Irrigation


Campbell Town water works, 1880 (AOT, PH30/1/4723)

Once early settlers had secured a reliable supply of drinking water, the excess could be harnessed for other purposes. During the dry years of the early 1840s the practice of irrigation spread from its beginnings in the valleys of the Derwent and Clyde Rivers, aided by the visits of foreign experts such as brothers Arthur and Hugh Cotton, Alfred Mault and Count Strzelecki, and their effect on the governors of the day.

Captain Arthur Cotton, engineer, inventor and designer, saw immense possibilities for the development of irrigation in Tasmania, and as early as 1841 spoke of the importance of reserving water supplies for the public interest. Polish explorer, scientist and humanist Count Paul de Strzelecki toured the colony in 184042 and greatly influenced his friend Lt-Governor John Franklin about the importance of irrigation to the colony's advancement. At the same time, the damming of Tooms Lake created wide public recognition and acceptance of the advantages accruing from irrigation. Major Hugh Cotton pleaded for the preservation and conservation of the waters of the Hobart Rivulet for the inhabitants of the city and persistently advocated an irrigation scheme for the Midlands which was never adopted, despite the urgings of Lt-Governor Eardley-Wilmot. Lt-Governor Denison in 1847 mooted the sale of water by measure and stated government policy on the implementation of national schemes: it was not desirable for the government to interfere in matters which were much better left to private or combined enterprise.

Italian irrigation consultant Alessandro Martelli was impressed with the potential of the colony's water resources, favouring small schemes financed by private companies. Alfred Mault, an ex-India engineer, played an important role in preparing and framing the Clyde Water Act (1898), securing a reliable supply of drinking water for the inhabitants of Bothwell. His call for drinking water to be taken directly from Lake Sorell was echoed by Danish hydraulic engineer KL Rahbek in 1902, and in 1915 by Public Works Department engineer W Nimmo, who even advocated the draining of Lake Crescent.

William Ebenezer Shoobridge was an important figure in the irrigation of the Derwent Valley from the 1860s, designing and building schemes, planning projects combining irrigation with hydro-electricity and persistently advocating state control and regulation of all water resources. Complete control was vested in the Hydro-Electric Commission in 1930, with no distinction being made for other uses of water. The Water Act (1957) established the Rivers and Water Supply Commission, giving it extensive powers over the regulation and use of Tasmanian water resources. This body oversaw the construction of three large-scale irrigation schemes: the Cressy-Longford Scheme (1974), the South-East Districts Scheme (1986) and the Winnaleah Scheme (1987), with the planned Meander Scheme still in contention. The Water Management Act (1999) retained the Commission as a government agency, giving it ownership, management and control over the operation of public irrigation schemes.

Further reading: M Mason-Cox, Lifeblood of a colony, Hobart, 1994.

Margaret Mason-Cox