian Standards and performance requirements for design, product and construction works Review and improvement processes (peer review of standards and performance criteria) Development of specific project management procedures and practices Adoption of sound record keeping process Change control process Procurement processes Records management Defects and non-conformance process Quality Management systems processes for Work Health Safety and Environmental Management.
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16 PROJECT GOVERNANCE
16.1 1 G o ve r na nc e O ve r vi ew
NSW DPI Water has commenced the initial stages of providing information and briefings for the relevant jurisdictions in relation to the Menindee Project; however, consultation to date has been minimal due to the commercial-in-confidence aspects of the proposal and conceptual nature of the proposal to date. NSW DPI Water notes the need for cooperative develop of a conceptual proposal inclusive of relevant operational rules, modelling outputs and pathways to amend the relevant legal instruments, that will require a significant increase in consultation with partner jurisdictions, under the MDB Agreement.
NSW DPI Water is proposing a more comprehensive engagement with interjurisdictional partners in the development of the Menindee Lakes Water Savings Project and SDL Adjustment Package Business Case, under Phase 3, as part of the SDL Adjustment Mechanism process. This will ensure that all matters that relate to the MDB Agreement and other jurisdictions, particularly in regard to reliability and ongoing water supply, have the ability to be fully discussed and integrated as part of the development of a Phase 3 business case.
This Business Case represents the best estimates of the Menindee Lakes Water Savings Project proposal at this point in time. As the development of the proposal progresses and further information is gained from Environmental Impact Statements and other planning activities, NSW will continue to work with the relevant jurisdictions to update and progress the proposal.
In regards to establishing an appropriate Governance arrangement, NSW proposes the following objectives to guide engagement:
All parties commit to working collaboratively, transparently and respectfully with each other, including acknowledging and respecting each other’s roles, responsibilities and legislative frameworks;
It is recognised that NSW, as the proponent state, has lead responsibility for progressing the Menindee project;
A working group will operate consistent with the intent of, and provisions in, the MDB Intergovernmental Agreement;
Consistent with this, the Menindee project will be implemented in a way that delivers a triple bottom line outcome for regional MDB communities and the environment;
The project will also be developed within an adaptive management and outcomes based approach, which will likely necessitate ongoing adjustments to the project to incorporate expert advice and the best available information;
A specific working group will be required to be established for the purposes of discussing and providing advice to NSW DPI Water on issues that relating to the Menindee project that will have a potential impact on Victoria, South Australia and the Commonwealth;
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NSW will work with jurisdictions to develop final terms of reference for the group by early July 2017, based on the draft provided in Appendix 1 to guide the activities and focus of the working group;
The Inter-Jurisdictional Working Group forum will facilitate timely and open provision of information to the relevant jurisdictions to ensure informed discussions and due consideration of issues;
Membership of the Working Group will include representatives from NSW, Victoria, South Australia and Commonwealth Governments. Membership will also include the MDBA in an advisory capacity;
The Working Group will operate in the first instance for to the duration of the development of the details of the Menindee project proposal to a level consistent with the SDLAM Phase 3 business case requirements, this also includes the period for amending or revising the Intergovernmental Agreement regarding Basin Plan Implementation, from 1 June to 30 November 2017;
At this point the ongoing requirement of the working group to be reviewed by NSW DPI Water, with input from the group to determine the framework for continuance of the Working Group in relation to ongoing discussions required to identify and assess the rules or operating changes that are required to give effect to the Menindee Lakes project proposal. This will be in a manner that gives effect to the intent of the MDB Agreement water sharing arrangements; and
NSW will manage community and stakeholder consultations on the project, but will work closely with Victoria, South Australia and the Commonwealth on relevant communications regarding implications of the project for each jurisdiction.
Responsibility for the business case development and implementation, should it proceed, lies with NSW DPI Water. Delivery of the Menindee Water Savings Project will also engage key agencies including:
MDBA as coordinator of Murray–Darling Basin water resources;
DPI Water, as the project proponent and NSW’s water manager;
DAWR (Cth), DEWLP (Vic) and DEWNR (SA);
Water NSW, as the manager and operator of river assets;
NSW OEH: as the environmental authority; and
Other NSW agencies as appropriate, including NSW Fisheries, NSW National Parks and Wildlife Service.
Governance arrangements led by the DPI Water will be continued with these parties during project implementation.
Within NSW, NSW DPI will manage agency consultation through the IAWG (Inter-Agency Working Group for which the terms of reference are included in Appendix 2.
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17 LEGISLATIVE AND REGULATORY FRAMEWORKFOR MENINDEE LAKES
17.1.1 Overview
The ownership, operations and maintenance of the Menindee Lakes sits within a complex suite of independent but interrelated legislative, regulatory and commercial instruments and agreements. The changes contemplated in this Business Case will necessitate changes to these guiding documents. Whilst a detailed legal review is yet to be undertaken, provision has been made in both time and cost to undertake such a review as part of the Phase 3 final submission.
The following represents a preliminary scan of the key instruments and an indication of areas that may require further consideration by the jurisdictions. It is not intended to be a definitive term sheet at this stage, the relevant clauses that will require review.
17.1.2 Murray Darling Basin Agreement
The operation of the Lakes are subject to the MDB Agreement. Murray Darling Basin Authority controls the allocation of the waters stored by Menindee assets and the MDB Agreement links the control of the assets to the control of the water. However, the Menindee Lakes are not (and never were) listed as “Works” in Schedule A of the MDB Agreement and unlike other MDB joint venture assets, there is no responsible State nominated in the case of Menindee.
This is a legacy of history, dating back to an agreement in 1962 between then Premier of NSW and the Prime Minister, later ratified in a 1963 Agreement between the Victoria, South Australia, NSW and the Commonwealth and codified in the Menindee Lakes Storage Agreement Act 1964 (1964 Act). The 1964 Act established cost sharing arrangements, requiring the MDB Commission (MDBC) to make annual payments to NSW to operate and maintain the works. Effectively the 1964 Act linked Menindee assets and operations to the MDB Agreement, but they otherwise stood to the side of the detailed machinery of the Agreement (pers com. Nosworthy).
Relevant provisions within the MDB Agreement include: -
Part XII Clause 94(c) sets out the entitlements of NSW and Victoria to Menindee Resources
Part XII Clause 95 provides further detail on the NSW entitlement to water in Menindee including the effect of control triggers on operations.
Part XII Clause 98 provides that the MDBA may give directions for the release of water and that water must be released in accordance with that Direction.
Part XII Clause 99 details the current 480GL/640GL control thresholds.
Part XII Clause 107 deals with the Allocation of water in Menindee between NSW and Victoria in respect of Darling River inflows.
Part XII Clause 120 defines and details accounting for Menindee releases.
Part XII Clause 121 deals with reallocation of water between NSW and Victoria.
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Part XII Clause 136 requires NSW to maintain the Menindee Lakes Storage and associated works in good order and condition necessary to meet full supply levels and storage capacity.
Part XII Clause 137 specifies Full Supply Levels for each of the Lakes.
Part XII Clause 138 details the annual payments to NSW in return for operating and maintaining the assets.
Schedule G Part 4 Clause 23 details provisions for accounting deferred water stored in Menindee including the interplay with Additional Dilution Flow for South Australia.
The MDB Objectives and Outcomes for River Operations 2016 (O & O) provides more prescriptive guidance on the MDB system operations and has provisions relevant to Menindee and this proposal. Relevant provisions under Appendix A Specific Objectives and Outcomes include:
Clauses 10.1 through to 10.4, dealing with
o maximum downstream releases;
o rates of rise and fall;
o planned seasonal release rates, and
o planned distribution of water between the Lakes to increase efficiency.
Clause 12.2 details the harmonisation practices between Menindee and Lake Victoria.
Clause 12.3 provides guidance on, and amendment to, the delivery of Additional Dilution Flows to South Australia.
17.1.3 NSW Water Sharing Plan
The Water Sharing Plan for the New South Wales Murray and Lower Darling Regulated Rivers Water Sources (2016) applies to water sources that include the Menindee Lakes. As such as number of provisionswithinthe Planwillrequirereviewand potentialamendmenttoaccommodatetheproposed changes, including: -
Clause 31 – deals with environmental water rules in the Lower Darling including the interaction between storage levels and environmental account management.
Clause 34 deals with flood operation rules and the requirement for consistency with the MDB Agreement.
Clause 35 deals with the need to provide airspace in accordance with the MDB Agreement.
Clause 52(7)(b) deals with water allocation accounts and evaporative losses.
Clauses 54 (6) and (7) deals with access to supplementary water and the requirement not to impact on obligations to South Australia.
Appendix 3 deals with triggers around Additional Dilution Flows and minimum flows into the Lower Darling.
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17.1.4 NSW Works Approval
Also at the NSW level, Menindee infrastructure and operations are recognized in the 2012 NSW Murray Lower Darling Work Approval issued to WaterNSW. The infrastructure listing is high level, referring only to “Menindee Lakes and Associated Structures” and “Weir 32 and Fishway”. In respect of operation, relevant provisions include: -
Clauses 8 and 9 deals with the Lower Darling Environmental Contingency Allowance (ECA) and the requirement for an account to be kept for credits and debits to the ECA.
Clauses 10 and 11 deals with the Murray Additional Environmental Allowance, requiring the Approval holder to keep and account of credits and debits and for releases of water in accordance with Ministerial Directions.
Clause 12(f) deals with water delivery and channel capacity constraints in the Lower Darling, requiring regulated flows no greater than 20,000ML/day at Pooncarie; and
Clause 13 compels the Approval Holder to “advise the Minister of any new information that becomes available that is relevant to the maximum channel capacities and maximum regulated rates required by condition twelve (12)”, including:
o inundation of private land or interference with access;
o the transmission losses expected to occur; and
o capacities of water management structures.
Clauses 15-17 deal with Menindee flood operations and specifically the requirement
o to meet Dam Safety obligations and Directions
o to mimic natural hydrographs during flood operations releases
o not to exceed daily threshold flow reduction changes in the flood recession phase of operations.
Clause 18 compels the Approval Holder to achieve minimum flow targets at Weir 32.
Clause 20 specifies weir pool draw down and fill rates that cannot be exceeded in anything other than “natural” events.
17.1.5 Additional Dilution Flow
Alternative operating procedures were examined for Menindee Lakes and Lake Victoria as part of studies into options for mitigating salinity in the River Murray system. As a result of these studies a package of measures were adopted by the Murray Darling Basin Commission in June 1987. This package included rules in relation to the distribution of water between the Lakes in at Menindee; the harmonisation of operations between Menindee and Lake Victoria; flushing rules at Lake Victoria and the provision of Additional Dilution Flow(ADF) to South Australia.
ADF requirements are allowed for but not specified in the MDB Agreement however they are specified in the MDBA Specific Objectives and Outcomes. ADF is 3,000ML/day and is only provided when the
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storage in Menindee Lakes and the combined storage in Hume and Dartmouth exceeds agreed triggers described in the O&O document.
ADF therefore influences the operations at Menindee and as such changes proposed in this project will need to be assessed in terms of ADF objectives.
Preliminary advice (Turner, 2016) suggests that the Menindee Savings will provide outcomes consistent with the original intent of the ADF rules, although ADF itself will effectively become obsolete.
17.1.6 Accounting for Additional Inflows
Clause 107 of the MDB Agreement specifies that the water entering Menindee Lakes is shared between Victoria and NSW in equal shares. This project effectively increases the inflows at Menindee (by reducing evaporative losses) as do the concurrent Northern Basin measures.
It is proposed as part of the Menindee Project, that the MDB Agreement quarantine the additional flows into environmental accounts. The revised modelling currently underway will provide details on options to pursue this change with consideration provided for third party issues or impacts as a result of this change.
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REFERENCES
Balme, J. and Hope, J., (1990). Radiocarbon dates from midden sites in the lower Darling River area of western New South Wales. Archaeology in Oceania 25, 85-101.
Bogenhuber D. Wood D. Pay T. and Healy S., (2014). The Darling Anabranch Adaptive Management Monitoring Program Final Report 2014. Prepared in conjunction with NSW Office of Environment and Heritage by the Murray-Darling Freshwater Research Centre.
NSW Public Works (2015), Menindee Water Saving Optimisation Study & Concept Design, report No. DC15012 July 2015
GHD, (2015). Menindee Water Savings Project Stages A1 and A2 - Environmental Water Needs and Water Management Arrangements. GHD.
Gippel C. J. and Blackham D., (2002). Review of environmental impacts of flow regulation and other water resource developments in the River Murray and Lower Darling River system. Final Report. Fluvial Systems Pty Ltd, Stockton, to Murray-Darling Basin Commission, Canberra, ACT.
Green D., Ali A., Petrovic J., Burrell M., Moss P. (2012). Water resources and management overview: Lower Darling River Catchment, NSW Department of Primary Industries, Sydney.
Green D. L. Shaikh M. Maini N. Cross H. and Slaven J., (1998). Assessment of environmental flow needs for the Lower Darling River. A report to the Murray–Darling Basin Commission. NSW Land and Water Commission, Sydney.
Martin S. Witter D. and Webb C., (1994). The archaeology of Lakes Menindee and Cawndilla and the impact of artificial water storage : a report to the NSW NPWS and the NSW Department of Water Resources. NSW NPWS and the NSW Department of Water Resources.
Maunsell Australia Pty Ltd, (2007). Darling River Water Savings Project – Part A Report. Maunsell Australia Pty Ltd.
MDBA Licenced under a Creative Commons Attribution 3.0 Australia Licence, (2012) Assessment of environmental water requirements for the proposed Basin Plan: Lower Darling River System. (MDBA).
SKM (2002) Menindee Lakes Aquatic Fauna, Integration Report for Menindee Lakes ESD Project, DLWC, Sydney.
SKM, (2010). Darling River Water Savings Project – Part B Final Report. SKM.
Taylor-Wood, E. McCormick S. Mueck S. Richardson M. and Jukic M., (2001). Vegetation/Habitat Mapping of Inundated Areas of Menindee Lakes. Report for the Menindee Lakes Ecologically Sustainable Development Project Steering Committee: Biosis.
Turner G, (2016). River Murray Operations Framework Changes to support SDL Adjustment : Menindee Lakes – Issues Paper – Draft
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APPENDIX 1 – MENINDEE LAKES INTER-JURISDICTIONAL WORKING GROUP
Establishment of the Working Group
The Menindee Lakes Water Savings Project Intergovernmental Working Group (the Working Group) is established to identify inter-jurisdictional issues and jurisdictional issues associated with the project, and provide advice to NSW on such issues in the further development of the Menindee Lakes Water Savings Project Business Case.
Role of the Working Group
The Working Group will provide advice to NSW as the lead jurisdiction in the development of the Menindee Lakes Water Savings Project and has the following roles:
The Working Group will focus on specific details within this framework on implications of MDBA June 2017 modelling; Reconciliation milestones; Reviewing changes to the River Murray Framework; Processes for recognising the additional inflows to Menindee from the Northern Basin; and Discussion of framework changes will build on the work commissioned by the MDBA.
NSW will continue to hold primary responsibility for Commonwealth and NSW regulatory approvals for the design and construction of the proposed infrastructure changes. This will include community engagement and cultural heritage requirements. It is likely that the project, if approved to proceed will be NSW State Significant Infrastructure. The Working Group will need to operate within the constraints of this structure as provided by the NSW Government.
The Commonwealth will lead negotiation of the structural adjustment and strategic water entitlement purchase activities for the Lower Darling.
Both these elements of the project development will be outside the scope of the Working Group but will need to report to the Working Group on progress and if issues arise that will affect the broad cost benefit of the project.
Membership
Membership of the Working Group will include up to two representatives each from NSW, Victoria, South Australia and the Commonwealth.
NSW will Chair the Working Group as the lead jurisdiction for the Menindee Lakes Water Savings Project.
Recognising its role in water management, the MDBA is requested to nominate two representatives to attend meetings as observers and in the provision of advice to the Working Group in relation to river operations, Menindee Lakes and SDL Adjustment Mechanism modelling, and MDB Agreement matters.
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Other representation may occur at the discretion of NSW as the lead jurisdiction.
Members and alternates should be appropriately authorised to provide advice and make decisions on behalf of their jurisdiction and/or agency.
Relevant technical staff may attend meetings and provide advice as appropriate.
Chair and Committee Support
Department of Primary Industries, Water will Chair the Committee and provide secretariat services.
Procedural Directions
Best endeavours will be made to reach in principle agreement on the required changes post June 2017, with discussions extended beyond the November 2017 timeframe for agreement to the revised or new Intergovernmental Agreement for Basin Implementation if required.
An indication of the timing for the Menindee proposal development against the 2017 Ministerial Council endorsed Finalisation Plan is set out in Table 2 as a basis for the Working Groups activities, as part of the finalisation of the development of the amended notification advice and Phase 2 Business Case.
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APPENDIX 2 – MENINDEE LAKES INTER-AGENCY WORKING GROUP
Establishment of the Working Group
The Menindee Lakes Water Savings Project NSW Interagency Working Group (the IAWG) is established to provide whole-of-government input into the Final (Phase 3) Menindee Project Business Case, to be submitted for approval of the MDB Ministerial Council.
Role of the Working Group
The Working Group will provide advice to DPI as the Project Proponent in the development of the Menindee Lakes Water Savings Project and has the following roles:
Provide advice in relation to the development of the EIS Scoping Study, including o Identification of likely Environment and Heritage risks and issues o Development of the Director-General’s requirements o Provision of subject matter expertise where required o Review the EIS Request for Tender (RFT) documentation prior to public consultation Review and contribute to the MDBA modelling; Provide advice and support in relation to statutory / regulatory approvals processes Consider progress against the project plan and key milestones Assist with key stakeholder liaison and communications including respective Ministerial offices.
DPI Water will lead the NSW Government in Inter-government liaison and negotiations.
Membership
Membership of the Working Group will include a maximum of two representatives each from each of the following entities: -
Department of Primary Industries Water Department of Premier and Cabinet NSW Treasury Office of Environment and Heritage NSW Fisheries NSW Department of Planning WaterNSW
Members and alternates should be appointed and authorised to speak on behalf of the respective agency / corporation.
Relevant technical staff may attend meetings and provide advice as appropriate.
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Chair and Committee Support
Department of Primary Industries, Water will Chair the Committee and provide secretariat services.
Decision Making Authority
The IAWG is an advisory group only. Notwithstanding this advice, decisions in relation to the Phase 3 Business Case will reside with DPI Water, however opportunities to represent formal agency positions in relation to the proposal will be available through the normal regulatory approvals process for State Significant Projects in NSW.
Tenure
The initial tenure of the IAWG will be from June 2017 until the Basin Officials Committee approves the Phase 3 Business Case for the Menindee Project – expected to be November 2017.
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APPENDIX 4 – EIS REQUEST FOR TENDER – (DRAFT REQUIREMENTS)
Background
The Menindee Lakes are located in South-West New South Wales on the floodplain of the Darling River. The system consists of seven major Lakes; Menindee, Cawndilla, Pamamaroo, Tandure, Bijijie, Balaka and Malta and a number of smaller wetlands (Spectacle, Speculation and Eurobilli). The impounding of the Darling River has led to the creation of an additional waterbody, Lake Wetherell.
Although naturally intermittent, the Lakes have been used for water storage since the 1960s, increasing their permanence. They are listed on the Directory of Important Wetlands of Australia, primarily for their role in supporting waterfowl. They periodically support large numbers of ducks and cormorants acting as a feeding and breeding ground and an important drought refuge. The site also has significant cultural and social values.
The large shallow nature of the Menindee Lakes results in large amounts of water loss through evaporation, prompting calls for infrastructure and operating improvements. In September 1998, the Premier of NSW Bob Carr announced that the NSW Government would undertake investigations into the feasibility of structural and operational changes to the Menindee Lakes system for improved management.
Since that time there have been several iterations of proposed structural works and assessments of their effectiveness and impacts. In 2013, the Commonwealth and NSW governments agreed to further investigate a scope of infrastructure works and potential changes to the Murray-Darling Basin Agreement. The MDBA completed preliminary modelling of Menindee in 2013 for the proposed suite of works and measures at that time. This modelling indicated water savings of 72GL for the Menindee project.
A revised suite of works and measures designed to reduce evaporation, reduce water security demands, maximise water savings and improve water quality was developed and approved as an Interim Business Case in June 2017. The proposal builds on previous plans, to improve water savings and is considered sufficiently different from former works and measures to require a new assessment of potential benefits and impacts. Current proposed works
The current proposed works and measures are illustrated in Figure 17 and tabulated in Table 26.
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FIGURE 17: OVERVIEW OF PROPOSED WORKS
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Measure 13 Lower Darling constraints mitigation - Assumption holds. Works now protect and maintain Constraints Management landholders stock and domestic & some capacity of pumps during high flow events (ie : floating irrigation pump infrastructure. suctions, on farm storage and / or groundwater options)
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Scope
This RFT is to undertake a series of scoping investigations to assess the qualitative benefits and impacts of the proposed Menindee Project. On the assumption that the outcomes of this scoping study demonstrate project feasibility, a formal Environmental Impact Assessment (EIA) will be required. In order to ensure that this scoping study is an independent assessment of the benefits and impacts of the proposed works, the successful organisation for this scoping study will not be eligible to undertake the EIA.
Specifically, this scoping study comprises:
A collation and synthesis of existing information on the hydrology, ecology cultural significance and socio-economic features of the system. A preliminary, qualitative assessment of the potential benefits and impacts from the proposed works to the Menindee Lakes, lower Darling River and Great Darling Anabranch. Identification of any intolerable risks from the proposed projects and measures to mitigate those risks. Documentation of priority knowledge gaps to be filled in the EIS process. Facilitation of agreement between government agencies on the future water savings and feasibility of the proposed Menindee Project. Draft RFT documentation for the full EIS.
Tenderers require specialist knowledge and experience in the fields of hydrology (including hydrologically modelling), geomorphology, ecology, Aboriginal cultural heritage and economics. It would be advantageous if the members of the tenderers team were familiar with the Menindee Lakes and the lower Darling River.
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It should be noted that there will be no new field assessments or studies completed as part of this scoping study. Where significant knowledge gaps are identified, these will be documented and prioritised for consideration in the EIS process.
The successful tenderer will work closely with the Department of Primary Industries (DPI) and the NSW Office of Environment and Heritage (OEH) to reach agreement on the final operating regime and associated water savings. Exclusions
Impacts associated with the construction of the Murray pipeline from the Murray River at Wentworth to Broken Hill are not part of this scoping study. Project requirements
The current proposal for Menindee Lakes will alter the hydrology of Lake Cawndilla, reinstating a drying cycle. It will also result in changes to the hydrology of Lakes Wetherell, Menindee and Pamamaroo, with potential effects to the other Lakes in the system and the Darling River downstream.
There have been several large scale investigations into the Menindee Lakes system, including assessments of potential impacts of proposed water savings measures. This includes:
The Ecologically Sustainable Development Project, 2000 An Environmental Impact Statement, 2005 The Menindee Water Savings Project, Ecological Status and Scoping, 2014
It is not the intention of this consultancy to duplicate any previous work, but rather to consolidate the findings of these various studies and update with more recent information. In addition, there is new hydrological modelling being developed by the MDBA to assess the effects of the current proposed works and measures, which needs to be considered when assessing potential benefits and impacts. Task 1: Current values and condition of the Menindee Lakes system
Conduct a desktop review of existing information to describe the ecological, cultural and socio- economic values of the Menindee Lakes system and their current condition. The following components, processes and ecosystem services will need to be considered:
Current wetland hydrology, considering important parameters for the ecology of the system (duration and frequency of wet and dry periods, rate of rise and fall, water depths).
Water quality, primary productivity, phytoplankton, including variability over time.
The most recent extent and condition of vegetation communities in and around the Lakes, including identification of important or threatened species.
Aquatic fauna communities (invertebrates, fish, frogs), including important or threatened species.
Wetland dependent mammals.
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Waterbird abundance, diversity and breeding, including species that are listed under migratory agreements and threatened species legislation.
Bushbirds that are dependent on the Lakes or the vegetation communities around the Lakes.
The importance of the Menindee Lakes to downstream aquatic ecosystems of the Lower Darling River and Great Darling Anabranch.
Cultural heritage of the site and the broader study area (including a prediction of potential cultural heritage implications of infrastructure works).
Socio- economic values dependent on the Menindee Lakes, Lower Darling River and Great Darling Anabranch.
The above will be documented in a short, plain English report, which clearly identifies information sources and critical knowledge gaps.
Task 2: Hydrological regimes under the Menindee Project
The consultant team will need to work with the MDBA to determine the likely future water regime in the Menindee Lakes system under the proposed works and measures. This will at a minimum cover the affected Lakes (Menindee, Pamamaroo, Cawndilla and Wetherell) and the Lower Darling River and Great Darling Anabranch. This needs to be characterised in terms of the aspects of hydrology most important for maintaining the values of the system:
Frequency and duration of wetting
Frequency and duration of drying
Rate of rise and fall
Magnitude of flow regimes
Connectivity between Lakes and river systems.
The hydrological outputs need to consider likely future climate with respect to rainfall, run-off and evaporation. Task 3: Benefits and impacts of the Menindee Project
Using the outputs of Task 1 and 2, complete a qualitative assessment of the benefits and impacts of the proposed Menindee Lakes Project. At a minimum this will need to consider:
Hydrology Geomorphology
Water quality and primary productivity
Ecology
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Cultural heritage
Socio-economic effects
Contributions to the objectives of the Basin Plan.
Where there is insufficient information to determine potential benefits and impacts, priority knowledge gaps should be documented. Those knowledge gaps deemed critical to the successful assessment of benefits and impacts will be described, together with a rationale for their inclusion in the EIS process. A brief description of the methods recommended to fill each priority knowledge gaps is required. Task 4: Risk assessment
Conduct a preliminary risk assessment to identify any “intolerable” risks, consistent with ISO 31000:2009, Risk management – Principles and guidelines and the Standards Australia Handbook: Environmental risk management - principles and process (HB 203-2000; Standards Australia and Standards New Zealand 2006).
Intolerable risks in this context are those where environmental and / or heritage impacts from the current scope of works and measures are likely to threaten regulatory approval. These will be will be defined in conjunction with DPI Water. For each intolerable risk, a description of the proposed mitigation measures and residual risk will be provided. The effects of these mitigation measures on project costs and water savings needs to be considered. Task 5: Reporting
Produce a report that includes:
The requirements under State and Federal government legislation relating to environmental and heritage approvals for each of the sites in the Menindee Lakes system likely to be affected by the project.
The environmental, cultural and economic benefits and impacts of the proposed Menindee Lakes Project.
Identification of intolerable risks and mitigation required to address those risks.
The impacts of recommended mitigation options on the water savings and project costs.
Identification of critical knowledge gaps and recommendations to fill those gaps to the level of detail required for the EIS process.
Draft RFT specifications to form the basis of EIS procurement stage 2. Task 6: Facilitation of agreement on the Menindee Lakes Project
The consultant team will need to work with several agencies at the local, State and Federal level to reach agreement on the feasibility of the Menindee Lakes Project. Activities will include:
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Working with the MDBA to produce the hydrological model outputs required to assess benefits and impacts of the project, including:
o Modelling to inform the expected water savings to be gained from the project; and o Modelling of likely operating regime and effects on the hydrology of the Lakes, Lower Darling River and Great Darling Anabranch.
Facilitation of a cross agency technical advisory group/steering committee to oversee the technical quality of the study and to:
o Reach agreement on the definition of intolerable risks
o Identify realistic mitigation options
o Determine the effects of mitigation options on the project costs and water savings. o Reach agreement on the feasibility of the project to progress to the next stage.
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EIS milestones
To be confirmed during further Phase 3 refinements.
Selection criteria
This tender will be judged on (in ascending order of importance):
Standard NSW Government contractual requirements and formats apply inclusive of public and professional liability insurances.
Ability to work closely, continually and collaboratively with DPI Water staff, under direction and by negotiation without variations to cost
Knowledge and understanding of ecological surveys, environmental management, floodplain ecology, functions and processes, knowledge of arid zone river, wetland and terrestrial ecosystems, familiarity with the Menindee Lakes System, its history, ecology and socio-economic features.
Innovation or value adding components, including creative solutions to optimising environmental benefit while minimising any harm to cultural heritage and cultural or ecological systems.
Price and value for money
Experience - demonstrated experience, reliability, and successful performance by the Respondent in undertaking similar projects.
Ability to meet timelines.
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Relevant documents
Balme, J. and Hope, J., (1990). Radiocarbon dates from midden sites in the lower Darling River area of western New South Wales. Archaeology in Oceania 25, 85-101.
Bogenhuber D. Wood D. Pay T. and Healy S., (2014). The Darling Anabranch Adaptive Management Monitoring Program Final Report 2014. Prepared in conjunction with NSW Office of Environment and Heritage by the Murray- Darling Freshwater Research Centre.
Brown, G.W., Cherry, K.A., Dickins, M.J., Grgat, L.M., Nelson, J.L., and B.D. Van Praagh, (2001) The terrestrial flora and fauna of the Menindee Lakes System, New South Wales – Interpretation and Assessment, Arthur Rylah Institute for Environmental Research, Department of Natural Resources and Environment, Heidelberg, Victoria, Australia.
Brown, G.W., Cherry, Grgat, L.M., Nelson, and Tumino, M., (2001) The terrestrial flora and fauna of the Menindee Lakes System, New South Wales – Literature Review, Arthur Rylah Institute for Environmental Research, Department of Natural Resources and Environment, Heidelberg, Victoria, Australia
GHD, (2015). Menindee Water Savings Project Stages A1 and A2 - Environmental Water Needs and Water Management Arrangements. GHD.
Gippel C. J. and Blackham D., (2002). Review of environmental impacts of flow regulation and other water resource developments in the River Murray and Lower Darling River system. Final Report. Fluvial Systems Pty Ltd, Stockton, to Murray-Darling Basin Commission, Canberra, ACT.
Green D. L. Shaikh M. Maini N. Cross H. and Slaven J., (1998). Assessment of environmental flow needs for the Lower Darling River. A report to the Murray–Darling Basin Commission. NSW Land and Water Commission, Sydney.
Martin S. Witter D. and Webb C., (1994). The archaeology of Lakes Menindee and Cawndilla and the impact of artificial water storage : a report to the NSW NPWS and the NSW Department of Water Resources. NSW NPWS and the NSW Department of Water Resources.
Maunsell Australia Pty Ltd, (2007). Darling River Water Savings Project – Part A Report. Maunsell Australia Pty Ltd.
MDBA Licenced under a Creative Commons Attribution 3.0 Australia Licence, (2012) Assessment of environmental water requirements for the proposed Basin Plan: Lower Darling River System. (MDBA).
Nicol, J.M., (2004). Vegetation dynamics of the Menindee Lakes with reference to the seed bank Thesis (Ph.D.)-- School of Earth and Environmental Studies, University of Adelaide.
NSW Public Works (2015), Menindee Water Saving Optimisation Study & Concept Design, report No. DC15012 July 2015
SKM, (2010). Darling River Water Savings Project – Part B Final Report. SKM.
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Taylor-Wood, E. McCormick S. Mueck S. Richardson M. and Jukic M., (2001). Vegetation/Habitat Mapping of Inundated Areas of Menindee Lakes. Report for the Menindee Lakes Ecologically Sustainable Development Project Steering Committee: Biosis.
URS (2005). Menindee Lakes Structural Works Project – Environmental Impact Statement, URS Australia, Sydney, NSW.
Witter, D., (2009), Lake Bed Archaeological Survey for Menindee, Cawndilla and Pamamaroo Lakes, including appendices, Witter Archaeology, New Zealand Assistance provided by DPI Water
Provision of time series model outputs for ‘without development’, ‘benchmark’ and ‘draft proposal’
Hydrological data related to flow scenarios that is held or readily accessible by DPI Water
Any reports that the Agency may have
Access and introduction to local Office of Water operational staff and provide a contact for local knowledge regarding operations.
Description of the watering regime in the draft proposal and previously proposed watering regimes
Australian GeoScience LIDAR mapping analysis of Lower Darling floodplain
Access to technical personnel – timeframes need to be negotiated well in advance.
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APPENDIX 5 – MENINDEE PROJECT COSTINGS
TABLE 26: MEASURE 1 – ENLARGED MENINDEE REGULATOR (PRIME COSTS)
Source: NSW Public Works
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TABLE 27: MEASURE 2 – MENINDEE DRAINAGE CHANNEL (PRIME COSTS)
Source: NSW Public Works
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TABLE 28: MEASURE 3 – MORTON-BOOLKA REGULATOR (PRIME COSTS)
Source: NSW Public Works
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TABLE 29: MEASURE 4 – OLD MENINDEE TOWN WEIR REMOVAL (PRIME COSTS)
Source: NSW Public Works
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TABLE 30: MEASURE 5 – EMU LAKE OFFTAKE REGULATOR (PRIME COSTS)
Source: NSW Public Works
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TABLE 31: MEASURE 6 – YARTLA LAKE OFFTAKE REGULATOR
Source: NSW Public Works
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TABLE 32: MEASURE 7 – CAWNDILLA CREEK REGULATOR (PRIME COSTS)
Source: NSW Public Works
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TABLE 33: MEASURE 8 – DARLING ANABRANCH OFFTAKE REGULATOR (PRIME COSTS)
Source: NSW Public Works
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TABLE 34: MEASURE 9 – DARLING ANABRANCH E-FLOW REGULATOR (PRIME COSTS)
Source: NSW Public Works
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TABLE 35: MEASURE 10 – MAIN WEIR FISHWAY (PRIME COSTS)
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TABLE 36: MEASURE 11 – 183 DAM REGULATOR, ROAD BRIDGE & FISHWAY (PRIME COSTS)
Source: NSW Public Works
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TABLE 37: MEASURE 12 – MENINDEE TOWN FLOOD PROTECTION WORKS (PRIME COSTS)
Source: NSW Public Works
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TABLE 38: MEASURE 13 – LOWER DARLING CONSTRAINTS MITIGATION WORKS (PRIME COSTS)
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APPENDIX 6 – ENGINEERING CONCEPT DESIGN DRAWINGS AND SPECIFICATIONS
FIGURE 18: MEASURE 1 – MENINDEE REGULATOR – AERIAL VIEW
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FIGURE 19: MEASURE 1 – MENINDEE REGULATOR – SIDE VIEW
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FIGURE 20: MEASURE 2 – MENINDEE CHANNEL – CROSS SECTIONS 1
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FIGURE 21: MEASURE 2 – MENINDEE CHANNEL – CROSS SECTIONS 2
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FIGURE 22: MEASURE 3 – MORTON-BOOLKA REGULATOR
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FIGURE 23: MEASURE 8 – DARLING ANABRANCH OFFTAKE REGULATOR
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APPENDIX 7 – ENVIRONMENTAL WATER NEEDS AND WATER MGMT ARRANGEMENTS
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APPENDIX 8 – DETAILED PROJECT SCHEDULE
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APPENDIX 9 – PROCUREMENT PLAN
EOI & ECI Process
An Expression of Interest and shortlisting process will be run in parallel to the concept design and planning approval works. The benefit of running the EOI / ECI processes are:
Open invitation and shortlisting of capable Engineering, Procurement and Construction (EPC) companies to proceed to the ECI and Tender phases. Commitment of shortlisted companies to the ECI process (3 short listed companies) Incorporation of construction industry knowledge into design requirements and tender documents Agreement to the project objectives, specification, operational and functional requirements Agreement on commercial terms and conditions - limitation of qualification and exclusion and contractual negotiations to expedite the delivery contract award process Consolidated ‘Request for Tender’ package developed prior to RFT stage. Tender Process and Evaluation criteria
A General Conditions of tendering and Tender Evaluation Criteria will be established prior to the commencement of the formal Request for Tender process. These documents will guide the tender process to ensure a fair and equitable outcome is achieved that provides the project team with a value for money solution.
The tender process (including the EOI/ECI) is be overseen by an independent Probity officer to ensure adherence to process and procedures. INSW Gateway 3 Process – Pre-Tender Review
A Gateway 3 process will be undertaken prior to issuing the final tender document to contractor companies for pricing. This review confirms that a suitable Procurement Strategy is selected to meet the project objectives within the budget and time constraints and that the project is ready to proceed to the tender stage. It is undertaken after a discrete project has been defined and approved, but before any commitment to a procurement methodology contracting system, or market approach.
The key checklist items for the project team to address as part of the gateway process are:
Is the specification of requirements clear and unambiguous? Are we being realistic about our ability to achieve a successful outcome? Can we confirm that the Business Case still meets the business need and is complete? Have we explored all the procurement options? Have we devised trade off criteria, contingency fund management? Is the procurement strategy legal, robust, appropriate and understood by suppliers? Is there a realistic project plan through to completion, with the right people allocated? Do we have adequate financial controls, funding and resourcing? Can we confirm funding availability for the whole project? Are we taking the right approach to development and delivery – broken down into small enough components? Do we have enough commercial expertise to understand the current supplier market capability and track record?
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Are the issues relating to business change understood? Can we confirm that funding is secured for the procurement?
Request for Tender
At the completion of the INSW Gateway Review, tender documents will issued to the selected participants as a Request for Tender. It is anticipated the tender process will take approximately 8 - 10 weeks to complete including the evaluation of tenders and recommendation of preferred tenderer. The recommendation report and award of Contract will signal the completion of the Planning Phase and commencement of the Execution project phase
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APPENDIX 10 – INTERIM PROJECT PROPOSAL – APRIL 2017
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Menindee Lakes
Interim Project Proposal
Menindee Lakes Notification - Attachment B
1. Table of Contents
1. Table of Contents ...... 3 2. Executive Summary ...... 4 3. Background ...... 6 4. Summary of Scope Changes ...... 9 5. Details of Revised Scope to inform revised modelling ...... 13
A. Morton-Boolka Regulator ...... 13 B. Lake Menindee Drainage channel to outlet regulator ...... 14 C. Cawndilla Creek Regulator ...... 15 D. Menindee outlet regulator ...... 16 E. Lower Darling Channel capacity ...... 17 F. Anabranch offtake regulator ...... 17 G. Broken Hill TWS ...... 19 H. Removal of Menindee Town Weir...... 20 I. Lower Darling stock and domestic supplies ...... 20 J. Flood protection works for Menindee town residents ...... 21 K. Menindee Main Weir Fish Passage ...... 22 L. Menindee control transfer triggers and sequencing ...... 22 M. Broken Hill entitlement ...... 23 N. Capacity for additional Eflows into Lake Cawndilla ...... 24 O. River Murray Improved Operations ...... 25 P. Lake Wetherell (floodplain) drying cycle ...... 26 Q. Acquisition of Lower Darling / Tandou Entitlements ...... 26 R. Temporary trade rules ...... 29 6. Proposed interjurisdictional governance and engagement ...... 30 7. Conclusions and next steps ...... 31 Appendix A ...... 33 Draft Terms of Reference Menindee Lakes Water Savings Project Working Group ...... 33
A. Establishment of the Working Group ...... 33 B. Role of the Working Group ...... 33 C. Membership 34 D. Chair and Committee Support ...... 34 E. Procedural Directions ...... 34
Menindee Lakes Notification - Attachment B
Figure 1 – Location overview of Menindee Lakes system
Menindee Lakes Notification - Attachment B
4. Summary of Scope Changes
Proposals for the augmentation of Menindee Lakes have been around for decades but have gathered momentum in recent years as a result of the Murray-Darling Basin Plan and the associated MOU between the Commonwealth and NSW Governments, signed in 2013.
The initial SDL modelling undertaken by the MDBA in 2013, based on works and measures proposed by NSW at that time, indicated water savings of only 72GL for the Menindee project. The collective view of the jurisdictions was that more needed to be done to capture a greater percentage of the well documented system losses at Menindee.
Table 1 in this Section 4 provides a reconciliation of the project elements that have been added, deleted or modified since Model Run 35 was tabled and the supply measure notified. Section 5 of this report then provides more detail on each element of the proposed new package.
Amendment 1 to Menindee Lakes Water Saving Project Notification
Structural adjustment There are a number of entitlement holders of various categories in the Lower Darling Water Source who will need to be considered in the changes to the management of the lakes with the primary objective is to remove irrigation demand from the Darling downstream of Menindee.
This in turn will reduce NSW commitment to holding upstream water reserves in the system and therefore maximise potential water savings from the project.
Reduced use of Lake Cawndilla impacts on the gravity supply frequency to Lake Tandou. The infrastructure cost of providing alternate pumping and channel infrastructure to supply 80 GL annually to Lake Tandou are significant. It is better value to facilitate a cessation of irrigation on the property.
Additionally, Lower Darling irrigation creates system commitments which when removed will enable quicker and more extensive evacuation of the Lakes.
The enhanced Menindee project is predicated on reducing or removing high security licence obligations and some targeted general security entitlements in the Lower Darling. To reflect this in the model, all irrigation entitlements for the Lake Tandou and the Lower Darling horticulture irrigation are switched off.
Modelling approach to assess SDL adjustment A two staged approach is used as below to assess SDL adjustment potential from this project.
1. Structural and rule changes a. Without additional flows from North, determine the size of entitlements in Murray that can be created without affecting third party users when the project is fully implemented. b. The third party impacts are assessed against the Benchmark conditions. c. The entitlements to be created are NSW Murray general security and Vic Low Reliability Water Share. The size of entitlements will be determined so that long term yields are shared equally. 2. Northern system inflows a. When the final package is formed, the additional flows from the Northern basin are included. b. Additional benefits due to the increased inflows are modelled as a part of the final package assessment through the default method as per schedule 6 of the Basin Plan.
Attachment D - Menindee Lakes Water Saving Project (NSW) Accounting for evaporative savings For the purpose of modelling the Menindee Lakes proposal in the SDL adjustment framework in 2017, the MDBA’s approach to determining the water savings amount using the benchmark model is outlined below: 1) Extract an amount downstream of Hume Dam based on the typical pattern of irrigation demands 2) For simplicity, the extracted volume use in NSW and Victoria is based on allocation levels for NSW Murray general security entitlements 3) Total extraction in a month is attributed equally between NSW and Victoria 4) Adjust the volume of extraction until allocation and use are equivalent to a base case scenario, in which: a) the benchmark is used, with baseline inflows to the Menindee system b) the use of the Tandou inter-valley transfer is assigned to NSW Murray users c) Broken Hill township water needs are supplied from Murray, through a new NSW Murray diversion with the modelled diversion from the River Murray at Wentworth.
Using this methodology, MDBA modelling shows that the project can allow a long term average of 106 GL/y to be extracted downstream of Hume Dam without adversely affecting existing water users.
Representation of the project in the total SDL adjustment project package assessment used assumptions adopted for the SDL benchmark. For modelling purposes, the savings have been distributed equally between NSW and Victoria for the environment as follows: NSW Murray (10:90 high security: general security) Vic Murray (82:18 high reliability water share: low reliability water share). Note: This modelling does not bind the NSW or Victorian governments and does not represent agreement by the NSW or Victorian governments to create the entitlements as modelled, noting that changes to modelling parameters may change the determination outcome. The enduring environmental outcomes attainable under the Menindee project (modelled by the MBDA as 106 GL LTAAY) will be provided by means agreed by all jurisdictions and the MDBA. If entitlement is created it must be based on realistic information, have no impact on reliability of existing water users and comply with all NSW and Victorian statutory requirements for the creation of new entitlement. If entitlements are created the quantum, type and location of entitlement must be reflective of the water saved. Changes to the project may require further notification amendments which would be considered by all jurisdictions via the SDL Implementation Committee and BOC. The final mechanism used to provide enduring protection of the evaporative and system loss savings from the project will be subject to further detailed investigation including modelling by MDBA plus ongoing discussion and agreement between Basin governments.
Accounting for additional northern Basin environmental inflows For the purpose of modelling for the determination the increased northern Basin environmental flows were subject to water sharing arrangements in the Murray-Darling Basin Agreement. That is, the 50/50 sharing arrangement between NSW and Victoria that applies to all Menindee inflows.
Note: The final mechanism used to provide enduring protection of the additional inflows for environmental benefit will be subject to ongoing discussion and agreement between Basin governments.