TheLachlan River (Wiradjuri:Kalari,Galari,[5]Galiyarr) is anintermittent river that is part of theMurrumbidgeecatchment within theMurray–Darling basin, located in theSouthern Tablelands,Central West, andRiverina regions ofNew South Wales, Australia.
The Lachlan River is connected to the Murray–Darling basin only when both the Lachlan and Murrumbidgee Rivers are in flood. It is the only river in New South Wales with significantwetlands along its length, rather than just towards its end, includingLake Cowal-Wilbertroy,Lake Cargelligo andLake Brewster, and nine wetlands of national significance.[2]
The river rises on the western slopes of theGreat Dividing Range in the Southern Tablelands district of New South Wales, formed by theconfluence of Hannans Creek and Mutmutbilly Creek, 13 kilometres (8.1 mi) east ofGunning, and 26 kilometres (16 mi) west ofGoulburn. The river flows generally north-west, north, west and south-west, joined by thirty-seventributaries including theCrookwell,Abercrombie,Boorowa, andBelubula rivers before terminating nearOxley in the 500-square-kilometre (190 sq mi)Great Cumbung swamp that joins theMurrumbidgee River to the south and becomes part of theLowbidgee Floodplain. The river descends 632 metres (2,073 ft) over its 1,440-kilometre (890 mi)course.[1][3]
The river is impounded byWyangala Dam, nearCowra and Brewster Weir, located betweenLake Cargelligo andHillston; and passes through the towns ofBreadalbane,Reids Flat,Wyangala,Cowra,Gooloogong,Forbes,Euabalong,Condobolin, Lake Cargelligo, Hillston,Booligal, andOxley.
The annual flow of the Lachlan is erratic. Annual flows have ranged from less than 1,000 megalitres (35×10^6 cu ft) in 1944 to as much as 10,900 megalitres (380×10^6 cu ft) in 1950. In dry years, the Lachlan can have periods ofzero flow of over a year (for example from April 1944 to April 1945), which is a complete contrast to the Murray and Murrumbidgee which have not been known to cease to flow since European settlement. The river has flooded every seven years since 1887 atForbes.[6]
The social-ecological systems of the Lachlan River and itscatchment include its upper tablelands, mixed farming slopes, through to plains, rangelands, and then lower floodplains.[7] More than 100,000 people live in the Lachlan catchment. It is estimated that 12% of the state's agricultural businesses are located from within the Lachlan River catchment.[2]
The Lachlan River is located in the traditional homelands of theWiradjuriAboriginal people.[8] The Wiradjuri lived along theMacquarie, Lachlan andMurrumbidgee Rivers,[9] in the area known as "the land of the three rivers".[10]
Acting-SurveyorGeorge William Evans visited the river in 1815, naming it the Lachlan River afterLachlan Macquarie, thegovernor of the colony of New South Wales. The Lachlan River was substantially explored byJohn Oxley in 1817.[11] In the early days of colonial New South Wales, the southern part of the Lachlan was known asFish River. It was only after further exploration that it was realised that these two rivers were the same river and the name Fish River was dropped.
The explorer and naturalist, James H B Shaw, was one of the first Europeans to write about the birds and habitat along the Lachlan River. His article appeared in the Australian Town and Country Journal (Sydney, NSW : 1870 – 1907), Saturday 7 March 1885, page 28, 29https://nla.gov.au/nla.news-article71024608
In 1870 the river peaked at 15.9 metres (52 ft) at Cowra.[12] Since 1887, the highest flood level at Forbes was in June 1952 when the river peaked at 10.8 metres (35 ft) at the Forbes Iron Bridge.[6] More than 900 families were evacuated, with many rescued from roof-tops by boat and helicopter.[13] During the flood in August 1990, 132 houses in Forbes were affected by flood with their yards or their floors covered by water.[6] Floods in 1992 did not reach the same levels at Forbes as in 1990, however,Lachlan Valley farmers lost about 30 percent of their lucerne crops just before harvest. At least 500 sheep were drowned on properties in theEugowra/Trundle area and most of Eugowra's 400 residents were evacuated and some residents from Trundle.[14] Other significant years of floods were: 1891, 1916, 1951, 1956, 1961, 1974, 1976, 1993, 1998,[15] 2012, 2016 and 2021.[16]
The Lachlan River is mentioned in theBanjo Paterson poemClancy of the Overflow as well as the folk songStreets of Forbes.
Rivers of theMurrumbidgee River catchment,New South Wales and theAustralian Capital Territory, Australia | |||||
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Rivers of theMurray–Darling basin, Australia | |||||||||||||||
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