Menindee Lakes Water Savings Project Business Case

DISCLAIMER:

This is a preliminary business case, used to inform decision-making by the Murray-

Darling Basin Ministerial Council and Basin Officials’ Committee on sustainable

diversion limit adjustment mechanism projects.

The document represents the Business case for Menindee Lakes Water Savings

Project at June 2017.

The NSW Department of Industry is currently developing project summary documents

that will summarise project details, and will be progressively published on the

Department of Industry website.

Detailed costings and personal information has been redacted from the original

business case to protect privacy and future tenders that will be undertaken to deliver

these projects.

https://www.industry.nsw.gov.au/water/basins-catchments/murray-darling/supply-efficiency-measures

Menindee Lakes Notification - Attachment A

Menindee Lakes

Water Savings Project

Phase 2 Business Case J

une 2017


Menindee Lakes Water Savings Project

COMMERCIAL IN CONFIDENCE PAGE 2

Blackwatch Consulting Pty Ltd

37 Avenue Rd Mosman NSW 2088

0409164566

[email protected]

The document may only be used for the purpose for which it was commissioned and in accordance with the Terms of Engagement for the commission. Unauthorised

use of this document in any form whatsoever is prohibited.

Document Status

Status Version Date Author Review Date Approval

Preliminary draft for internal review 2.1 23 May 2017 BT BWC team 23-31 May 2017

Draft Business Case for submission to client 2.43 8 June 2017 BWC Team DPI 8 June 2017

Final Business Case for submission to BOC 2.5 9 June 2017 BWC Team DPI 9 June 2017

mailto:[email protected]




LIST OF FIGURES .................................................................................................................................................. 5

LIST OF TABLES ................................................................................................................................................... 6

GLOSSARY OF TERMS AND ACRONYMS ............................................................................................................... 7

1 PROJECT SYNOPSIS .................................................................................................................................. 8

Key Features of this Proposal ..................................................................................................................................... 8 1.1

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

Lower Darling & Menindee Lakes ........................................................................................................................................... 19 2.1

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

Measure 1 – Enlarged Menindee Regulator Outlet ................................................................................................... 37 6.1

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

Measure 15 - Menindee System Control Transfer & Storage Drawdown ............................................................................ 59 8.1

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




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




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




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




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

watering

Provision of water, authorised by an access entitlement, to a location for the

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

Murray Darling Basin

(MDB)

Comprises the catchment of the Murray and Darling Rivers and their many

tributaries, extending from north of Roma in Queensland to Goolwa in South

Australia.


Agreement Commonwealth Water Act (2007) : Schedule 1 Murray Darling Basin Agreement


Authority (MDBA)

The authority responsible for managing the Basin’s water resources in the national

interest, in cooperation with state authorities, with the aim of ensuring reliable water

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

Water Year An accounting period from 1 July to 30 June, seasonally aligned and corresponding

to water allocation policy in the River Murray system.




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.




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.




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.



COMMERICAL IN CONFIDENCE PAGE 11

TABLE 1: SUMMARY OF WORKS AND MEASURES

Measure 1 Menindee outlet regulator capacity increased

from 5,000ML/day.

Measure 2 Lake Menindee drainage channel to feed

outlet and improve discharge

Morton-Boolka transfer regulator to control

Works to increase up to 14,000ML/day SDL supply measure, and

Constraints Management

Drainage channel up to 14,000ML/day SDLsupply measure

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

Menindee outlet regulator flows by reducing downstream

head


Measure 5, 6 &

11

Increased Lower Darling channel capacity to

take higher Menindee discharge – offtake

regulators at Emu Lake and Yarta Lake

Two regulators to prevent escape flows into Yartla Lake

and Emu Lake + bridge at Charlie Stone Crossing

SDL supply measure, and


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

14,000ML/day



Measure 10 Works to facilitate fish passage at Menindee

Main Weir

New Anabranch environmental Regulator #2 to control up

to 1,000ML/day, and Dam183 road bridge, regulator, and

fishway

No change to hydrology but fishway on Main Weir included

in costings

Environmental mitigation

Lake Nearie Nature Reserve

Measure 12 Flood protection measures for Menindee

residents

Construction of Menindee town high flow levee bank Constraints Management




Measure 13 Lower Darling constraints mitigation -

landholders stock and domestic & some

irrigation pump infrastructure.

Assumption holds. Works now protect and maintain

capacity of pumps during high flow events (ie : floating

suctions, on farm storage and / or groundwater options)





Feature Details Basin Plan

Outcomes St

ruct

ura

l

Ad

just

men

t M

easu

res

Measure 14

Acquisition of Lower Darling and Tandou

water entitlements

Purchase all Tandou entitlements and purchase or convert

Lower Darling HS entitlement.

Structural adjustment

mechanism

nges to

Opera

tin

g R

ule

s an

d A

gre

em

ents

Measure 15

Menindee System control transfer rule

(between NSW and the MDBA) and storage drawdown sequencing

No control transfer in place – MDBA to assume full control

of Menindee on understanding 80GL Wetherell reserve is retained for riparian demands to end of following year.

SDL supply measure

Measure 16

Broken Hill Entitlement

10,000M TWS entitlement shifted to Murray upstream

SDL supply measure

Wentworth.

Measure 17 Capacity for additional E-flows into Lake

Cawndilla

Potential use of Environmental account water to inundate

key assets in addition to natural events. Environmental mitigation

Measure 18

Improved operations of the River Murray

connected system

Proposed recalibration of the SDL Projects Pack OPLOSS

regression equation to better reflect current operating

environment

SDL supply measure

Cha

Measure 19

Lake Wetherell drying cycle

Hardwired drying cycle for Wetherell floodplain


Measure 20 Broken Hill TWS system – alternate supply Pipeline from Murray River @ Wentworth SDL supply measure




Feature Details Basin Plan Outcomes

W

ork

s &

Mea

sure

s

O

the

r M

easu

res

Rem

ov

ed f

rom

Sco

pe

Measure 21 Recognition of additional Northern basin

inflows to Menindee Lakes from Basin Plan

environmental recovery

Formally recognise the additional inflow and make callable

from a separate account

Supply measure

Measure 22 Limited temporary general security trade to

the Lower Darling subject to resource

assessment

Will be reflected in water planning rules

Basin Plan dealing rules

Deleted

Lake Pamamaroo Drainage channel to

capture dead storage

N/A – works removed from scope

N/A

Deleted

Penellco Channel increased capacity to

service Tandou

N/A - Works removed from scope

N/A

MeMneinndienedLeaekeLsaNkeotsificWataiotenr- SAattavcinhmgsenPt rAoject


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.



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:



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.



The table below summarises the proposed project delivery plan, involving five phases:

TABLE 4: PHASED DELIVERY OF MENINDEE WATER SAVINGS PROJECT

Project Phase Description Completion

Phase 1

Phase 2a

Draft Business Case – Options Report

Concept design outlining the basic suite of works and

management rule changes

August 2016

Interim Project Proposal Project scope definition and modelling requirements

April 2017

Phase 2b

Preliminary Business Case

Phase 2 submission

June 2017

(this submission)

Phase 3

Final Business Case Phase Residual Phase 2 information and Phase 3 requirements

November 2017

Phase 4a

Project Initiation, Planning and Approvals All activities required to take the project to the point of

December 2021^

Phase 4b

construction/implementation.

Project Execution and Completion Implementation of all construction works and other measures

^ (excluding structural

adjustment processes)

September 2023

through to commissioning and handover



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.



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)



The climate is semi-arid, characterised by low rainfall (average annual rainfall of approximately 300 mm) and

high evaporation (average annual evaporation of 2,700 mm) (Figure 2).

Rainfall Evapora on

450

400

350

300

250

200

150

100

50

0

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

FIGURE 2: AVERAGE MONTHLY RAINFALL (MENINDEE) AND EVAPORATION (BROKEN HILL) 1

The Menindee Lakes are a key storage in the Murray-Darling system, supplying towns and irrigation along the

Murray and Lower Darling rivers. They are also an area of significant environmental importance, and provide

recreational amenity and tourism opportunities for the region.

The Lakes area is also rich in cultural history. Aboriginal people have occupied the Menindee region for at least

47,000 years (Balme and Hope, 1990); and in 2015, the Barkandji people were granted native title over lands

and waters extending from Wilcannia to Wentworth. The Lakes and the Lower Darling and Darling Anabranch

continue to be important to the wider Aboriginal community as resources and places of significance.

2.2 2 Deve lo pm e nt of a re gula ted rive r syste m

In the 1960s the Menindee Lakes were modified to act as a water resource storage to supply Broken Hill, users

in the Lower Darling, and the Lower Murray Region. A series of weirs, regulators, channels and levees were

constructed to store large upstream events.

The townships of Menindee, Broken Hill, Silverton and Pooncarie are all supplied with water from the Lower

Darling system. There are also a number of private irrigators located south of Menindee Lakes who extract water

directly from the river.

The regulated storage system consists of four main interconnected Lakes. Of these, three are modified

natural depressions (Lakes Pamamaroo, Menindee and Cawndilla), while the fourth (Lake Wetherell) is an

artificial lake along the main river channel, formed by the construction of Main Weir. A channel was built to connect

Lakes Pamamaroo and Menindee (via Copi Hollow), while the other

1 1995 - 2017 (DATA FROM THE BUREAU OF METEOROLOGY CLIMATE DATA ONLINE)

Avera

ge

month

ly (

mm

)



interconnections are modified natural channels. In total, there are seven main regulating structures, as shown

in Figure 3.

FIGURE 3: SCHEMATIC DIAGRAM SHOWING REGULATING STRUCTURES IN MENINDEE LAKES SYSTEM

Total releases from Menindee Lakes to the Darling River are measured at Weir 32, located downstream

of all lake outlet locations Figure 3. Weir 32 was constructed in 1958 to provide additional security for the

Broken Hill and Menindee town water supplies, and has a capacity of approximately 4 GL.

The structures in Figure 2 and further detailed in Table 5 allow water to be transferred both between the Lakes

and to the main Darling River channel. Releases to the River can be made independently from Lakes Wetherell,

Pamamaroo and Menindee — water cannot be released directly from Lake Cawndilla to the Darling River,

instead it must first pass through Lake Menindee, otherwise Lake Cawndilla may only be diverted down the

Great Darling Anabranch from the Lake Cawndilla outlet regulator. This water passes via Cawndilla channel to

Tandou Creek, where it’s contained by a block bank and regulator at Packers Crossing. From this point, water

is diverted to Lake Tandou for irrigation by Tandou Limited, or released downstream to Redbank Creek and

then into the main channel of the Great Darling Anabranch.

The maximum release rates listed in



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.



TABLE 5: MAXIMUM RELEASE RATES OF MAIN REGULATING STRUCTURES IN THE MENINDEE LAKES SYSTEM

Regulator Max Release Rate (ML/day)

Main Weir (and associated levees) (Main Weir gates) 70,000

(Main Weir spillway) 110,000

Lake Wetherell outlet 5,000

Lake Pamamaroo inlet 33,000

Lake Pamamaroo outlet 5,000

Lake Menindee inlet 25,000

Lake Menindee outlet 4,000

Lake Cawndilla outlet 2,000

Weir 32 (Fixed Crest) Drowned at 8,000

Note: actual rate of release dependent on lake levels at any given time.

2.3 3 S to ra ge Ca pa ci ti e s

The four major Lakes (Pamamaroo, Menindee, Cawndilla and Wetherell) have a nominal full supply volume of

1,731GL and can be surcharged to hold up to 2,050GL during floods. However, the Lakes are located in a hot,

windy, semi-arid environment, with a combined surface area of 457.3 km2, making them relatively shallow

and prone to average annual evaporation losses of over 420GL of water per annum, which is significantly

higher than other storages throughout the Murray–Darling Basin.

TABLE 6: STORAGE CAPACITIES

Lake Full Supply

level

(m AHD)

Full Supply

Volume

(GL)

Maximum

Surcharge

Level

(m AHD)

Maximum

Surcharge

Volume

(GL)

Dead

Storage

(m AHD)

Dead

Storage

Volume

(GL)

Wetherell 61.67 193.0 62.30 262.2 52.50 0.5

Pamamaroo 60.45 277.7 61.50 353.0 56.00 10.9

Menindee 59.84 629.5 60.45 729.0 55.90 60.0

Cawndilla 59.84 631.0 60.45 705.0 54.00 48.0

TOTAL 1,731.2 2,049.2 119.4

Copi Hollow only 61.50 12.2 58.30 2.7

Lake Tandure only 61.67 77.4 57.80 9.4

The nominal full supply levels and maximum surcharge levels presented in Table 6 are lower than the original

design capacity of 2,400GL. These lower levels have been adopted to minimise risks to a number of structures.

Reduced surcharge levels and lower operating levels also minimise lake foreshore erosion, particularly

erosion of the sensitive lunettes, and subsequent impacts on the indigenous archaeology contained in the

sediments surrounding the Lakes.



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)



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.



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.



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).



TABLE 7: VEGETATION COMMUNITIES IDENTIFIEDi 2

Group Vegetation Community Lake Lake

Pamamaroo Cawndilla

Lake

Menindee

Lake

Wetherell

Darling

Anabranch

Floodplain

woodland

Coolibah - Black Box Community

(EPBC Listed)

X

Floodplain Woodland (Black Box) X X X X X

Floodplain Woodland (Red Gum) X X X X X

Rarely Flooded Woodland

X

Woodland with Lignum

X

Shrubland Chenopod Shrubland

X X

Hop-bush / Senna / Turpentine Shrubland

Low Chenopod/Blue Bush Shrubland

Herb / grass

/ sedge Cane Grass Shrubland

X

Dry Lake-bed Herbfield/Grassland/Sedgeland

X X X X

Sandy Lake Fringe

X X X

Wetland Dead Trees with Persicaria and or Lignum

X

X

Lake Fringe herbland (Live & Dead Trees)

X X

Lignum Swamp

X X X

Shallow Freshwater Marsh X X X X

Shallow Freshwater Marsh with Dead trees

X

Unvegetated Dry Floodplain Woodland (Dead Trees)

X

Dry Lake Bed (Dead Trees)

X X X X

Introduced species

X

Open Water Channel

X X X X

Open Water Lake X X X X X

Open Water Lake (Dead Trees) X X X X

Recently Exposed Lake-bed

X X X

Inflow - Outflow channel

X

The Menindee Lakes and surrounding habitats are known to provide habitat for a large number of threatened

species listed under Commonwealth (EPBC Act) and State (NSW TSC Act) Legislation.

2 Taylor-Wood et al. 2001identiified vegetation in Pamamaroo in 2001, GHD provided detail for all other lakes in 2015.



Some species are likely to be dependent on the regulated water regime of the Lakes, but other species are found

at higher elevations in areas unlikely to be dependent on flooding. URS (2005) reported seven listed flora

species that are likely to be wetland / inundation dependent known to occur at the Menindee Lakes (Table 7). In

addition, the EPBC listed endangered ecological community Coolibah

- Black Box Woodlands of the Darling Riverine Plains and the Brigalow Belt South Bioregions is known to occur in the

region and has been recorded around Lake Wetherell (GHD 2015).

TABLE 8: LISTED WETLAND FLORA SPECIES FROM THE MENINDEE LAKES3

Scientific Name Common Name IUCN EPBC TSC

Atriplex infequens

V V V

Brachyscome papillosa Mossgiel Daisy V V V

Haloragis exalata Square Raspwort

V V

Leptorhynchos waitzia Button Immortelle

E

Phyllanthus maderaspatensis

E

Solanum karsense Menindee Nightshade

V V

Swainsona adenophylla Violet Swainson-pea

E

3.1.2 Fauna

Riparian and wetland vegetation and habitats associated with the inundated areas of the Menindee Lakes

system provide important habitat for a broad range of terrestrial and aquatic fauna species, including

macroinvertebrates, amphibians, aquatic reptiles, aquatic mammal species, fish and waterbirds. Diverse

vegetation and habitat types are important for the various fauna groups, which may use different vegetation and

habitat types for different purposes and at different times.

A desktop review (GHD, 2015) of all available relevant previous studies, literature and a number of databases

indicate that a total of 348 native and 17 exotic vertebrate fauna species have been documented to occur

within the study area, and an additional four native species have been predicted to occur within the study area.

These include 11 native frog species, 249 native and six exotic species of bird, 27 native and eight exotic mammal

species and 54 native reptile species.

A total of 14 native and two introduced species of fish have been recorded or are predicted to occur in the

Menindee Lakes (URS 2005). This includes threatened species such as silver perch (Bidyanus bidyanus) and

Murray Cod (Maculochella peelii). The Lakes, however, are dominated by four native and two introduced species

(SKM 2002):

Australian Smelt (Retropinna semoni)

Bony Bream (Nematalosa erebi)

Western Carp Gudgeon (Hypseleotris klunzingeri)

Golden Perch (Macquaria ambigua)

3 (URS 2005) Listing Codes: E = endangered, V= vulnerable.



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).



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)



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.



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.



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.



FIGURE 5: PROPOSED LOCATION OF INFRASTRUCTURE WORKS IN SCOPE





6 PROPOSED INFRASTRUCTURE MEASURES

This section provides details of individual construction projects contemplated within the overall package of

works and measures, consistent with Table 1 and summarised again below: -

Proposed Infrastructure Works

Measure 1 Enlarged Menindee Regulator

Measure 2 Lake Menindee Channel

Measure 3 Morton-Boolka Regulator

Measure 4 Old Menindee Town Weir removal

Measure 5 Emu Lake Offtake regulator

Measure 6 Yartla Lake Offtake Regulator

Measure 7 Cawndilla Regulator

Measure 8 Anabranch Offtake Regulator

Measure 9 Anabranch E-flow Regulator & Road Bridge

Measure 10 Main weir fishway

Measure 11 183 Dam regulator, road bridge & fishway

Measure 12 Menindee Flood Protection

Measure 13 Lower Darling Constraints Mitigation works




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.



FIGURE 6: MEASURE 1 - ENLARGED MENINDEE REGULATOR




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.




FIGURE 8: MEASURE 2 - LAKE MENINDEE DRAINAGE CHANNEL (CONCEPT PLAN)




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 f low

conditions from Cawndilla to Menindee downstream fish passage will be able to be achieved through an

open structure with gates fully raised.




FIGURE 9: MEASURE 3 - MORTON BOOLKA REGULATOR (SHOWN SOUTH TO TOP OF PLAN)


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.


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.


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.


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 asse ts, 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.



FIGURE 7: MEASURE 7 - CAWNDILLA CREEK INUNDATION MAPPING



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.


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.


FIGURE 8: MEASURE 8 – APPROXIMATE LOCALITY OF ANABRANCH REGULATOR



FIGURE 9: MEASURE 8 – PROPOSED ANABRANCH OFFTAKE REGULATOR


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.


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.


FIGURE 10: MENINDEE TOWNSHIP INUNDATION MAP AT 25,000ML/DAY

6. 10 M ea sure 1 3 – L o w er D ar l ing C onstra i nts M i ti ga ti on Wor k s

6.10.1 Objectives

Increased flows in the Lower Darling as a result of the enlarged Menindee regulator and flows up to 14,000ML/day

will have an impact on private diversion points for stock and domestic supplies along the river. The objective of this

component of the package is to undertake works which allow continued stock and domestic access and irrigation

access for impacted landholders under the proposes changed river operations.

During periods of low flow, it is anticipated the water will be pulsed down the river to minimise losses. This pulsing

may necessitate the provision of on-farm storage or access to ground water alternatives to maintain supply for

stock and domestic purposes.

6.10.2 Description

As a result of the changed operations a number of licence holder pumps and installations will be impacted

and need to be modified, replaced or relocated. The impact will be limited primarily to stock and domestic and some

irrigation pumps given the intended buyback of high security licences and structural adjustments.

TABLE 9: LICENCE NUMBERS BY CATEGORY IN LOWER DARLING

Standard^

Licences

Stock & Domestic 114

Regulated River (General Security) 84

Regulated River (High Security) 59

Local Water Utility 2

Supplementary Water 1

Total 260

Source: http://www.water.nsw.gov.au/water-licensing/registers ^Excludes zero allocation licences

It has been assumed that all stock and domestic installations will require further review and potential modification

along with all irrigation equipment related to remaining irrigation licences. In excess of 200 licences may be

impacted to some extent. It is expected that each licence may have more than one piece of infrastructure related

to a licence requiring attention.

As part of the Phase 4 design process, a full audit and survey of the infrastructure at each licence holder

location would be undertaken.

The scope of the work required at each location is yet to be determined but may include:

Pump relocation;

Fitment of floating pickups;

On-site storage or groundwater options; and

Pump replacement due to changed head conditions.

http://www.water.nsw.gov.au/water-licensing/registers

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.

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.

7.1.3 Current Licence Entitlements

According to the Lower Darling Water Sharing plan there are a total of 282 open licences covering 347GL of

entitlement in the Lower Darling, including 250GL of supplementary water and with a total of 86GL allocated against

high and general security licences.

Of the 7.7GL of high security entitlements, the State and Federal Governments currently hold 1.2GL. The further

high security entitlements of 6.5GL are covered by 59 high security licences but dominated by Websters Limited

(Tandou) at 2.5GL.

TABLE 10: LICENCES

Standard

Licences

Zero Value

Licences

Total

Licences Shares

Stock & Domestic 114 0 114 1.4 GL

Local Water Utility 2 0 2 10.1 GL

Regulated River (General Security) 84 10 94 78.3 GL

Regulated River (High Security) 59 10 69 7.7 GL

Supplementary Water 1 2 3 250.0 GL

Total 260 22 282 347.4 GL

TABLE 11: LICENCE ENTITLEMENTS (VOLUMES)

Websters

Limited

(Tandou)

Other Lower

Darling Water

Licences

WAMC /

Commonwealth

Total

Entitlement – High Security 2.5 GL 4.0 GL 1.2 GL 7.7 GL

Entitlement – General Security 19.4 GL 10.1 GL 48.8 GL 78.3 GL

Entitlement – Total 21.9 GL 14.1 GL 50.0 GL 86.0 GL

7.1.3.1 Small Licence Holders

Beyond Webster Ltd. (Tandou) and some larger

scale irrigators, there are a high proportion of

small licence entitlements held in the Lower

Darling (as identified in Figure 11). A number of

these have been inactive in regard to physical

use, but have been regularly traded.

Any change to the nature of entitlements in

this region will generate significant

interest from the licence holders.

3,000

2,500

2,000

1,500

1,000

500

0

1 4 7 10 131619222528 3134 3740 4346495255

FIGURE 11: LICENCE ENTITLEMENTS – HIGH SECURITY

LIC

ENC

E EN

TITL

EME

NT

(ML)

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.

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.

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

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.

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.

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.

The Scheme requires a substantial volume of water (200-250 GL) to be stored in the Menindee Lakes System, in

order to ensure a minimum of 18 months security of supply for Broken Hill. Recent drought periods have resulted

in extended low/no flow periods that have required the implementation of various contingency measures to

ensure ongoing supply for Broken Hill. Essential Water operates to minimise evaporation within their Water Supply

Scheme and therefore minimise pipeline transfers.

FIGURE 12: BROKEN HILL WATER SUPPLY - SCHEMATIC

Due to recent prolonged periods of drought, the Menindee Lakes System did not provide an adequate security of

supply for Broken Hill. In 2015, the volume of inflows to the Menindee Lakes system fell to new historic lows, and

emergency measures were required; including block banks and pumping to concentrate the remaining volume

of water in the most efficient parts of the Lakes system, the commissioning of the desalination plant at Broken

Hill, which is now in operation, and the investigation and drilling of two bore fields at Lake Menindee and Talyawalka.

In 2016 the NSW Government approved for the construction of a pipeline from the Murray River at Wentworth to

Broken Hill. WaterNSW is currently out to market for a Design, Build, Operate and Maintain project. The project

is set for completion in late 2018.

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.

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.

The reinvigoration of this project provides an opportunity to reengage 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 currently

focused on commercial negotiations with directly affected parties, as a precursor to the development of a

structural adjustment package.

Appendix 1 and 2 detail the proposed Terms of Reference for the NSW Inter-Agency Working Group and Inter-

Jurisdictional Working Group (MDB). Consultation has already commenced informally and will be formally

commenced from July 2017. Broader community consultation is expected to commence in the last quarter of

2017 when commercial discussions are more advanced.

A communication strategy is required to engage and provide information to all key stakeholders and the local

community on:

1. Each major component of the proposed Menindee Lakes Water Savings Project;

2. The current water management policy at Menindee Lakes, and the relationship to wider Murray-

Darling Basin management; and

3. The structural and water management options being considered how the operation of the

Menindee Lakes would change if these were implemented.

Following advice and feedback local Aboriginal Elders at a pre-engagement meeting held in Menindee on 5 March

2014, it has been agreed that there need not be any specialised tools or methods of engagement be used

for Aboriginal people. The Elders advised that they would like a single point of contact for information coming from

DPI Water, that is the Menindee Local Aboriginal Land Council, and that they would provide advice directly to DPI

Water, or via the Regional Advisory Group.

TABLE 12: STAKEHOLDER MATRIX

Stakeholder Communication Objective Principal Communication / Engagement Strategy

Group 1: Stakeholders directly involved in commercial negotiations over buyback / structural adjustment.

Webster Ltd

(Tandou)

Commercial negotiations Direct communications

Lower Darling

Horticultural Group

Commercial negotiations and

consultation in relation to

ongoing service

Direct communications

Lower Darling

Landholders

Consultation in relation to

ongoing service


Group 2: Stakeholders directly involved in decision making processes during the project.

Commonwealth,

NSW & other

Jurisdictional

Governments

Seek key approvals

throughout project via

BOC/MinCo

Governance - representation on IJWG

Formal Presentations & reports – key project milestones

to IJWG.

Media Releases

Modelling liaison and review


MDBA Technical liaisons in relation

to key agreements and

operating rules. Iterative

modelling changes.


NSW DPI Water Inform, provide direction and

approval

Governance meetings including facilitation of Project

Governance through IAWG.

Review key documents

NSW Premiers &

Cabinet

Inform and seek support IAWG

Formal Presentations, reports.

NSW Planning Direct approval IAWG – Meetings, presentations, reports

Planning Focus meeting

Environmental Assessment, AHIP.

NSW Office of

Environment &

Heritage, EPA

Inform and seek approvals IAWG - Governance meetings, presentations, modelling

progress and review

Formal consultation v/v SSP approvals

DPI Fisheries Inform and seek requirements

as part of approvals

IAWG - Governance meetings, presentations, modelling

progress and review

Formal consultation v/v SSP approvals

WaterNSW Modified Operational Plans,

licence changes, potential

project delivery

IAWG - General project communications, Iinstitutional

arrangements

Future O&M - working group / task force leading to

modified ops plan / strategy to achieve savings and

appropriate water management.

Potential project delivery – CEO to CEO

Group 3: Stakeholders who are important to the Project, will be engaged and will provide input which may influence

the project outcomes, but who may not necessarily influence the decision-making processes.

Aboriginal

Community,

Traditional Owners,

Elders Groups

Inform and engage

community, particularly during

cultural heritage assessment

in planning phase & cultural

heritage monitoring during

construction

Briefing to community groups

Representative(s) on Regional Consultative Committee.

Engagement during cultural heritage assessment &

monitoring.

Likely that an Aboriginal Heritage Impact Permit (AHIP) is

required. An AHIP has statutory engagement strategies.

Menindee Township Inform and engage the

community, particularly

regarding Menindee Flood

ProtectionWorks

Media Releases

Council newsletters

Regional Consultative Committee representation.

Broken Hill, Sunset

Strip & Silverton

Communities

Inform and engage

communities

Media Releases

Council newsletters

Representation via a regional consultative committee.

Local Tourist Industry

& Mining Industry

Inform and engage tourist

and mining industry


Broken Hill City

Council

An informed community Representation via a regional consultative committee.

Media Releases

Council briefings.

Water Users Inform and engage

communities


Media Releases


NSW Irrigators Council

Group 4: Stakeholders who need to be kept informed of the Project.

Media An informed community Manage external media opportunities to promote

milestones

Manage external media enquiries regarding the project

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.

12.1.2 Activities to be completed

There has been considerable work completed in various iterations of the Menindee Lakes Water Savings

Project over the past two decades. The works and measures, and consequent operating regime, however,

have changed since previous investigations were completed. In order to ensure that any impact assessment builds

on previous work, rather than duplicating studies and investigations, a two-stage process is proposed:

1. A Scoping Study - which collates all existing information, confirms the proposed operating regime of

the new scheme configuration and completes a preliminary qualitative assessment of benefits and

impacts; and

2. An Environmental Impact Statement (EIS) - guided by the scoping study and the Director General’s

(Planning) requirements, which fulfils statutory obligations for environmental and heritage impact

assessment under NSW legislation.

The Menindee project falls under the State Significant Infrastructure category of development, which requires

approval from the Department of Planning and Infrastructure. The formal Environmental Impact Assessment

for the project will likely follow the process prescribed by NSW policy and legislation.

TABLE 13: LIKELY APPROVALS PROCESS FOR THE MENINDEE LAKES PROJECT

Activity Outcome Likely timing

DPI Water submits and

application to the

Director-General of

Planning and

Infrastructure

Director-General prepares site-specific environmental

assessment requirements (DGRs) which DPI Water must

address in an environmental impact statement (EIS)

28 days

DPI water prepares EIS EIS which contains:

a summary of the environmental impact statement,

a statement of the objectives of the development,

an analysis of any feasible alternatives to the

carrying out of the development in relation to its

objectives, and the consequences of not carrying it

out,

an analysis of the development, including:

o a full description of the development,

o a general description of the environment

likely to be affected by the development,

o a detailed description of those aspects of the

environment that are likely to be significantly

affected,

o the likely impact of the development on the

environment,

o a full description of mitigation measures

proposed,

o a list of any approvals that may be obtained

under any other Act – such as a licence to

6 - 12 months

Activity Outcome Likely timing

pollute (environment protection licence)

from the Office of Environment and Heritage,

and

Reasons justifying the carrying out of the

development in the manner proposed.

Director General accepts

EIS

Public consultation period 30 days

Director General

produces a report

detailing issues that must

be addressed

DPI Water responds to the issues outlining any proposed

changes to the project 10 weeks

provided as

estimate in plan

Director General prepares

an environmental

assessment report for the

Minister

Report must be considered by the Minister in the decision-

making process.

6 months

provided as

estimate in plan Planning Minister makes

a decision

Approval, approval with modifications, not approval.

12.1.3 EIS Scoping Study – Statement of Requirements (Draft)

Appendix 4 provides a draft “statement of requirements” for the request for tender (RFT) for Stage 1 the EIS

process. It is intended that these will be finalised by DPI Water once the finer details of the project are decided.

It should be noted that the Director-General of the Department of Planning and Environment establishes the

requirements for the EIS and that these RFT will need to reflect those requirements.

12.2 2 C ultur al H er ita g e

12.2.1 Current State of Activities and I nvestigations

The Menindee area continues to be a focal point for Barkandji people because of the close proximity of the

important riverine landforms belonging to the Darling River, Menindee Lakes and the Talyawalka-Anabranch

system (Martin, 2001). Aboriginal people have occupied the Menindee region for at least 47,000 years (Balme

and Hope, 1990) consequently the lake system and surrounding floodplains contain many sites of significance

to Aboriginal Cultural Heritage.

The Lakes are an element of the Aboriginal cultural landscape and the proposed Menindee Lakes Water

Savings Project would impact on this landscape and potentially the associated Aboriginal cultural heritage

values.

A list of Aboriginal sites recorded on the Aboriginal Heritage Information Management System (AHIMS) that

are located within the four areas of interest as follows:

1. Lake Cawndilla - Lake Cawndilla, Cawndilla Creek, Morton-Boolka and Lake Eurobilli.

2. Lake Menindee - Lake Menindee and Speculation Lake.

3. Lake Wetherell - The section between the Darling River and Lake Pamamaroo, including Tandure

Lake, Bijije Lake and Balaka Lake.

4. Darling Anabranch - The section between the southern edge of Lake Cawndilla and Lake Tandou.

Table 14 summarises the Registered Aboriginal Sites within the Study Area received from the NSW Office of

Environment and Heritage (OEH) on the 22nd September 2014. The sites represent point data (Aboriginal sites)

and do not represent site extents.

TABLE 14: REGISTERED ABORIGINAL SITES WITHIN THE STUDY AREA

Study Area Registered Aboriginal Sites

Lake Cawndilla 220

Lake Menindee 155

Lake Wetherell 10

Darling Anabranch 57

Total 442

A total of 442 registered Aboriginal sites were located within the four areas of interest comprising the study area.

Many of these Aboriginal sites may be impacted by the proposed Menindee Lakes Water Savings Project.

Registered Aboriginal sites within the study area include artefact scatters, burials, hearths, scarred trees, shell

middens, non-human bone and organic materials, potential archaeological deposits and combinations of up to

four individual features in one registered site. Aboriginal Ceremony and Dreaming sites are also located within

the study area. Each Aboriginal site is protected under Section 90 of the National Parks and Wildlife Act 1974.

Lake Cawndilla is the study area most affected by the proposed structural changes and encompasses the largest

number of registered Aboriginal sites. Preliminary investigations indicate that the majority of recorded sites are

likely to be located above the full supply level. This is based on the point data from the AHIMS which does not

represent the full extent of each site.

Potential impacts include:

A decrease in water levels may lead to further unearthing and destruction of archaeological material

through wind erosion.

Lower water levels may be beneficial to scarred trees.

A more rapid fill rate may lead to an increase in wave erosion, further damaging and

repositioning archaeological deposits located along the lake margin, lunettes and banks.

A marked decrease in total inundation may have a beneficial effect of Aboriginal cultural heritage

located within the shoreline by reducing shoreline erosion.

A reoccurring increase in artificially raised water levels may create inundation and further impact

archaeological deposits through shoreline erosion from inundation.

Wave erosion, created by increasing and decreasing water levels will further damage

archaeological deposits around the lunettes, lake margins and banks.

The high density of burials and artefact scatters surrounding the lake would be particularly impacted

by an increase in water levels

TABLE 15: ISSUES SUMMARY

Issue Impact Potential Mitigation

Construction

activities will be in

the vicinity of

traditional sites

Future water

management will

increase the

frequency that the

Lakes are dry

The benefits arising

from estimated

water savings have

not been clearly

articulated

Unless construction is carefully

planned, items would be damaged

leading to a reduction in cultural

heritage

Increased frequency of drying

could lead to increased erosion

risks potentially exposing and

damaging cultural heritage items.

General skepticism of the benefits

of the project will reduce support

from the local community or lead

to active disapproval.

- Ensure that thorough site assessments are completed in

collaboration with the community to identify sites/items at

risk.

- If at-risk Aboriginal items are identified at proposed

construction sites, determine jointly with the community

how these items can be protected, including potential

removal and reinstatement.

Studies of potential increases in erosion to be completed and, if increases are identified, develop plans to protect heritage items.

- Clearly articulate the benefits to all stakeholders,

including the benefits to the local community. If it is found

that there are negative impacts, consider what form of

compensation is required.

- Implement a well-planned, culturally sensitive and

comprehensive communications strategy with the local

Aboriginal community to ensure there is a better

description of the project and develop a deeper

understanding of the activities and benefits.

- Implement a well-planned socio-economic analysis

(leading to mitigation strategies) giving due regard to the

potential effects to the local Aboriginal community.

Delay in receiving

information on

project activities

Inability to provide well informed

feedback to guide construction

activities while at the same time

protecting cultural heritage sites

and artefacts.

NSW DPI Water to include a representative of the local

Aboriginal community within a formal project consultation

committee that meets as required to ensure full disclosure

of plans, with access to independent dispute resolution, if

this is required.

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



13.1.3 Consequence Matrix

Table 17 provides the consequence matrix adapted for use to clearly assess the consequence of currently identified risks.

TABLE 17: CONSEQUENCE MATRIX

Consequence Category

Negligible Minor Moderate Major Severe

Facto

r o

f C

on

sequ

en

ce

Stakeholders

No impact. Confident that all stakeholders and their

needs/views have been identified and issue under

active management. All groups that may influence the

project have also been identified and management

strategies have been developed.

Localised issues only, very small number of

stakeholders involved, negligible risk of contagion,

under active management, unlikely to be risks to client

or contractor reputation.

Localised issues with potential risk of contagion,

moderate and growing number of stakeholders

involved, under active management but some risks to

client or contractor reputation if not resolved.

Broader and growing distribution of concerns with high

risk of major breakout if not addressed, large number

of vocal and/or influential stakeholders involved,

management interventions not containing issue, large

risks to client or contractor reputation if not resolved.

Adverse short and long-term i mpact on contractor or

client reputation or i mage. Signi ficant government

intervention/involvement, protracted legal dispute,

Major loss of shareholder or community support.

Scope

Isolated issue, neglible impact on time, cost, quality.

Client’s requirements are generally understood. Client

communicates requirements clearly. The indicative

program is realistic.

More than an isolated issue with some minor impacts

on time, cost & quality. Client's requirements not well

communicated or understood. Some components of

program require clarification. In the context of a minor

number of RFI's submitted.

More frequent issue and moderate impact on time, cost

and quality. Client has not communicated requirements

clearly or contractors understanding is limited. The

indicative program may not be realistic. In the context of

moderate number of RFI's but able to be resolved.

Common issue and/or major impact on time, cost and

quality. Client has not communicated requirements

clearly or contractors understanding is poor. The

indicative program is not be realistic. Unable to be

resolved and requires escalation to Snr Leadership

Client’s requirements and/or contractor claims are

disputed. Agreement canot be reached on delivery of

the program . Objectives of the project at significant

risk. Significant number of outstanding RFI's with high

likelihood of contractual dispute.

Cost

Less than $50K $50K-$250K $250K-$1M $1M-$5M >$5M

Time

No impact. Delays less than 5% Delays of 5% to 10% Delays of 10% to 20% Delays >20%

Environment

- Ecosystems

Alteration or disturbance to ecosystem within natural

variability. Ecosystem interactions may have changed

but it is unlikely that there would be any detectable

change outside natural variation / occurrence.

Localised measurable changes to the ecosystem

components without a major change in function (no loss

of components or introduction of new species that

affects ecosystem function). Recovery (if relevant) in

less than 1 year.

Widespread measurable changes to the ecosystem

components without a major change in function (no loss

of components or introduction of new species that

affects ecosystem function). Recovery (if relevant) in 1

to 2 years.

Widespread measureable changes to the ecosystem

components with a major change in function. Recovery

(i.e. within historic natural variability) in 3 to 10 years.

Long term and possibly irreversible damage to one or

more ecosystem function. Recovery, if at all, greater

than 10 years.

- Habitat

Alteration or disturbance to habitat within natural

variability. Less than 1% of the area of habitat affected

or removed.

1 to 5% of the area of habitat affected in a major way or

removed.

5 to 30% of the area of habitat affected in a major way

or removed.

30 to 90% of the area of habitat affected in a major way

or removed.

Greater than 90% of the area of habitat affected in a

major way or removed.

- Species

Population size or behaviour may have changed but it

is unlikely that there would be any detectable change

outside natural variation / occurrence.

Detectable change to population size and / or

behaviour, with no detectable impact on population

viability (recruitment, breeding, recovery) or dynamics.


behaviour, with no impact on population viability

(recruitment, breeding, recovery) or dynamics.


behaviour, with an impact on population viability and or

dynamics.

Local extinctions are imminent / immediate or

population no longer viable.

Project Communications

Isolated issue. Otherwise good communication.

Information generally available and shared and if not

being resolved at operative level.

One of small number of communication issues between

client/contractor. Requiring escalation to steeri ng

committee level. No delays to project.

Consistent with a moderate number of communication

issues between client/contractor, escalation to steering

committee for resolution . Causing delays to project.

Client / contractor communications have broken done

at a steering committee level requiring escalation to

Snr leadership group to resolve, potentially requiring a

change in client and/or contractor personnel.

Major dispute in progress. Threatened and /or actual

litigation, arbitration and/or mediation in train. Change

in client and/or contractor personnel required if project

proceeds.

Quality

Isolated and minor non-conformance with quality

requirements otherwise clearly defined and being

delivered.

Some quality requirements are requiring further

clarification with some minor corrective actions

required.

Related to moderate number of quality issues, not

clearly defined by Client and/or a number of corrective

actions required.

Quality requirements not clearly defined by Client

and/or significant number of corrective actions and/or

works suspended.

Contract suspension actual or highly likely, major

dispute over quality standard being requested versus

delivered, threatened or actual litigation, arbitration,

mediation

Safety

• OHS: Incident - no lost time.

• Security: No notifiable or reportable incident.

• OHS: Injury - no lost time. First aid may be required.

• Security: Localised incident. No effect on operations.

• OHS: Injury - lost time.

Compensable injury.

• Security: Significant effect on operations.

• OHS: Serious injury resulting in hospitalisation / long

term illness or serious injury.

• Security: Signi ficant incident affecti ng multiple

locations.

• OHS: Fatality / permanent disability or ill health.

• Security: Extreme incident affecting organisation's

survival.

Hazard

Isolated and negligible WHS or public safety

consequence. Confident that all hazards have been

identified and a management strategy (SWMS) has

been established for each identified hazard. A Risk

Register has been established for the project, and all

Minor public or WHS safety consequence. All hazards

have been identified and a management strategy

(SWMS) has been established for key hazards. A Risk

Register has been established for the project, and all

risks are managed throughout the project.

Moderate WHs or public safety consequence. Some

hazards have been identified and a management

strategy (SWMS) has been established for some

hazards. A Risk Register has been established for the

project.

Major WHS or public safety consequence. All key

hazards have not been identified and a management

strategy (SWMS) has not been established for key

hazards. A Risk Register has been established for the

project, but is not re-visited throughout the project.

Severe safety consequence. Hazards have not been

identified. A Risk Register has not been established

for the project.

Sub-Contractors

Negligible issue and able to be dealt with in the normal

course of business. No time,cost or quality impacts, no

risk of SOPA claim,

Minor issue(s) requiring more effort but with little impact

on time, cost, quality. Little risk of SOPA claim.

Moderate issue(s) requiring considerable effort and

impacting on time, cost, quality. Reasonable risk of

SOPA claim. Some concerns over competency or

viability.

Major issue(s) with significant impact on resourcing,

time, cost, quality. Parts of proejct threatened. Major

risk of SOPA claim. Real competency or viability

issues.

Severe issue(s), whole project delivery threatened,

SOPA clai m and / or litigation, arbitration, mediation in

motion. Real competency or viability issues.

Page 77



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.

Page 78



Page 79

13.2 R i sk a nd I ssue s – I nher e nt H ea t M a p ( b e f or e m i ti g a ti o n )

TABLE 18: INHERENT RISK HEAT MAP

BUDGET (10) COMMUNICATION (4) DEPENDENCY (4) ENVIRONMENT (16) GOVERNANCE, LEGAL &

REGULATORY (6) HERITAGE(4) OPERATIONS (2) POLITICAL (7) PROJECT MANAGEMENT (4) STAKEHOLDER (3)

Scope changes increase cost of

project significantly beyond the

contingecy allowance.

Perception of waste, due to

duplication of previous work already

carried out and representations

made.

EIS consent conditions recommend

works and/or operating rules that

reduce the overall water saving

benefits.

Reductions in bankful and overbank

flows decrease stream metabolism

and affect primary productivity in

the Lower Darling River and Great

Darling Anabranch

3rd parties raise injuction against

any or all of the project procesing.

Project is unable to meet all of the

aspirations of Native Title Owners /

local / wider aboriginal interests.

Potential for interested stakeholder

groups to require excessive works

and operations that impose costs on

the project.

The assumed impacts of the changes

to licence entitlements is broader

than expected and the planned

structural adjustment package is

insufficient to address all impacts.

Increased noise & traffic during

construction phases.

Menindee Township & Sunset Strip

concerned about future water

quality and supply.

Potential to undersize or oversize

design elements.

Key stakeholders are not clearly

identified and re-engaged at an early

enough stage in the process and

actively campaign against the

project.

Third party approval process have

significant potential to delay project

program.

Impacts to threatened species during

construction activities

Landowners are reluctant / unwilling

to permit easements on title for

levee construction.

Heritage concerns and located

artifacts providing potential to delay

or require major scope changes to

the project or program.

Modelled outcomes from the

inclusions of SDL package are

insufficient to justify the

expenditure.

Removal of Old Menindee Town

Weir is resisted by commu nity.

Risk of flooding or inundation during

construction.

Total compensation paid for

structural adjustments distorts

Water Licence markets and sets

unwanted precedents.

Potential to exceed construction

budget, if construction constraints

are not managed.

Project currently assumes sequential

program to reduce regret cost.

Pressure to bring program forward

will increase the likelihood of regret

costs and need to re-do some

activity if scope changes.

Perceptions that evaporation

occurring elsewhere in the basin is

not being addressed, and that

Menindee Lakes is being unfairly

targeted.

The benefits arising from estimated

SDL offsets, environmental benefits

and basin plan objectives have not

been clearly articulated to all

stakeholders.

Clash between stucture of State

Significant Project framework and

timelines vs stakeholder processes

Without parallel scheduling,

program has no capacity to slip due

to extreme weather conditions and

still meet 2024 deadline.

Operation changes create negative

impacts on Kinchega National Park

Operation changes impacts on

Wetting & Dying cycles of the

Menindee Lakes

Change of o wnership of properties in

Lower Darling occurs and new

owners do not h onour option for

licence buy-back & impairment of

works approvals.

Intra state institutional

arrangements pose constraints on

the project that threaten the

projects viability

Concerns that the Morton Boolka

regulator would attract vistors who

would collect artefacts in the area.

Increased frequency of drying could

lead to increased erosion risks

potentially exposing and damaging

cultural heritage items.

Property values in Menindee and

other related townships decrease

due loss of amenity and/or economic

activity from buy-back of Lower

Darling licences and changes to

operations.

Community feels previously raised

concerns/issues have been ignored.

Significant weather event delays

planning activities in project (geo,

survey)

Project works are completed during

dry spell in lakes and works can't be

adequately tested and

commissioned.

Landholders on the Anabranch are

concerned that installation of

regulators could lead to poorer

ecological & socio-economic

outcomes in the Anabranch, & fear

that the Anabranch regulators will

be used to stop flows to the

Anabranch more frequently,

Budget has been constructed in real

dollars. Final nominal project costing

will be significantly higher and is

largely subject to agreement on

timeline & inclusions.

Fish management act will trigger

requirement for fish passage

structures at each of the new works

and potentially the existing main

weir.

Interstate institutional arrangements

pose constraints on the project that

threaten the projects viability

Upstream communities try to link

otherwise unrelated issues to the

project and threaten its viability.

A significant body of work has

already been undertaken

(particularly environment). Budget

assumes that some benefit will be

derived in time/cost from use.

Budget will be negatively impacted if

prior body of work is not used or no

longer relevant.

Risks associated with wet

construction costs will be high.

Contractual risk sharing will need to

be considered carefully to avoid

having the full cost embedded in the

base price

Death of trees due to lack of

flooding.

Risk to Black Box-Coolabah as listed

Endangered Ecological Community.

Concerns that inter-jurisdictional

stakeholders aren't adequately

consulted and engaged during the

project leading to delays during final

approval processes.

Potential action by residents of

Sunset Strip & Copi Hollow based on

the perceived reduction in

availability of water for water sports

and other recreational activity.

Interest groups use project to

increase pressure to have Lake

system listed with Ramsar and

potentially delays project.

Websters Limited (Tandou) currently

have a zero value supplementary

licence available. Government have

previou sly purchased a

supplementary licence from Tandou.

Rapid rises during filling events may

drown emergent species & rapid rate

of draining may expose aquatic

species.

A12 :

RSK

020

R20 :

RS

K009

A12

: R

SK007

R20 :

RS

K006

A12 : R

SK

005

Y9 : R

SK004

Y9 :

RSK

003

A

12 : R

SK

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A12 : R

SK

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R15 :

RS

K012

R20 : R

SK

011

A12 : R

SK

010

R15 :

RS

K019

A12 : R

SK

018

R20

: R

SK

017

R25 : R

SK

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A12 :

RSK

027

A12 :

RSK

025

R1

5 :

RS

K02

4

R15 :

RS

K023

R20 :

RS

K022

Y9 : R

SK021

Y9 :

RSK

016

A

12 : R

SK

014

A12 :

RSK

068

R16 :

RS

K050

R16 :

RS

K047

A12 : R

SK

046

Y9 :

RSK

045

R

15 : R

SK

008

Y9 : R

SK042

Y9 : R

SK041

A12 : R

SK

040

R16 : R

SK

039

R15 : R

SK

051

Y9 :

RSK

048

A12 :

RSK

061

R20

: R

SK

059

A

12 :

RSK

058

A12 : R

SK

057

R15 :

RS

K053

Y9 :

RSK

052

R

15 : R

SK

001

Y9 : R

SK065

Y9 : R

SK064

A12 : R

SK

063

Y9 :

RSK

062

R16 :

RS

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R16 : R

SK

066

A12 : R

SK

049



Page 80

Risk and Issues – Inherent Heat Map (before mitigation) cont….

BUDGET (10) COMMUNICATION (4) DEPENDENCY (4) ENVIRONMENT (16)

GOVERNANCE, LEGAL &


Buy back is rejected by Licence

Holders and Government required to

use alternate measures for removing

high security entitlements from

Lower Darling.

Impacts to threatened species due to

altered hydrology.

No certainty for funding for ongoing

O&M costs.

Impact on recruitment success from

waterbird breeding and frog

breeding.

Changes to water levels impact

feeding and roosting of waterbirds

(including international migatory

species)

Elevated water levels in Menindee

Lake adjacent to the empty Lake

Cawndilla leading to salinization

nearby (including within Lake

Cawndilla),

Potential for sediment to be

generated in channels

Impact of clearing operations on

threatened ecological species or

endangered ecological communities

Concern that the environment of the

Lower Darling, the Lakes and the

Anabranch will be less valued than

downstream environments;

EIS identifies endangered fauna/flora

and require acquisition of significant

off-sets. Location and agreement of

offsets have the potential to delay

project and increase costs.

A1

2 : R

SK

069

R15 : R

SK

055

R16 :

RSK

037

Y9 :

RSK

036

A12 :

RS

K035

Y9

: R

SK0

34

Y9 :

RSK

033

R16 : R

SK

030

A12

: R

SK

029

A12 : R

SK

028



Page 81

RS

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


REGULATORY (6)

HERITAGE (4) OPERATIONS (2) POLITICAL (7) PROJECT MANAGEMENT (4) STAKEHOLDER (3)

Scope changes increase cost of

project significantly beyond the

contingecy allowance.

Perception of waste, due to

duplication of previous work already

carried out and representations

made.

EIS consent conditions recommend

works and/or operating rules that

reduce the overall water saving

benefits.

Reductions in bankful and overbank

flows decrease stream metabolism

and affect primary productivity in

the Lower Darling River and Great

Darling Anabranch

3rd parties raise injuction against

any or all of the project procesing.

Project is unable to meet all of the

aspirations of Native Title Owners /

local / wider aboriginal interests.

Potential for interested stakeholder

groups to require excessive works

and operations that impose costs on

the project.

The assumed impacts of the changes

to licence entitlements is broader

than expected and the planned

structural adjustment package is


Increased noise & traffic during

constru ction phases.

Menindee Township & Sunset Strip

concerned about future water

quality and supply.

Potential to undersize or oversize

design elements.

Key stakeholders are not clearly

identified and re-engaged at an early

enough stage in the process and

actively campaign against the

project.

Third party approval process have

significant potential to delay project

program.

Impacts to threatened species during


Landowners are reluctant / unwilling

to permit easements on title for

levee construction.

Heritage concerns and located

artifacts providing potential to delay

or require major scope changes to

the project or program.

Modelled outcomes from the

inclusions of SDL package are

insufficient to justify the

expenditure.

Removal of Old Menindee Town

Weir is resisted by community.

Risk of flooding or inundation during

constru ction.

Total compensation paid for

structural adjustments distorts

Water Licence markets and sets

unwanted precedents.

Potential to exceed construction

budget, if construction constraints

are not managed.

Project currently assumes sequential

program to reduce regret cost.

Pressure to bring program forward

will increase the likelihood of regret

costs and need to re-do some

activity if scope changes.

Perceptions that evaporation

occurring elsewhere in the basin is

not being addressed, and that

Menindee Lakes is being unfairly

targeted.

The benefits arising from estimated

SDL offsets, environmental benefits

and basin plan objectives have not

been clearly articulated to all

stakeholders.

Clash between stucture of State

Significant Project framework and

timelines vs stakeholder processes

Without parallel scheduling,

program has no capacity to slip due

to extreme weather conditions and

still meet 2024 deadline.

Operation changes create negative

impacts on Kinchega National Park

Operation changes impacts on

Wetting & Dying cycles of the

Menindee Lakes

Change of ownership of properties in

Lower Darling occurs and new

owners do not honour option for

licence buy-back & impairment of

works approvals.

Intra state institutional

arrangements pose constraints on

the project that threaten the

projects viability

Concerns that the Morton Boolka

regulator would attract vistors who

would collect artefacts in the area.

Increased frequency of drying could

lead to increased erosion risks

potentially exposing and damaging

cultural heritage items.

Property values in Menindee and

other related townships decrease due

loss of amenity and/or economic

activity from buy-back of Lower

Darling licences and changes to

operations.

Community feels previously raised

concerns/issues have been ignored.

Significant weather event delays

planning activities in project (geo,

survey)

Project works are completed during

dry spell in lakes and works can't be

adequately tested and

commissioned.

Landholders on the Anabranch are

concerned that installation of

regulators could lead to poorer

ecological & socio-economic

outcomes in the Anabranch, & fear

that the Anabranch regulators will

be used to stop flows to the


Budget has been constructed in real

dollars. Final nominal project costing

will be significantly higher and is

largely subject to agreement on


Fish management act will trigger

requirement for fish passage

structures at each of the new works

and potentially the existing main

weir.

Interstate institutional arrangements

pose constraints on the project that

threaten the projects viability

Upstream communities try to link

otherwise unrelated issues to the

project and threaten its viability.

A significant body of work has

already been undertaken

(particularly environment). Budget

assumes that some benefit will be

derived in time/cost from u se.

Budget will be negatively impacted if

prior body of work is not used or no

longer relevant.

Risks associated with wet

construction costs will be high.

Contractual risk sharing will need to

be considered carefully to avoid

having the full cost embedded in the

base price

Death of trees due to lack of

flooding.

Risk to Black Box-Coolabah as listed

Endangered Ecological Community.

Concerns that inter-jurisdictional

stakeholders aren't adequately

consulted and engaged during the

project leading to delays during final

approval processes.

Potential action by residents of

Sunset Strip & Copi Hollow based on

the perceived reduction in

availability of water for water sports

and other recreational activity.

Interest groups use project to

increase pressure to have Lake

system listed with Ramsar and


Websters Limited (Tandou) currently

have a zero value supplementary

licence available. Government have

previously purchased a


Y9

: R

SK009

Y6 :

RSK

007

G4 : R

SK

006

A12 :

RS

K005

Y9 :

RSK

004

Y9 :

RSK

003

Y6 :

RSK

002

Y9 :

RSK

013

A12

: R

SK

012

Y9 :

RSK

011

Y9 :

RSK

010

A12 :

RS

K019

G4 :

RS

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Y9

: R

SK0

17

A12 : R

SK

015

Y6 :

RSK

027

Y6 :

RSK

025

Y6 :

RSK

024

G4 : R

SK

023

A

12 :

RS

K022

G6 :

RS

K021

G2 :

RS

K016

Y9 :

RSK

014

Y9 :

RSK

068

Y9 :

RSK

050

A12 :

RS

K047

G4 :

RS

K046

G4 :

RS

K045

Y6 :

RSK

008

Y9 :

RSK

042

Y6 :

RSK

041

Y9

: R

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Y9 :

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039

A12 :

RS

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Y6 :

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048

Y9 :

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061

Y9 :

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059

G6 : R

SK

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Y9 :

RSK

057

A12

: R

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Y9

: R

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Y9 :

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001

Y9 :

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065

Y9 :

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Y9

: R

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Y9 :

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062

Y9A

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S6K7

066

Y9 :

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R s.

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e Page 82



Risk and Issues – Residual Heat Map (after mitigation) cont….



Buy back is rejected by Licence

Holders and Government required to

use alternate measures for removing

high security entitlements from

Lower Darling.

Impacts to threatened species due to

altered hydrology.

No certainty for funding for ongoing

O&M costs.

Impact on recruitment success from

waterbird breeding and frog

breeding.

Changes to water levels impact

feeding and roosting of waterbirds

(including international migatory

species)

Elevated water levels in Menindee

Lake adjacent to the empty Lake

Cawndilla leading to salinization

nearby (including within Lake

Cawndilla),

Potential for sediment to be

generated in channels

Impact of clearing operations on

threatened ecological species or

endangered ecological communities

Concern that the environment of the

Lower Darling, the Lakes and the

Anabranch will be less valued than

downstream environments;

EIS identifies endangered fauna/flora

and require acquisition of significant

off-sets. Location and agreement of

offsets have the potential to delay

project and increase costs.

Page 83

G4

: RS

K06

9

A12 : R

SK

055

Y9 :

RSK

037

Y9 :

RSK

036

Y9 :

RSK

035

Y9 :

RSK

034

Y9 :

RSK

033

Y9 :

RSK

030

Y6 :

RSK

029

Y6 :

RSK

028



Page 83

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,



Page 84

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.



Page 85

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.



Page 86

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.



Page 87

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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An overall 30% contingency factor of Prime Costs has been used in this phase of the business case, which

compares to overall 25% and 15% contingency margins usually applied by NSW Public Works for the full concept

and detailed design phase cost estimates respectively.

A key recommendation is to conduct a contingency assessment as the project develops in detailed design to

provide cost estimate figures and corresponding likely probabilities/confidence levels of not being exceeded (Monte

Carlo type analysis).

Currently all construction estimates have been made based on good weather conditions with no significant

delays and no other latent site defects. It would be expected that adverse weather conditions would be

expected to be funded from the contingency provision.

What is not expected to be covered by the contingency allowance is construction to be undertaken in “Wet”

conditions.

In addition to wet weather, it is possible that construction may be required to be carried out in the “wet”.

Currently all project costs have been assumed to have been based on construction taking place in the “dry”.

Construction in the “wet” includes a number of additional activities such as, the construction of coffer dams and

significant dewatering of the sites. The time taken to deliver projects will also be significantly higher. The additional

costs of developing the structures in the “wet” is significant and would add between 30% and 300% to the

construction costs of the various elements of the proposal and have a material impact on the total cost / benefit

results for the project.

To mitigate the cost impact of the potential “wet” construction costs the recommended approach will be to adjust

the project plan according to the prevailing site conditions nearer to construction and delay construction if

possible until “dry” conditions return. This will have the effect of delaying a proportion of the water savings until

construction can be carried out but will result in significantly lower overall costs of the project.

Alternately the construction can be undertaken in the “wet” if the benefits are considered significant enough to

justify the amended cost/benefit.

14.4 4 S tructural Adj ustme n t Cost s

Additional costs for structural adjustment package for the Lower Darling will largely be determined by the

Commonwealth after discussions with the relevant licence holders in the Lower Darling and have not been

assessed at this time.

TABLE 22: STRUCTURAL ADJUSTMENT PROVISIONS



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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

$100

$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

Mill

ions



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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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FIGURE 15: KEY MILESTONES FOR PROJECT

15.2 2 Pr o ject Sc hedu le

The implementation timeframe is heavily influenced by two key activities being:

Environmental planning and approvals (including stakeholder engagement)

Conditions for construction (dry or inundated)

The Environmental Planning and Approval process is a gateway activity that requires finalisation prior to awarding a

contract for construction. This activity impacts the schedule in terms of time to complete the EIS and time to

implement resultant management actions prior to construction activities commencing. A scoping study will

establish the extent of general and specialist studies required and refine the estimated time to complete. The

resultant management measures may require further invasive testing and test pitting prior to construction to

assess the likelihood and significance of aboriginal heritage within the area. These two items are critical path

activities and are yet to have a full investigation undertaken. A conservative approach has been adopted for

estimation of timeframes which is consistent with industry best practice at this stage of project development.

Construction conditions, in particular the scenario of either dry or inundated conditions, is a ‘extreme’ risk to the

schedule and budget. The schedule incorporates a ‘dry’ construction program with risk to time and cost included

in the detailed risk register. Whilst construction activities can be undertaken in inundated conditions, there is a

cost premium for alternative construction methods (coffer dams/dredging etc) and a time for alternative site set-

ups.

Table 24 below lists the milestones for the project, along with their estimated completion timeframe.

TABLE 24: ESTIMATED PROJECT MILESTONES

Milestones Estimated

Completion Timeframe

Phase 4a: Planning & Approvals

Detailed project Plan February 2018

Basis of Design March 2021

Planning Approvals November 2020

EOI August 2020

ECI & Finalise Tender Documentation July 2021



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Milestones Estimated

Completion Timeframe

RFT/Award Contract December 2021

Phase 4b: Detailed Design & Construction

Detailed Design May 2022

Construction and testing July 2023

Commissioning and Handover September 2023

15.2.1 Project Resourcing – Phase 4a & 4b

Client side resourcing requirements for Phase 4 have been assessed for each component of the Project;

this includes project management and administration, procurement, contract management, legal,

intergovernmental and stakeholder engagement. The resourcing requirements are reflected in the Project budget

and early guidance of requirements in Figure 16.

FIGURE 16: EARLY ESTIMATES OF FTE REQUIREMENTS



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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



Page 101

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.




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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 3 – RISKS AND ISSUES – RISK REGISTER

IDENTIFICATION INHERENT RISK ANALYSIS TREATMENT AND RESIDUAL RISK EVALUATION

Risk ID Risk Title Risk Description Risk Category Inherent Risk

Likelihood

Inherent Risk

Consequence

Inherent Risk

Rating

Risk Treatment / Actions to Mitigate Residual Likelihood Residual

Consequence

Residual Risk

Rating

RSK002 Program Scope changes increase cost of project Budget

significantly beyond the contingecy allowance.

Possible Major A12 Early en gagement of PW and other advisors used to Unlikely refine scope for necessary measures and design

concepts. Outcome of EIS findings for enviro an d

heritage impacts will impact final req'ts.

Moderate Y6

RSK003 Third Party Impacts Potential to undersize or oversize design Budget

elements.

Possible Moderate Y9 Multi stage process used to refin e the necessary Possible measures and design concepts.

Moderate Y9

RSK004 Costs Potential to exceed construction budget, if Budget

construction constraints are not managed.

Possible Moderate Y9 Commercial terms to be developed during pre- Possible

tender phase to ensure appropriate risk sharing

is included in final contractual documentation.

Moderate Y9

RSK005 Program Project currently assumes sequential program Budget

to reduce regret cost. Pressure to bring program

forward will increase the likelihood of regret

costs and need to re-do some activity if scope

changes.

Possible Major A12 Continue to monitor deadline requirements. Possible

Ensure that bulk of activity is targetted for

completion under dry conditions prior to EOY

2024.

Major A12

RSK006 Stakeholders Budget has been constructed in real dollars. Budget

Final nominal project costing will be significantly

higher and is largely subject to agreement on


Almost Certain Major R20 Ensure that all funding parties are made aware Unlikely

of the 'real' pricing used in project. Where

possible, lock contracts in place with fixed

pricing with limited escalation clauses.

Minor G4

RSK007 Program A significant body of work has already been Budget

undertaken (particularly environment). Budget

assumes that some benefit will be derived in

time/cost from use. Budget will be negatively

impacted if prior body of work is not used or no longer relevant.

Likely Moderate A12 Two phase EIS process to be used to narrow Unlikely

down scope of additional work required. EIS

scoping phase to provide listing of known

previous bodies of work in relation to Menindee

works.

Moderate Y6

RSK009 Costs Risks associated with wet construction costs will Budget

be high. Contractual risk sharing will need to be

considered carefully to avoid having the full cost

embedded in the base price

Almost Certain Major R20 Early Contractor Involvement (ECI) to be used Possible

prior to the formal tender process to identify

significant contractor risks and appropriate cost

sharing mechanisms.

Moderate Y9

RSK020 Water Licences Websters Limited (Tandou) currently have a Budget

zero value supplementary licence available.

Government have previously purchased a


Possible Major A12 Treatment of zero share licence and Unlikely

relationship with prior purchase (if any) to be

resolved.

Negligible G2



Risk Register Cont…



Likelihood

Inherent Risk

Consequence

Inherent Risk

Rating


Consequence

Residual Risk

Rating

RSK055 Water Licences Buy back is rejected by Licence Holders and Budget

Government required to use alternate

measures for removing high security

entitlements from Lower Darling.

Possible Severe R15 Develop stuctural adjustment strategy and Likely

engage the Licence Holders as early as possible.

Fall-back position will be to have licence holders

accept alternate measure to convert licences

from high security entitlement.

Moderate A12

RSK069 Budget No certainty for funding for ongoing O&M costs. Budget Likely Moderate A12 O&M provisions to be identified early. Unlikely

Confirmation required on where assets will be vested

and whether funding will be by way of

return on RAB or externally provided.

Minor G4

RSK010 Community Concerns Perception of waste, due to duplication of Communication

previous work already carried out and

representations made.

Likely Moderate A12 Engage sufficient resources to manage comms Possible

plan and stakeholder engagement process.

Moderate Y9

RSK011 Stakeholders Key stakeholders are not clearly identified and Communication re-

engaged at an early enough stage in the

process and actively campaign against the

project.

Likely Severe R20 Engage sufficient resources to manage comms Possible


Broader stakeholders to be provided with

regular communications.

Moderate Y9

RSK012 Community Concerns Perceptions that evaporation occurring Communication

elsewhere in the basin is not being addressed,

and that Menindee Lakes is being unfairly

targeted.

Almost Certain Moderate R15 Refer broader basin plan issues back to Likely

appropriate authority to provide response.

Moderate A12

RSK013 Stakeholders The benefits arising from estimated SDL offsets, Communication

environmental benefits and basin plan

objectives have not been clearly articulated to

all stakeholders.

Likely Moderate A12 Engage sufficient resources to manage comms Possible


Moderate Y9

RSK015 Operating Rules EIS consent conditions recommend works Dependency

and/or operating rules that reduce the overall

water saving benefits.

Almost Certain Severe R25 Project to only proceed based on acceptable Possible

level of cost/benefits.

Major A12

RSK017 Third Party Impacts Third party approval process have significant Dependency

potential to delay project program.

Likely Severe R20 Sufficient time has been allowed for in the Possible

project plan for necessary responses from

authorities, public and other significant

stakeholders.

Moderate Y9






Likelihood

Inherent Risk

Consequence

Inherent Risk

Rating


Consequence

Residual Risk

Rating

RSK018 Governance Clash between stucture of State Significant Dependency

Project framework and timelines vs stakeholder

processes

Possible Major A12 Project plan has provided sufficient time to Unlikely

meet State Significant project processes to be

met.

Minor G4

RSK019 Program Without parallel scheduling, program has no Dependency

capacity to slip due to extreme weather

conditions and still meet 2024 deadline.

Possible Severe R15 Utilise parallel scheduling where possible for Possible

geo, survey and some preliminary design works

where possible to provide a 6 month buffer for

wet weather delay.

Major A12

RSK014 Ecological – Operations Reductions in bankful and overbank flows Environment

decrease stream metabolism and affect primary

productivity in the Lower Darling River and

Great Darling Anabranch

Possible Major A12 Adverse impacts to be assessed and mitigated Possible

through extensive EIS and EMP.

Moderate Y9

RSK016 Environmental Impacts – Construction Impacts to threatened species during Environment


Possible Moderate Y9 Adverse impacts to be assessed and mitigated Unlikely

through extensive EIS and EMP. Requirement

for Construction Contractors to develop suitable

management plan to remove impact on

threatened species during construction.

Negligible G2

RSK021 Community Concerns Operation changes create negative impacts on Environment

Kinchega National Park

Possible Moderate Y9 Adverse impacts to be assessed and mitigated Possible

through extensive EIS and EMP.

Minor G6

RSK022 Community Concerns Operation changes impacts on Wetting & Dying Environment

cycles of the Menindee Lakes

Almost Certain Major R20 Adverse impacts to be assessed and mitigated Likely

through extensive EIS and EMP. Some long term

changes to flora/fauna inevitable due to

changes in cycles.

Moderate A12

RSK023 Ecological – Operations Fish management act will trigger requirement Environment

for fish passage structures at each of the new

works and potentially the existing main weir.

Almost Certain Moderate R15 Include cost of fish passage in concept designs. Unlikely Minor G4

RSK024 Ecological – Operations Death of trees due to lack of flooding. Environment Almost Certain Moderate R15 Adverse impacts to be assessed and mitigated Unlikely

through extensive EIS and EMP

Moderate Y6






Likelihood

Inherent Risk

Consequence

Inherent Risk

Rating


Consequence

Residual Risk

Rating

RSK025 Ecological – Operations Risk to Black Box-Coolabah as listed Endangered Environment

Ecological Community.

Possible Major A12 Adverse impacts to be assessed and mitigated Unlikely


Moderate Y6

RSK027 Ecological – Operations Rapid rises during filling events may drown Environment

emergent species & rapid rate of draining may

expose aquatic species.

Likely Moderate A12 Adverse impacts to be assessed and mitigated Unlikely


Moderate Y6

RSK028 Ecological – Operations Impacts to threatened species due to altered Environment

hydrology.



Moderate Y6

RSK029 Ecological – Operations Impact on recruitment success from waterbird Environment

breeding and frog breeding.



Moderate Y6

RSK030 Ecological – Operations Changes to water levels impact feeding and Environment

roosting of waterbirds (including international

migatory species)

Likely Major R16 Adverse impacts to be assessed and mitigated Possible


Moderate Y9

RSK033 Ecological – Operations Elevated water levels in Menindee Lake Environment

adjacent to the empty Lake Cawndilla leading to

salinization nearby (including within Lake

Cawndilla),



Moderate Y9

RSK034 Ecological – Operations Potential for sediment to be generated in Environment

channels


through extensive EIS and EMP. Operational

plan to be developed to manage sediment build-

up in channels.

Moderate Y9

RSK035 Environmental Impacts – Construction Impact of clearing operations on threatened Environment

ecological species or endangered ecological

communities

Possible Major A12 Adverse impacts to be assessed and mitigated Possible


Moderate Y9






Likelihood

Inherent Risk

Consequence

Inherent Risk

Rating


Consequence

Residual Risk

Rating

RSK036 Community Concerns Concern that the environment of the Lower Environment Possible

Darling, the Lakes and the Anabranch will be

less valued than downstream environments;

Moderate Y9 Adverse impacts to be assessed and mitigated Possible


Moderate Y9

RSK037 Community Concerns EIS identifies endangered fauna/flora and Environment Likely

require acquisition of significant off-sets.

Location and agreement of offsets have the

potential to delay project and increase costs.

Major R16 Adverse impacts to be assessed and mitigated Possible


Moderate Y9

RSK008 Stakeholders 3rd parties raise injuction against any or all of Governance, Legal & Possible

the project procesing. Regulatory

Severe R15 Early & active engagement of community Unlikely Moderate Y6

RSK045 Legal Landowners are reluctant / unwilling to permit Governance, Legal & Possible

easements on title for levee construction. Regulatory

Moderate Y9 Negotiations to take place early during project. Unlikely Agreement to create easement sought by way of

option or other instrument. In ducement paid as

part of early option. Fallback to use compulsory

acquistion powers.

Minor G4

RSK046 Legal Change of ownership of properties in Lower Governance, Legal & Possible

Darling occurs and new owners do not honour Regulatory

option for licence buy-back & impairment of

works approvals.

Major A12 Caveat to be placed on title at time of Unlikely

negotiating option to buy-back. Caveat to be

removed if project does not proceed.

Minor G4

RSK047 Legal Intra state institutional arrangements pose Governance, Legal & Likely

constraints on the project that threaten the Regulatory

projects viability

Major R16 Identification of approvals needed and Possible

associated drafting to be undertaken as early as

possible.

Major A12

RSK050 Consent Authorities Interstate institutional arrangements pose Governance, Legal & Likely

constraints on the project that threaten the Regulatory

projects viability

Major R16 Identification of approvals needed and Possible

associated drafting to be undertaken as early as

possible.

Moderate Y9

RSK068 Stakeholders Concerns that inter-jurisdictional stakeholders Governance, Legal & Possible

aren't adequately consulted and engaged Regulatory during

the project leading to delays during final

approval processes.

Major A12 Engage all inter-jurisdictional stakeholders early Possible

include requirements in communications plan.

Moderate Y9






Likelihood

Inherent Risk

Consequence

Inherent Risk

Rating


Consequence

Residual Risk

Rating

RSK039 Community Concerns Project is unable to meet all of the aspirations Heritage

of Native Title Owners / local / wider aboriginal

interests.

Likely Major R16 Engage with aboriginal interest groups early and Possible

seek input into possible heritage concerns.

Moderate Y9

RSK040 Heritage Heritage concerns and located artifacts Heritage

providing potential to delay or require major

scope changes to the project or program.

Likely Moderate A12 Engagement of Project Archaeologist throughout Possible planning and construction phases. Undertake early

extensive cultural heritage investigation in

partnership with the local Aboriginal communities.

Moderate Y9

RSK041 Heritage Concerns that the Morton Boolka regulator Heritage

would attract vistors who would collect

artefacts in the area.

Possible Moderate Y9 Engagement of Project Archaeologist to identify Unlikely likely heritage artefacts. Develop plan in

consultation with indigenious stakeh olders to

protect heritage items.

Moderate Y6

RSK042 Operational changes Increased frequency of drying could lead to Heritage

increased erosion risks potentially exposing and

damaging cultural heritage items.

Possible Moderate Y9 Engagement of Project Archaeologist to identify Possible likely heritage artefacts. Develop plan in

consultation with indigenious stakeh olders to

protect / relocate h eritage items where possible.

Moderate Y9

RSK048 Operations Potential for interested stakeholder groups to Operations

require excessive works and operations that

impose costs on the project.

Possible Moderate Y9 Develop robust stakeholder engagement Unlikely

processes that clearly specify roles and

responsibilities.

Moderate Y6

RSK051 Modelling Modelled outcomes from the inclusions of SDL Operations

package are insufficient to justify the

expenditure.

Possible Severe R15 Project is unlikely to proceed until sufficient SDL Possible

benefit is available vs the expenditure.

Major A12

RSK052 Community Concerns Removal of Old Menindee Town Weir is resisted Political

by community.

Possible Moderate Y9 Early community consultation on need to Possible

remove weir to gain most long term benefit.

Moderate Y9

RSK053 Community Concerns Property values in Menindee and other related Political

townships decrease due loss of amenity and/or

economic activity from buy-back of Lower

Darling licences and changes to operations.

Almost Certain Moderate R15 Review options to provide structural adjustment Likely

package to Menindee township.

Moderate A12






Likelihood

Inherent Risk

Consequence

Inherent Risk

Rating


Consequence

Residual Risk

Rating

RSK001 Water Licences The assumed impacts of the changes to licence Political Possible

entitlements is broader than expected and the

planned structural adjustment package is


Severe R15 Modelling is required to confirm reliability Possible

changes for all water entitlement holders that

remain and quantify any impacts.

Moderate Y9

RSK057 Community Concerns Community feels previously raised Political

Likely concerns/issues have

been ignored.

Moderate A12 Specialist to be engaged for the development of Possible

comprehensive comms and community

engagement plan.

Plan to clearly address why (if any) community

issues not addressed.

Moderate Y9

RSK058 Stakeholders Upstream communities try to link otherwise Political Possible

unrelated issues to the project and threaten its

viability.

Major A12 Communication plan to clearly outline the Possible

savings relate to agreements under the basin

plan.

Minor G6

RSK059 Community Concerns Potential action by residents of Sunset Strip & Political Almost Certain

Copi Hollow based on the perceived reduction

in availability of water for water sports and

other recreational activity.

Major R20 Engage with local residents/users to fully Possible

understand their needs and the capacity of the

project to accommodate their.

Moderate Y9

RSK061 Community Concerns Interest groups use project to increase pressure Political Possible

to have Lake system listed with Ramsar and


Major A12 Manage stakeholder expectations through intra Possible

and inter government processes.

Moderate Y9

RSK062 Environmental Impacts – Construction Increased noise & traffic during construction Project Management Possible

phases.

Moderate Y9 Development of a memorandum of understanding Possible for monitoring of construction activities.

Moderate Y9

RSK063 Environmental Impacts – Construction Risk of flooding or inundation during Project Management Possible

construction.

Major A12 Development of a memorandum of understanding Possible for monitoring of construction activities.

Moderate Y9

RSK064 Program Significant weather event delays planning Project Management Possible

activities in project (geo, survey)

Moderate Y9 Planning activities including Geo & Survey to be Possible

undertaken as early as possible after agreement

has been reached on potential regret cost

budgets.

Moderate Y9






Likelihood

Inherent Risk

Consequence

Inherent Risk

Rating


Consequence

Residual Risk

Rating

RSK065 Program Project works are completed during dry spell in Project Management Possible

lakes and works can't be adequately tested and

commissioned.

Moderate Y9 Construction contracts to make provision for Possible

extended testing / commission period if lakes

are subject to an extreme weather event.

Moderate Y9

RSK049 Community Concerns Menindee Township & Sunset Strip concerned Stakeholder Likely

about future water quality and supply.

Moderate A12 This issue is being addressed as part of Broken Possible

Hill pipline project.

Moderate Y9

RSK066 Water Licences Total compensation paid for structural Stakeholder Likely

adjustments distorts Water Licence markets and

sets unwanted precedents.

Major R16 Recommend to Commonwealth that market Possible

price is paid for high security water licence

purchases. Any additional payments required

should reflect compensation for other impacts.

Major A12

RSK067 Community Concerns Landholders on the Anabranch are concerned Stakeholder Likely

that installation of regulators could lead to

poorer ecological & socio-economic outcomes

in the Anabranch, & fear that the Anabranch

regulators will be used to stop flows to the


Major R16 Adverse impacts to be assessed and mitigated Possible


Moderate Y9



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.

Page 115



Page 116

FIGURE 17: OVERVIEW OF PROPOSED WORKS



Page 117

TABLE 25: COMPARISON OF THE CURRENT PROSED MENINDEE PROJECT WITH THE 2013 PROPOSAL.

residents


Outcomes

Infr

ast

ruct

ure

Measure 1 Menindee outlet regulator capacity increased from 5,000ML/day.

Works to increase up to 14,000ML/day SDL supply measure, and Constraints Management

Measure 2 Lake Menindee drainage channel to feed outlet and improve discharge

Drainage channel up to 14,000ML/day SDLsupply measure

Measure 3

Morton-Boolka transfer regulator to control

releases to and from Menindee and

Up to 14,000ML/day regulator SDLsupply measure

Measure 4

Cawndilla

Old Menindee Town Weir removal

Removal of redundant Menindee town weir to improve

Menindee outlet regulator flows by reducing downstream


Measure 5, 6 &

Increased Lower Darling channel capacity to

head

Two regulators to prevent escape flows into Yartla Lake


11 take higher Menindee discharge – offtake and Emu Lake + bridge at Charlie Stone Crossing Constraints Management

Measure 7

Measure 8 & 9

regulators at Emu Lake and Yarta Lake

Cawndilla Creek Regulator

Anabranch offtake regulators constructed

Up to 14,000ML/day regulator

New Anabranch diversion regulator #1 to control up to

14,000ML/day




New Anabranch environmental Regulator #2 to control up

to 1,000ML/day, and Dam183 road bridge, regulator, and


Lake Nearie Nature Reserve

Measure 10

Works to facilitate fish passage at Menindee

Main Weir

fishway

No change to hydrology but fishway on Main Weir included

in costings

Measure 12

Flood protection measures for Menindee

Construction of Menindee town high flow levee bank




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Measure 13 Lower Darling constraints mitigation -

landholders stock and domestic & some

irrigation pump infrastructure.

Assumption holds. Works now protect and maintain

capacity of pumps during high flow events (ie : floating

suctions, on farm storage and / or groundwater options)




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Outcomes St

ruct

ura

l

Ad

just

ment

Measu

res

Measure 14

Acquisition of Lower Darling and Tandou

water entitlements

Purchase all Tandou entitlements and purchase or convert

Lower Darling HS entitlement.


mechanism

Chan

ges to

Opera

tin

g R

ule

s an

d A

gre

em

ents

Measure 15

Menindee System control transfer rule

(between NSW and the MDBA) and storage

drawdown sequencing

No control transfer in place – MDBA to assume full control

of Menindee on understanding 80GL Wetherell reserve is

retained for riparian demands to end of following year.

SDL supply measure

Measure 16

Broken Hill Entitlement

10,000M TWS entitlement shifted to Murray upstream

SDL supply measure

Wentworth.

Measure 17 Capacity for additional E-flows into Lake

Cawndilla

Potential use of Environmental account water to inundate

key assets in addition to natural events. Environmental mitigation

Measure 18

Improved operations of the River Murray

connected system

Proposed recalibration of the SDL Projects Pack OPLOSS

regression equation to better reflect current operating

environment

SDL supply measure

Measure 19

Lake Wetherell drying cycle



Measure 20 Broken Hill TWS system – alternate supply Pipeline from Murray River @ Wentworth SDL supply measure




Outcomes

O

ther

Measu

res Measure 21 Recognition of additional Northern basin

inflows to Menindee Lakes from Basin Plan

environmental recovery

Formally recognise the additional inflow and make callable

from a separate account

Supply measure

Measure 22 Limited temporary general security trade to

the Lower Darling subject to resource

assessment

Will be reflected in water planning rules

Basin Plan dealing rules



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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.



Page 121

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.



Page 125

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.



Page 126

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.



Page 127

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.



Page 128

APPENDIX 5 – MENINDEE PROJECT COSTINGS

TABLE 26: MEASURE 1 – ENLARGED MENINDEE REGULATOR (PRIME COSTS)

Source: NSW Public Works



Page 129

TABLE 27: MEASURE 2 – MENINDEE DRAINAGE CHANNEL (PRIME COSTS)




Page 130

TABLE 28: MEASURE 3 – MORTON-BOOLKA REGULATOR (PRIME COSTS)




Page 131

TABLE 29: MEASURE 4 – OLD MENINDEE TOWN WEIR REMOVAL (PRIME COSTS)




Page 132

TABLE 30: MEASURE 5 – EMU LAKE OFFTAKE REGULATOR (PRIME COSTS)




Page 133

TABLE 31: MEASURE 6 – YARTLA LAKE OFFTAKE REGULATOR




Page 134

TABLE 32: MEASURE 7 – CAWNDILLA CREEK REGULATOR (PRIME COSTS)




Page 135

TABLE 33: MEASURE 8 – DARLING ANABRANCH OFFTAKE REGULATOR (PRIME COSTS)




Page 136

TABLE 34: MEASURE 9 – DARLING ANABRANCH E-FLOW REGULATOR (PRIME COSTS)




Page 137

TABLE 35: MEASURE 10 – MAIN WEIR FISHWAY (PRIME COSTS)



Page 138

TABLE 36: MEASURE 11 – 183 DAM REGULATOR, ROAD BRIDGE & FISHWAY (PRIME COSTS)




Page 139

TABLE 37: MEASURE 12 – MENINDEE TOWN FLOOD PROTECTION WORKS (PRIME COSTS)




Page 140

TABLE 38: MEASURE 13 – LOWER DARLING CONSTRAINTS MITIGATION WORKS (PRIME COSTS)



Page 141

APPENDIX 6 – ENGINEERING CONCEPT DESIGN DRAWINGS AND SPECIFICATIONS

FIGURE 18: MEASURE 1 – MENINDEE REGULATOR – AERIAL VIEW



Page 142

FIGURE 19: MEASURE 1 – MENINDEE REGULATOR – SIDE VIEW



Page 143

FIGURE 20: MEASURE 2 – MENINDEE CHANNEL – CROSS SECTIONS 1



Page 144

FIGURE 21: MEASURE 2 – MENINDEE CHANNEL – CROSS SECTIONS 2



Page 145

FIGURE 22: MEASURE 3 – MORTON-BOOLKA REGULATOR



Page 146

FIGURE 23: MEASURE 8 – DARLING ANABRANCH OFFTAKE REGULATOR



Page 147

APPENDIX 7 – ENVIRONMENTAL WATER NEEDS AND WATER MGMT ARRANGEMENTS



Page 148

APPENDIX 8 – DETAILED PROJECT SCHEDULE



Page 149

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?



Page 150

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



Page 151

APPENDIX 10 – INTERIM PROJECT PROPOSAL – APRIL 2017

Menindee Lakes Notification - Attachment B

Menindee Lakes

Interim Project Proposal


Blackwatch Consulting Pty Ltd

37 Avenue Rd Mosman NSW 2088

0409164566

[email protected]

This document is and shall remain the property of Blackwatch Consulting. The document may only be used for the purpose for which it was

commissioned and in accordance with the Terms of Engagement for the commission. Unauthorised use of this document in any form

whatsoever is prohibited.

Document Status

Status Version Date Author Reviewed Date Approval

Table of contents 1 12th April 2017 BT DPI 12th April 2017

Preliminary Draft 1 18th April 2017 BT DPI - DJ 19th April 2017

Draft 2 22nd April 2017 BT BH 23rd April 2017

Draft 2.1 23rd April 2017 BT DPI 23rd April 2017

Draft 2.3 25th April 2017 BT DPI 26th April 2017

Final 2.4 26th April 2017 BH DPI 26th April 2017

Final (Amended) 2.41 1st May 2017 BH DPI - GH 1st May 2017

© Blackwatch Consulting Pty Ltd

Interim project proposal - modelling submission V2.41_FINALclean

mailto:[email protected]


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



2. Executive Summary

Previous studies over a long period have focused on the need to save water at Menindee by reducing the evaporative surface area

of Menindee Lakes. Prior studies have mostly focused on increased release rates, new outlet paths and tightening up sequential

releases from the four lakes. However, the various proposals to date have failed to overcome the many constraints which limit our

capacity to capture water savings.

The current package of works proposed for Menindee builds on previous submissions and model runs but introduces some new

works and measures which address the key limitations. The package represents a more balanced approach, incorporating a wider

range of infrastructure, operations, regulatory and adjustment options which in combination will deliver greater water savings and

value for money.

In broad terms, the package now includes :-

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

Confirmation that Broken Hill’s Town Water Supply will be secured 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

Maximum offsets and savings are only achieved through the integrated package. Withdrawal of individual elements has implications

for other aspects of the proposal, and in some cases renders the project unviable. For example, the benefits from constructing the

enlarged Menindee outlet regulator cannot be fully realised without related works upstream (Menindee lake drainage channel) and

downstream (Menindee Town weir removal). Similarly, the institutional changes allowing removal of transfer triggers and changes

to Lake management arrangements, are only possible when high security demand on the Lakes from Broken Hill TWS, Tandou and Lower

Darling irrigators have been resolved – thus making the structural adjustment package and the Broken Hill pipeline essential for success.

The purpose of this report is to provide details of the proposed new package; a comparison of how this package relates to

previously notified Menindee proposal, recommendations in relation to the modelling approach required to capture the changes

and a governance framework for ongoing intergovernmental discussions of project refinement, focussing on those elements of

the proposal that relate to the MDB Agreement and other jurisdictions, particularly in regard to reliability and ongoing water supply

requirements. A brief analysis of key risks and issues is also provided for each element of the package.

This document outlines the key parameters of the amended Menindee supply and constraint measure. Following submission of

this interim Menindee proposal, the MDBA will be required to confirm that sufficient



modelling direction is provided to ensure inclusion of this proposal in the MDBA June 2017 interim advice. Following this, an

amended notification document will be developed taking into account the advice from the MDBA for BOC consideration by mid-June

2017 for the purposes of notification by 30 June 2017.

Additionally, Business Case document which addresses Phase 2 guideline requirements will also be provided at this time, which will

reflect initial input from the proposed Menindee Project SDL inter-governmental working group. Business case issue resolution and

confirmation of the proposal is anticipated to occur in mid- September 2017, to be informed by the MDBA modelling of the full

package, the Menindee Lakes Water Savings Project Intergovernmental Working Group advice and discussions of River Murray

Framework changes.



3. Background

The Menindee Lakes are a significant natural, cultural and economic resource for Australia. The Lakes are an integral asset in the

Murray-Darling system, encompassing areas of significant environmental and heritage importance; supplying towns and irrigation

along the Murray and Lower Darling rivers; and providing recreational amenity and tourism opportunities for the region.

The Lakes were significantly modified in the 1950’s and 1960’s to improve water availability and security for Broken Hill, irrigated

agriculture in SW NSW and for managing South Australian entitlement flows. The regulated storage system now consists of

four main interconnected lakes – three of these being modified natural depressions and one artificial lake along the main river

channel.

The Menindee operating environment is dominated by high evaporative losses, long periods of zero inflows, and significant base

salinity inputs from the Barwon-Darling system. With average evaporative losses in the order of 425 gigalitres (GL) per annum, there

have long been calls for infrastructure and operating improvements to reduce water losses.

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 elements of which were captured in Model Run 35 and formed the basis for the

Menindee supply and constraints proposal included in the package of measures notified in May 2016 (DPI Water, 12 May 2016)

The current proposal builds on previous investigations and proposals, now incorporating changes and additions based on issues

identified during the millennium drought and through broader stakeholder engagement. The proposal provides for an integrated

suite of infrastructure works, rules changes, operating changes, structural adjustment measures and environmental offsets which in

combination seek to maximise water savings available for Basin Plan outcomes, whilst ensuring local environmental values are not

unduly compromised. An amended notification, reflecting the new scope of this proposal, will be provided for BOC consideration by

mid-June 2017, with further amendments to be made post-notification if required. It is proposed that these changes would be

made in mid-September 2017.


Figure 1 – Location overview of Menindee Lakes system


Figure 2 – Overview of proposed works

Figure 3 – Satellite Imagery of Menindee Lakes System


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.



Table 1 – Reconciliation of changes to the Menindee Lakes package of works and measures

Category Feature Run35 Current Proposal Basin Plan Outcomes

Infrastructure A. Morton-Boolka transfer regulator Up to 14,000 ML/d regulator No Change SDL supply measure

to control releases to and from Menindee and Cawndilla

B. Lake Menindee drainage channel to feed outlet and improve discharge

Some assumed improvement in drainage captured in outlet rating curve

Drainage channel up to 14,000 ML/d SDL supply measure

C. Cawndilla Creek Regulator

Not included

Up to 14,000 ML/d regulator


D. Menindee outlet regulator Works to increase up to 14,000 ML/d No Change SDL supply

capacity increased from measure, and 5,000ML/d Constraints

Management

E. Increased Lower Darling channel capacity to take higher Menindee

No works included in prior submissions but assumptions made in modelling that

Two regulators to prevent escape flows into Yartla Lake and Emu Lake + bridge at


discharge – offtake regulators at Emu Lake and Yarta Lake

F. Anabranch offtake regulator constructed

constraints would be lifted

Works (regulator) to exclude up to 14,000 ML/d

Charlie Stone Crossing

New Anabranch diversion regulator #1 to control up to 14,000 ML/d

New Anabranch environmental Regulator #2 to control up to 1,000 ML/d, and Dam183 roadbridge, regulator, and fishway

Constraints Management SDL supply measure, and Constraints Management

Environmental mitigation Environmental mitigation Lake Nearie Nature

Reserve



G. Broken Hill TWS system – alternate supply

Assumed groundwater / desal supply required when HS fully restricted

Pipeline from Murray River @ Wentworth SDL supply measure

H. Old Menindee Town Weir removal to improve Menindee outlet regulator flows by reducing downstream head

No included Removal of redundant Menindee town weir


I. Lower Darling landholders stock and domestic pump supplies

No inclusion of costs but assumption in modelling would be fixed

Assumption holds. Works now protect and maintain capacity of pumps during high flow events (ie : floating suctions)


J. Flood protection measures for Menindee residents

K. Works to facilitate fish passage at Menindee Main Weir

Not included Construction of Menindee town high flow levee bank

Not included as no impact on modelling No change to hydrology but fishway on Main Weir included in costings


L. Menindee System control transfer rule (between NSW and the MDBA) and storage drawdown sequencing

615GL/275GL triggers. Residual 275GL stored in Wetherell and Pamamaroo - No MDBA orders supplied when 275GL or less.

No control transfer in place – MDBA to assume full control of Menindee on understanding 80GL Wetherell reserve is retained for riparian demands to end of following year.

SDL supply measure

M. Broken Hill Entitlement Entitlement retained from Darling via Menindee + supplementation from groundwater

10,000 ML TWS entitlement shifted to Murray upstream Wentworth.

SDL supply measure

N. Capacity for additional Eflows into Lake Cawndilla

O. Improved operations of the River

Murray connected system

Commence Cawndilla filling only when Bourke exceeds 600GL/Mth and >3yrs return interval.

Benchmark OPLOSS regression model calibrated with data pre-2000, not recognising changes since millennium drought and underestimating Lake Vic

airspace Potential use of Env account water to inundate key assets in addition to natural events.

Proposed recalibration of the SDL Projects Pack



OPLOSS regression equation to better reflect current operating environment


SDL supply measure

P. Lake Wetherell drying cycle Informal annual drying cycle to protect trees





Category Feature Run35 Current Proposal Basin Plan Outcomes


Q. Acquisition of Lower Darling and Tandou water entitlements

Pro-rata water recovery of entitlement based on Basin Plan age recovery = 9GL reduction IVT

Purchase all LD HS and Tandou entitlement and no IVT.

Structural adjustment mechanism

Additional northern basin inflow

R. Recognition of additional northern basin inflows to Menindee Lakes from Basin Plan environmental recovery

Additional water modelled as increased default shares to NSW and Victoria

Formally recognise the additional inflow and make callable from a separate account

Supply measure

Trade S. Limited temporary general security trade to the Lower Darling subject to

Not included Will be reflected in water planning rules Basin Plan dealing rules

Works measures

and

resource assessment

T. Lake Pamamaroo Drainage channel to

capture dead storage

Drainage channel in scope N/A – works removed from scope N/A

U. Penellco Channel increased capacity to service Tandou

Increased capacity to 2,000 ML/d channel and pumps

N/A - Works removed from scope N/A



5. Details of Revised Scope to inform revised modelling

The following chapter expands on the summary contained in Chapter 4, in order to inform the revised modelling effort. Only

those works and measured proposed to be carried forward in the revised Menindee package are included.

A. Morton-Boolka Regulator

i. 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. In effect this will reduce the average volume of water released into Cawndilla to only that

required to periodically maintain environmental values (see section N). These works are central to achieving the water

savings for the Menindee Project and therefore critical to project success.

ii. Brief Description of works (if any)

Scope includes a new regulator capable passing flows of at least half the peak inflows from Copi Hollow. Structure to

include adjacent levee banks 8 dual-leaf gates, 3m wide x 4.95m high

iii. Change from prior submissions

No change is proposed from previous modelling undertaken for Runs 35. The structure will be designed to pass flows

of up to 14,000 ML/d.

iv. Model Parameters

No additional model changes required.

v. Key assumptions, risks and issues

Key risks for this component of the package relate to environmental and heritage management and approvals.

Firstly, the preferred location of the regulator presents a significant risk of uncovering heritage artefacts and this will

make approvals more difficult and (potentially) project costs higher than normal. There is some risk the location may be

deemed unacceptable, however the draft designs and configuration have attempted to minimise disturbance where possible

to reduce this risk.

Secondly, Lake Cawndilla incorporates parts of Kinchega National Park. The upper bound of savings possible from

decommissioning Cawndilla as a regulated storage may be attenuated by a requirement



to periodically inundate the Lake, unless separate environmental entitlement is secured to achieve same.

Finally, as with all Menindee works, there are construction risks resulting from the potential inundation of the site, although

construction methods can overcome this risk to a large extent.

B. Lake Menindee Drainage channel to outlet regulator

i. 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.


Scope involves construction of a channel bed of varying width approximately 8,991m long and up to 9m in depth.


Model Run 35 incorporated some changes to outlet rating curves however some additional work may be necessary to capture

higher flow rates at bottom end of discharges.


Menindee outlet discharge curves to be reviewed in light of new Public Works Hydraulic model, based on 14,000 ML/d channel

and outlet works.


Key risks will include approvals and construction risk.

In the project planning stage the significant risk of uncovering heritage artefacts will prolong the approvals process

and potentially add consent conditions that increase the cost of works above comparable works in non-sensitive areas.

Construction risk results from working in the lake bed. Preliminary concept designs show substantial cost differentials

between wet and dry construction and the risk of complete demobilisation due to



flooding will be ever present. Furthermore, geotechnical investigations have not yet been undertaken so the risk of unsuitable

ground conditions remains until proven otherwise.

Operationally, a key risk will be maintenance of channel capacity due to likely siltation. Periodic maintenance will be

required to ensure capacity is not constrained.

In terms of key assumptions, the capacity of this channel is clearly linked to decisions in relation to the Lake Menindee outlet

capacity and subsequent downstream structures.

C. Cawndilla Creek Regulator

i. 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).


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 form part of the consent conditions. Scope includes a regulator (incl.

adjacent levee banks 6 dual-leaf gates) 3m wide x 4.61m high.


Model Run 35 made no provision for these works. Proposed change is to construct a regulator with a capacity of up to 14,000

ML/d.


No additional model changes required. Held environmental entitlements/account water to be used.




In light of issues raised during stakeholder engagement to date, the project team is anticipating that the construction of this

regulator will form part of the consent conditions for the Menindee project.

Key risks are comparable with that of the Morton-Boolka regulator, being the issues arising during the process of environment

and heritage approvals and to a lesser extent construction risks.

D. Menindee outlet regulator

i. Objectives

The objective of these works is to :-

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

remove a major operational constraint for achieving lower Murray Basin Plan flow targets.


The proposal is to replace the existing limited capacity pipe outlet of approximately 5,000 ML/d maximum flow with a

more substantial gated structure capable of passing flows of up to 14,000 ML/d under low driving head conditions.

Scope includes a 14,000 ML/d structure (incl. outlet channel sections and downstream creek widening) with 5 dual-leaf gates,

3m wide x 8.15m high


Model Run 35 incorporated some changes to outlet rating curves however some additional work may be necessary to capture

the latest data from Public Works concept designs to 14,000 ML/d.



and outlet works.


The risk profile surrounding environmental and heritage approvals compared with Morton-Boolka and Cawndilla Creek is

similar even with the level of pre-existing disturbance at the location of the works. Additionally the enlarged / realigned

channel to the Darling River traverses known sites of cultural



heritage significance. Construction risks remain comparable, given the new outlet regulator is being constructed in the close

vicinity (but not the exact location) of the existing structure.

E. Lower Darling Channel capacity

i. Objectives

These works will allow flows in the Darling River channel downstream of Menindee of up to 14,000 ML/d by preventing

water from escaping at key locations; Yartla Lake and Emu Lake offtakes. These works will reduce losses under managed,

high flow conditions, helping to maximise SDL offsets by allowing operators to discharge higher volumes from Menindee to

achieve environmental flow targets in the Lower Murray. The works at Charlie Stone Creek Crossing on the Talyawalka

flood plain are necessary to allow for road access during high flow events.


Scope 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.


Previous submissions did not include these works although assumptions were made in Model Run 35 that channel capacity

constraints would be overcome.


MDBA to confirm if the loss function has already been altered to account for the impact of these works


Relaxing the constraints in the Lower Darling river from 9,000 ML/d to 14,000 ML/d involves mitigating the effects of the

relaxation on landholder practices and land.

No other special risks identified other than ones already described in other works and measures.

F. Anabranch offtake regulator

i. Objectives

Existing Menindee releases to the Lower Darling are limited to 9,000 ML/d 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 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.


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 x 2.4m high and

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 x 3.5m high; and

o a channel bed of width 6.5m and length approx. 800m; and

o a road bridge of 4m width, dual carriage approach and giveway bay; and

Works at Dam 183 o a regulator with 4 dual leaf gates, 2.1m wide x 2.5m vertical height; and

o a roadbridge of 4m width single span; and

o a vertical slot fishway of height 2.24m


Model Run 35 assumed a single regulator upgrade to enable flows of up to 14,000 ML/d to be kept out of the current

Anabranch offtake. The default model configuration is “gates fully open” but with no flows through offtake until flows exceed

14,000 ML/d.

This current proposal includes the original proposed works and in addition a second regulator of 1,000 ML/d at the Anabranch

environmental offtake.

The two regulator configuration is required to provide efficient delivery of held environmental account water and potentially

transmission flows to the Darling Anabranch over a range of flows in the Lower Darling River.


Some minor refinement of the model configuration may be required to accommodate new works.




No special risks identified other than ones already described in other works and measures.

G. Broken Hill TWS

i. Objectives

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.

NSW has adopted a Murray pipeline as the alternate supply for Broken Hill. The pipeline is currently in procurement phase

with WaterNSW, with completion set for late 2018.


Not applicable


Prior submissions assumed the TWS for Broken Hill would continue to be sourced via the Menindee pipeline, utilising surface

water from Weir 32 and Lake Menindee with groundwater supplementation towards the end of extreme drought sequences.

The new pipeline, with a point of offtake from the Murrray River at Wentworth, completely removes the Broken Hill high

security surface water demand from the Lakes system.


To model this work the Broken Hill demand should be connected to the Murray near Sunraysia and an equal sized TWS licence.

The Lower Darling licence should be deleted. This can be approximated by adding the TWS licence to NSW Sunraysia, and

scaling up the demand to have the same long term average increase as the former Broken Hill demand.


Design, approvals and procurement are now well advanced with WaterNSW following early concept development by NSW

Public Works on behalf of DPI. Construction risk is not expected to be significant in light of the proposed..



H. Removal of Menindee Town Weir

i. Objectives

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 WNSW. The existence of this redundant fixed crest weir

does however lift the height of the pool downstream of the Menindee Lake outlet, thereby reducing head differential and

limiting flows through the outlet. The objective of this proposal is to remove the weir and allow operators to extend the

duration of peak flows emanating from Lake Menindee outlet by up to 1 week. An additional benefit will be an improvement

in fish passage in the Darling River.


Removal of original Menindee town weir assumed to comprise a 2.44m high U/S steel sheet pile, D/S timber crib structure

with rockfill infill.


This measure was not included in Run35. Its inclusion will enable the modellers to factor in an extended discharge

curve for releases from Lake Menindee.



and outlet works together with improved downstream head conditions.


Notwithstanding the environmental benefits of weir removal, this proposal may encounter significant opposition from

Menindee residents who may place social amenity and historical value on retention of the weir. This would need to be

carefully considered in the EIS and approvals process.

I. Lower Darling stock and domestic supplies

i. Objectives

Increased flows in the Lower Darling as a result of this Menindee project will have an impact on private diversion points for

stock and domestic supplies along the river. The objective of this component of the package is to undertake works which

allow continued stock and domestic access for these landholders.




Not applicable


Previous submissions assumed that this constraint would be resolved but no costings were provided to undertake pump

relocation works.


No additional change proposed to the modelling.


The key concern of landholders on the Lower Darling will be riparian water security, related to the adequacy of the

proposed reserves held in Lake Wetherell. The approvals process will justifiably necessitate consultation with Lower

Darling landholders and it can be expected the issue of pump relocation will be raised in the course of these discussions

with landholders.

J. Flood protection works for Menindee town residents

i. Objectives

The intention to pass regulated high flows past Menindee to achieve lower Darling flows of up to 14,000 ML/d 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 residential properties from these managed events.


Flood protection for at least ten properties and access roads. Scope includes levees and access road raisings for a design

flood level at a flow of 25,900 ML/d (moderate flood level)


The prior submissions assumed higher Darling River flows but no allowance was made for works to manage the impacts of

these flows.






There may be some slight lowering of inundation levels with the removal of the Menindee Town Weir. Further detailed survey

and analysis is required.

No further special risks identified other than those already described in other works and measures. Management of

stakeholder expectations and concerns will be critical.

K. Menindee Main Weir Fish Passage

i. Objectives

The objective of these works is to improve fish passage in the Darling River

ii. Change from Prior Submissions

Model Run 35 made no provision for these works. The proposed change is to construct a fishway at Menindee Main weir.

iii. Model Parameters


iv. Key assumptions, risks and issues

In light of the issues raised during stakeholder engagement to date, the project team is anticipating that the provision of

fish passage through the lakes will form part of the consent conditions for the Menindee project. The NSW Fisheries

Management Act provisions will be triggered by the works associated with this project, which will necessitate consideration

of fish passage.

L. Menindee control transfer triggers and sequencing

i. Objectives

The removal of thresholds provides MDBA with increased control of the Menindee system, 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.


Not applicable




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 ). Run35 modelling assumed a continuance of (reduced) Broken

Hill, Tandou and Lower Darling demand, thereby limiting the relaxation of these thresholds 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

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 further 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.


The Model needs to be set to assume an ability to continue ordering water for the Murray until 80GL remains in Wetherell

Old Channel, after which orders will cease.


Menindee and Lower Darling stakeholders have put forward the view that an 80GL reserve in Wetherell is insufficient

security for their needs. Formal consultation is yet to take place however the project can expect some local community anxiety

over operating changes which would result in more rapid and complete evacuation of the Lakes.

M.Broken Hill entitlement

i. Objectives

With interrelated works underway to construct a pipeline supply from the Murray River for Broken Hill, agreement will also

be required on the shift of water entitlements. The component of the package will establish and model the likely operating

conditions attached to the new licence.


Not applicable




Model Run 35 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 above

Wentworth confluence.


The model needs to remove Broken Hill demand from the Darling and create a new demand node connected to the

Murray near Sunraysia. The design pipeline capacity will be up to 37ML/d.


Key risks for this component of the package will be reaching agreement on water yield and security equivalence by shifting

entitlement to the Murray.

N. Capacity for additional Eflows into Lake Cawndilla

i. 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 cultural

and environmental values by developing a regime of managed, periodic inundation of the Lake using held entitlement.


Not applicable


Modelling will assume 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.


No additional changes to the model are proposed as it is assumed that water used for these events would be sourced from

held entitlement.




In light of the issues raised during stakeholder engagement to date, the project team is anticipating that consent conditions

will require provision of environmental flows for Lake Cawndilla or a variation of this.

O. River Murray Improved Operations

i. 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.


Not applicable


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 reregulate additional water emanating from this Menindee project is

intrinsically linked to the ability of operators to reregulate 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.


DPI understands that the MDBA is currently working on a potential recalibration of the MSM.


The key risk with this issue is a failure of the modelling framework to capture the full extent of benefits arising out of key

projects such as Menindee, with associated detrimental impacts on benefit/cost ratios.



P. Lake Wetherell (floodplain) drying cycle

i. 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.


Not applicable


No provision was made for Wetherell drying cycles in prior submissions however this change can easily be accommodated in

operating protocols by allowing 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

will require provision of wetting and drying cycles for Lake Wetherell.

Q. Acquisition of Lower Darling / Tandou Entitlements

i. 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 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.


Not applicable


Prior submissions assumed a reduction (but continuance) of demand consistent with Basin Plan recovery targets.

The current proposal is predicated on drastically reducing licenced obligations other than basic landholder rights.

This component of the package is therefore fundamental to the success of the package.


This initiative should be modelled by switching off the Lake Tandou and the Lower Darling horticulture irrigation demand..


Structural adjustment will require extensive negotiations with entitlement holders involved. These negotiations will take

time and potentially may trigger Just Terms Acquisition if agreements cannot be reached. Expectations management will be a

key risk in this process.

This modelling may demonstrate a small reduction in allocation liability to the remainng licence holders (anticipated

to be less than 1GL). NSW will negotiate mitigation options with affected licence holders to increase supply in non-critical

years which do not increase overall take and are consistent with the broader Menindee project outcomes.

The project can also expect community concern about the withdrawal of irrigation, particularly from Lake Tandou. Menindee

township is heavily reliant on Tandou for employment and other economic activity so the residents may be understandably

anxious about this issue.

R. Additional Northern Basin Inflows

i. Objectives

The primary objective is to provide formal recognition of additional Menindee inflows related to Basin Plan environmental

recovery in the portion of the basin.

Formally recognised additional inflow would be made callable for environmental purposes in the Lower Murray and

Darling systems.



Additional inflows may be the result of return flows from environmental watering 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.


Not applicable


Prior submissions assumed that additional inflows were assigned equally to NSW and VIC shares consistent with the

default set by the Murray Agreement, and the additional water contributes to increased allocations across the system.

Since irrigation cannot increase, the environmental benefit will be expressed as an increase in spill volumes.

The current proposal assumes that States will make changes to the Agreement that result in the additional inflows

becoming callable in the Murray system after being recognised through a process determined by the development of

arrangements for protecting environmental flows in the Barwon- Darling.


This initiative should be modelled by creating equal LTCE value entitlements for NSW Murray General Security and VIC Murray

Low Reliability.


Changes to the Agreement require consent by all States and it is difficult to know in advance what form of water holding

and inflow recognition will be acceptable to everyone involved. A bilateral agreement between NSW and VIC may be

required in the absence of a broader arrangement.

Further development of arrangements for protecting environmental flows in the Barwon-Darling (Phase 2 Shepherding

project)is intended to address the question of downstream recognition and delivery arrangements, but has not commenced

and is subject to Commonwealth funding.



S. Temporary trade rules

i. 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

outlined in Q below


No works are required


Not explicitly included in prior submissions.


No additional modelling is required


The key risk with allowing trade into the Lower Darling is that new water allocations could be used for permanent plantings

which cannot be sustained with periodic access to water under the proposal. These issues are likely to raise some concerns

in the process of stakeholder engagement.



6. Proposed interjurisdictional governance and engagement

NSW DPI Water has commenced the initial stages of providing information and briefings for the relevant jurisdictions

in relation to the Menindee Lakes project. However, consultation to date has been minimal, which reflects the need to

cooperatively develop of a conceptual proposal inclusive of relevant operational rules, modelling outputs and pathways to

amend the relevant legal instruments

NSW DPI Water is proposing a more comprehensive engagement with interjurisdictional partners in the development of the

Menindee Lakes Water Savings Project Menindee Lakes Water Savings Project and SDL Adjustment Package Business Case, 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 business case for submission by 30 June 2017.

However, it should be noted that the Phase 2 Business Case that will submitted as part of the 2017 notification will

represent best estimations of the Menindee Lakes Water Savings 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 principles 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 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;

It is recognised that, 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

downstream impact on Victoria, South Australia and the Commonwealth;



NSW will work with jurisdictions to develop final terms of reference for the group by early May 2017, based on

the draft provided in Appendix A, to guide the activities and focus of the working group;

The 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, and the MDBA;

The Working Group will operate in the first instance for as long as it takes to develop the details of the

Menindee project proposal to a level consistent with the other SDL projects’ final business cases, and then in a

future capacity to identify 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;

This group will operate within a limited time span commencing 1 May 2017 to 30 November 2017, in line with the

proposed timeframe for the revised or new Intergovernmental Agreement regarding Basin Plan Implementation.

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 need for continuance; 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.

7. Conclusions and next steps

This document outlines the key parameters of the amended Menindee supply and constraints measure. NSW has worked

closely with the MDBA to provide clarity on the modelling assumptions which are required to incorporate this reshaped

proposal into the MDBA assessment framework.

Following submission of this interim Menindee proposal, the MDBA will need to confirm that sufficient modelling direction and

resources are provided to ensure inclusion of this proposal in the MDBA June 2017 interim modelling advice. An amended

notification will be developed in light of this advice for the Basin Officials’ Committee (BOC) consideration by mid-June 2017.

Preparation of a more detailed Business Case document based on the parameters outlined in this document, which

meets Phase 2 Business Case guidelines, has commenced. This document will be provided for inter-jurisdictional

consideration in mid-June 2017, ahead of the 30 June 2017 notification date. Recognising that key requirements (eg.

risk identification and mitigation, responsibility for operations and management, etc.) will not be fully understood at this

stage, it is proposed that some Phase 2 Guideline requirements will be described using the best available information,

with a process and timeline outlined for further refinement of the proposal post-30 June 2017.

The proposed Menindee Lakes Water Savings Sustainable Diversion Limit Adjustment Mechanism Project

Intergovernmental Working Group, as outlined in Appendix A will provide the necessary



governance framework for the agreement on those elements of the proposal which have the potential to affect the Murray

Darling Basin Agreement and other jurisdictions.



Appendix A

Draft Terms of Reference Menindee Lakes Water Savings Project Working Group

A. 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.

B. 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 Menindee IG 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.

.



C. Membership

Membership of the Working Group will include a maximum of two representatives each from NSW, Victoria and South

Australia.

NSW will Chair the Working Group as the lead jurisdiction for the Menindee Lakes Water Savings Project.

Recognising its funding role the Commonwealth Department of Agriculture and Water Resources will nominate one member.

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.

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.


D. Chair and Committee Support

TBC

E. 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.



Table 2

9 June 2017

Stage in Process Menindee Project Timeframes (proposed)

Interim Menindee proposal (Modelling) Amended Menindee Phase 2 Business Case proposal

27 April 2017

Phase 2 assessment & issue resolution, including: Mid-June 2017

Initial reconciliation milestones

Amended notification Menindee proposal

In principle agreement to scope of changes to River Murray Framework

Mid-June 2017

Agreement on IGA provisions, if required, covering

Menindee IG WG

September 2017 (BOC)

Further development of River Murray Framework

changes

Reconciliation milestones

Confirmation and further notification amendment if

required

November 2017 (MinCo)

Mid-September 2017

Final package (removal of projects) Detailed design (as part of an EIS process, including:

Consultation, cultural heritage

-

March 2020

Structural adjustment September 2020

Procurement September 2020

Construction (wet conditions) December 2022

NSW licensing and water sharing plan changes By June 2024

Agreement and implementation of processes for By 30 June 2024 recognising Northern Basin environmental water

River Murray Framework changes By June 2024

Amendment 1 to Menindee Lakes Water Saving Project Notification

Attachment C: Amendment 1 to Structural and operational changes at Menindee Lakes (NSW)

Appendix A: Evaporation loss calculation

A standard loss rate for net evaporation is applied based on monthly data from climate station at Menindee Lake for pan evaporation with a pan

factor of 0.7 and at Wentworth for monthly rainfall.

Appendix B: Summary of the modelling parameters changed to represent proposed structural and rule

changes

Overview

Proposals to improve operations at Menindee Lakes with combinations of rule changes and structural works targeted at reducing evaporation

losses from storage have been under investigation for a many years. After a number of broad ranging studies, NSW and the Commonwealth

agreed to focus the ongoing effort on the package of measures described in the MSM/Bigmod modelling scenario known as Run 35. This

project has been built on Run 35 with some additional changes to reflect the Menindee Lakes Interim Project Proposal (DPI Water, May 2017).

In this attachment, the model changes required from the SDL benchmark are documented in detail.

Morton-Boolka Regulator

This regulator allows Lake Menindee to be operated independently of Lake Cawndilla. Changes to relevant model parameters are

presented at Table 1.

Table 1: Changes to MSM parameters for representing Morton-Boolka regulator

Variable Card Benchmark Proposal Purpose

RCMMEN Card 33, Column

21-26

0.0 60.5 To represent the water level for the

crest of the regulator (mAHD)

RCMCAW Card 33, Column 27-32

0.0 60.0 To represent the trigger level

(mAHD) for Cawndilla operation rule

ICMRULE

ICMRULE Card 33, Column

33-38

0 5 To represent the hard wired

Cawndilla operational rule which

codification is available from MSM

Rev No. 929. This rule is used in

conjunction with environmental targets specified on Card 79-2

Lake Menindee enlarged release capacity and drainage channel to outlet regulator

These works will allow flows in the Darling River channel downstream of Menindee of up to 14,000 ML/d with the inclusion of works improving

the upstream head conditions for the Lake Menindee Outlet and also enabling operators to access the residual pool of water otherwise

considered to be “dead storage” in Lake Menindee. Specific model changes are implemented by revising Lake Menindee discharge rate

with/without backwater effects. The changes are made to model variable BWOutCap at MSMConstant file (MSM Rev No. 929). Figure 1 shows

an example of outlet discharge capacity when backwater is not a constraint factor.


HighFlow

Figure 1: Lake Menindee outlet discharge without backwater effect

Lower Darling channel capacity and anabranch offtake regulator

These works will allow flows in the Darling River channel downstream of Menindee of up to 14,000 ML/d by preventing excessive losses into

the Great Darling Anabranch. The model has been changed to reflect less overbank flow losses due to the Anabranch offtake regulator. The

hard-wired high flow loss for the lower daring reach in MSM has been changed to reflect regulator controls as below.

𝐿 =max(0, 0.0464×(Q-DarlHighLossThres))+ 0.210×max(0, Q-max(550,DarlHighLossThres))+ 0.214×max(0, Q- 1000) − 0.445×max(0, Q-2450) − 0.150×max(0, Q-3180),

where:

𝐿HighFlow is the high flow loss,

Q is flow at Weir 32 in GL/month,

DarlHighlossthres is set to be min(darlch, AnaoffRegThres),

darlch is the channel capacity without the regulator (279 GL/m = 9,300 ML/d) and AnaoffRegThres is the

capacity with the regulator fully closed (426 GL/m = 14,000 ML/d).

In Bigmod, impacts of the regulator are modelled as flow control from Lower Darling to Anabranch depending on

opening of the regulator as per Table 2.

Table 2: Flows from Lower Darling to Anabranch

Flow at Lower Darling

(ML/d)

Anabranch flow

(ML/d)

fully

closed

fully

open

Menindee Lake discharge without backwater effects

25000

20000

15000

10000 Existing

Proposed

5000

0

49.5 51.5 53.5 55.5 57.5 59.5 61.5 63.5

Reduced Level (m) of Menindee Lake

Ou

tlet

Cap

city

of

Men

ind

ee L

ake

(ML/

d)


0 0 0

9000 0 0

14000 0 1250

15000 340 1500

18000 2007 3167

19500 2840 4000

20000 3231 4391

21340 4280 5440

25080 6020 7180

29000 8840 10000

78000 51840 53000

120000 68840 70000

190000 85840 87000

Alternative supply for Broken Hill TWS

Critical to the management of Menindee Lakes in drought periods is the security of water supply for Broken Hill and its population of

approximately 20,000 people. The existing share management arrangements (480/640GL storage thresholds for ceasing and resuming shared

management of the Lakes) is already resulting in the need for contingency works to provide adequate surety for Broken Hill’s ongoing supply of

water. Any reduction to existing thresholds would require an alternate source of water to augment supply for Broken Hill to ensure adequate

security of supply.

In the modelling, it is assumed that an alternative supply is available for Broken Hill through a pipe-line infrastructure directly from Murray. To

model the alternative supply, the Broken Hill TWS entitlement has been transferred to Murray. Other relevant changes to MSM parameters are

presented at Table 3.

Table 3: Changes to MSM parameters for representing the alternative water supply for Broken Hill TWS


BROKHILLMurrayPump Card 8, Column

25-30

0 1 To divert water directly from Murray

US Lake Victoria

nummonthsproj Card 97, Column

1-2

18 -1 To indicate that the resource

assessment should cease to forecast

18 months into the future, and

instead project to the end of the

current water year to supply existing

allocation commitments

Changes to Shared Management Thresholds

The removal of the thresholds used for the Benchmark (480 GL/640 GL) provides MDBA with increased control of the Menindee system, helping

to increase drawdown rates, reduce evaporation, increase the overall regulated supply to the Murray and harmonise operations with Lake

Victoria.


Relevant changes to MSM parameters are presented at Table 4.

Table 4: Changes to MSM parameters for representing shared management thresholds


RMLDDD Card 42, Column

1-6

480 80 To represent the NSW reserve in the

lakes when the system is draining

WETPAMMDBA Card 42, Column 13-18

0 80 To represent the volume in

Wetherell & Pamamaroo that is not

available for MDBA supply

RMLDFIL Card 43, Column

1-6

640 80 To represent the NSW reserve in the

lakes when the system is filling

Lake Cawndilla Environmental Operation

At present, Lake Cawndilla is operated to meet water conservation objectives, which means that the lake will typically fill to a high level during

wet periods, and then be held for a period of time until system demands gradually empty the lake over a few years.

This has heavily modified the natural state of the lake, creating an artificial vegetation ring around the top of the lake, at a higher level

than under natural conditions.

Following consideration of a number of options, the modelled NSW proposal is to fill Lake Cawndilla to maximum surcharge level, when there is

a major high flow event (i.e. when Burke flow > 600 GL/m) in the Barwon-Darling and more than 3yrs since the last surcharge event, hold the

water briefly, and then release water from the storage over a short period of time. This is expected to maintain existing vegetation higher in the

lake profile and allow a transition through to ephemeral colonising species in the lower parts of the lake.

Relevant changes to MSM parameters are summarised below.

Table 5: Changes to MSM parameters for representing Lake Cawndilla environmental operation


LevlkCawnEnvThreshStart(4) Card 79-2, 0.0 60.43 Level in Lake Cawndilla that

Column 85-90 indicates an environmental filling target

lkMeniEnvTarg(4) Card 79-2, 0 36 A number of months to wait before Column 91-96 attempting a new environmental

filling event

MeniEnvDump Card 79-2, 0 2 To release water after Column 100-102 environmental filling event has

occurred via Darling Anabranch

CawndillaShare Card 79-2, 0 1 To represent that the dumped water Column 103-105 is owned equally by NSW and

Victoria

BourkTrig Card 79-2a, 0 600 To represent the monthly flow Column 1-6 (GL/m) at Bourke that must be

exceeded before an environmental fill of Lake Cawndilla is attempted



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.

Menindee Lakes Water Savings Project Business Case

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