Alkimos Seawater Desalination Plant

Closed 20 May 2019

Opened 14 May 2019


The Western Australian Water Corporation is proposing to construct the Alkimos Seawater Desalination Plant (ASDP) as part of Perth’s Integrated Water Supply Scheme which aims to provide additional sources of drinking water to supplement the existing metropolitan water supply.

The ASDP Proposal will be located within the Alkimos Water Precinct (Lot 1050 Marmion Avenue), approximately 40 km north of the Perth, within the northwest corridor, north of Quinns Rock beach and south of Yanchep beach.

ASDP will be developed in four stages (each with a capacity to supply 25 GL) with the timing of each stage based on actual growth in water demand, potential groundwater allocation reduction, actual streamflow conditions and timing of other source option development (e.g. construction of the proposed PSDP2 at Kwinana).

The Proposal requires the installation of two seawater intakes and two seawater return outlets (approximately 4 km offshore) to enable the discharge of return seawater (brine) to the marine environment.

Why We Are Consulting

At this initial stage of the EIA process, comment is simply sought on whether or not the EPA should assess a proposal and, if so, what level of assessment is considered appropriate.

What Happens Next

Following the seven day public comment period and consideration of any comments received, the EPA will decide whether or not this proposal requires environmental impact assessment and, if so, what level of assessment will be applied.

The EPA's decisions on level of assessment are released each Monday on the EPA's website.


  • All of Western Australia


  • Public


  • Seven-day comment on referrals