Alkimos to Wanneroo desalination pipeline

Project scope

The Alkimos to Wanneroo desalination pipeline will be a belowground pipeline that transfers drinking water produced by the future Alkimos Seawater Desalination Plant to Wanneroo Reservoir to be integrated with Perth's Integrated Water Supply Scheme. The pipeline will be the largest water pipeline Water Corporation has constructed, with a diameter of up to 1600mm. It will stretch for around 33.5 kilometres, taking water to Carabooda Tank, the future Nowergup Tank, and on to Wanneroo Reservoir.

Why is this pipeline needed?

Perth's next major water source, the Alkimos Seawater Desalination Plant will produce up to 50 billion litres of drinking water per year. This water needs to be efficiently transferred across Perth to be integrated with the broader water network before it is supplied to homes and businesses across Perth and beyond. The Alkimos to Wanneroo desalination pipeline has been designed to accommodate this significant amount of water and also allow for future desalination expansions.

Where will the new pipeline be installed?

The pipeline will start at the Alkimos Seawater Desalination Plant. It will pass through Carabooda to Carabooda Tank, before heading south-east through Nowergup, Neerabup and along the outskirts of Banksia Grove, Mariginiup and Jandabup before reaching the Wanneroo Reservoir.

This alignment was determined in consultation with local stakeholders including the City of Wanneroo, Main Roads WA, Department of Planning, Lands and Heritage, and Whadjuk Aboriginal Corporation. Construction projects of this scale will cause disruption, but this alignment is considered to minimise impacts to the environment, residents, businesses and road users.

The pipeline will be located mainly in road reserves and public areas. The final pipeline will be entirely belowground expect for a small section crossing the rail line near Alkimos Station and some discreet access valves installed at intervals along the pipeline.

When will this work take place?

Around 6 kilometres of the pipeline are being constructed early as part of major transport infrastructure projects in Alkimos - some of these sections have already been completed. The remaining 27.5 kilometres between Wanneroo Road in Carabooda and Wanneroo Reservoir are expected to be constructed across two and a half years between 2025 and 2027.

We expect to be able to start communicating an indicative construction schedule with you from 2025 once a construction partner has been appointed to do this work. We will work with the City of Wanneroo to coordinate construction work as best as possible to minimise disruption to the community.

How will the community be impacted by this work?

The majority of the pipeline will be constructed by excavating a trench, laying sections of pipe, then covering and restoring the ground above. During construction you may notice some increased noise, vibration, dust, traffic detours and temporary fencing. We will manage these impacts carefully and ensure you have access to your property at all times.

Our worksites need to be large enough to accommodate the large pipe and the special installation equipment, and to ensure the safety of our workers and the community. This means we may need to enter the boundaries of some nearby properties - but never anyone's home. We will work closely with residents and businesses whose property we may impact, and ensure we carefully reinstate any affected areas,

Protecting Aboriginal heritage

Aboriginal heritage surveys with representatives from the Whadjuk Indigenous Land Use Agreement group were completed in 2022 and 2023. One Department of Planning Lands and Heritage Aboriginal Heritage site and one Other Heritage Place were identified along the original alignment. The pipeline alignment was then changed to avoid impacting Aboriginal heritage. We will engage local Aboriginal monitors onsite in case any potentially significant items or sites are discovered during the project.

Protecting the environment

The main environmental impacts assessed for the installation of the pipeline are the clearing of native vegetation and associated impacted to fauna habitat. The proposal for the pipeline was assessed at the highest level by the State's environmental regulator. Find out more about that assessment process.