Goldfields Water Supply Scheme (GWSS), Goldfields

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Goldfields Water Supply Scheme, built in 1903, includes a 556km pipeline from Mundaring Weir in Perth to Kalgoorlie. Image courtesy of SeanMack. The GWSS receives water from the Helena River in Mundaring. Image courtesy of SeanMack. The Mundaring Dam was considered to be the highest overflow dam when constructed. Image courtesy of SatuSuro. Pipes were made of flat steel plates that were bent to form semi-circles. Image courtesy of SeanMack. Goldfields Water Supply Scheme (GWSS), called the ‘Scheme of Madness’ by its critics, was constructed in 1903. It still continues to supply water to the Goldfields region in Western Australia. The construction work was undertaken from 1898-1903 under the guidance of engineer C. Y. O’Connor. The Public Works Department of Western Australia once owned the scheme. It is now owned by the Water Corporation of Western Australia. The £2.5m scheme included the Mundaring Weir, a 30in diameter, 556km steel pipe from the dam to Kalgoorlie, eight pumping stations and two small holding dams to lift the water over the Darling Scarp ridge. With a capacity to pump 90 million litres of water a day, the scheme serves around 100,000 people and various mines located in an area of 44,000 square kilometres. The GWSS was recognised as an international historic civil engineering landmark by the American Society of Civil Engineers in 2009. The Coolgardie and Kalgoorlie regions in Western Australia were formed in the 1890s by people who came searching for better prospects on learning that gold was found in these two regions. The two regions are basically dry throughout the year. The idea to pump potable water from Perth to supply water to the dry regions in Western Australia was first brought up by Sir Forest John, the then premier of Western Australia. The scheme was given the green signal by the Parliament in 1896 and construction began in 1898. The project had to face a lot of criticism for being impractical. After C. Y. O’Connor’s death in 1902 the project work was taken over by his engineer-in-chief, CSR Palmer. The scheme receives water from the Mundaring Weir which forms part of the scheme. The weir is fed by the Helena River in Mundaring. The water from Mundaring Weir is pumped from a station located at the dam site and then to successive pumping stations. The scheme, which originally had eight pumping stations, currently has 20. The pumping of water was initially undertaken with the help of 20 steam turbines. They were later replaced with electric turbines. Water pumped from the weir is lifted over the Darling Range and stored at Mount Charlotte Reservoir located 419m above sea level. The water is carried through the world’s longest potable water pipeline, measuring 556km long. Distribution of water used to take place from Mount Charlotte Reservoir. A main holding tank at the north of Mt Percy constructed in 1985 has replaced the Mount Charlotte Reservoir, which is now used as a reserve tank. Mundaring Water Treatment Plant (WTP) is a A$300m public private partnership (PPP) project being undertaken in Mundaring. Construction of Mundaring Weir was completed in 1902. The dam has a discharge capacity of 1,020 cubic metres a second with a catchment area of 1,470 square kilometres. The height of the dam wall measures 40.23m. It was considered to be the highest overflow dam when it was built. The pipes used for the scheme consist of flat steel plates. The flat pipes were bent, forming semi-circles which were then joined by using the locking bar system. The pipes were laid by placing them in trenches to minimise expansion-contraction. The pipes were initially laid manually until the introduction of the caulking machine. The pipes used for the scheme were 5-8mm thick. A total of 60,000 pipes were estimated to have been used for the entire scheme. The Mount Charlotte Reservoir, with its reservoir capacity of 9,000kl, is located at the highest hill within the vicinity of the scheme. The reservoir was dug through the pick and shovel method. The high altitude of the reservoir provides enough pressure for the water supply. The scheme necessitated the use of both riveted and welded pipes. An A$17m state-of-the-art upgrade of the Shepparton wastewater treatment plant by Tenix Alliance began in November 2002. The contract to supply the welded pipes was awarded to Mephan Ferguson, while the riveted pipes supply contract was awarded to G. & H. Hoskins. The steel plate for the riveted pipes was supplied by Carnegic Steel, while the plate for the jointing rings was supplied by Ebbw Vale Steel, Iron and Coal. The locking bars were supplied by Nettlefolds. Earl Dudley Ironworks provided the locking bars and joint ring plate to be used for the welded pipes. The plate for the welded pipes was manufactured by four companies: Thyssen & Cie, Actien (10,200t), Gesellschaft der Dellinger (9,100t), Phoenix Actien Gesellschaft der Bergban (7,100t) and Gewerkschaft Grille Funke (6,100t). The caulking machine was developed by James Couston. Utilities used for the construction of the pumping stations were provided by James Simpson.

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