A NSW Government website

Wyangala Dam

Frequently Asked Questions

Project snapshot

In October 2019, the Prime Minister and NSW Premier announced the planning and delivery of three new or augmented dams in NSW. The NSW and Commonwealth governments are jointly investing in these major dam projects to secure water supplies for regional NSW.

Included in this package was the raising of Wyangala Dam wall to provide thousands of Lachlan Valley residents, businesses and communities with improved water security and increased drought resilience. The Wyangala Dam Wall Raising project has been declared Critical State Significant Infrastructure.

As part of the Wyangala Dam Wall Raising project’s final business case, the team is assessing infrastructure and non-infrastructure options to improve water security and reliability in the Lachlan Valley.

The Wyangala Dam Wall Raising project will involve raising the Full Supply Level (FSL) by 10 metres, which will increase storage by 53 percent – an additional 650 gigalitres.

The Final Business Case and EIS are underway.

A new water treatment plant at Wyangala is being delivered as part of the early work, with construction starting later in 2021 (Public health orders permitting).

When did the Wyangala Dam Wall Raising project transition to Water Infrastructure NSW?

The NSW Government has recently established Water Infrastructure NSW, which sits within the Department of Planning, Industry and Environment. This agency will be responsible for delivering critical water infrastructure projects in NSW and provide a coordinated and unified infrastructure delivery approach across several NSW water agencies. The model of infrastructure specific delivery agencies has successfully been used in education and health over several years.

This means that from 1 July 2021, responsibility for the proposed Wyangala Dam Wall Raising project transitioned from WaterNSW to the Department of Planning, Industry and Environment’s Water Infrastructure NSW, which is a Division of the Water Group.

As the owners and operators of Wyangala Dam, WaterNSW will continue to work with the project team. Why increase storage at Wyangala?

The past 20 years have demonstrated the Lachlan Valley’s susceptibility to climatic events, with the Millennium drought causing profound hardship through consecutive years of zero to little general security water allocation, and towns and mining companies experiencing water restrictions for extended periods.

Recently the region has experienced further drought, once again bringing hardship through more years of zero to little general security water allocations and water restrictions for towns.

Wyangala Dam’s storage fell as low as nine percent at the peak of the drought crisis during the summer of 2019-20, and in February 2020, the Lachlan Valley was in drought stage 4. At that time, if the drought were to continue and there were zero inflows, four major regional towns would have had less than 18 months until their only water source ran out – Cowra with a population of 10,000 residents, Forbes with 8,400 residents, Condobolin with 3,500 residents, and Lake Cargelligo with 2,600 residents.

At the other extreme, communities and farm families in the Lachlan Valley downstream of Wyangala Dam suffered extensive flooding in 2012 and 2016. In 2016, crop losses alone were valued at $500 million.

This pattern is set to continue unless a change in storage capacity provides resilience.

In the State Infrastructure Strategy Review 2014, the Lachlan Valley scored the worst of all valleys, with low and medium scores across their index assessment including for irrigation drought security, flow utilisation, flood management and delivery efficiency.

This project will reduce the risk and impact of climatic events (both floods and droughts) and mitigate associated social and economic impacts:

  • Without the increased capacity it is estimated that the region would fail to realise its full economic potential with agriculture production likely to be two to three times less productive than comparative agriculture.
  • The potential loss in production could equate to a loss in annual economic uplift of $167 million (Lachlan Valley Water Security Preliminary Business Case).
  • Wyangala Dam has filled and spilled at least eight times since the spillway gates were installed in 1971, including in 2012 and 2016 and more recently with the controlled releases in 2021.
  • Had the Wyangala Wall Raising project been delivered earlier, the 2012 flood event would have filled the new dam. The 2016 rains would have spilled over the new dam wall. Based on experiences of past events, these floods would have given us more than one extra year of water supply for the 100,000 people living across the Lachlan Valley.
  • Between 2017 and 2020 the region experienced severe drought, bringing hardship through more years of zero to little general security water and severe water restrictions for towns.

What are the benefits of the project? 

There are many benefits which will be realised during and after the construction of this project, including:

  • Regional economic growth during both construction and operation
  • Improving productivity of primary industries
  • Providing greater certainty around water availability to support additional investment by businesses and allow a transition to higher yield agricultural products
  • Providing clean, safe drinking water to Wyangala and Wyangala Waters Holiday Park through a new water treatment plant in this township
  • Securing the region’s urban water supply, stimulating the growth of the regional economy and supporting future population growth.

As a result of the project itself:

  • Dam storage capacity will be increased by 53 percent
  • An additional 21GL per annum estimated yield will be achieved for general security license use.

A significant improvement for the Lachlan Valley in:

  • Water security
  • Drought resilience
  • Flood attenuation
  • Local business and employment opportunities

How long will this project take? 

If the project is approved, construction of the raised wall is estimated to take about four years, depending on the final design and staging.

As planning, hydrology modelling, field surveys and site investigations offer insight into the complexity and scope of this project, a clearer understanding is emerging on likely timeframes and scheduling for key stages of the project.

The proposed Wyangala Dam Wall Raising project is in the planning stage with the business case expected to be submitted to the NSW Government in 2022.

Construction work on the main dam wall would only take place if all government approvals are obtained.

How will this project be delivered?

The project’s construction program will start with an early work package that includes a new water treatment plant at Wyangala.  In April, the NSW Government announced the successful contractor for this work was Enviropacific Services.

The water treatment plant is a ‘no regrets’ project because it will provide clean drinking water for the Wyangala township and the Wyangala Waters Holiday Park. This project is in detailed design and construction will start later in 2021 (Public health orders permitting).

Work is also continuing on Reflections Wyangala Waters Holiday Park and Grabine Lakeside Holiday Park, to reconfigure the location of van and amenity sites which will be inundated from the dam’s additional storage capacity.

In parallel, the NSW Government has announced the appointment of two prospective design and construction partners for the Wyangala Dam Wall Raising project main wall.  After an extensive assessment process, Acciona and Seymour Whyte have been shortlisted because of their strong regional experience as well as expertise in dam projects and major complex infrastructure.  This contracting approach is called an Alliance Partnership.

Each partner is working closely with the project team to develop two separate potential designs for the project and provide expert construction advice for the business case and environmental impact assessment.

The successful contractor is expected to be announced in 2022.

Construction work on the main dam wall would only take place if all government approvals are obtained.

How much will it cost?

The NSW and Commonwealth governments are jointly funding this project. Before the project can proceed, in addition to NSW and Commonwealth governments’ planning approvals, a final business case will be considered by the both governments to ensure the project is delivering value for money for the people of NSW.

Planning and approvals

What is a state significant project? 

The Wyangala Dam Wall Raising project was declared as Critical State Significant Infrastructure (CSSI) in 2019. A CSSI project is essential for NSW for economic, environmental or social reasons.  Because this is a CSSI project, some planning stages are being carried out in parallel.  This approach is standard practice for major infrastructure which is declared CSSI.

The Wyangala Dam Wall Raising project is in the planning stage with the Final Business Case expected to be submitted to the NSW Government in 2022.

Construction work on the main dam wall would only take place if all government approvals are obtained.

Will this project go ahead?

The Wyangala Dam Wall Raising project is in the planning stage. Projects of this scale are complex and significant work is required before final approvals are obtained. There are a number of approvals required at both NSW and Australian Government levels which need to be obtained.  If these are obtained, then construction work on the main dam wall raising will start.

How will this project be assessed and approved?

The NSW Environmental Planning and Assessment Act 1979 (EP&A Act) and Environmental Planning and Assessment Regulation 2000 (EP&A Regulation) form the statutory framework for environmental assessment and planning approval in NSW and Australia. This project will also require Commonwealth Government approval as the Department of Agriculture, Water and Environment has determined it is a controlled action under the Environment Protection and Biodiversity Conservation Act 1991. This means the Wyangala Dam Wall Raising project will need an environmental approval from both the NSW and Commonwealth Governments.

The project team is continuing work on the business case which will be submitted to the NSW Government in early 2022.

Is the design finalised?  

The concept design for the Wyangala Dam Wall Raising is finalised and detailed design is underway as the project progresses through the planning.

We have appointed two prospective design and construction alliance partners, Acciona and Seymour Whyte, who bring extensive dam and complex major infrastructure experience to work with the project team on the design and construction staging.

What is the staging of the project? 

The first stage of the project is the delivery of a new water treatment plant to provide clean, safe drinking water in the Wyangala township and the Wyangala Waters Holiday Park. We refer to this treatment plant as ‘no regrets’ project as it is separate from the wall raising construction and brings significant local benefits.

In April 2021, the NSW and Commonwealth governments announced the contract to deliver the new water treatment plant had been awarded to Enviropacific Services. The new water treatment plant will be able to deliver up to 800,000 litres of clean drinking water each day.

Detailed design of the plant has now been completed, and construction will start later in 2021 (Public health orders permitting).

This work is going through a different planning approval pathway. The approvals process for the water treatment plant at Wyangala is on track with a Development Application (DA) lodged with Cowra Shire Council in October 2021. The DA will also require a ministerial approval of specific works under Section 60 of the Local Government Act 1993.

Water Infrastructure NSW is continuing with the design, business case and Environmental Impact Statement for a 10m increase in the Full Supply Level (FSL) for the Wyangala Dam.

Main construction work will include:

  • Raising the embankment and downstream rockfill to add an additional 650GL of storage
  • Raising the spillway and intake towers of the dam.

Because this project is a Critical State Significant Infrastructure, some planning stages are being carried out in parallel. The Final Business Case is expected to be submitted to the NSW Government in 2022.

Construction work on the main dam wall would only take place if all government approvals are obtained.

Landowners

Will my property be inundated from the increased storage level? Is my land going to be flooded? 

The hydrology and flood modelling and inundation mapping is complex work, and it is critical that we get it right.  Water Infrastructure NSW has spoken with all landowners believed to be impacted by inundation at their property based on early data and mapping.

Water Infrastructure NSW is continuing with the design, Environmental Impact Statement and Final Business Case for a 10m increase in Full Supply Level for Wyangala Dam.

We have started discussions with impacted landowners and inundation mapping was provided to them in June 2021.

The project team is continuing modelling and land survey work to further inform inundation impacts on properties and the acquisition of land due to inundation.

Inundation of this land is not expected to happen until after the proposed dam wall is built and there has been sufficient rain to fill the reservoir.

How is the modelling and mapping done?

The hydrology and flood models use historical data and predictive forecasts including the effects of climate change. Several iterations of the models are done to check they accurately reflect the movement and storage of water in, upstream and downstream of the dam.

For this project we are carrying out significant land surveying work including both by air and on the ground at many locations around the current reservoir to provide this detail into modelling as well as planning and design work. Additionally, we have gathered information from local residents, emergency services, councils and other government agencies including feedback about significant historical rain events.

We are continuing our modelling and mapping work and will use this information to guide design, environmental assessment, and the Final Business Case.

We will continue to work with key stakeholder groups and local community members to build our understanding of the current and future movement and storage of water for the reservoir and along the Lachlan River system.

What does the acquisition process look like, for example, how will Water Infrastructure NSW determine price?

The land acquisition process considers the level of inundation and use of the property, including if it is a business, and will generally include site inspections and consultation, as part of the valuation.  This information will then be used to inform one-on-one negotiations with each of the impacted landowner. Water Infrastructure NSW will work to the requirements of the Land Acquisition (Just Terms Compensation) Act 1991.

This process is used by the NSW Government for land acquisition.  For more information about this process, visit the NSW Government Centre for Property Acquisition.

This process will involve independent market appraisals and include support to property owners to undertake their own valuations to inform the negotiation process. Landowners will also be provided upfront agreed support for legal services and have a personal case manager appointed to guide them through the process.

For partial acquisitions, different options may be considered. This may involve, for example, where appropriate and where agreed, a lease back to the original owner if land may only be inundated periodically. The ’free from inundation’ period would need to be of sufficient duration to make a lease a suitable option (for example, an inundation occurrence of once every 10 years).

Water Infrastructure NSW will need to acquire all newly inundated land before construction of the raised dam wall is completed.

Construction work on the main dam wall will only take place if all government approvals are obtained.

Am I going to be paid out to the equivalent of starting my enterprise in the same capacity somewhere else? 

Business enterprises are considered as part of property valuations and negotiation process depending on the level of impact. If relocation is being considered, you may be asked to provide information about your existing enterprise to support the negotiation process.

This process is used by the NSW Government for land acquisition. For more information about this process, visit the NSW Government Centre for Property Acquisition.

How can early construction begin in 2021? Shouldn’t our land be acquired before any construction starts?

The first stage of the project will be the building of a new water treatment plant to provide clean drinking water in the Wyangala township and the Wyangala Waters Holiday Park.

In April 2021, Enviropacific Services was appointed as the contractor to build and commission the new plant.  The new water treatment plant will be able to deliver up to 800,000 litres of clean drinking water each day. Detailed design of the plant has now been completed, and construction will start later in 2021. This work is going through a different planning approval pathway. The approvals process for the water treatment plant at Wyangala is on track with a Development Application (DA) lodged with Cowra Shire Council in October 2021. The DA will also require a ministerial approval of specific works under Section 60 of the Local Government Act 1993.

The proposed Wyangala Dam Wall Raising project is in the planning stage with the Final Business Case expected to be submitted to the NSW Government in 2022.

We have started early discussions with impacted landowners about the acquisition process. Property acquisition with impacted landowners will start after government approvals are obtained and must be finalised before the dam wall construction is complete.

Can the acquisition process be fast tracked to settle within six months?

Acquisition is likely to be different for individual impacted landowners as it will depend on their needs, the valuation and negotiation process. There is a minimum period of six months that landowners and other interest holders are entitled to negotiate an outcome before the compulsory acquisition process can commence.

The project team has progressed hydrology modelling to be sufficiently detailed to inform inundation levels around the reservoir. Inundation maps were provided to impacted landowners in June 2021. We have started early discussions with impacted landowners about the acquisition process.

Water Infrastructure NSW will talk with individual landowners about the timing of acquisition and settlement – we’ll work closely with landowners throughout this project.

What if I don’t want to sell?

Water Infrastructure NSW understands that if your property is identified as being affected from the raised water levels this can create concern and anxiety for landowners, their families and about their enterprise. We are working closely with impacted landowners throughout this process and are working in accordance with statutory requirements.

This process will involve independent market appraisals and include support to property owners to undertake their own valuations to inform the negotiation process. Landowners will also be provided upfront agreed support for legal services and have a personal manager appointed to guide them through the process.

This process is used by the NSW Government for land acquisition. For more information about this process, visit the NSW Government Centre for Property Acquisition.

Water Infrastructure NSW will endeavour to reach a negotiated outcome within the project timeframes. Compulsory acquisition of land will only occur when necessary.

Van owners

Will my van site be inundated from the dam’s increased storage capacity?  

We are continuing to do hydrology and flood modelling which will inform the inundation levels at Wyangala Waters and Grabine Lakeside Holiday Parks. The hydrology and flood modelling and inundation mapping is complex work, and it is critical that we get it right. This includes land surveying at the holiday parks and on other private properties to provide more detail on topography which will help inform our project. We have confirmed inundation levels at both holiday parks and provided maps with this information to van owners in June 2021.

Can I move to a new location?

We are continuing to work with Reflections Holiday Parks management team including how many sites will be in each of the new precincts. This work includes designing areas for van sites, amenity buildings and other support infrastructure. Once design of the precincts is finalised, we will work with the Reflections management team to understand how they want to do allocations of new sites.

Can I move with friends?  

We understand this is a key concern for some van owners. It is expected to be one of many factors considered as part of relocation planning. Moving with friends will depend on several things including how many sites are in each precinct and the layout of these sites. We will work with Reflections Holiday Parks to accommodate van owner requests as best we can.

Can I have the same set up in the new location?

Each van owner has a very individual set up at their current site so there is no single answer to this question. It will depend on the size and make up of your current installation and the size of the new site you are allocated. Additionally, all new sites will need to be fully compliant with current regulations. This could mean, in some instances, that part of your current set up may not be able to be relocated. We will work directly with individual van owners on this matter.

Will everything be like for like in the new location? 

Park amenities will be like for like, or better. All new sites will be able to connect to clean drinking water, electricity, and sewage. Additionally, all new sites will need to be fully compliant with current regulations. We will work directly with individual van owners to understand which parts of their installation can be relocated.

What arrangements will be made for relocation? 

Some van owners have asked if their installations will be moved for them, or will they need to do it themselves. We don’t want to presume that one option suits everyone, so this will be part of our discussion with each van owner. Some people may wish to move their van and set up while others may not. Some aspects to be considered will be van owners’ preference and the feasibility of relocating your van.

Will Wyangala Waters and Grabine Lakeside Holiday Parks close during construction?       

Both holidays parks will remain open throughout the construction work. Van owners and recreational users will have access to the dam and holiday park. At times, there may be some changes to amenities and access, but the project team will work closely with Reflections Holiday Parks management team to minimise impacts for holidaymakers and keep van owners and casual recreational users updated as the project progresses.

Local businesses and jobs

Will this project create jobs locally? 

Yes. A key guiding principle for this project is to maximise local employment opportunities and benefits to local businesses. To help with this a portal has been developed where local businesses are able to register their services and products. This information will be provided to all contractors.

We are also working closely with business chambers and progress associations in the Lachlan Valley to encourage all local businesses to register their services and products. We will need the services of a broad range of businesses throughout the project including, but not limited to, plant and equipment hire, civil engineering, electrical installation, fabrication, printing, catering, cleaning, traffic management and material haulage.

In addition, we will require our main works contractors to demonstrate how they will maximise local businesses and people as part of the tender process. Water Infrastructure NSW project partners and contractors will be selected on the basis in part on their track record in using local suppliers and maximising local benefits from their projects.

The project’s construction program will start with an early work package including a new water treatment plant at Wyangala. In April, the NSW Government announced the successful contractor for this work was Enviropacific Services.

The new water treatment plant will be able to deliver up to 800,000 litres of clean drinking water each day. Detailed design of the plant has now been completed, and construction will start in 2021 (Public health orders permitting). This work is going through a different planning approval pathway (a development application and a Department of Planning, Industry and Environment Section 60) than the main construction of the dam wall.

The NSW Government has announced the appointment of two prospective design and construction partners for the Wyangala Dam Wall Raising project main wall construction. After an extensive assessment process, Acciona and Seymour Whyte have been shortlisted because of their strong regional experience and expertise in dam projects and major complex infrastructure. This contracting approach is called an Alliance Partnership.

We will provide regular updates on the use of local businesses, people and spend and encourage businesses who have registered to join us on regular webinars which will include members of the contractor teams in the future.

If you are a business who would like to register with the project, sign up to our local business register. For this project local business is defined as 150km from the project area, including Condobolin. Please note registering your interest does not guarantee employment.

We are a local business chamber or progress association. How can we be involved to support the project? 

Water Infrastructure NSW is working closely with local business chambers and progress associations to maximise opportunities and economic benefit in local villages, towns, and cities. Building these collaborative relationships and providing regular updates are important to the project team and we look forward to identifying more opportunities to work together throughout the project. If your group would like an update, please contact the project team on 1800 735 822.

We are a local employment agency. How can we partner with the project to seek employment opportunities for unemployed locals? 

We have established a portal for local businesses to register their interest and these details will be supplied to all project contractors. Water Infrastructure NSW project partners and contractors and part of the evaluation for tenders will be based on their submission and their track record in using local suppliers and maximising local benefits.

If you are a business who would like to register with the project, sign up to our local business register. For this project local business is defined as 150km from the project area, including Condobolin. Please note registering your interest does not guarantee employment.

What types of businesses can register?

Major projects use a wide range of services when planning and building infrastructure for governments.  The project team will need to procure a wide range of construction service providers and contractors for both the new water treatment plant at Wyangala and the main dam wall.  Examples of some other types of services which are likely to be needed include catering, printing, accommodation, vehicle hire, stationary, office equipment, furniture and training services.

If you are a business who would like to register with the project, sign up to our local business register. For this project local business is defined as 150km from the project area, including Condobolin. Please note registering your interest does not guarantee employment.

Procurement

Will you be employing local contractors for the construction phase of the project? 

For the Wyangala Dam Wall Raising project, we are seeking to maximise local benefits and the use of local people and businesses. To achieve this, we have established a portal for local businesses to register their interest and these details will be supplied to all project contractors.

Water Infrastructure NSW project partners and contractors and part of the evaluation for tenders will be based on their submission and their track record in using local suppliers and maximising local benefits.

If you are a business who would like to register with the project, sign up to our local business register. For this project local business is defined as 150km from the project area, including Condobolin. Please note registering your interest does not guarantee employment.

Will you be using one contractor for all construction work? 

We will be using different contractors throughout the project.

The project’s construction program will start with an early work package including a new water treatment plant at Wyangala. In April, the NSW Government announced the successful contractor for this work was Enviropacific Services.

The new water treatment plant will be able to deliver up to 800,000 litres of clean drinking water each day. Detailed design for the plant has now been completed and construction will start in 2021. This work is going through a different planning approval pathway (a development application and a Department of Planning, Industry and Environment Section 60) than the main construction of the dam wall.

The NSW Government has announced the appointment of two prospective design and construction partners for the Wyangala Dam Wall Raising project main wall construction.  After an extensive assessment process, Acciona and Seymour Whyte have been shortlisted because of their strong regional experience as well as expertise in dam projects and major complex infrastructure.  This contracting approach is called an Alliance Partnership.

We will provide regular updates on the use of local businesses, people and spend and encourage businesses who have registered to join us on regular webinars which will include members of the contractor teams in the future.

We are seeking to maximise local benefits and the use of local people and businesses. To achieve this, we have established a portal for local businesses to register their interest and these details will be supplied to all project contractors.

If you are a business who would like to register with the project, sign up to our local business register. For this project local business is defined as 150km from the project area, including Condobolin. Please note registering your interest does not guarantee employment.

When will the construction contractors be starting? 

Early works for this project is a new water treatment plant at Wyangala, with the successful contractor Enviropacific Services announced in April 2021. The new water treatment plant will be able to deliver up to 800,000 litres of clean drinking water each day. Design work is underway, and construction will start later in 2021 (Public health orders permitting). Procurement for the water treatment plant will happen in stages with tendering for services starting before the end of 2021.

This work is going through a different planning approval pathway (a development application and a Department of Planning, Industry and Environment Section 60) than the main construction of the dam wall.

The NSW Government has announced the appointment of two prospective design and construction partners for the Wyangala Dam Wall Raising project main wall construction. After an extensive assessment process, Acciona and Seymour Whyte have been shortlisted because of their strong regional experience as well as expertise in dam projects and major complex infrastructure. This contracting approach is called an Alliance Partnership.

Each partner will work closely with the project team to develop two separate potential designs for the project and provide expert construction advice for the project’s Final Business Case and Environmental Impact Statement.

The successful main works contractor will be announced in 2022 if the all government approvals are obtained. Construction work on the main dam wall would only take place if all government approvals are obtained.

Water users and licences

Will new water licences be made available? 

This project aims to create greater security and reliability for existing water licences in the Lachlan Valley. There are no intentions for any new water licences to be provided following the raising of the Wyangala Dam wall.

Will the extra water be used to supply the city of Orange? 

The project aims to provide better water reliability for the Lachlan Valley. Orange is within the Macquarie River catchment. There are no plans to transfer extra water captured in the Wyangala Dam to the city of Orange.

Will the extra water be used for new or existing mining operations?  

There are no intentions for any new water licences to be provided following the raising of the Wyangala Dam wall. This includes new and existing mining operations in Central West NSW.

Will the project costs be recovered from water users?

As part of developing the Final Business Case, the estimated project costs are being refined and a funding strategy is being prepared. The funding strategy will identify the costs that need to be recovered by water users. Once this is determined, the Independent Pricing and Regulatory Tribunal (IPART) will be asked to ensure the share of the cost borne by water users is fair and affordable.

IPART’s role is to independently set prices for water to reflect the efficient cost of providing services and ensure fair prices for customers. All other costs above the customer share determined by IPART will be met by the NSW Government.

The process IPART uses to make a price determination for water users involves an extensive consultation and review process, allowing ample opportunity for local issues and concerns to be raised and addressed. The IPART price determination will typically take into account:

  • The cost sharing arrangements between users and the Government
  • Any grant funding arrangements
  • Any agreements or arrangements for the ownership of the assets
  • Where relevant, any costs recovery arrangements negotiated directly with the customers.

Because of these factors, the Government is unable to provide an accurate assessment of the bill impact at this time.

Will dam storage be impacted during construction? 

We understand this is an important issue for many in the community. The dam must remain operational and safe throughout construction for the raising of the Wyangala Dam wall.

WaterNSW has experience in successfully undertaking significant dam-raising and modification works in an active operating environment, without impacting water users. Water Infrastructure NSW will continue its extensive engagement to date with landowners and other stakeholders to build on our understanding of any potential impacts.

Water Infrastructure NSW is currently working with the two shortlisted main construction alliance partners, Acciona and Seymour Whyte at construction staging and engineering solutions and designs to minimise impacts on the water level in the dam throughout construction. This work is ongoing.

Environment

What is an Environmental Impact Statement?

For any project that is classified as a Critical State Significant Infrastructure (CSSI) project, Water Infrastructure NSW is required to produce an Environmental Impact Statement (EIS). The EIS pathway is a hugely important process that requires Water Infrastructure NSW to understand environmental, economic and community impacts that could arise, and subsequently propose measures to effectively mitigate those impacts.

The NSW Department of Planning, Industry and Environment has issued Secretary’s Environmental Assessment Requirements (SEARs) for the Wyangala Dam Wall Raising project. The SEARs identify matters which must be addressed in the EIS and essentially form its terms of reference.

How is the environment considered in the approval process?  

The project team has generally completed environmental surveys and technical studies to be used as part of the environment impact assessment. However, further surveys and investigations may be required as the assessment and specialist reports are finalised. These studies will form part of an Environmental Impact Statement (EIS). This is the normal environmental assessment process for the NSW Government’s major projects. For more details go to www.planningportal.nsw.gov.au

While this is a project listed under the Water Supply (Critical Needs) Act 2019, it does not preclude it from undertaking environmental, heritage and planning assessment. Water Infrastructure NSW is committed to understanding, reducing, and offsetting the environmental impacts of the project.

The new water treatment plant, which is part of the early works of the project, is going through a different planning approval pathway than the main construction of the dam wall. The approvals process for the water treatment plant at Wyangala is on track with a Development Application (DA) lodged with Cowra Shire Council in October 2021. The DA will also require a ministerial approval of specific works under Section 60 of the Local Government Act 1993 and a Statement of Environment Effects.

Detailed design of the plant has now been completed, and construction will start later in 2021. The new water treatment plant will be able to deliver an additional 800,000 litres of clean drinking water each day.

Construction work on the  main dam wall will only take place if all government approvals are obtained.

What progress has been made on the Environmental Impact Assessment? 

The project team has been in the field for about a year working with Aboriginal people, gathering seasonal information about flora and fauna, monitoring current conditions, interviewing stakeholders and working with communities. The project team has generally completed environmental surveys and technical studies to be used as part of the environment impact assessment. These studies will detail environmental risks and impacts and how they will be managed and form part of an Environmental Impact Statement (EIS).

Progress of the significant number of specialist reports which will inform and be part of the EIS.

the status of specialist studies

This is the normal environmental assessment process for the NSW Government’s major projects. For more details go to www.planningportal.nsw.gov.au

What impact will there be on medium to large flows that flush the bottom of the system and provide water to wetlands?   

This will be included into the final modelling and assessments that inform operational approvals of the dam. The Environmental Impact Statement is expected to be open to comment and feedback when it is placed on public display. Potential impacts on lower system wetlands will be considered in our environmental assessments.

What work will be done on the dam to increase fish passage and fish ways?  

This will be included in the Environmental Impact Statement (EIS) and approvals process.

Will the dam’s storage capacity be impacted by the silt in the dam? 

WaterNSW has previously carried out studies to look at potential silting in the Wyangala Dam and has not found it to be an issue. There is ongoing management of the dam and any potential impacts on its efficient and effective operations.

The impact of silt in Wyangala Dam is being considered as part of the environmental assessments. These studies will detail environmental risks and impacts and how they will be managed and form part of an Environmental Impact Statement (EIS).

Tourism and Recreation

Will tourism and recreation be affected? 

Water Infrastructure NSW understands the importance of the Wyangala Dam for recreation and the significant value to the tourism industry and local economy and to the people who live, work, and enjoy the reservoir.

Managing community safety throughout construction will be our priority at all time. There will not be any limitations on accessing the lake during the construction and multiple access points to the lake will be maintained.

There will be restrictions to accessing the actual dam structure (for example, walking on the dam wall) and downstream of the dam structure once construction starts.

New infrastructure will be developed in the relocation of the Wyangala Waters Holiday Park creating an opportunity to maximise benefits to tourism and recreation users.

Some community assets will be relocated before finishing construction of the dam wall. Relocating these assets provides an opportunity to improve amenities for the community and visitors. For example:

  • Boat ramps relocated to accommodate higher water levels
  • Car parks relocated/built at a higher level
  • Toilet amenities relocated and built at a higher level
  • Picnic spots available at a higher level
  • BBQs and other amenities relocated/renewed at a higher level.

Wherever possible existing infrastructure will be maintained.

We’re currently working very closely with Reflections Holiday Parks and Cowra Council on how best to improve the visitor experience for when the dam project is finished. We will also be working with local tourism groups and seeking broader community feedback as the project progresses.

Will fishing or water skiing stop in the reservoir during construction? 

There are no plans to stopping fishing, water skiing or other recreational activities on the reservoir during design or construction of the Wyangala Dam Wall Raising project.

At times during construction, there may be a need to have maritime exclusion zones in place for the safety of the workforce and holidaymakers. Once we have more information on any potential exclusion zones, we will work with NSW Maritime and local tourism operators to provide this information.

Other

Will the enlarged dam ever fill?

This project will reduce the risk and impact of climatic events (both floods and droughts) and mitigate associated social and economic impacts:

  • For example, without the increased capacity, it is estimated that the region would fail to realise its full economic potential with agriculture production likely to be two to three times less productive than comparative agriculture
  • The potential loss in production could equate to a loss in annual economic uplift of $167 million (Lachlan Valley Water Security Preliminary Business Case)
  • Communities and farm families downstream of Wyangala Dam suffered extreme flooding in 2012 and 2016. In 2016 crop losses alone were valued at $500 million.
  • Wyangala Dam has filled and spilled at least eight times since the spillway gates were installed in 1971, including in 2012 and 2016 and more recently with the controlled releases in 2021.
  • Had the Wyangala Wall Raising project been delivered earlier, the 2012 flood event would have filled the new dam. The 2016 rains would have spilled over the new dam wall. Based on experiences of past events, these floods would have given us more than one extra year of water supply for the 100,000 people living in the Lachlan Valley.
  • Between 2017 to 2020 the region experienced severe drought, bringing hardship through more years of zero to little general security water and severe water restrictions for towns.

How often does the current dam have controlled releases to manage rapidly increasing water levels?

Wyangala Dam has filled and spilled at least eight times since the spillway gates were installed in 1971, including most recently in 2012 and 2016 and more recently with the controlled releases in 2021.

In July 2021, the Wyangala Dam started controlled releases to proactively manage the water level. Then about a month later the dam filled again, and further controlled releases were carried out.

How do we estimate the chance of a flood occurring?

Understanding the chance of different sized floods occurring is important for managing flood risk.

The chance of a flood event can be described using a variety of terms. The most commonly used definition in planning is the one-in-100-year floods. This refers to a flood level or peak that has a one in a hundred, or one percent, chance of being equalled or exceeded in any year. Similarly, a one-in-200-year flood has a one in two hundred, or 0.5 per cent, chance of being equalled or exceeded in any one year.

Therefore, it is unlikely, but statistically possible, to get numerous one-in-100-year floods, within a shorter period of time than 100-years.

How do I subscribe to stay up to date with the latest information about the project?

We provide regular updates on the progress of the Wyangala Dam Wall Raising project. Register to subscribe and stay up to date on project news, milestones and events.

What is the background to the Lachlan Valley Water Security study?

The NSW Government identified the Lachlan Valley in its State Infrastructure Strategy (SIS) as the first of four ‘priority catchments’ for the investment and delivery of critical water infrastructure projects over the next decade.

The Lachlan Valley Water Security project was undertaken as part of the NSW Governments $1 billion Regional Water Security and Supply Fund and scoping studies for improving water security for the Central NSW region as part of the NSW Water Security for Regions program. This project was undertaken by WaterNSW and carried out in two phases.

The project findings included the raising the wall at Wyangala was shown to be superior to construction of a new dam near Cranky Rock on the Belubula River in terms of cost, hydrological modelling, construction risk and environmental sustainability.