In 1896, after discoveries of gold at Coolgardie and Kalgoorlie, the Western Australian Parliament authorised the raising of a loan to construct a pipeline to transport of water per day to the burgeoning population on the goldfields. The pipeline, known as the Goldfields Water Supply Scheme, was completed in 1903. O'Connor, Western Australia's first engineer-in-chief, designed and oversaw the construction of the pipeline. It carries water from Perth to Kalgoorlie, and is attributed by historians as an important factor driving the state's population and economic growth. Following a campaign led by Forrest, residents of the colony of Western Australia voted in favour of federation, resulting in Western Australia officially becoming a state on 1 January 1901. Geography Western Australia is bounded to the east by longitude 129°E, the meridian 129 degrees east of Greenwich, which defines the border with South Australia and the Northern Territory, and bounded by the Indian Ocean to the west and north. The International Hydrographic Organization (IHO) designates the body of water south of the continent as part of the Indian Ocean; in Australia it is officially gazetted as the Southern Ocean. The total length of the state's eastern border is . There are of coastline, including of island coastline. The total land area occupied by the state is . Geology The bulk of Western Australia consists of the extremely old Yilgarn craton and Pilbara craton which merged with the Deccan Plateau of India, Madagascar and the Kaapvaal and Zimbabwe cratons of Southern Africa, in the Archean Eon to form Ur, one of the oldest supercontinents on Earth (3 – 3.2 billion years ago). In May 2017, evidence of the earliest known life on land may have been found in 3.48-billion-year-old geyserite and other related mineral deposits (often found around hot springs and geysers) uncovered in the Pilbara craton. Because the only mountain-building since then has been of the Stirling Range with the rifting from Antarctica, the land is extremely eroded and ancient, with no part of the state above 1,245 metres (4,085 ft) AHD (at Mount Meharry in the Hamersley Range of the Pilbara region). Most of the state is a low plateau with an average elevation of about 400 metres (1,200 ft), very low relief, and no surface runoff. This descends relatively sharply to the coastal plains, in some cases forming a sharp escarpment (as with the Darling Range/Darling Scarp near Perth). The extreme