PWC Happy Valley Outfall Channel Upgrade Project WITHOUT COSTING COMMENT

PP 185

FINAL REPORT

HAPPY VALLEY OUTFALL CHANNEL UPGRADE

PROJECT

505TH REPORT

OF THE

PUBLIC WORKS COMMITTEE

Published pursuant to section 17(7) & (8) Parliamentary Committees Act 1991

Hon LcAtkinson, Speaker August 2014

First Session, Fifty-Third Parliament

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Public Works Committee Page 1 Happy Valley Outfall Channel Upgrade Project

CONTENTS

THE PUBLIC WORKS COMMITTEE ........................................................................................................................... 2

THE FUNCTIONS OF THE COMMITTEE ................................................................................................................... 2

PART ONE: PREAMBLE AND PROJECT SUMMARY............................................................................................ 3

1.1 TERM OF REFERENCE .......................................................................................................................................... 31.2 FURTHER REPORTING TO THE COMMITTEE......................................................................................................... 31.3 SCOPE OF THIS REPORT...................................................................................................................................... 3

PART TWO: EXECUTIVE SUMMARY & COMMITTEE CONCERNS.................................................................... 4

PART THREE: EVIDENCE PRESENTED TO THE COMMITTEE .......................................................................... 6

PART FOUR: CONCLUSION & RECOMMENDATION ............................................................................................ 7

PART FIVE: ATTACHMENTS....................................................................................................................................... 8

6.1 LIST OF SUBMISSIONS .......................................................................................................................................... 8


THE PUBLIC WORKS COMMITTEE

The Public Works Committee is established pursuant to sections 12A, B and C of the ParliamentaryCommittees Act 1991, proclaimed February 1992.

The following members constitute the Nineteenth Public Works Committee as reconstituted on 6 May2014:

Ms Annabel Digance MP (Presiding Member)

Hon Paul Caica MP

Ms Dana Wortley MP

Mr Michael Pengilly MP

Mr Tim Whetstone MP

Principal Research Officer: Ms Alison Meeks

Administrative Officer: Ms Amanda Sheeky

THE FUNCTIONS OF THE COMMITTEE

Section 12C of the Parliamentary Committees Act 1991 defines the functions of the Public WorksCommittee as:

(a) to inquire into and report on any public work referred to it by or under this Act, including-

(i) the stated purpose of the work;

(ii) the necessity or advisability of constructing it;

(iii) where the work purports to be of a revenue-producing character, the revenue that itmight reasonably be expected to produce;

(iv) the present and prospective public value of the work;

(v) the recurrent or whole-of-life costs associated with the work, including costs arisingout of financial arrangements;

(vi) the estimated net effect on the Consolidated Account or the funds of a statutoryauthority of the construction and proposed use of the work;

(vii) the efficiency and progress of construction of the work and the reasons for anyexpenditure beyond the estimated costs of its construction;

(b) to perform such other functions as are imposed on the Committee under this or any other Actor by resolution of both Houses.


PART ONE: PREAMBLE AND PROJECT SUMMARY

1.1 Term of Reference

Parliamentary Committees

Parliamentary Committees have the specific task of examining individual initiatives, projects orpolicies of the government of the day, or issues of importance to society as a whole. StandingCommittees are created by Act of Parliament and charged with the ongoing examination of subjectcategories such as public works.

Parliamentary Committees are made up of both government and opposition Members, with numbersof each calculated according to rules which reflect the numbers of seats each group holds in theParliament. Much of the Committee process is open to the public, and completed reports are publicdocuments.

This Project

SA Water has referred the Happy Valley Outfall Channel Upgrade Project to the Public WorksCommittee pursuant to the requirements of the Parliamentary Committees Act 1991. Please refer tothe "Functions of the Committee" on the previous page for a full description of the Committee's tasks.

1.2 Further Reporting to the Committee

SA Water must notify the Committee immediately in writing should there be substantial changes to thenature of the project or the evidence provided to the Committee. To enable appropriate monitoring ofthe project, SA Water must also provide quarterly reports to the Committee on the progress ofconstruction. Pursuant to section 12C (vii) of the Act, these reports must outline the efficiency andprogress of construction and provide an explanation of any expenditure beyond the estimated costsquoted in this report. Evidence of any substantial changes to, or the withdrawal of, any approval(provisional or otherwise) must also be relayed to the Committee immediately with an appropriateexplanation, and an assessment of the probability of a suitable resolution.

In addition, the Committee requires that it be notified of the proposed date for the commissioning ofthe works.

The Committee has the authority under Section 16 (1)(c) of the Parliamentary Committees Act 1991to re-open investigations into any project for the purpose of further examination and monitoring.

1.3 Scope of This Report

This Report examines the history of the proposal and the efficacy of the application of SouthAustralian taxpayer funds to the Happy Valley Outfall Channel Upgrade Project. The Reportstructure is guided by, and largely limited to, the terms of the Parliamentary Committees Act 1991. Itdescribes, in summary, the evidence presented to the Committee and concludes with a briefsummary incorporating findings and recommendations.

Detailed evidence upon which the Committee’s decision is based is held in Parliament and, in mostcases, can be examined by making an application to the Committee Administrative Officer.


PART TWO: EXECUTIVE SUMMARY

SA Water proposes to upgrade the existing outfall channel at the Happy Valley Reservoir at a cost of$5.76 million (excluding GST) in the second half of 2014. The permanent channel will be constructedto provide increased safety to local residents and the community and have a suitable capacity for a1:100 year flood event.

The Outfall Channel is currently a six metre deep, 500 metre long, unlined channel to the southwest ofthe reservoir. It is located on SA Water land and abuts private residential properties. The channel alsoacts as a dam spillway to maintain dam safety.

The land is well used by the local community for exercise, cycling or dog-walking. The Outfall Channelis in very poor condition, with sections undermined by erosion and continuing to degrade. In its currentstate of repair it poses a risk to users and the increased risk of blockage of the channel from fallentrees, etc. The channel also does not adhere to the Australian National Committee on Large Dams(ANCOLD) Guidelines on Dam Safety Management (2003) for a 1:100 year flood event.

The key aims of the project are to:

• upgrade the Happy Valley Outfall Channel to ANCOLD standards of dam safety;

• minimise the risk to the community of a dangerous fall into fast flowing water;

• stabilise the channel, reduce the risk of additional trees falling into the channel, causingblockages, dam safety issues and flooding local properties;

• providing an improved, safe and open community space for the residents; and

• reduce the likelihood of an embankment collapse causing an injury to a member of the public.

Three options were considered for this project; namely

• Base case – continuing the patch up work until collapse

This option does not address the key ongoing high public safety risk, potential bank collapseand property flooding. This option will require rectification and/or rebuilding works in futureyears, at a higher cost.

• Option 1 (preferred option) – upgrade channel with reinforced concrete lining

This option proposes to line up to 350 metres of the channel with reinforced concrete whereerosion has occurred, typically from the base of the channel up to two metres of theembankment. The remaining unlined channel will allow slowed, free flowing water to naturallyenter the adjacent wetlands. Concrete provides excellent erosion resistance and will meet theproject outcomes, principally upgrading the channel to a 50-year design life.

SA Water and the local community focus group supported this option.

• Option 2 – upgrade channel with inverted pre-cast culverts

This option proposes to use inverted (U-shaped) culverts to line up to 350 metres of thechannel. Culverts offer the same benefits as the reinforced concrete in Option 1 and will alsoachieve a 50-year design life but at a higher capital cost.


The Base case has the lowest cost option, however it does not address the risks to public safety andpotential loss of life if the banks were to collapse due to erosion, the potential injury while undertakingmaintenance or traversing through the channel, or the issue of non-compliance with the ANCOLDdam safety guidelines. Hence the base case is not considered a feasible option.

Based on the financial and economic evaluation, Option 1 (upgrading the channel with reinforcedconcrete lining) is the preferred option as it addresses the above risks and compliance issues at alower cost than Option 2.

The cost of the project is included in SA Water’s capital plan, and as such, there will be no impact onthe current regulatory budget due to this project. There will be no change in the recurrent cost of thechannel’s operation as a result of this redevelopment.

In preparing for the project, SA Water has consulted with the Aboriginal Affairs and ReconciliationDivision who have advised there are entries for Aboriginal sites within the Happy Valley Spillway area,which includes a 2 kilometre buffer. Given the works will be confined to existing highly disturbedareas, SA Water considers the risk low of finding heritage sites within the project area. It has aStandard Operating Procedure for the management of Aboriginal Heritage finds associated with anyworks, and this will be provided to the construction contractor as part of the project documentation.Tender specifications also require the contractor to stop all work immediately if any heritage issuesare encountered.

The Happy Valley Outfall Channel Reference Group, a reference group of local community members,has been established to develop and obtain alignment on a concept for the upgrade and rehabilitationof the channel. It continues to be regularly updated on the progress of this project. The broadercommunity has been made aware of the project via letters and doorknocking. Relevant governmentdepartments, including the Environment Protection Authority and the local council have beenconsulted regarding the project and are generally supportive.

Preliminary works for the project have commenced, including obtaining the necessary approvals fromthe Development Assessment Commission. The project should reach practical completion byDecember 2014, with final completion and the end of defect period being December 2015.


PART THREE: EVIDENCE PRESENTED TO THE COMMITTEE

A proposal from SA Water was referred to the Public Works Committee for consideration. Thisproject falls under policy guidelines adopted by the Public Works Committee for project hearingrequirements which appear before the Committee when they qualify for the Ministerial threshold ofover $4 million.

Given the straightforward nature of the proposed project, the Committee accepted that the writtenevidence provided was sufficient to satisfy the Committee’s responsibilities pursuant to section 12Cof the Parliamentary Committees Act 1991 and agreed a full Committee hearing would not berequired.

The written evidence submitted by SA Water (Attachment 1) was subsequently adopted by theCommittee as the basis for this Report.

nnabel Digance MP PRESIDING MEMBER Public Works Committee

PART FOUR: CONCLUSION & RECOMMENDATION

The Public Works Committee has examined written evidence in relation to the proposal for the Happy Valley Outfall Channel Upgrade Project. It has also been assured by SA Water that acquittals have been received from the Departments of Treasury and Finance, Premier and Cabinet and the Crown Solicitor that the works and procedures are lawful. The Committee is satisfied that the proposal has been subject to the appropriate agency and community consultation and meets the criteria for examination of projects as set out in the Parliamentary Committees Act 1991.

Based upon the evidence considered, and pursuant to Section 12C of the Parliamentary Committees Act 1991, the Public Works Committee reports to Parliament that it recommends the proposed public work.

August 2014

Public Works Committee

Page 7 Happy Valley Outfall Channel Upgrade Project


PART FIVE: ATTACHMENTS

6.1 List of Submissions

SA Water, Happy Valley Outfall Channel Upgrade Project, July 2014


ATTACHMENT

Happy Valley OutfallChannel Upgrade Project

Happy Valley Outfall Channel Upgrade Project

SUBMISSION TO THE PUBLIC WORKS COMMITTEE

OF THE PARLIAMENT OF SOUTH AUSTRALIA

July 2014

SA Water Corporation Happy Valley Outfall Channel Upgrade

Contents1. Proposal................................................................................................................................ 1

2. Background........................................................................................................................... 1

3. Key Aims ............................................................................................................................... 1

4. State Strategic Plan ............................................................................................................... 2

5. Expected Outcomes .............................................................................................................. 3

6. Options Investigated ............................................................................................................. 3

7. Financial Information ............................................................................................................ 4

8. Budget Impact....................................................................................................................... 5

9. Economic Evaluation ............................................................................................................. 6

10. Site and Ownership details.................................................................................................... 7

11. Project Program.................................................................................................................... 7

12. Project Procurement............................................................................................................. 7

13. Risk Management Strategy.................................................................................................... 8

14. Ecologically Sustainable Development (ESD) ......................................................................... 8

15. Environmental Management................................................................................................. 9

16. Aboriginal Heritage and Native Title.................................................................................... 10

17. Consultation ....................................................................................................................... 10

18. Communication Strategy..................................................................................................... 11

19. Approvals............................................................................................................................ 11

Appendix A – Current condition of the Happy Valley Outfall Channel............................................... 13

Appendix B – Concept cross section of Happy Valley Outfall Channel............................................... 14

Appendix C – Financial and Economic Evaluation............................................................................. 15

Appendix D - Environment and Heritage Assessment Report. .......................................................... 18

Appendix E – Department of Treasury & Finance – Costing Comment.............................................. 40

SA Water Corporation Happy Valley Channel Upgrade Page 1

1. Proposal

This submission outlines a proposal to upgrade the existing outfall channel at the Happy Valley Reservoir.

The estimated capital cost of this project is $5.76 million in escalated dollars (excluding GST).

2. BackgroundThe Happy Valley Outfall Channel is a 6m deep unlined channel located immediately to the south-west of the reservoir. The 500m long channel is located on SA Water owned land and abuts private residential properties. The land is widely used by the local community for recreational activities such as dog-walking, exercising and cycling.

Happy Valley Reservoir is an off-stream storage with runoff from the local urban catchment diverted around the reservoir and conveyed to the Field River via the outfall channel. The channel also acts as a dam spillway to maintain dam safety.

The Happy Valley outfall channel is in very poor condition. Sections of the 6m deep channelhave become undermined by erosion and they continue to degrade. There is a risk that the current state of the channel (with continued degradation) will cause additional trees to fall into the channel resulting in blockages which could cause local property flooding (estimated to be up to 25 houses), and potentially impact on dam safety.

A flood hydrology study commissioned by SA Water determined that the Happy Valley Outfall Channel does not adhere to the Australian National Committee on Large Dams (ANCOLD) Guidelines on Dam Safety Management (2003) for a 1:100 year flood event.

SA Water under an Early Contract Involvement (ECI) contract has performed early site investigations into the geotechnical and topographical conditions. The aim being to make the site safer for the public, fully understand the project scope and develop a concept design with cost estimate.

3. KeyAims

The key aims of the Happy Valley Outfall Channel Upgrade Project are to:

Upgrade the Happy Valley Outfall Channel to ANCOLD standards of dam safety

Minimise the risk to the community of a dangerous fall into fast flowing water

Stabilise the channel, reduce the risk of additional trees falling into the channel, causing blockages, dam safety issues and flooding local property

Provide an improved, safe and open community space for the residents

Reduce the likelihood of an embankment collapse causing an injury to a member of the public.


4. StateStrategicPlan

This project helps underpin Target 73 –Recycle stormwater - and Target 32 of the State

Strategic Plan – Customer and client satisfaction with Government services.

Table 1: State Strategic Plan Targets

Target Description Relevance to the Project

Target 73. Recycled stormwater:

South Australia has the system capacity to

harvest up to 35 GL of stormwater per annum

by 2025

Happy Valley Outfall channel supplies

the Onkaparinga Council’s Byards Road

Stormwater Harvesting project. This

project will provide an improved level of

water quality more suitable for reuse.

Target 32. Customer and Client satisfaction

with Government services

Increase the satisfaction of South Australians

with government services by 10% by 2014,

maintaining or exceeding that level of

satisfaction thereafter.

Maintain a safe system of managing

stormwater and ensure risk to the

community are minimised.

The proposal aligns with these targets by:

by improving the flow and quality of stormwater into the Councils Stormwater Reuse system

Minimising risks to public safety and reducing the likelihood of person and property damage.


5. ExpectedOutcomes

The project will upgrade the Happy Valley Outfall Channel suitable capacity to handle a 1 in

100 year flood through the channel, further clearing it of debris and foreign objects. A

permanent channel will be constructed to provide increased safety to the local residents and

community.

The Happy Valley Channel will be designed to meet Australian National Committee on Large

Dams Inc. (ANCOLD) standards and address key structural and capacity risks that the current

channel possesses.

6. OptionsInvestigated

During the optioneering phase, two options were identified that could meet the required

objectives for this project. These were compared to the Base Case to determine the best

course of action from a risk and financial perspective:

Base Case – patch up work until collapse

Listed for comparison only, this does not address the key the ongoing high public safety

risk and potential for bank collapse and property flooding. The channel will continue to

degrade and this project will be required in future years at a higher cost. This is not

recommended and does not align with SA Waters Asset Management and dam safety risk

management practices.

Option 1 – Upgrade channel with reinforced concrete lining (Preferred Option)

This option proposes the use of reinforced concrete to line up to 350m of the channel where erosion has occurred, typically from base of the channel, up 2m of the embankment.

The remaining unlined channel will allow slowed, free flowing water to naturally enter the adjacent wetlands.

Concrete will provide excellent erosion resistance and meet the project outcomes, principally upgrading the channel to a 50 year design life.

The local community focus group supported this option.

Option 2 – Upgrade channel with inverted pre-cast culverts

This option proposes to use inverted (U-shaped) culverts to line up to 350m of the channel. Culverts offer the same benefits as Option 1 but have a higher capital cost and will also achieve a 50 year design life.

Both Option 1 and 2 discussed incorporated the needs to:

Remove trees identified as being likely to block the channel or that need removal for

construction access. Some of this has occurred as part of early investigation works.


Stabilise sections of the channel embankments that have experienced undermining and

erosion

Replace existing 1.2m high stock fence with similar higher barrier to reduce risk to public

safety

Undertake plantings and revegetation of the site to restore aesthetic amenity.

Due to the poor condition of the channel and the local community’s vocal opinions, it is proposed that Option 1 proceeds as soon as possible.

Other options were considered during the early optioneering phase, however were discarded as they could not meet the objectives of the project such as using gabions (large wire mesh baskets filled with medium sized rocks) and rock beaching. Therefore these options were removed from further analysis.

7. FinancialInformation

The analysis is based on a 25-year study period using a cost of capital (discount rate) of

5.06% (real, pre-tax) in line with SA Water’s current regulatory weighted average cost of

capital (WACC) used for analysis of all regulated projects.

The Options analysis was performed on the Base Case, Option 1 and Option 2 as outlined in

section 6. The detailed results of the analysis can be found in Appendix C.

The following assumptions were made for the financial analysis:

Base Case – patch up work until collapse (Listed for comparison only)

Under the Base Case, it is expected the channel will continue to erode by approximately

500mm every year. This will require patch up costs every year due to rain events and will

increase the financial costs to remediate the channel (by lining the channel as per the

preferred option) once the current channel collapses.

For the purposes of the financial analysis it is expected the channel may collapse within the

next 5 years. Once the channel collapses, additional costs will be incurred to clear out the

channel. There are also significant public safety risks associated with this option, which

cannot be quantified.

A residual value has been included to recognise remaining design life of the lining after the

analysis period.

Note: This does not address the key the ongoing high public safety risk and potential for bank

collapse and property flooding.

Option 1 - Upgrade channel with reinforced concrete lining (Preferred Option)

This option includes the capital costs to upgrade the channel and an allowance for residual

value to recognise remaining design life of the lining after the analysis period.


Option 2 Upgrade channel with inverted pre-cast culverts

This option includes the capital costs to upgrade the channel and an allowance for residual

value to recognise remaining design life of the lining after the analysis period.

A summary of the results of the NPV analysis is shown in the table below.

Base Case* Option 1* Option 2*

Review period (years) 25 years 25 years 25 years

Total capital expenditure ($k) 4,415 5,238 6,445

Total residual value ($k) 889 822 994

Total operating expenditure ($k) 454 0 0

Total NPV ($k) (3,980) (4,416) (5,451)

NPV incremental to Base Case ($k) n/a (436) (1,471)

NPV ranking 1 2 3

* All figures are in real, discounted dollars and do not include sunk costs incurred to date

The Base Case is the lowest cost option however:

Does not address public safety risks and potential loss of life if the banks of the

channel collapsing due to erosion.

Does not address potential injury while undertaking maintenance or traversing

through the channel.

Does not address key non-compliance with ANCOLD dam safety guidelines

Hence Option 1 is the preferred Option compared to Option 2 based on a financial analysis

as it can mitigate the public safety risks at a lower cost than Option 2.

Sensitivity testing was applied to the discount rate (increase/decreases 2%). This did not

change the rankings.

8. BudgetImpact

The financial approval estimate is shown in the table below.


Table 3: Cost Estimate

Cost Component Cost ($k)

Construction Cost 3,895

Project Development Costs 426

Project Delivery Costs 232

Contingency 1,207

Escalation 0

Total Estimated Capital Cost 5,760

The cost of the project is catered for in SA Waters capital plan. As such, there will be no impact on the current regulatory budget as a result of this project. There will be no change in the recurrent cost of the channel’s operation as a result of this redevelopment. The project will therefore have no budget or customer pricing impacts.

9. EconomicEvaluation

A number of high-risks were identified through the risk assessment. These risks have not

been quantified due to the nature of the risks and difficulty to establish an accurate

monetised cost. However each of the risks described below are unacceptable under the Base

Case and would be considered a benefit under both Option 1 and Option 2.

Public safety risks and potential loss of life with the banks of the channel collapsing due

to erosion. This may include falling into the channel or having the bank collapse on top

of a person whilst in the channel undertaking maintenance or traversing through the

channel.

A 1 in a 100 year flood may cause flooding in the local area and substantial damage to

properties located adjacent to the channel

In floods greater than the 1 in 100 year flood, water from the catch drain may spill into

the reservoir and then through the outlet back into the outfall channel. A

partial blockage of the outfall channel could result in the Dam overtopping and possibly

failing causing significant injury/damage to downstream population and residences.

Significant customer complaints.

Both Option 1 and Option 2 can lower the above risks to an acceptable level.

The quantified costs and benefits from the financial analysis were discounted at the

preferred Department of Treasury and Finance rate of 7% pre-tax real WACC for economic

analysis. This did not change the ranking of the Options.


10. SiteandOwnershipdetails

All works associated with this project will be carried out on land owned by SA Water. All

deliverables from this project will be owned by SA Water and operated by SA Water or their

appointed operators or contractors.

11. ProjectProgram

The forecast key project milestone dates are:

Early preliminary works on site (via ECI) 17th March 2014

Full Financial Approval 28st July 2014

Major Orders Placed 31st July 2014

Start Major Work 8th September 2014

Practical Completion 19th December 2014

Final Completion / End Defects Period 19th December 2015

12. ProjectProcurement

SA Water adopted an ECI (Early Contractor Involvement) process to perform early site

investigation and develop an acceptable design, based on the site conditions and geology.

This process has provided a better understanding of the site risks, a well-defined concept

design and more accurate construction cost estimate.

SA Water’s preferred procurement strategy is based on using this ECI agreement which has

defined the project concept and cost, transferring this agreement to a lump sum design and

construct contract.

SA Water’s Construction Panel was used to make the initial selection of the ECI (Early

Contractor Involvement) Contractor.

SA Water’s Procurement section has prepared a procurement plan to document this

strategy.

This project is being managed in accordance with the SA Water Corporate Project

Management Methodology.

SA Water’s appointed project manager for this project is responsible for seeking the

necessary approvals and management of the selected contractor.

Cost estimation was verified by SA Water’s estimating department, during the ECI. SA

Water’s Services Panels have been utilised to develop initial concept design, site

investigations involving geotechnical and structural surveys.


13. RiskManagementStrategy

This project has undergone review under the SA Water Business Risk Management Policy

and Framework, which requires the identification of risks, their likely impact and severity

and associated risk mitigation strategies. The policy and framework are consistent with the

Australia/New Zealand Risk Management Standard AS/NZS ISO 4360.

A risk assessment session was held on 27 Sept 2013, attended by representatives from key

stakeholder groups.

The risk session identified the key risks of continuing operations without the upgrade as

follows:

Non-compliance with the ANCOLD guidelines on Dam Safety Management (2003) for a 1:100 year flood.

public safety incident resulting in serious injury or death;

flooding nearby property, media attention, ministerial enquiry, public image;

Adverse environmental impacts; contamination of reservoir (source) water, and sediment contamination of wetland.

14. EcologicallySustainableDevelopment (ESD)

SA Water’s Environmental Sustainability Policy embraces the following principles:

1. Everything is connected - All elements within the environment (including ourselves) are interconnected. Impacts in one area will have systemic and sometimes unpredictable impacts in other areas.

2. The environment has physical limits - SA Water recognises these limits and will work in collaboration with other users of natural resources to operate within them. To this end, SA Water aims to use resources and raw materials efficiently in undertaking its activities.

3. Water is a limited resource - SA Water has a shared responsibility with others (including legislated authorities) in the management of the water cycle and we will work collaboratively to manage water resources in a way that maintains and where possible, restores the functionality of ecosystems.

4. Climate Change effects – SA Water recognises that climate change impacts on the whole environment including SA Water’s infrastructure and activities. SA Water will work to mitigate and adapt to climate change and support essential research.

5. Pollution should be prevented wherever possible - SA Water is committed to pollution prevention by reducing the contamination of land, water and air from its activities and improving environmental outcomes.


6. Environmental management requires a systematic approach - SA Water is committed to the ongoing implementation of an environmental management system for continual improvement of our environmental performance and minimisation of risk.

Implementation of this project supports these commitments with a cost effective solution

that manages the risk of property damage and injury to the community from flood and bank

failure.

SA Water’s standard contract documents include that tenderers are encouraged to develop

processes with due regard for short and long term, local and global, environmental, social

and economic considerations. From an infrastructure perspective, this includes

consideration of sustainability aspects such as the conservation and efficient use of

resources and raw materials, energy efficiency, generation/use of renewable energy,

development of flexible processes and products, design of closed loop processes where

possible and where not, the implementation of recycling and reuse to reduce waste,

operating within the carrying capacity of natural systems, providing a safe and healthy work

environment, enhancing or not detracting from the amenity of the area, and cost effective

delivery.

In addition, SA Water’s Environmental Management System requires that greenhouse

emissions associated with a project are quantified as part of determining impacts. The

template includes:

Forecast and actual diesel use in construction;

Forecast and actual electricity use during construction;

Forecast tonnages of concrete, steel and chemical use; and

Forecast significant consumables.

15. EnvironmentalManagement

SA Water is committed to ensuring that any potential adverse environmental impacts

associated with the project are minimised through the design and construction phases of the

project.

An Environment and Heritage Assessment Report (enclosed in Appendix D) has been

developed outlining the potential environmental impacts associated with the project and

includes management measures or requirements to be implemented to reduce those

impacts. This project may have a significant environmental impact on the downstream

wetland area. Sediment currently deposited within the wetland from early works will be

cleaned up as part of this additional work. SA Water and the EPA have been working closely

and collaboratively understand the risks and developing mitigation strategies. The

construction contractor will be required to submit a project specific Construction

Environmental Management Plan (CEMP) outlining how the potential environmental issues

identified during the assessment will be managed during the project.


SA Water’s Environment and Resource Services Group will manage the overall responsibility

for the environmental management of the project by:

Identifying the potential environmental impacts associated with the project and appropriate management measures to mitigate and minimise those impacts;

Ensuring relevant environmental standards, guidelines and regulations will be adhered to by SA Water officers and contractors involved with the construction, and delivery of the project;

Reviewing and approving the contractor’s EMPs prior to works commencing on site; and

Performing site audits of the contractor’s EMPs to ensure that the works are being undertaken in accordance with the EMP and/or if additional environmental controls are required.

16. AboriginalHeritageandNativeTitle

A request for the Happy Valley Spillway area was sent to Aboriginal Affairs and

Reconciliation Division (AARD) to determine if the Central Archive, which includes the

Register of Aboriginal Sites and Objects, contained entries for the project area, inclusive of a

2km buffer. AARD has advised there are entries for Aboriginal sites within the area searched

for the project.

SA Water has reviewed the available information from AARD and consulted with relevant

stakeholders, given the works work will be confined to existing highly disturbed areas,

considers the risk of finding sites within the project/works area is low.

SA Water recognises that the Register is not a comprehensive record of all sites and objects

and has in place a Standard Operating Procedure for the management of Aboriginal Heritage

finds associated with its works. This procedure will be provided to the Construction

Contractor and included as part of project documentation. In addition, the tender

specification requires the contractor to stop all work immediately if any heritage issues are

encountered during construction.

SA Water will comply with any applicable legal requirements relating to non-indigenous

heritage and obtain any necessary approvals (if any) relating to non-indigenous heritage.

17. Consultation

Project consultation has and continues to take place with relevant government agencies:

• Department of Treasury and Finance (DTF)

• Department of the Premier and Cabinet (DPC)

• Environment Protection Agency


Department of Manufacturing Innovation, Trade, Resources and Energy

• Aboriginal Affairs and Reconciliation Division, Department of the Premier and

Cabinet

• Local Council

Discussions about this project have been held on site with senior officers from the

Environmental Protection Authority. The EPA is supportive of the Happy Valley Outfall

Channel Upgrade project as it will reduce erosion and the sediment runoff that would

otherwise enter the Field River downstream.

Similarly, senior officers of the Onkaparinga Council have been consulted on-site and they

are supportive of the project being implemented as soon as possible to assist their

stormwater harvesting project.

Department of Treasury and Finance has been consulted regarding the Financial and

Economic Analyses. Their Costing Comment is attached as Appendix E.

18. CommunicationStrategy

SA Water established a Happy Valley Outfall Channel Reference Group to develop and obtain

alignment on a concept for the upgrade and rehabilitation of the channel.

A communications plan has been developed by SA Water’s Stakeholder Group to ensure that

the community is made aware of any potential impacts of the works.

A series of meetings were conducted while developing the concept design, which provided

in principle support for SA Water’s remediation of the Happy Valley Outfall Channel.

The Reference Group continues to be regularly updated on the progress of this project with

respect to concept designs and landscape principles.

Additionally, the broader community has had letters and doorknocking etc. take place to

ensure it is aware of the project.

19. Approvals

Development Assessment Commission

SA Water has obtained from the Development Assessment Commission (DAC) all approvals

required in relation to this project. These pertain to removal of several trees.


Cabinet Approval

The Department of Treasury and Finance and Cabinet have been briefed about this project

and it was approved by Cabinet on the 28st of July 2014.

SA Water Corporation Happy Valley Outfall Channel Upgrade Page 13

AppendixA – CurrentconditionoftheHappyValleyOutfallChannel

Photos - Outfall channel blockages and undermining


AppendixB– ConceptcrosssectionofHappyValleyOutfallChannel

Hatched area indicated soil

to be excavated


AppendixC– FinancialandEconomicEvaluation

Base Case – patch up work until collapseFINANCIAL YEAR (June ending) Present Total Over 2014/ 2015/ 2016/ 2017/ 2018/ 2019/ 2020/ 2021/ 2038/ 2039/

Value Horizon 2015 2016 2017 2018 2019 2020 2021 2022 2039 2040

5.06% year 0 year 1 year 2 year 3 year 4 year 5 year 6 year 7 year 24 year 25

Capital Costs

Cost of Failure (1/5 chance) 4,233 4,714 524 1,048 1,048 1,048 1,048

Additional Erosion Cost 181 210 21 42 63 84

0 0

0 0

0 0

0 0

0 0

0 0

Total Escalation 285 0 27 55 85 117 0 0 0 0 0

Sunk Costs 522 522

Total Capital Costs (excl. sunk & escalation for NPV calc.) 4,415 4,924 524 1,069 1,090 1,111 1,132 0 0 0 0 0

Total Capital Costs (incl. sunk & escalation for approval) 5,731 1,046 1,095 1,145 1,196 1,249 0 0 0 0 0

Annual Operating Costs

Patch Up Costs 454 500 100 100 100 100 100

0 0

0 0

0 0

0 0

0 0

0 0

0 0

Total Annual Operating Costs (real) 454 500 100 100 100 100 100 0 0 0 0 0

TOTAL CAPEX & OPEX COSTS (excl sunk) 4,869 5,424 624 1,169 1,190 1,211 1,232 0 0 0 0 0

Benefits (revenue/cost savings)

Residual Value 889 3,053 3,053

0 0

0 0

0 0

0 0

0 0

0 0

0 0

TOTAL BENEFITS (real) 889 3,053 0 0 0 0 0 0 0 0 0 3,053

NET BENEFITS/(COSTS) (3,980) (2,371) (624) (1,169) (1,190) (1,211) (1,232) 0 0 0 0 3,053

Sensitivity

Cost of Capital (Real) 5.06% 3.06% 7.06%

Net Present Value (NPV) (3,980) (3,638) (4,123)

Benefit Cost Ratio 0.183 0.28 0.12

Financial Evaluation (using a real pre-tax WACC)


Option 1 - Upgrade channel with reinforced concrete lining (Preferred Option)

FINANCIAL YEAR (June ending) Present Total Over 2014/ 2015/ 2016/ 2017/ 2018/ 2019/ 2020/ 2021/ 2038/ 2039/

Value Horizon 2015 2016 2017 2018 2019 2020 2021 2022 2039 2040


Capital Costs

Concrete Channel Capital Cost 5,238 5,238 5,238

0 0

0 0

0 0

0 0

0 0

0 0

0 0


Sunk Costs 522 522

Total Capital Costs (excl. sunk & escalation for NPV calc.) 5,238 5,238 5,238 0 0 0 0 0 0 0 0 0

Total Capital Costs (incl. sunk & escalation for approval) 5,760 5,760 0 0 0 0 0 0 0 0 0


0 0

0 0

0 0

0 0

0 0

0 0

0 0

0 0


TOTAL CAPEX & OPEX COSTS (excl sunk) 5,238 5,238 5,238 0 0 0 0 0 0 0 0 0



0 0

0 0

0 0

0 0

0 0

0 0

0 0


NET BENEFITS/(COSTS) (4,416) (2,416) (5,238) 0 0 0 0 0 0 0 0 2,822

Sensitivity






Option 2 Upgrade channel with inverted pre-cast culverts

FINANCIAL YEAR (June ending) Present Total Over 2014/ 2015/ 2016/ 2017/ 2018/ 2019/ 2020/ 2021/ 2038/ 2039/

Value Horizon 2015 2016 2017 2018 2019 2020 2021 2022 2039 2040


Capital Costs

6,445 6,445 6,445

0 0

0 0

0 0

0 0

0 0

0 0

0 0


Sunk Costs 522 522

Total Capital Costs (excl. sunk & escalation for NPV calc.) 6,445 6,445 6,445 0 0 0 0 0 0 0 0 0

Total Capital Costs (incl. sunk & escalation for approval) 6,967 6,967 0 0 0 0 0 0 0 0 0


0 0

0 0

0 0

0 0

0 0

0 0

0 0

0 0


TOTAL CAPEX & OPEX COSTS (excl sunk) 6,445 6,445 6,445 0 0 0 0 0 0 0 0 0



0 0

0 0

0 0

0 0

0 0

0 0

0 0


NET BENEFITS/(COSTS) (5,451) (3,031) (6,445) 0 0 0 0 0 0 0 0 3,414

Sensitivity






AppendixD- EnvironmentandHeritageAssessmentReport.

ContentsPurpose ................................................................................................................................................ 19

Background........................................................................................................................................... 19

Scope ................................................................................................................................................... 19

Happy Valley Spillway Land .................................................................................................................. 20

Happy Valley Reservoir Stockpile Management..................................................................................... 21

Contaminated Soil ................................................................................................................................. 24

Development Act Approvals .................................................................................................................. 25

Vegetation............................................................................................................................................. 25

Vegetation Removal Requirements ....................................................................................................... 26

Weeds .................................................................................................................................................. 27

Landscaping.......................................................................................................................................... 29

Fauna ................................................................................................................................................... 31

Heritage ................................................................................................................................................ 32

Aboriginal Heritage................................................................................................................................ 32

Water Affecting Activities....................................................................................................................... 33

EPA Licenses........................................................................................................................................ 33

Green House Gas Emissions ................................................................................................................ 33

Air Quality ............................................................................................................................................. 34

Storage & Handling of Dangerous Substances ...................................................................................... 34

Environmental Incidents ........................................................................................................................ 34

Fire ....................................................................................................................................................... 34

Sediment and erosion ........................................................................................................................... 34

Project Specific Environmental Management Plan................................................................................. 36

Key Contacts......................................................................................................................................... 39


PurposeThis Environment and Heritage Assessment Report explains the environmental assessment and approvals received to date, environmental controls required on site and reinstatement. The contractor is required to use this document to prepare their own Environmental Management Plan. This plan will need to include applicable environmental controls associated with the planned works. This plan will need to be reviewed by Environmental Services prior to commencing works and include a site plan.

BackgroundHappy Valley Dam is located in the southern suburbs of Adelaide and is used primarily as a head storage for water supply to a large part of the suburban water network. The dam has a small natural catchment, part of which is occupied by residential housing. A catch drain protects the reservoir from runoff from the surrounding suburbs during flood events.

The dam has an informal spillway (location detailed in Figure 1) whose crest is formed by a gravel access road. The spillway and catch drain both flows into an outfall channel that runs under Chandlers Hill Road and connects to Field River. The spillway channel is notionally designed to handle extreme flood outflows from the reservoir but is currently in a degraded condition. Large areas of the channel are experiencing active bed and bank scour, undercutting and collapse of channel banks, which in turn has resulted in deepening and widening of the channel. In addition to this, the channel is lined with a large number of mature trees which present a significant risk of collapsing into the channel during flood events. The channel, embankments and reserve are all SA Water owned land which abuts private residential properties. SA Water has also noted that the channel and its surrounding environment are highly valued by the local community for their amenity.

The Outfall channel is currently in poor condition and presents 3 main areas of concern:

Presence of a many large trees (located in or close to channel) that have the potential to fall in the channel, restricting flows and potentially causing local flooding and/ or risking Dam safety.

Significant active erosion resulting in the embankments being severely undercut in several locations. If not addressed this erosion will continue, contributing to increased slope instability.

Public safety/ SA Water liability exposure due to a 1.2m high stock fence being the only barrier between a 5-6m fall into the channel. A risk assessment has identified that the current fence is not adequate.

ScopeThe project requires the outfall to be upgraded within sections that are most at risk from collapsing and have also suffered the greatest degradation. This will stabilise the channel, reduce the likelihood of channel blockages causing property damage and increase the public safety of the site. The scope of work includes, but is not limited to:

Selective removal of trees that have been identified as causing a high risk of blocking the channel/flood mitigation, required for access to the channel for the upgrade works and trees recommended removal due to arborist recommendations for public safety.

Stabilisation of embankments that will cater for current and future flows, through installation of an anchored reinforced concrete slab and partial height side walls in consideration of longevity and the community views.

Approximately 1000m of new fencing.


Figure 1: Blue Line indicates the location of the Spillway.

HappyValleySpillwayLandThe Happy Valley Spillway is situated wholly on SA Water land; the planned excavation and lay down of equipment will be restricted to this location. The adjacent Happy Valley Reservoir will be utilised for stockpiling excavated material from the site and is all owned by SA Water. There is no private property access or land acquisitions anticipated in association with this project.

Happy Valley Outfall

Channel start point

Happy Valley Outfall

Channel end point at

wetlands


HappyValleyReservoirStockpileManagementThe Happy Valley Reservoir has been highlighted as the preferred location to stockpile excavated material from the Happy Valley Spillway. Approval has been obtained from the District leader of Mt Bold, who also looks after the Happy Valley Reservoir. He originally provided three suitable locations based on available open space, little presence of native vegetation and the presence of weeds. SA Water’s Environmental Impact Assessment Officer then reviewed these three sites against the Happy Valley Reservoir Land Management Plan and identified site 3 as the most suitable due to the Land Use Category description F2 –Previously cleared agricultural land, mainly planted with low diversity revegetation, with olive, bridal veil and boneseed invasion. A site visit confirmed the location due to its open space and area dominated by wild fennel (Land use detail from Happy Valley Reservoir Land Management Plan attached in Appendix 1).

The volume of material required to be stockpiled is estimated as 6000m3. This can be spread over a 4000m2 area at a height of 1.5m flattened on top (detailed in Figure 3). To adequately control sediment runoff from the stockpile Silt fences are required on the downward sides and a tow drain be installed to prevent sediment runoff into the Happy Valley Reservoir. The planned location is in Figure 2 below. In order to access the stockpile location a designated access track is required to be installed. The current access track to the weather station is to be utilised with a permanent extension of 150m to be made with dolomite with no rocks to be imported due to mowing and slashing in the area (location detailed in Figure 4).

Figure 2: Planned location for the stockpile and access track in relation to the reservoir.


Figure 3: 4000m2 area to stockpile 1.5m high

Figure 4: Access to planned Stockpile area


During the site inspection to determine the required area it was determine two small planted rows of Acacia paradoxa (approximately 15 bushes) on the north side of the planned stockpile area may need to be removed and/or impacted on in order to achieve a suitable batter (see Figure 5 below). This vegetation removal/trampling is permitted if required or land required in order to install a suitable tow drain.

Figure 5: Approved veg removal to Acacia paradoxa (approximately 15 bushes)

It was also noted Juvenile planted Eucalyptus trees were present on the southern side of the planned stockpile area. These are required to be bunted off with flagging outside their Tree Protection Zone to ensure no vehicle tracking or stockpile in this zone. Flagging off is required 2m from the edge of the drip line as detailed in Figure 6 below.

Figure 6: Juvenile planted Eucalyptus trees to be fenced off during works

Once the stockpile has been completed to 1.5m high and the area has been flattened, watered down (to avoid dust) the site is to be managed by SA Water’s Environmental Services Team to be sowed with native grass for site establishment.

The site itself already has a large population of a Fennel weed already present, the District Leader of Mt Bold is happy for the weed to be trampled on and buried under the planned stockpile. There is a risk the


excavated material may have Aleppo pine seeds present, however The District Leader of Mt Bold is notconcerned with this as they can treat this as required if they germinate.

SA Water’s Senior Asset Planner has confirmed the planned truck route over the dam wall is ok and there is no risk to the integrity of the dam wall, a suggested truck route has been developed in coordination with the District Leader of Mt Bold Reservoir (see below Figure 7 and a larger version attached in appendix 2). The Happy valley Reservoir access road is to be utilised by trucks during these works. A traffic management plan is required to be developed by the contractor for safe access for vehicles. The access track is required to be resinated to its original condition at the completion of the works.

Figure 7: Access to planned Stockpile area

ContaminatedSoilThere has been no contaminated soil identified as part of the project to date. However, there is a potential

of contaminated soil presence in the bed of the Happy Valley Spillway Channel due to stormwater runoff

from trafficable roads. Therefore the excavated material removed from the base of the channel is required

to be stockpiled separately at Happy Valley Reservoir. It is up to the contactor to determine the logistics of

this separate stockpile location within the proposed area. However it will need to be lined at the base and

covered after stockpiling to ensure no runoff from the stockpile occurs. It is SA Water’s preference this is

stockpiled at the furthest point from the Reservoir. This will then need to be sampled after the works to

determine if indeed it is contaminated. This is to limit the volume of material to be impacted on, so that if

further management of the material is required (e.g. dumping to an EPA licensed facility), this can be

achieved at a minimal dumping cost.


DevelopmentActApprovalsSimon Bower, Project Manager has receive advice from Simon Neldner, Principal Planning Officer at the Planning Office of the Development Assessment Commission (DAC) confirming there is no development approval required for the planned concrete lining of the spillway. However, a Development Application has been submitted for the removal of two regulated trees, see vegetation section below for further details.

VegetationThe Happy Valley Reservoir and associated spillway is located within the metropolitan area of Adelaide and therefore the legislation to protect Regulated and Significant Trees (Development Act 1993) is applicable to this project. The majority of the trees located along the spillway have been identified as Aleppo pine or Pinus halepensis (a pine native to the Mediterranean region). This species of tree is exempt from control under the current provisions of the Development Act 1993 due to its statusas an identified weed. Due to the large number of Regulated and Significant trees on site (see Figure 8 below), the listed weed species and the risk to public safety, an arborist report (attachment 3) was completed on 3rd October 2013 by Arborman Tree Solutions that included:

An assessment of the general condition and structure of the subject trees and others within the subject area.

Assess the trees against the current provisions of the Development Act 1993 relating toRegulated and Significant Trees.

Determine the extent and long-term effect of possible damage to the subject tree/sassociated with the adjacent development and supporting infrastructure.

Determine what risk the trees represent to users of the subject land or adjacent properties.

Recommend appropriate action for both the immediate and ongoing management of thetrees. This may include crown and root zone treatments and management principles.

Provide any additional relevant information as appropriate.

The report highlighted two trees that required approval through the DAC. An application to remove these two trees as per the arborist recommendations was submitted to DAC in late October 2013 under reference number 145/v020/13. SA Water have since spoken to the City of Onkaparinga Council Planning Officer who confirmed they have provided comment to DAC approving the removal and a final approval from DAC is imminent. Further to this, the contractor is required to review the arborist report and undertake recommended tree removals and tree trimming as specified in conjunction with community consultation.

The City of Onkaparinga Council also includes the Native Vegetation Act 1991 within their council area. Therefore any native vegetation within the project area that is remnant (not planted) is protected and requires an offset for its removal. SA Water has a Native Vegetation Standard Operating Procedure (SOP) with the Native Vegetation Council (NVC), which provides delegated approval for minor clearances to SA Water. A minor clearance under the SOP is defined as less than 0.5ha or 20 scattered trees. A clearance larger than this will require a NVC formal review and is expected to take 8-12 weeks. As per the attached arborist report the majority of the vegetation present at the Happy Valley Spillway is planted Aleppo pines, SA Blue Gum and Grey Box. A site visit will determine the presence of native remnant vegetation and if any are required to be removed.

The planned vegetation for removal includes:

Trees situated on the spillway and spillway banks that cause an immediate threat to spillway flow and risk blocking the channel (mainly Aleppo pines)

The trees recommended by the arborist in attachment 3 to be removed due to the risk to public safety.

Trees where the spillway will be widened and they cannot be retained

Selected weed species such as olives and peppercorn trees.


Trees to be removed to provide construction access to the spillway.

Figure 8: Vegetation present adjacent the Happy Valley Reservoir Spillway

SA Water will work collaboratively with the contractor to determine the trees that require removal for access to the site. The access tracks will be designed to follow the future walking tracks around the channel in an effort to retain existing vegetation where possible so the planned revegetation has a mix of advanced and juvenile trees.

There is a series if wallaby grass present adjacent the spillway on the northern side, to assist in future landscaping of the site, scrape the top 100mm of soil with the grass present and stockpile to one side for future use by the Environmental Services Team. This will be coordinated by the Environmental Services Team during on site direction.

VegetationRemovalRequirementsThe majority of vegetation to be removed from site will be Aleppo pines, these are to be mulched and taken to an agreed location at Happy Valley Reservoir for re-use next year as this takes time to stabilise prior to spreading of native plants. SA Water request a mix of approximately 1m cut logs/branches varying in lengths and thicknesses to be stockpiled out of the way for future landscaping feature use. Any Eucalypts that require removal in association with the works are to be retained on site in the form of approximately 1m logs (mixed lengths) and mulch to be stockpiled. All Olive removal, African boneseed, Falatious Aquatica and Peppercorn Tree removal and other weeds are to be taken off site to avoid the spread of weeds (see weed section below for details in regards to removal of weed species). SA Water to provide further site instruction during vegetation removal.

A site walkover is required between the contractor and the SA Water Environmental Services Team to confirm the trees to be removed to make way for the access track for machinery to the spillway. This access pathway will later form the basis for the pedestrian access pathway through the suite. Therefore the route will be chosen that will form a windy journey through the site rather than being up against the back fence of


the properties. The pathway will also be chosen to limit the native vegetation removal (where possible), and mature native trees will be given preference for retaining.

WeedsVehicles and machinery are to arrive clean and any materials brought on site must be from an approved weed free facility, approved by the Natural Resources Management Board. The martial excavated from the spillway site has the potential to transport Aleppo seed to the Happy Valley Reservoir. Extreme care must be taken to ensure not to spread this excavated material during truck hauling; all trucks are required to have covers pulled over when transporting loads. The District Leader of Mt Bold is not concerned with the stockpile having the potential to have seeds present as if they are contained they can be sprayed accordingly.

There is a section of Fallacious Aquatica weed present adjacent the western entrance to the spillway (Figure 9 below). This is a fire hazard and also a noxious weed, this soil to be scraped 50mm off the top and taken to a licensed waste facility.

Figure 9 Fallacious Aquatica to be removed from site.

There are numerous olive weeds situated adjacent the spillway that need to be removed to avoid spreading during works. Olive tree removal has to be done carefully to ensure it doesn’t spread in the process, there are numerous failed olive removal techniques evident throughout the site. Olive removal can be via the following methods:

Cut down and paintSuitable for all size plants, leaves a clean work site if debris is mulched. Mulch can be carted off site or sprayed directly onto stumps for re-use on site. This is highly effective and has the highest success rate. Application of chemical to stump is time critical (within 30 seconds), work is best completed in teams of two, one cutting, one painting. Repeat applications of herbicide are often used. Can be combined with drilling of lignotuber beneath the cut surface and fill holes with glyphosate if tree is large (>450 mm diameter). Notching of the cut stump surface is often used to increase surface area and enable pocketing of herbicide for improved absorption (photo attached).

Stump – lignotuber removalIf an excavator is available, removal of the lignotuber will result in death of the tree, even if some roots are left behind.


Stem injectionDepending upon exposure of the lignotuber either a drill and fill method or axe frill and dribble method can be used. Glyphosate is used as the injected chemical. Typically time consuming, and leaves a dead tree standing on site, mostly only suitable for trees with limited numbers of stems.

These methods can be mixed and matched to achieve the highest rate of complete kill, with decisions made by the operator for each situation. The branches with olives are to be taken off site, however the stem branches can be mulched on site for re-use. The waste martial (with olives) is to be taken to a licensed waste facility.

Figure 10 Olive Tree to be removed from site (some mulching of limbs to retain on site ok)

On the North West corner of the access to the channel there is African Boneseed that is likely to be disturbed in association with the works (Figure 11 below). If these are to be impacted upon they are to be removed to ensure not to spread it throughout the site. This is removed by a saw cut at the base and apply a swop with 1% glyphosate within 30 seconds of the cut applied to the fresh cut. The waste material is to be taken to a licensed waste facility.


Figure 11 African Boneseed to be cut and swabbed and removed from site

There is a Peppercorn tree on the South East corner of the site, at the back of a residents' property that is required to be removed in order to make room for the construction access and eventually new pathway through the site (Figure 12 below). This tree was also requested to be removed from the residents who live adjacent. This tree is required to be removed, mulched and taken offsite due to risk of spread of weeds through seed. SA Water Environmental Services have confirmed this tree is exempt under Development Act Regulated 2011 as a listed exempt species with the Onkaparinga Council arborist. The waste martial is to be taken to a licensed waste facility.

Figure 12 Peppercorn Tree to be mulched and removed from site.

LandscapingThe landscaping component of the works is to be coordinated by the Environmental Services Team and is separate from the contract with Bardavcol.A desktop assessment of the Happy Valley outfall channel was undertaken to determine the vegetation species based on Pre-European Vegetation Mapping of the site (DEWNR). This mapping indicates that the


site historically supported a Eucalyptus microcarpa +/- E. leucoxylon ssp. leucoxylon Woodland over a grassy and herbaceous understorey. SA Water’s Environmental Services will select numerous species from this vegetation community as a suggested sub-set for inclusion in the final Landscape Design, on basis of those species that are readily available from specialist indigenous plant nurseries, growth form, reliability and contrasting foliage texture and colour.

Figure 13: Pre-European Vegetation Mapping highlighting (in red) a historically supported an Eucalyptus microcarpa +/- E. leucoxylon ssp. leucoxylon Woodland over a grassy and herbaceous understorey.

The Happy Valley drain site is likely to occur within a distinctive soil type called a Black Cracking Clay (Bay of Biscay Clay). In Happy Valley this soil type was strongly associated with Grey Box Woodland Vegetation (Eucalyptus microcarpa). This Woodland Community is critically endangered under the Environmental Protection Biodiversity Conservation Act (EPBC). This is detailed in the red section in Figure 13.

Landscaping will aim to meet the objectives of the local residents including screening vegetation and trees of varying heights, while also incorporating locally sourced natives (where possible) of eucalyptus leucoxylon, eucalyptus microcarpa, eucalyptus camaldulensis, shrubs and ground covers. SA Water will also speak to the City of Onkaparinga Council to look for opportunities to link in with planned revegetation along creek lines.

Grey Box woodland Communities provide important natural habitats for many native animals such as possums, reptiles, butterflies and birds. Traditionally they extended from Sellicks Hill to Burnside, mainly along the Hills Face and Adelaide Plains. However since clearance its distribution has been reduced from over 20,000 hectares to under 2,000 hectares with most of the remaining woodland threatened by weeds, introduced animals, urbanisation and inappropriate recreational activities. The federal environment minister listed the Grey Box (Eucalyptus microcarpa) Grassy Woodlands and of South-Eastern Australia as an endangered ecological community in March 2010 on the advice of the Threatened Species Scientific Committee.

Other benefits of Woodlands include providing shelter for native fauna and wind breaks, and ecological communities with grassy ground layers have a degree of resilience and adaptability of ground vegetation during periods of drought and longer-term climate change.


Many of Australia’s ecological communities have been heavily cleared since European settlementand continue to be degraded. Ecological communities provide vital wildlife corridors and habitat refuge for many plant and animal species, including threatened species and other Australian plants and animals that are in decline. This is a rare opportunity to re-create this indigenous native vegetation corridor along a water source.

SA Water’s Environmental Services Team will coordinate the trees to be retained (where possible) around the spillway works. These will need to be fenced off during works with bunting to ensure no impacts on their tree protection zone. These trees will form the basis for the landscape plan that aims to reinstate a grey box woodland community.

FaunaA search of the Environmental Protection Biodiversity Conservation Act Search tool found Grey Box (Eucalyptus microcarpa) Grassy Woodlands and Derived Native Grasslands of South-eastern Australia listed as an endangered community in the area. This is the community we are trying to protect and re-establish through landscaping. There are numerous bird species both local and migratory that are listed as endangered and vulnerable. It is unlikely these will be affected during the project as their habitat will not be affected by the removal of mainly Aleppo pines, however extra care needs to be taken if vegetation which has the potential to have habitat value are required to be removed. Prior to all tree removals trees will need to be banged to allow native fauna to escape and bird nests to be relocated where possible. Contacts with parks and wildlife will be key here to maintain. Be sure to look inside trenches and pipes if left uncovered overnight. Call the Environmental Coordinator if any fauna is discovered in the project area. Seeing as the whole site will not be disturbed by the majority of the works, it is likely fauna can migrate to nearby vegetated areas as required.

Yellow-Tailed Black Cockatoo have been identified as prevalent in that area due to the presence of Aleppo Pines (one of their food sources). These will need to be identified during works to ensure no impacts on nested areas. There are alternative food sources of a native variety that can be introduced into the area to continue to promote a native environment, while also keeping the cockatoo is regular abundance. This has been requested by the residents in the local area. Yellow-Tailed Black Cockatoo favourite meal is those fruits that are present on the Hakea Carinata (see Figures 14 & 15). An erect shrub grows that grows to 1.5-3m tall, flowers through spring, easily grown from seed and looks after itself once established.

Figure 14 – Hakea Carinata- Fruits and Flowers


Figure 15 – Hakea Carinata- Fruits and Flowers

The Grey Box (Eucalyptus microcarpa) Grassy Woodlands of South-Eastern Australia provide valuable habitat for those animal species that are both resident and temporary visitors. In particular, the landscape position of the ecological community is such that it supports fauna, particularly birds, representative of the more temperate forest and woodland ecosystems, as well as species from the drier inland semi-arid environments.

HeritageThe Happy Valley Spillway is adjacent a State Heritage Site the Happy Valley Reservoir (Dam Wall and Towers). Constructed in 1896, this was the third significant water catchment structure to be completed to service the Adelaide metropolitan area and was prompted, in part, by the increase in water consumption created by the establishment of the water-borne sewage system in the early 1880s. The reservoir, fed by water via a tunnel from the Clarendon Weir (registered place 12711), is a relatively early example of a large and complex water storage system and reflects the expansion of Adelaide's population and improvements in the provision of public utilities. The construction of the earth dam wall and the 5 kilometre long inlet tunnel was a significant engineering project at the time. During works there is to be no excavation, parking of vehicles or lay down of machinery/equipment permitted in the Dam wall side of Chandlers Hill Road as to not impact on this Heritage Site. Truck movements are permitted on the dam wall as approved by the SA Water dam safety team.

AboriginalHeritageA request for the Happy Valley Spillway area was sent to Aboriginal Affairs and Reconciliation Division (AARD) to determine if the Central Archive, which includes the Register of Aboriginal Sites and Objects, contained entries for the project area, inclusive of a 2km buffer. AARD has advised there are entries for Aboriginal sites within the area searched for the project.

SA Water has reviewed the available information from AARD and consulted with relevant stakeholders, given the works work will be confined to existing highly disturbed areas, and the Grey Box (Eucalyptus microcarpa) Grassy Woodlands that previously encompass the area considers the risk of finding sites within the project/works area is low.

However, with any ground disturbing works that occur within an area that is deemed culturally sensitive there is a potential for encountering Aboriginal heritage. It is advised that sites or objects may exist in the proposed development area, even though the Register does not identify them and the ground is relatively disturbed. All Aboriginal sites and objects are protected under the Aboriginal Heritage Act 1988 (the Act),


whether they are listed in the Register or not. In the event, that any Aboriginal sites, objects or remains are found work should cease immediately contact made with Environmental Services. A Standard Operating Procedure (SOP) has been attached in appendix 4 to be provided to the contractors and is required to be referenced in their Environmental Management Plan. This SOP will need followed in the event that any Aboriginal heritage is discovered during the life of the project. To assist in what artefacts, tools or sites may look like please see Appendix 5 ‘DPC-AARD Identifying Heritage Sites Guide’ and Appendix 6 ‘DPC-AARD Identifying Stone Tools Guide’.

WaterAffectingActivitiesDue to the works excavating in the base of a watercourse a Water Affecting Activity Permit (WAAP) application was submitted to the Adelaide and Mount Lofty Ranges (AMLR) Natural Resources Management (NRM) Board on 12 November 2013. A WAAP was received (attached in appendix 7) from the AMLR NRM Board on the 13 January 2014 with 7 conditions, which are listed below:

1. This water affecting activity must be completed in accordance with the permit application (appendix 8).

2. The proposed works must be undertaken in a way that prevents silt or sediment leaving the site by the use of sediment control measures.

3. The proposed works must not have detrimental impact on the bed and bank stability of the watercourse.

4. The proposed works must not affect the migration of aquatic biota.5. The proposed works must not increase the risk of flooding upstream or down.6. There must be a minimum distance of 20 metres between a watercourse or well and the fuelling site

for machinery used to undertake construction.7. To reduce any potential risk of damage to the watercourse bed and banks construction shall not be

undertaken during a forecast high rainfall event and an elevated level of discretion will be used when operating in a watercourse in the days before and after severe rainfall . Weather forecasts reported by Bureau of Meteorology are available on-line and the seven day forecast must be checked before work commences.

EPALicensesBardavcol has been chosen as the preferred contractor who have a dredging license with the EPA. The dredging license has a series of conditions in regards to notice providing 7 days notice to the EPA prior to works, water quality requirements and a nominated fee of $623 per day ‘dredging occurs’. The further confirm what dredging means under a dredging license, SA Water’s Environmental Services Team met with the EPA Senior Environmental Protection Officer on the 28 February 2014. He confirmed that the works are only defined as ‘dredging’ when the base of the watercourse is excavated and physically removed from the channel. Therefore excavating the walls of the channel and moving the base material around the channel is not classified as ‘dredging’, and if therefore not required to pay the nominated daily fee. The nominated daily fee is required no matter how much or how little material is excavated from the base of the channel.

If any dewatering is required to be undertaken with the planned works this is to be aligned with the contractors earthworks and drainage license. This license has its own set of conditions that the contractor is required to adhere to, and has a nominated fee of ¼ of the dredging license fee at $155.75 per day. This is only required if greater than 100kL of water is required to be discharged as part of the whole job.

GreenHouseGasEmissionsAll machinery and vehicles should be shut off when not in use to minimise GHG emissions. All machinery and vehicles should be maintained in good working order to minimise GHG emissions. New contracts as of 1 January 2014 will involve revised greenhouse gas reporting requirements for our construction contractors.


SA Water Procurement will advise on these requirements (including providing new spreadsheet templates) at contract award (Guidelines and templates will be provided to the contractor at engagement). A summary of the changes includes:

Contracts above $4 million dollars will require reporting of Scope 1, 2 and 3 emissions.

Contracts below $4 million will require reporting of Scope 1 and 2 emissions only.

AirQualityDust will be generated during excavation and stockpiling of spoil. All exposed areas and stockpiles will be watered down to remove risks of dust spreading over the reserve area where required. Trucks are required to have loads covered when on public roads and in Happy Valley Reservoir. The stockpile area at Happy Valley is required to be watered down as required to manage dust.

Storage&HandlingofDangerousSubstancesThe only hazardous substance to be used during the project is fuel for the machinery and vehicles, this will need to be stored in a secure bunded aea. Ensure machinery is maintained in good working order to minimise drips and spills. No refuelling of machinery within 100m of a watercourse. Spill cleanup kit will be available on site at all times. Fuel to be stored in a bund at all times.

EnvironmentalIncidentsAll personnel on site will be inducted on the Environment and Heritage Report. An induction register will be maintained. Emergency procedures will be developed and all persons onsite will be inducted before entering. Spill cleanup kits will be available on site. Emergency contact numbers will be readily available/displayed across the site at all times and within the SEP. MSDS for all hazardous substances will be available on site at all times. An environmental incident register will be maintained, documenting all incidents that occur during construction.

FirePotential fire risks are associated with fuels and lubricants used in construction machinery as well as any required ‘hot works’ (e.g. grinders). The potential of these causing fires is low. Fire extinguishers are to be available on all work vehicles and machinery. Water storage is required to be on site when hot works are underway.

SedimentanderosionSediment runoff from stockpiles and excavated areas will need to be managed with silt fences as required.

Disturbed areas will need to be bunded and sediment control structures will be installed to prevent sediment

leaving the works area. Any excess soil should be used immediately on site or taken to an EPA licensed

landfill. Figure 16 below illustrates the installation technique of a silt fence.

To ensure no sediment runoff from excavation in the channel to the council stormwater lagoons and to

ensure compliance with the WAAP conditions, silt control structures or similar are required to be installed in

the channel to handle sediment runoff. Close attention to forecast rain events will be required to plan for

adequate sediment controls. A Sediment Erosion Drainage Management Plan (SEDMP) is required to

prepared by the contractor.


Figure 16: Installation technique of a sediment control fence

Key Notes:

Aboriginal Heritage Flow Chart SOP to be on site with each crew. All personnel on site will be inducted into the Environment and Heritage Report. No stockpiling in the drip line of any trees. Remnant trees to be fenced off in accordance with their Tree Protection Zones. When excavating in close proximity to trees, all roots 50mm in diameter or greater

are to be hand dug around and bridged over the trench. While every endeavour should be made to retain tree roots, if any tree roots are

broken during works <50mm they are to be clean saw cut. No refuelling of machinery within 100m of a the spillway. Minor tree trimming of the three protected trees is permitted up to 10% of the trees

canopy. All trucks are required to have covers pulled over when transporting loads. Excavated material from the bed of the watercourse is required to be trucked and

stockpiled separately at the Happy Valley Reservoir. See key weed removal detail for Olives, Fallacious Aquatica and African Boneseed. Silt fences are required on the downward sides and a tow drain be installed to

prevent sediment runoff into the Happy Valley Reservoir. A traffic management plan is required to be developed by the contractor for safe


access for vehicles. The access track around the Happy Valley Reservoir is required to be resinated to its

original condition at the completion of the works. The excavated material removed from the base of the channel is required to be

stockpiled separately at Happy Valley Reservoir - lined at the base and covered after stockpiling to ensure no runoff from the stockpile occurs.

The contractor is required to review the arborist report and undertake recommended tree removals and tree trimming as specified in conjunction with community consultation.

Prior to all tree removals trees will need to be banged to allow native fauna to escape and bird nests to be relocated where possible.

A Sediment Erosion Drainage Management Plan (SEDMP) is required to prepared by the contractor.

ProjectSpecificEnvironmentalManagementPlanThis plan is to be followed in conjunction with the Environment and Heritage Assessment report requirements detailed above.

Issue Controls

Sedimentation and

Erosion Excavated spoil to be stockpiled away from vegetated and drainage

lines. Excavated areas and spoil to have silt fences placed on the downward

side if on slope or adjacent a watercourse. No stockpiling in the drip line of any trees. Disturbed areas will be bunded. Sediment control structures will be installed to prevent sediment

entering drainage systems on haul roads. To limit the tracking of mud and/or soil on to public roads, vehicles

will be inspected and cleaned down if required. Effectively control surface runoff entering and leaving the site. Install erosion control works and measures to minimise the amount of

soil erosion. When required, install sediment collection devices to prevent the export

of sediment from the site.Water Quality Dewatering of excavation/trench via vac truck or pumped to SA Water

land. No discharge of dirty water to a watercourse Or use the License conditions associated with the Earthworks and

Drainage License


Issue Controls

Water greater than 20NTU not to be discharged to a wet watercourse. Air Quality Water cart to be used if required to wet-down the work area if dust

persists. Any trucks transporting material from the site will be covered

immediately after loading to prevent spillage. All machinery and vehicles shall be maintained in good working order

to minimise Green House Gas Emissions. All machinery and vehicles are to be shut off when not in use to

minimise Green House Gas Emissions. In the event of dust levels on site becoming a nuisance or unacceptable,

measures will be taken to suppress the dust using water. Dust may be generated during excavation. Deposit material directly

into truck where possible and if stockpiling of spoil is required it is to be wet down as required. All exposed areas and stockpiles will be watered down as required.

Flora and Fauna If distressed fauna found on site alert the Environmental Coordinator. No stockpiles / equipment to be placed within the drip line of trees. Avoid impacts to roots (10m from drip line optimal) wherever possible.

If any roots are discovered during the works these are to be bridged where possible (roots 50mm or greater). Roots discovered less then 50mm which are broken are to be clean cut with a saw.

All machinery and vehicles are to follow existing tracks, roads or cleared road verges, or enter through previously disturbed, cleared vegetation/disturbed corridors.

Routes to be chosen to minimise damage to isolated mature trees and shrubs.

If further tree trimming or vegetation removal is required, please call the SA Water Environmental Services Team to discuss. No further tree trimming or vegetation removal is approved without consultation with the SA Water Environmental Services Team.

See vegetation section in the Environmental and Heritage Report for details of which trees to mulch and which trees to retain/remove from site.

Avoid the removal of living or dead branches which contain hollows or nests. Check for flora and fauna prior to disturbance. If any fauna is found, advise the SA Water Site Representative who will report details of discovered fauna to the SA Water Environmental Services Team for relocation if required.

Waste Management No general waste to be left on site – site to be kept clean. Any regulated waste to be disposed of at licensed facilities and

dockets/certificates to be reported to the Environmental Coordinator. All wastes (food, packaging, human waste, etc) will be removed from

site and disposed of appropriately. Covered bins will be provided. Access to amenities will be provided for the construction workforce. Weeds to be taken to a licensed EPA Landfill.

Storage / Handling of

Hazardous Materials

Spill kit to be available on site at all times during works. No refuelling of machinery within 20m of a watercourse. Spill cleanup kit will be available on site at all times. Fuel to be stored in a bund at all times. Fuel trailers/containers should

be located within a bunded area that can accept a minimum of 133% of the volume of the fuel containers stored within.


Issue Controls

No concrete washout to occur on site. Minimise quantities of hazardous substances, fuels and lubricants

stored on site. Store and handle chemicals / hydrocarbons as per the product MSDS. MSDS to be available at all times for hazardous substances that are used or stored.

Noise and Vibration Work hours are from 7am until 7pm Monday – Saturday unless otherwise approved.

Excessively noisy plant / equipment to begin works at 9am.Aboriginal Heritage If Aboriginal heritage items are discovered during construction all work

would cease immediately and an SA Water representative would be contacted.

Work would not start again until written authorisation to do so has been received from the Minister for Aboriginal Affairs and Reconciliation.

Follow the Discovery of Aboriginal Heritage During Works Stop Work Procedure stop work and call the Environmental Representative immediately should any unexpected finds be encountered.

Heritage Sites The Dam wall is not to be used as a stockpile area. Dam wall access track is to be reinstated to original condition.

Weed and Pest Control Ensure that all plant / vehicles / equipment arrive clean. Materials bought on site must be from an approved weed free facility

and ensure the source of any imported fill is weed/pest free. Contractor must confirm imported fill is weed/pest free with the local Natural Resources Board.

Site to be kept clean. Sediment control measures to be used to minimise the spread of weeds. See Environment and Heritage Report detail for specified weed

removal techniques.Emergency Management Site Emergency Procedure to be followed.

Fire Prevention If hot works undertaken extinguishers and water to be available on site. Fire Extinguishers to be fitted to each vehicle.

Contamination The discovery of contaminated soil is to be immediately reported to the

SA Water Site Representative so as the appropriate authorities can be notified.

In the case of unusual odours or visual observation being made during excavation, work is to cease and the SA Water Environmental Coordinator contacted.

See stockpile requirements for excavated material from the base of the channel in the Environment and Heritage Assessment Report.

Traffic Management Traffic management plan required for vehicles exiting the spillway site and entering the public Chandlers Hills Road.

Traffic Management Plan with turnaround areas and locations for safe passing in the Happy Valley Spillway.

Visual Amenity Site to be kept clean and tidy.

Inspection and

Monitoring

As required by the Environment and Resources Services Team.

Green House Gas

Emissions

All machinery and vehicles should be shut off when not in use to minimise GHG emissions.

All machinery and vehicles should be maintained in good working


Issue Controls

order to minimise GHG emissions. Scope 1 and 2 emissions are required to be tabled for SA Water

Greenhouse reporting.

KeyContacts

Area Details Number

Project Manager Chas Allen 0488 451 042

Stakeholder Alyssa Freeman 0408 836 772

Environmental Alex Czura 0433 122 655

PWC Happy Valley Outfall Channel Upgrade Project WITHOUT COSTING COMMENT

Documents