Yan Yean Reservoir is the oldest water supply for the city of
Melbourne,
Victoria,
Australia.[1] At the time of its completion in 1857 it was the largest artificial
reservoir in the world.[2][3] It is 30 kilometres (19 mi) north of the city within the eponymous locality of
Yan Yean, and is built on the
Plenty River, a tributary of the
Yarra River. An
embankment 9.5 metres (31 ft) high holds back 30,000 ML (1.1 billion cu ft) of water.
The reservoir is managed by
Melbourne Water as part of the water supply system for Melbourne.
History
The name Yan Yean refers to the
Aboriginal leader who signed the
Batman's Treaty in 1835 with the name "Yan Yan" ("young male").[4]
Work commenced on 20 December 1853 when Governor
Charles La Trobe turned the first
sod.[3] Construction took place at the height of the
gold rush[5] employing a tent city of 1,000 workers returning from the goldfields.[3] The Board of Commissionaires of Sewers and Water Supply was formed that same year in response to the demand for a reliable water supply system.[6]
The reservoir took four years to construct at a cost of £750,000.[7][8] Other sources estimate the cost of the project to be £1,017,087.[9] Most of the pipes were imported from London.[10] It was designed by
James Blackburn, an English
civil engineer and former London sanitary inspector who was transported to
Tasmania as a
convict following charges of embezzlement. After being pardoned he came to Melbourne in 1849.[11]
The water was originally supplied by the Plenty River; however, the water quality was poor due to
stock crossings and pollution from rural towns.[3] The problem was solved by bypassing the Plenty River and diverting water from Wallaby Creek and Silver Creek, both originating in the
Great Dividing Range feeding the
Goulburn River. This mountain water was captured in the
Toorourrong Reservoir system, constructed in 1883–1885, and supplies water to Yan Yean via an
aqueduct to this day.[3] During its construction, the nearby neighbourhood
Mernda was created and grew rapidly. Morang became South Yan Yean, and later Mernda.[4]
At the time of its completion in 1857, it was the largest artificial reservoir in the world.[2][3] Photographer
Fred Kruger was commissioned by the government to provide images of the extensive works for display at the
Colonial and Indian Exhibition of 1886. By 1857, the city of Melbourne had grown to a population of 100,000.[6] The reservoir was inaugurated in the city in 1857's new year's eve.[12]
The region was frequently hit by floods.[13] The reservoir resisted a flood that hit Melbourne in 1923, and became the city's main water emergency resource after the incident.[14] In 1871–72, it is an arid season that led to low water levels in the reservoir and a failure to distribute water throughout the city. During the
Second World War, the catchment area was closed for security reasons.[10]
Description
The site of the reservoir is 183 metres in altitude, allowing sufficient
hydraulic head for the water to be piped throughout the city under gravity. The dam is 963 metres long. The reservoir has a capacity of 30 gigalitres. The catchment covers 2,250 hectares.[10]
^
abClode, Danielle (11 September 2006). Continent of curiosities: A journey through Australian natural history. Cambridge University Press. p. 45.
ISBN0-521-86620-0.
^R. C. Seeger, 'The History of Melbourne's Water Supply-Part 1', Victorian Historical Magazine, vol 19, no 3, June 1942,
pp 107–119 and vol 19, no 4, Dec 1942,
pp 133–38