PSDP stage 2

What is being planned?

Water Corporation is investigating the establishment of a possible future seawater desalination plant on land adjacent to its Perth Seawater Desalination Plant site in Kwinana. The investigations are part of long term planning to secure Perth’s water supply.

The possible future Stage 2 Perth Seawater Desalination Plant (PSDP2) is proposed to be delivered in stages. Initially a 25GL/year plant, with supporting intake, outfall and pipeline infrastructure, with a further 25GL/year expansion to follow.


Why is it needed?

Water Corporation is planning ahead to secure water supplies in our drying climate for a growing city. Streamflow into dams has reduced from an average of 394 billion litres per year pre-1975 to an average of 50.6 billion litres over the past five years.  This represents an 87 per cent reduction in average streamflow to our dams.  In 2015, Perth’s dams received their worst streamflow on record.

When will the plant be built?

We are completing early investigations for a number of climate independent sources (including PSDP2) as part of our long-term planning. No firm timing is known for when a new source will be required, however we do not expect to require a major new source to be required for at least five years.


How does desalination work?

Why desalination and not other options (such as groundwater replenishment)?

More than 40% of Perth's water supply is from our two desalination plants (in Kwinana and Binningup). Desalination is a proven and trusted water supply solution that does not depend on climate. We will continue to deliver a range of water sources (including expanding our groundwater replenishment scheme) to secure Perth's water supply.

Why can’t you expand the existing Perth Seawater Desalination Plant?

Perth Seawater Desalination Plant is operating at capacity and will continue to produce a significant portion of Perth's drinking water supply while we complete investigations and should a future desalination plant commence construction. The possible future plant is planned to be independent to the existing plant to further secure Perth’s water supply.

What will it cost?

A desalination plant is a significant State asset. The focus of our current work in relation to the new desalination plant is on feasibility in relation to plant design, environmental impact assessment and engaging with stakeholders. Costs in relation to construction and operations will be considered closer to when the new plant is needed.

What will the plant’s energy requirements be?

Every effort is being taken to ensure the future plant’s design is energy efficient. The expected plant performance will match or exceed industry becnchmarks for energy efficiency.

Instead of a major new water source, shouldn’t we be concentrating on reducing and recycling water?

New water sources are only a part of the picture and we will continue to invest in programs to encourage efficient water use – this will help to defer the need for new water sources for as long as reasonably possible.

How are you protecting the Cockburn Sound marine environment?

We have responsibly operated our existing desalination plant in Cockburn Sound for more than a decade. As part of our planning and approvals for the possible future desalination plant, we are completing detailed studies and modelling of the marine environment.  

Water Corporation will continue to work with the Cockburn Sound Management Council (of which we are a member), our environmental regulators and the community, on mitigating environmental impact.

Where will the pipeline from the plant run?

Our investigations will consider the capacity for existing pipelines, which connect the Perth Seawater Desalination Plant to Perth's water scheme, to be utilised for a possible future plant. If any additional pipelines are required we will be sharing these plans with impacted landowners and stakeholders and seeking feedback.


Will your planning consider the potential future Outer Harbour Project (being considered to be located at Cockburn Sound)?

We are working with, and will continue to work with, all Cockburn Sound stakeholders, including the State government appointed Outer Harbour Taskforce regarding our operating and possible future desalination plant.