Delivering Kangaroo Island’s latest desalination plant

Reliable water access and enhancing bushfire preparedness.

At a glance:

50-kilometre pipeline network will support long-term water security and resilience for Kangaroo Island communities
Network features advanced reverse osmosis technology to convert seawater into safe, clean drinking water
Pipeline bushfire preparedness strengthened through the installation of 400+ fireplugs, providing instant access to water during emergencies.

The construction of Kangaroo Island’s second desalination plant was a transformative infrastructure project designed to support long-term drinking water security for SA Water customers on the island, ensuring sustainable water security for residents, businesses and the local Country Fire Service (CFS).

Kangaroo Island, renowned for its pristine landscapes and unique biodiversity, has historically faced challenges relating to long-term drinking water security. Seasonal rainfall variability, coupled with devastating bushfires in 2019-20, highlighted the need for a climate-independent solution.

The primary objective of the new desalination plant was to provide a dependable source of potable water for 4 island communities who previously relied on rainwater tanks and trucked water, leaving them vulnerable during droughts and emergencies. By introducing a desalination facility to supply mains water to these communities, the project delivers resilience against climate variability and supports long-term economic growth.

Beyond meeting basic water needs, the plant plays a strategic role in enhancing bushfire preparedness. The installation of more than 400 fireplugs along the new pipeline network ensures the CFS has immediate access to water during critical events. This dual purpose, community supply and disaster resilience, positioned the project as a cornerstone of Kangaroo Island’s recovery and future development.

Innovative engineering delivers robust solutions

WSP was engaged by SA Water and John Holland Guidera O’Connor joint venture to deliver the preliminary and detailed design for Kangaroo Island’s new reverse osmosis desalination plant and its associated pipeline. We led concept development, engineering drawings, spatial alignment mapping, and comprehensive structural and mechanical design of key infrastructure, including buildings, pump chambers, and pipeline systems. Our technical advisory ensured robust solutions for both the plant and the extensive 50-kilometre pipeline network, supporting long-term water security and resilience for the island’s communities.

Engineering considerations were paramount throughout the design phase: detailed geotechnical investigations revealed highly variable coastal soils and zones of instability, requiring bespoke foundation solutions and carefully sequenced trenching to stabilise the pipeline route. Advanced hydraulic modelling was vital in optimising pressure performance along the 50‑kilometre pipeline corridor, managing dynamic coastal conditions and safeguarding sensitive marine ecosystems.

The desalination plant’s buildings and subterranean pump station were constructed to withstand harsh coastal conditions, guaranteeing operational reliability for decades to come. Marine works, including the installation of intake and outfall pipelines amongst the protected seagrass meadows, were among the most complex components, requiring temporary causeways and precision trenching for environmental protection.

The plant and pipeline became fully operational in late 2024. The project represents an investment of approximately $147.7 million by SA Water, reflecting its importance to regional water sustainability and resilience.

Delivering a resilient water supply for Kangaroo Island required innovative engineering and a deep understanding of the island’s unique challenges. Our team is proud to have developed robust, future-ready solutions that will support the community’s water security and growth for decades to come.

Dean Toomey Director of Water, WSP

Dean Toomey Director of Water, WSP

Scalable technology delivers safe water and emergency resilience

Located near Penneshaw, the facility employs advanced reverse osmosis technology to convert seawater into safe, clean drinking water. Two underwater intake pipelines draw seawater into the system, while a separate outfall pipeline safely returns saline concentrate to the ocean under strict environmental controls.

On land, the pipeline delivers potable water to the townships of American River, Baudin Beach, Island Beach and Sapphiretown integrating with fire protection systems to reinforce emergency response capabilities in the area. The system also connects to the existing Middle River drinking water network, providing a back-up potable water and fire protection supply to the township of Kingscote.

Community and environmental impact

The benefits of the desalination plant extend well beyond water supply. For many residents, this project delivered mains water access for the first time, reducing reliance on rainwater tanks and costly water cartage.

Environmental stewardship was integral to the project’s execution. Measures were implemented to minimise marine impacts during pipeline installation, and revegetation programs were launched to restore native habitats affected by bushfires. By reducing pressure on local catchments and groundwater sources, the plant contributes to the long-term health of Kangaroo Island’s ecosystems.

Industry collaboration delivers community-focused infrastructure

The success of the project reflects collaboration among leading industry players. WSP’s collaborative approach with the John Holland and Guidera O’Connor joint venture as the project’s major delivery partner enabled seamless integration from early contractor involvement through to construction delivery. Specialist contractors supported marine and civil works, while WSP’s engineering leadership helped ensure technical excellence, operational reliability and strong community engagement throughout the project.

A blueprint for resilient communities

Construction of Kangaroo Island’s new desalination plant is more than an infrastructure project—it is a symbol of resilience and forward planning. By securing a reliable water supply, the island is better equipped to withstand environmental challenges and support sustainable growth. As climate pressures intensify globally, this project offers a blueprint for how regional communities can adapt and thrive through innovative engineering and collaborative delivery.

Contact us

Dean Toomey

Director, Water

Australia

Mike Campbell

Associate Design Manager & Team Manager, Water

Australia

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Location

South Australia - Australia

Client

SA Water

Frequently Asked Questions (FAQs) about the Kangaroo Island Desalination Plant:

What role did WSP play in the Kangaroo Island desalination plant project?

WSP was engaged by SA Water and the John Holland Guidera O’Connor joint venture to deliver the preliminary and detailed design of the reverse osmosis desalination plant and its associated 50-kilometre pipeline, including concept development, engineering design, spatial mapping and technical advisory.

Where is the Kangaroo Island desalination plant located and which communities does it support?

Located near Penneshaw on Kangaroo Island, the desalination plant supplies potable water to the townships of American River, Baudin Beach, Island Beach and Sapphiretown, while also connecting to the Middle River network to support Kingscote.

Why was the Kangaroo Island desalination plant important for the region?

The project was designed to provide a dependable, climate-independent source of drinking water for island communities that previously relied on rainwater tanks and trucked water, while also enhancing bushfire preparedness through the installation of more than 400 fireplugs along the pipeline network.