The Perth Seawater Desalination Project comprises the design, construction and operation of a 45 gigalitre per year desalination plant to be located in Kwinana, 25km south of Perth, Western Australia. The project scope includes seawater intake, pretreatment, reverse osmosis desalination, drinking water potabilisation and pumping station. Multiplex is responsible jointly with Degremont for the design and construction of the $387 million plant.

The Project is executed in an Alliance Arrangement with the Water Corporation in two phases covered by separate Design/Construct and Operation/Maintenance contracts. The plant is scheduled for completion by end of April 2007, with potable water supplies being progressively delivered following commissioning in October 2006.