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 ..........................................................................................................................................................