Future water source planning in Great Southern Region

As part of our water supply planning, we are now investigating new areas for a potential future seawater desalination plant near Albany. 

The areas are:

• Nanarup 
• South Coast - Sandpatch

A new water source is expected to be required for the Lower Great Southern drinking water supply by 2030.

Please see a map showing the new areas of investigation below. 

What did you do to arrive at these options?  

We completed an initial desktop assessment, which found these two areas to be the most promising for further investigation. 

This assessment considers what we currently know about environmental, social, technical, economic, operations and construction related factors as well as regulatory and approval requirements.  
It is not a comprehensive assessment and is only an initial step in determining the most suitable area for further detailed investigations. 

Community and stakeholder engagement will be a key part of the next steps.

We also acknowledge that there may not be a perfect solution. Finding a location to satisfy community, environmental, constructability and operating constraints will be challenging.

Why are these areas looking favourable?

Distance from Albany

The two areas are located close to Albany. Early investigations indicate we should be able to connect into the current water supply network at both locations. The Nanarup area is near the large water main pipeline from the existing Two People’s Bay Water Treatment Plant. The South Coast – Sandpatch area is near the South Coast Water Treatment Plant.

Seawater desalination plants (like most water sources) need long and large water pipelines to carry the water to where it is needed. 

We look to find efficient routes for pipelines and install them in areas already clear of vegetation, where possible. However, long and large pipelines usually involve some vegetation clearing and can also impact private landowners. 

That’s why it’s usually better to have seawater desalination plants closer to where the water is needed - to help reduce environmental and social impacts.

Environmental considerations

New water infrastructure must ensure the unique and important environmental value of the South Coast region is protected. Wherever possible, we avoid installing new water infrastructure in sensitive areas, such as National Parks and Nature Reserves. Large areas of Albany’s coastline are protected by National Parks and Nature Reserves, and with King George Sound ruled out for seawater desalination infrastructure, limited areas are available. 

What other areas have you considered? 

We’ve been looking at potential seawater desalination infrastructure sites since an initial study was completed in 2009. We’ve reviewed a large area, spanning from Walpole to 50km east of Albany. In late 2022 we began community and stakeholder engagement, and some investigation activities at three potential seawater desalination infrastructure sites: Princess Royal Harbour, South Coast – Torndirrup and Frenchman Bay. Through this process we also explored Vancouver Peninsula and Salmon Holes.

Princess Royal Harbour was ruled out in late 2024 due to water quality concerns identified through monitoring, and the presence of significant Aboriginal cultural values highlighted during engagement with Traditional Owners. We also ruled out progressing Vancouver Peninsula and Salmon Holes due to significant Aboriginal cultural heritage values.  

Investigations at the South Coast – Torndirrup site were discontinued due to safety and logistical challenges. Sea conditions and shifting ocean sediments made continued environmental monitoring unsafe. High cliffs would pose issues for the installation, commissioning, operation and maintenance of marine infrastructure.   

Hydrodynamic modelling of the marine environment in Frenchman Bay had commenced, however desalination options in King George Sound were ruled out in January 2025 due to community concern and this work was discontinued. 

We’ve re-assessed our options and identified two alternative areas for investigation.

What happens next?

We're still in the early stages of investigating these areas. We want your feedback to help shape our next steps. That’s why, over the coming months, we’ll be inviting you to share your thoughts on the two areas. We want to understand what matters most to you as we plan new water infrastructure.

Visit us in-person this Saturday 5 July at All at Sea, at the Albany Boatshed.  
Our team will be there to listen and answer any questions you have. 

Or reach out to the team at Community.Engagement@watercorporation.com.au to share feedback or ask a question. 

Join the team on Saturday 5 July at All at Sea Saturday, to discuss future water source planning with our team. 

23 January 2025

Following recent announcements, we are no longer progressing investigations into a potential desalination plant at King George Sound in Albany. 

We are still in the planning phase of the project will continue investigating seawater desalination and groundwater options. We will provide further updates in coming weeks.

27 April 2024

The project team attended the Albany Port Open Day on the 27th of April 2024 to share the latest on our new water source investigations with the local community.

It was great to take part in such a well-run event. Seeing the scale of the operations and learning about the inner workings of the port was fascinating! 

We spoke to over 100 local community members on the day and had really valuable conversations, not only about our investigations, but also about our existing water source and the challenges we're facing with the effects of climate change and forecast increases in demand.

Thanks to everyone who came down and we look forward to seeing you again when we are next in Albany. 

15 February 2024

In mid-February 2024, the project team took six members of the Wagyl Kaip Southern Noongar Aboriginal Corporation Cultural Advisory Committee on a half-day tour of the proposed desalination sites.

The purpose of the tour was for the project team to understand the cultural values of the proposed desalination sites and incorporate any feedback from Wagyl Kaip SNAC CAC into our decision making.

We will now progress with further surveys to support our ongoing investigations. 

 

28 June 2023

Water Corporation’s authorised consultants, Advisian, and a commercial boat operator will begin investigations in Frenchman Bay, Princess Royal Harbour and off the South Coast in late June 2023. 

The work will take three days. Exact work dates will depend on weather conditions and availability of contractors and their vessels. Further sampling and data collection will take place on a quarterly basis for up to 24 months. 

27 May 2023

The project team hosted two drop-in sessions in Albany on Friday, 26 May and Saturday, 27 May 2023. 

We had many interesting conversations and received useful feedback that will help inform our investigation pathway. Thank you to those who joined us to learn more about our new water source investigations.

We are now progressing with further planning for the investigations, and will keep the community updated as we progress. Sign up for updates via the link on the webpage to hear the latest project news.

29 July 2022

We’re pleased to advise fieldwork for our Aboriginal Heritage survey in the Manypeaks, Two Peoples Bay, Big Grove, Little Grove and Goode Beach areas has now been completed. This work is part of an investigation into groundwater and seawater desalination as future water source options in the areas.

Thank you to those landowners for facilitating access to private properties.

16 December 2021

We’re pleased to advise fieldwork for our environmental survey in the Manypeaks, Two Peoples Bay, Torndirrup, Big Grove, Little Grove and Goode Beach areas has now been completed. This work is part of an investigation into groundwater and seawater desalination as future water source options in the areas.

Thank you to those landowners for facilitating access to private properties. The survey area was large – extending much further than the actual area required for any infrastructure – to ensure we could capture accurate environmental data and to put any results into context. The consultants will now take the next few months to sort and analyse all the data collected, and prepare findings.

Next, we are preparing to undertake Aboriginal heritage surveys in the same areas with Traditional Owners, in the new year. We will write to affected landowners regarding this.

Happy holidays!

The LGSTWSS supplies drinking water to Albany, Mount Barker, Kendenup and Narrikup and Denmark (as required) from local groundwater sources on the South Coast and from surface water from Angove River near Two Peoples Bay, east of Albany. 

In response to climate change impacts and forecast increases in demand on our drinking water supplies, we are currently investigating what water sources are needed to maintain a reliable drinking water supply via the Lower Great Southern Towns Water Supply Scheme (LGSTWSS).

We’ve explored different ways to find more water, like using groundwater, and recycling water. Groundwater is still being investigated and will continue to play a part in our water future, but it won’t be enough on its own.

That’s why seawater desalination needs to be part of the long-term plan to supply water to a growing and climate-resilient community. We've now shared new investigation areas for a potential future seawater desalination plant near Albany with the community. These areas are:

• Nanarup
• South Coast - Sandpatch

Our modelling shows that a new water source is required for the Lower Great Southern by 2030. 

We are still in the planning phase of the project and our timeframes will be led by the outcomes of our investigation activities. We will engage with key stakeholders, including government agencies, Traditional Owners and the community, before and after making a decision on the location for a desalination plant.

Seawater desalination works by separating water molecules from seawater. First, seawater is screened and pre-treated to remove large particles like seaweed and sand. Next, the seawater is fed through reverse osmosis membranes, where water molecules pass through, and the remaining seawater becomes saltier. About 40-45% of the seawater becomes freshwater for drinking and the remaining 55-60% is brine.  The brine is nearly twice as salty as the original seawater. 

• Location: The intake is usually placed in deep water where the water quality is good and environmental impact is minimal. The intake pipeline does not have to be near the plant. However, the longer the pipeline, the higher the construction and maintenance costs.
• Design: It is designed to handle large volumes of water and withstand harsh marine conditions.
• Environmental impact: Care is taken to minimise impacts to marine life by using protective structures, such as velocity caps (to slow the intake speed) and screens (to keep out larger marine life).  We complete habitat surveys to identify areas of bare sand. Low disturbance installation methods such as horizontal directional drilling are considered.

• Location: The diffuser is generally located offshore, away from sensitive marine habitats and in deep water where brine can be effectively dispersed.  The diffuser pipeline does not necessarily need to be near to the plant; however, the longer the pipeline is the more it costs to construct.
• Design: The diffuser is designed to minimise environmental impacts, often using multiple diffuser ports to increase brine dilution and spread. Instead of releasing all the salty water from a single point, the ports spread it across multiple locations, promoting faster mixing and more efficient dispersion over a larger area.
• Environmental impact: Brine dispersion modelling is done prior to construction to ensure the diffusers are designed for the location. This ensures we comply with the Environmental Protection Authority’s environmental quality framework for marine discharges. We complete habitat surveys to identify areas of bare sand. Low disturbance installation methods such as horizontal directional drilling are considered.
• Regular environmental monitoring of the water quality and marine habitat is completed to ensure compliance with licence conditions and environmental standards.

In seawater desalination plants, brine is the salty byproduct returned to the ocean. It is nearly twice as salty as seawater because about 40-45% of the freshwater is removed. Brine may contain very small amounts of food-grade chemicals like anti-scalants and cleaning agents. They are used to keep the membranes working efficiently. Only chemicals approved by the Department of Health for use in drinking water are used. 

Bitterns are salts and minerals left after seawater evaporates. Bitterns are sometimes used in table or industrial salts. They are much saltier than seawater and can be toxic to some marine life.  Water Corporation will not produce or discharge bitterns into the environment.

Brine is returned to the ocean through a brine pipeline with a diffuser at the end. Diffusers help rapidly mix and dilute the brine with seawater. The diffuser helps to quickly reduce the brine's salinity to match the surrounding seawater generally within tens of metres. Mixing and dilution minimises the impact on marine life and ecosystems.
Brine continues to mix with seawater after it leaves the diffuser. It will not form pools of hypersaline water or collect in depressions or basins.
Brine dispersion modelling is used to predict how the brine will mix and dilute when it enters the ocean. The modelling uses wave, tide and current data collected from the proposed site and helps us design diffusers that would work best for the specific site conditions.

No, the diffusers are designed specifically for the chosen location and waves are not always required for the diffuser to work effectively. However, periods of wave energy would improve the dispersion. We consider the slope of the seabed (bathymetry) and complete modelling that uses local wave, current and tide data to tell us the best place to put the diffuser. 

Whenever we can, we try to avoid sensitive marine habitats, such as seagrass. We prefer to install brine diffusers in areas with bare sand. 

We regularly monitor the marine environment, including seagrass, around the diffusers to detect any changes.

The impact of brine on the marine environment depends on factors like the brine's saltiness, the seabed terrain and how well the mixing and dilution process works. 

The effect on stationary marine life, like seagrass, will be limited to the area where the highly diluted plume touches the seabed. We use brine dispersion modelling and habitat mapping to predict where this will happen. This helps us find areas that reduce impacts and avoid sensitive spots, like seagrass. It also helps us design the brine diffusers specifically for the location where they will be installed, so that we ensure the brine is being effectively dispersed into the surrounding ocean.

Mobile marine life that prefers lower salinity will move away from the brine. However, many species that tolerate high salinity will thrive near the diffuser. Mussels, starfish, seahorses and fish often gather around these structures and grow on them, creating unique ecosystems.

Our diffusers at the Southern and Perth Seawater Desalination Plants show that they create habitats for marine life. Fish, mussels, starfish, seahorses, and crayfish all thrive on and near the diffusers.

The seawater intake and diffuser should not create noise during normal operation. However, machinery and equipment will produce temporary noise during installation. Once the construction methods are established, we will conduct a noise impact assessment. Noise-generating activities will be short-term and managed according to the relevant guidelines.

The intake is expected to use gravity to draw in water gently, ensuring a slow and steady flow.  Most organisms that can swim will be able to move away from the intake.  Some small organisms, like larvae, may be drawn into the intake and pipelines.  Research has shown that the number of larvae that enter into the pipelines is very low.

Environmental monitoring and data collection starts before a site is selected for any seawater desalination plant. This information helps us design and position the infrastructure to minimise environmental impact. It also forms part of the environmental impact assessment and approval application that is sent to the Regulator.  
Monitoring of the marine environment includes:

• water quality monitoring of the ocean including existing contaminants, salinity, temperature and dissolved oxygen levels (up to two years) 
• benthic habitat mapping, which is the process of identifying and mapping underwater environments, specifically the seafloor and the organisms that live there. This includes mapping of reefs, troughs and freshwater seeps
• targeted surveys of marine flora and fauna, where required.

In addition to monitoring, we also complete the following studies:

• desktop review of existing historical data and literature 
• ecotoxicity testing in a laboratory, which tests whether the brine could have an impact on the larvae and adults of local marine species 
• we engage with Traditional Owners and other community and industry stakeholders to identify their key uses, and values and concerns.

The potential environmental impacts of the proposal will be defined, assessed, managed, and monitored under the Environmental Protection Authority’s (EPA’s) Environmental Quality Management Framework (EQMF) for the State’s marine waters.  The EQMF is set out in the EPA’s (2016) Technical Guidance: Protecting the Quality of Western Australia’s Marine Environment.   

We begin the environmental impact assessment (EIA) and approval process after we complete our planning, investigations and concept design. The process includes referring the proposal to the EPA under Part IV of the Environmental Protection Act 1986. EIA is a step-by-step way to assess how a proposal might impact the environment. A key step in EIA is finding effective controls and management measures. These help reduce possible negative environmental impacts.  The referral must show we're using the best measures. It must also show we have genuinely evaluated the location and design options for the proposal. This, along with the proposed environmental management measures, will ensure the EPA’s environmental objectives are met. The public is encouraged to join the EPA process via its consultation hub.

Water Corporation adheres to the EPA’s EQMF for the State’s marine waters, as described above. No breaches of marine water quality criteria have occurred due to the brine discharge at the Southern and Perth Desalination Plants. We will also be using the EQMF standard for the third desalination plant currently under construction in Alkimos. 

The Manypeaks area was highlighted as a potential groundwater resource area primarily based on findings summarised by the Department of Water and Environmental Regulation (DWER) in the Albany Hinterland Prospective Groundwater Resource Map and Explanatory Notes from 2017. 

Out of all resources highlighted on the map, as part of the 2020 source plan we investigated the potential of:

• The water resource beneath Elleker (King River Paleochannel which extends south towards the Grasmere subarea);
• The water resource beneath the airport (King River Paleochannel); 
• Nanarup paleochannel;
• Manypeaks paleochannel. 

These options were selected based on water quality (lower salinity) and the potential to find a confined water resource for better source protection. The Kalgan paleochannel did not offer good prospect in that sense and therefore was not considered.

The King River resource is situated beneath tree farms and Elleker town site, both of which present source protection risks. It was therefore not considered further. 

We did not pursue the Nanarup option further due to the limited size of the aquifer and low yield estimates.

Following a detailed assessment of all groundwater options, we decided to pursue further investigations at Manypeaks, based on (but not limited to) hydrogeological, water quality and source protection, economic and environmental criteria.

While a new groundwater source currently remains an option, seawater desalination – as a proven, sustainable and reliable water source – will need to form part of the plan for the region’s longer-term water supply.

The majority of climate projections for Albany indicate 30-year average annual rainfall will decline by up to 21% out to 2050 (under worst case of the RCP8.5 climate projections). This will mean less water to replenish underground aquifers – with groundwater currently supplying around 90 per cent of the region’s drinking water – and dams and river sources.

On current projections, annual demand in the region will outstrip supply by 2030, with an additional 1.8 billion litres of drinking water needed by 2050.

We encourage residents to install rainwater tanks in regions with reliable annual rainfall patterns such as the South West and Great Southern regions. Though the efficiencies gained from collecting rainwater are valuable, they don’t close the gap between supply and demand, particularly in a changing climate where rainfall is increasingly less reliable. Rainwater tanks are also more expensive than other options when compared on a per kilolitre basis, which is why we encourage homeowners to collect rainwater for household use if this is their personal preference and we offer financial incentives to help. 

Read more about declining rainfall in the lower Great Southern in our Why do we need a new water source - Information Sheet. 

We run a number of Waterwise offers such as showerhead swaps and rebates for rainwater tanks to help customers achieve this, and to reduce the cost difference. The rebates on rainwater tanks are only available in the Great Southern and South West regions due to the more reliable annual rainfall patterns. Visit our Waterwise Towns webpage for further information about offers relevant to your area each year. 

Local Government is responsible for the operation approvals and installation of greywater systems in Western Australia. The West Australian Greywater Guide provides further information on how to best reuse domestic greywater in Western Australia

There is no change in pricing of water linked to new capital investment. Albany residential customers pay the same price as other residential customers across the state for water use up to 300kL/year.

As part of the Western Australian Government’s commitment to achieving net-zero emissions from its direct activities, this new desalination plant will achieve net zero scope 1 and 2 emissions during all phases of construction and operations.

• Scope 1 emissions are the greenhouse gases released directly by the desalination plant itself. For example, if the plant has equipment or backup generators that burn fuel on-site, the emissions from burning that fuel are Scope 1 emissions.
• Scope 2 emissions are the indirect emissions from the electricity the plant buys to run. Desalination plants use electricity for things like pumping and filtering seawater. If that electricity is made at power plants that burn fossil fuels, the emissions from generating it are Scope 2 emissions.

Our planners begin with a high-level desktop assessment using publicly available data and data we have already gathered to identify potential areas for further investigation.
Following this, we conduct initial site visits and gather information from our local operations team and subject matter experts to determine if these options are worth further investigation.
We then complete a 'multi-criteria assessment,' evaluating each option based on the following factors: Social, Technical, Delivery & Operation, Economic, Environmental, Regulatory and Approvals, based on information we know at the time. This results in ranking of: Preferred, Acceptable, Negotiable, Not Desirable. 
At this stage, we present the options to stakeholders and the wider community for feedback. We also commence environmental, marine, heritage, and/or engineering investigations. We are at this stage currently, having shared South Coast – Sandpatch and Nanarup as new areas of investigation. 

As further engagement and investigation activities occur, these are fed back into the multi-criteria assessment tool, meaning areas of investigation can change in ranking at any time.
The combined feedback and findings of those investigations is what informs a decision on the preferred option.

Albany accounts for approximately 80% of the demand for water in the lower Great Southern, so it makes most sense to locate a seawater desalination plant close to the town of Albany. 

Seawater desalination plants (like most water sources) need long and large water pipelines to carry the water to where it is needed.
We look to find efficient routes for pipelines and install them in areas already clear of vegetation, where possible. However, long and large pipelines usually involve some vegetation clearing and can also impact private landowners.
That’s why it’s usually better to have seawater desalination plants closer to where the water is needed - to help reduce environmental and social impacts.

We value the input of our key stakeholders and community members. We are committed to engaging with all interested parties including government agencies, industry and the community, before and after making a decision. This has been our approach since 2022 and will continue. 
Part of this commitment means we have set up a Community Consultation Group to help with advice and feedback.
Engagement in 2025 will include:

• six Community Consultation Group meetings between May and December 2025 
• detailed briefings with key government agencies 
• detailed briefings with community, industry and stakeholder groups  
• in-person community information opportunities in Albany 
• regular progress updates via email on the project and engineering investigations.

Our initial customer research gathered key insights from Albany residents to inform our planning. It included six focus groups and 450 surveys. Early stakeholder engagement began in 2022 with project information sheets issued to over 50 community, industry and stakeholder groups and over 20 in-person meetings.
Following the Minister’s project announcement in May 2023, we began engaging with the wider community through information sessions held in Albany and email project updates. 
 While investigation activities were underway, engagement continued with:

• in-person meetings with landowners on groundwater options
• a site visit with the Traditional Owners from Wagyl Kaip Southern Noongar Aboriginal Corporation’s Cultural Advice Committee 
• further stakeholder briefings with City of Albany and Councillors, community and industry groups. 

During engagement in late-2024 some stakeholders expressed concern about the Frenchman Bay option. Options in King George Sound were subsequently ruled out.

In May 2025, we began the process to establish a Community Consultation Group. The Group will provide advice and feedback to Water Corporation from July 2025 to late 2026 as we move through the planning process for new water source options. 

In July 2025, we shared two new seawater desalination investigation areas with the community:

• Nanarup
• South Coast - Sandpatch.