Desalination plant at Billy Lights Point

The Eyre Peninsula Landscape Board has indicated there will be a significant reduction in the licensed volume of water we can source from Uley South Basin once amendments to the Water Allocation Plan for the Southern Basins take affect from 1 July 2026 – see the Board’s media release. Uley South currently supplies the majority of water to the Eyre Peninsula.

In response to this advice, we are undertaking an urgent review of our broader water security response plan for the region, detailing what actions may need to be taken if there are changes to our ability to supply water from local groundwater sources or if there are significant delays to the delivery timeframe of our proposed desalination plant. These actions aim to maintain a level of water supply to the region while also protecting vital groundwater sources until a desalination plant is operating.

This plan will include working with the local community and stakeholders on a water efficiency program, as well as serious consideration to introducing staged water restrictions for primary production, industrial, businesses and residential customers.

This work will in happen in parallel with our continued plans to construct a desalination plant at Billy Lights Point, which we are working towards being operational by mid-2026. A climate-independent desalination plant remains critical to augment supply from an under stress Uley South Basin and deliver a long-term drinking water solution.

The Board’s review is prompted by findings from investigations and modelling by the Department for Environment and Water, which show if water extraction from Uley South continues at current rates, there is an increasing risk of further environmental decline and irreversible damage from saltwater intrusion.

We expect to complete a review of our water security response plan with the Eyre Peninsula community in coming weeks.

From early March through to May 2024, geotechnical activities will be undertaken using a barge and small drill rig to collect soil and rock samples from the ocean floor.

This will help us better understand the site’s geology to determine a potential construction method for the marine infrastructure which will connect to the proposed desalination project.

The geotechnical investigations will involve:

• Establishing a small jack-up barge in the east of Billy Lights Point.

• Drilling small diameter holes around 20-30 metres deep to extract samples for scientific analysis.

• Backfilling boreholes on completion of work.

Read the project update to find out more about these geotechnical investigations.

Thanks to everyone who came along to our forum in Port Lincoln this week, to learn about the range of employment and training opportunities available through our proposed Eyre Peninsula desalination project.

Close to 100 business owners and job seekers attended, where they heard from several speakers including our project director and contract partner ACCIONA.

With up to 230 jobs per year of construction to be created, along with new supply chain opportunities, it was fantastic to speak with local people about how they can work with us on this important water security project.

If you couldn’t make it to the forum but would still like to receive updates on related job opportunities, register your interest via the Industry Capability Network (ICN gateway) webpage.

We are continuing to mature the design for our proposed desalination plant at Billy Lights Point, with key changes made in response to feedback gathered through early engagement and further scientific analysis, reinforcing our commitment to minimising any impacts to the coastal and marine environment.

These changes include using a trenchless construction method for the installation of the plant’s intake and outfall pipes, and the placement of these pipes in a deeper area off the coast of Billy Lights Point within a higher flushing zone.

We have listened to and responded to feedback from the Project Reference Group and other key community groups, our regulators and various other government agencies, which highlighted the importance of minimising disturbance to the Billy Lights Point coastline and avoiding the shallow waters of Proper Bay.

We will need to conduct additional geotechnical studies to refine the scope of the trenchless construction method, and from March 2024, we will use a barge and small drill rig off the coast of our existing nearby wastewater treatment plant to collect soil and rock samples from the ocean floor.

This will enable a better understanding the site’s geology, to determine the exact type of construction method, which could include directional drilling or tunnelling.

The geotechnical work is expected to take several weeks to complete, and the results will help inform a detailed concept design which will be incorporated into our Development Application for the project.

To support this work, we will also be undertaking further hydrodynamic modelling within the preferred marine zone and a re-run of the particle tracking model, which will add to existing knowledge of mussel spat movement and narrow down the exact alignment and location of the intake and outfall pipes.

We are planning to place the pipes in a zone to the east of Billy Lights Point, up to 1.5 kilometres offshore and more than 2.5 kilometres from existing mussel leases. This location is near a commercial shipping corridor which extends from the marina to Cape Donnington and is within water around 10 to 15 metres deep.

The outfall for our Port Lincoln Wastewater Treatment Plant sits outside of this zone further to the south, and our extensive monitoring to date has demonstrated no negative impact to the local marine environment from this marine infrastructure.

Acciona has been awarded the contract for the Early Contractor Involvement (ECI) phase of the Eyre Peninsula desalination project. Acciona will be undertaking further investigations at the proposed desalination plant location of Billy Lights Point over the coming months to support SA Water in developing the detailed design of land and marine infrastructure as part of the project.

An Expression of Interest for early contractor involvement (ECI) in the design and constructability of the desalination plant and marine systems was released to market earlier this year. Shortlisted tenderers have submitted detailed responses as part of a Request for Tender which was released in June. The Project Team is currently reviewing and assessing the tender submissions, with the contract to be awarded in the coming months.

The ECI contractor will support SA Water to further develop the concept design of the plant and marine infrastructure. Subject to final approvals, the successful contractor will be required to prioritise local workforce engagement, with significant opportunities for local industry to be involved in the construction phase of the project.

Further updates will be provided when the ECI contractor is appointed and as procurement for the project progresses.

As we proceed with work to deliver a desalination plant at Billy Lights Point, ensuring long-term water security for the Eyre Peninsula, we will provide regular project updates through the detailed design, development application preparation, approvals, and construction processes.

Read the project update.

Billy Lights Point is our preferred location

Our proposed site at Billy Lights Point is:

• close to existing water and electricity networks, requiring a short, 4 km powerline route and a 7.4 km transfer main to North Side Hill storage tanks
• formerly industrial and not located near residential properties, which will help to minimise visual and environmental impact on the landscape
• relatively sheltered with a mostly flat landscape, helping to reduce construction risks and challenges, delivering the best value option for our customers.

A number of alternative locations have been assessed and investigated for the Eyre Peninsula desalination plant, however, these presented challenges including:

• nationally and state protected flora and fauna
• internationally and nationally protected species such as migratory whales
• location within or adjacent to a State Marine Park
• unique geology
• high cliffs and exposed coastline requiring significant engineering design and complex construction processes, resulting in an additional $150 million cost impost on customers.

Billy Lights Point is our preferred location because it offers the quickest solution to ensuring long-term water security for the region, with the least impact on future water costs for customers. Marine science research undertaken to date indicates that with the right engineering design, a desalination plant at Billy Lights Point can be built with minimal impact on the marine and coastal environments.

Concept design for Eyre Peninsula desalination plant. Final design to be confirmed.

First water expected mid-2026

By mid-2026, a desalination plant at Billy Lights Point would produce 0.016 gigalitres or 16 megalitres of fresh, clean drinking water per day – with the capacity to be expanded to around 0.024 gigalitres or 24 megalitres per day.

Further scientific investigations and assessments will inform the detailed design of the plant, including the location of the intake (where the plant draws in seawater) and outfall (where the plant disperses saline concentrate from the desalination process) pipes.

The data from these investigations and assessments, along with community input, will inform our development application for the project, which will be lodged with the State Planning Commission. Our application will be assessed by multiple agencies and regulators through a comprehensive approval process, which also provides for further community consultation.

How desalination works

1. Pre-treatment - seawater is pumped through intake screens and filters to remove particles, before passing through an ultrafiltration membrane.
2. Reverse osmosis - semi-permeable membranes allow water molecules to pass through but block larger salt molecules, resulting in the removal of impurities and salt in the water.
3. Post-treatment - the desalinated water is disinfected and re-mineralised to increase alkalinity to reduce the potential for corrosion in the network and customers’ plumbing. Treated water meets the Australian Drinking Water Guidelines, ensuring it is safe to drink.
4. Storage - the clean drinking water is then stored and supplied to homes and businesses.
5. Outfall - the remaining concentrated seawater is returned to the ocean through the outfall pipe and diffusers to ensure it reaches the natural salinity levels of the environment.
   
   

After desalination, clean, fresh water from the desalination plant would be pumped to the North Side Hill storage tanks near Port Lincoln. The water would then be distributed through our network to ensure it reaches regional and remote communities across the Eyre Peninsula, for use in homes, schools, hospitals, businesses, and agriculture.

Eyre Peninsula’s water security challenges

In 2007, we began working with the Eyre Peninsula community as we prepared a long-term water plan for the region. The plan identified seawater desalination as the preferred future water supply option to supplement existing groundwater sources and ensure water security for 35,000 local customers.

Uley South Basin is the last remaining major productive groundwater source on Eyre Peninsula, currently supplying approximately 75 per cent of the region’s drinking water. The basin refills when rain seeps through the soil and ground into the underground aquifer – a process known as groundwater recharge. Extensive monitoring of water levels in different parts of the basin has shown a long-term trend of reduced recharge.

Continued extraction from the Uley South borefield at current levels, in combination with the long-term trend of reduced recharge, is predicted to cause water levels in parts of the basin to reach historically low levels by the mid-2020s. Sustained over-extraction risks the freshwater in the basin becoming more saline, as well as seawater intrusion – which would permanently decrease the size of the freshwater aquifer.

Data for 2021-22 indicates that despite being an above average period for rainfall, Uley South Basin experienced only average recharge with water levels remaining stable. To ensure the basin remains a viable resource for the long term, it is essential that a climate-independent desalination plant is delivered.

The timeframe for delivery is critical, with a very real risk of irreversible damage to the Uley South Basin if current extraction rates continue beyond 2025-26. Without a desalination plant, we are unlikely to be able to supply water to Eyre Peninsula at current demand, and significant delays would likely lead to water restrictions.

In our conversations with the community, we are frequently asked questions such as:

• Why do we need a desalination plant?
• Why wasn’t the Site Selection Committee’s recommendation of Sleaford West accepted?
• Will the intake pull in fish and mussels like a vacuum cleaner?

Find the answers to these questions and more on our frequently asked questions page.