The Binningup Desalination Plant is a desalination plant near Binningup, Western Australia, about 150 kilometres (93 mi) south of Perth. It supplies water to the state capital Perth, as well as the nearby regional city of Bunbury and is known as the Southern Seawater Desalination Project It was designed to initially deliver 50 gigalitres of potable water per year but was expanded to deliver 100 gigalitres of potable water per year, or 20% of Perth's requirements.