Chowilla Dam was a proposed water storage reservoir on the

Murray River The Murray River (in South Australia: River Murray; Ngarrindjeri language, Ngarrindjeri: ''Millewa'', Yorta Yorta language, Yorta Yorta: ''Dhungala'' or ''Tongala'') is a river in Southeastern Australia. It is List of rivers of Australia, Aust ...

in the 1960s. The dam wall would have been in

South Australia South Australia (commonly abbreviated as SA) is a States and territories of Australia, state in the southern central part of Australia. With a total land area of , it is the fourth-largest of Australia's states and territories by area, which in ...

, but the reservoir behind it would have stretched upstream into

Victoria Victoria most commonly refers to: * Queen Victoria (1819–1901), Queen of the United Kingdom and Empress of India * Victoria (state), a state of Australia * Victoria, British Columbia, Canada, a provincial capital * Victoria, Seychelles, the capi ...

and

New South Wales New South Wales (commonly abbreviated as NSW) is a States and territories of Australia, state on the Eastern states of Australia, east coast of :Australia. It borders Queensland to the north, Victoria (state), Victoria to the south, and South ...

. The site was selected in 1960. Early preparations for its construction were conducted before the project was halted. These included a 23 km service railway from the Barmera railway line, which was dismantled without ever actually being used.

Purpose

The dam was proposed to provide flood regulation and reliable water supplies for South Australia, which pumps water from the lower Murray through pipelines across the

Mount Lofty Ranges The Mount Lofty Ranges are a range of mountains in the Australian state of South Australia which for a small part of its length borders the east of Adelaide. The part of the range in the vicinity of Adelaide is called the Adelaide Hills and d ...

Adelaide Adelaide ( , ; ) is the list of Australian capital cities, capital and most populous city of South Australia, as well as the list of cities in Australia by population, fifth-most populous city in Australia. The name "Adelaide" may refer to ei ...

, and parts of the

Mid North The Mid North is a region of South Australia, north of the Adelaide Plains and south of the Far North and the outback. It is generally accepted to extend from Spencer Gulf east to the Barrier Highway, including the coastal plain, the souther ...

Yorke Peninsula The Yorke Peninsula, known as Guuranda by the original inhabitants, the Narungga people, is a peninsula located northwest and west of Adelaide in South Australia, between Spencer Gulf on the west and Gulf St Vincent on the east. The peninsula ...

and

Eyre Peninsula The Eyre Peninsula is a triangular peninsula in South Australia. It is bounded by the Spencer Gulf on the east, the Great Australian Bight on the west, and the Gawler Ranges to the north. Earlier called Eyre's Peninsula, it was named after e ...

. It was announced on 21 April 1960 by Tom Playford, the

Premier of South Australia The premier of South Australia is the head of government in the state of South Australia, Australia. The Government of South Australia follows the Westminster system, with a Parliament of South Australia acting as the legislature. The premier i ...

Cross border agreement

It had been agreed by the River Murray Commission in September 1961 and governments of South Australia, Victoria, New South Wales and Australia in 1963. A preliminary meeting was held on 16 April 1962 to start discussion on Chowilla Dam. Participants in that meeting were

Prime Minister of Australia The prime minister of Australia is the head of government of the Commonwealth of Australia. The prime minister is the chair of the Cabinet of Australia and thus the head of the Australian Government, federal executive government. Under the pr ...

Bob Menzies,

Tom Playford,

Premier of Victoria The premier of Victoria is the head of government of the state of Victoria in Australia. The premier leads the Cabinet of Victoria and selects its ministers. The premier is appointed by the governor of Victoria, must be a member of the Vic ...

, Deputy

Premier of New South Wales The premier of New South Wales is the head of government in the state of New South Wales, Australia. The Government of New South Wales follows the Westminster system, Westminster Parliamentary System, with a Parliament of New South Wales actin ...

and Minister for Development

Jack Renshaw John Brophy Renshaw (8 August 190928 July 1987) was an Australian politician. He was Labor Premier of New South Wales from 30 April 1964 to 13 May 1965. He was the first New South Wales Premier born in the 20th century. Early life Jack Rensh ...

Treasurer of Australia The Treasurer of Australia, also known as the Federal Treasurer or more simply the Treasurer, is the Federal Executive Council (Australia), minister of state of the Australia, Commonwealth of Australia charged with overseeing government revenu ...

Harold Holt Harold Edward Holt (5 August 190817 December 1967) was an Australian politician and lawyer who served as the 17th prime minister of Australia from 1966 until Disappearance of Harold Holt, his disappearance and presumed death in 1967. He held o ...

, Minister for National Development Bill Spooner. The follow-up meeting at which an agreement was reached was held on 19 November 1962. Participants were Spooner (also President of the River Murray Commission) and Menzies for the Commonwealth, Renshaw and George Enticknap for NSW, Premier of Victoria

Henry Bolte Sir Henry Edward Bolte ( ; 20 May 1908 – 4 January 1990) was an Australian politician who served as the 38th premier of Victoria from 1955 to 1972. He held office as the leader of the Victorian division of the Liberal Party of Australia ...

and Premier of South Australia Thomas Playford. The four governments would share the costs evenly, however the Commonwealth would extend a loan for the New South Wales component in exchange for water from the Menindee Lakes during construction.

Reservoir

The reservoir would have been long and up to wide with a surface area of due to the flat terrain. The dam wall would have been long and the reservoir depth up to with a capacity of . The reservoir would have been approximately in South Australia, in Victoria and in New South Wales.

Engineering

The dam was proposed to be an earth embankment up to high and long. It was to include a concrete spillway long, as well as a navigation lock. In later versions of the plan, the lock was removed to save cost. The embankment would block the

, as well as both Chowilla Creek and Monoman Creek in the Chowilla floodplain. Most of the impervious core and the compacted sand shoulders of the dam embankment were to be sourced from local materials of specific layers of soil. There was also going to be an -deep cut-off wall under the concrete spillway and a lock to reduce seepage. The plan to deal with the highly saline groundwater was to drill relief wells and drains, and pump the saline water to evaporation ponds several miles away. That was similar to what had been done previously at several points along the Murray for what were known as "salt interception schemes". Rock would need to be transported from further away to provide protective

riprap Riprap (in North American English), also known as rip rap, rip-rap, shot rock, rock armour (in British English) or rubble, is human-placed rock or other material used to protect shoreline structures against scour and water, wave, or ice erosion. ...

, filters, and aggregate in concrete, as well as bituminous membrane, which would be transported by rail from away. The

South Australian Railways South Australian Railways (SAR) was the organisation through which the Government of South Australia built and operated railways in South Australia from 1854 until March 1978, when its non-urban railways were incorporated into Australian Natio ...

was engaged to transport the required rock. A railway line was built, branching from the Barmera line north of Yamba. Sixty FCD-class flatcars were constructed by the

Islington Railway Workshops The Islington Railway Workshops are railway workshops in the northern suburbs of Adelaide, South Australia. They were the chief railway workshops of the South Australian Railways, and are still in operation today.Murray Bridge and Monarto South, to collect the stone. When the project was cancelled, the branch line had been completed, except for the laying of ballast and the terminal siding. Work to remove the line began in September 1972, and the rails were used to upgrade the Waikerie line.

Controversy

The dam and reservoir would have flooded the wetlands in what is now the

Chowilla Game Reserve Chowilla Game Reserve is a protected area covering the floodplain on the north side of the River Murray in South Australia from about north-east of Renmark to the New South Wales border. It was proclaimed 8 April 1993 in conjunction with the ...

, Chowilla Regional Reserve and northern edge of the Murray-Sunset National Park and potentially raised salinity in the Riverland and lower Murray as the reservoir would have been quite shallow in a hot dry climate. The dam was first proposed and announced by Tom Playford, the

Liberal and Country League The South Australian Liberal Party, officially known as the Liberal Party of Australia (South Australian Division), and often shortened to SA Liberals, is the South Australian Division of the Liberal Party of Australia. It was formed as the Lib ...

premier of South Australia The premier of South Australia is the head of government in the state of South Australia, Australia. The Government of South Australia follows the Westminster system, with a Parliament of South Australia acting as the legislature. The premier i ...

in 1960. Playford's government had been in office since 1938, and through that time had presided over significant economic and infrastructure development in the state. This had included encouraging new industries, establishing satellite cities around

, nationalising the electricity generators and stimulating self-sufficiency by using Leigh Creek brown coal instead of importing black coal from interstate. The Chowilla Dam would have continued this theme by providing greater certainty and control over water supplies as Adelaide's water requirements were increasing. Playford and the LCL won the 1962 state election only with the support of independent

Tom Stott Tom Cleave Stott Order of the British Empire, CBE (6 June 1899 – 21 October 1976) spent 37 years as an independent member of the South Australian House of Assembly, from 1933 to 1970. He served as Speaker of the South Australian House of Assemb ...

in an otherwise-hung parliament. Stott was a strong supporter of building the dam, which would be in his electorate. The

Frank Walsh Francis Henry Walsh (6 July 1897 – 18 May 1968) was the 34th Premier of South Australia from 10 March 1965 to 1 June 1967, representing the South Australian Branch of the Australian Labor Party. Early life One of eight children, Walsh was b ...

-led

Australian Labor Party The Australian Labor Party (ALP), also known as the Labor Party or simply Labor, is the major Centre-left politics, centre-left List of political parties in Australia, political party in Australia and one of two Major party, major parties in Po ...

won the 1965 election. After leadership changes in both parties, the LCL led by

Steele Hall Raymond Steele Hall (30 November 1928 – 10 June 2024) was an Australian politician who served as the 36th Premier of South Australia from 1968 to 1970. He also served in the federal Parliament as a senator for South Australia from 1974 to 1 ...

defeated the ALP led by

Don Dunstan Donald Allan Dunstan (21 September 1926 – 6 February 1999) was an Australian politician who served as the 35th premier of South Australia from 1967 to 1968, and again from 1970 to 1979. He was a member of the House of Assembly (MHA) for th ...

in the 1968 election again through the support of Stott. Hall became convinced that the Chowilla Dam was not a good idea and favoured agreements for water supply from Dartmouth Dam instead. This was due to a combination of the increasing cost estimates of building the dam, and the increasing awareness of the environmental impacts of the proposed dam. As Stott still believed that the dam would be valuable in his electorate, and with local community opinion mostly in its favour, he switched his support from Hall to Dunstan (who supported both Chowilla and Dartmouth Dams), resulting in the 1970 election which returned the ALP with a majority to govern in its own right (27 out of 47 seats). Chowilla was one of the first instances of a campaign in which there was strong advocacy for environmental protection. The Sunraysia Salinity Committee opposed the dam as it believed that the combination of high evaporation and saline groundwater would lead to increased salinity downstream which would be harmful to horticulture. The future salinity concerns were raised in contrast to the local economic benefits to be brought by the construction project. The Victorian government was the first to change from support to opposition of the project.

Cancellation

The Dartmouth Dam was built on the

Mitta Mitta River Mitta Mitta River, a perennial river and a direct tributary of the Murray River within the Murray–Darling basin, is located in the Alpine district of Victoria, Australia. The name Mitta Mitta derives from the Aboriginal word ''mida-modoen ...

(a tributary of the Murray) in the 1970s. There are agreements in place to assure South Australia of a supply of water, and management to control the flow, because it takes six weeks for water from Dartmouth Dam to reach South Australia.

Lake Victoria Lake Victoria is one of the African Great Lakes. With a surface area of approximately , Lake Victoria is Africa's largest lake by area, the world's largest tropics, tropical lake, and the world's second-largest fresh water lake by surface are ...

in southwestern New South Wales, on an

anabranch An anabranch is a section of a river or stream that diverts from the main channel or stem of the watercourse and rejoins the main stem downstream. Local anabranches can be the result of small islands in the watercourse. In larger anabranches, ...

of the Murray, provides closer guaranteed supply and is operated by South Australian water authorities.

References

{{reflist Riverland Cancelled dams Dam controversies Unbuilt buildings and structures in Australia Cancelled projects in Australia