The Murray River is the most important single stream in Australia. Geographically, it is the second-longest river on the continent — the Murray is 2,575 kilometres long, second only to its tributary the Darling. Economically, it is the most significant single source of fresh water. Historically, the Murray provided the setting for many of Australia's most important events. Environmentally, it is home to a huge variety of distinctively Australian flora and fauna.
Near Tom Groggin in the mountain headwaters.
Near Howlong, NSW, at the start of the plains.
Lake Mulwala, Victoria: former red gum forest.
The Murray at Berri, South Australia. Note the large area of dead and dying River Red Gums in the middle distance.
Near Walkerie, South Australia.
The Murray rises on the inland western side of the highest mountains on the continent, tumbling down through the rugged, inaccessible ranges of the eastern NSW-Victorian border area, before reaching the vast flat former seabed that makes up the major part of the Murray-Darling Basin. For the major part of its length, the Murray flows slowly, meandering westward in great loops across the plains towards South Australia, branching and rejoining from time to time.
Once in South Australia, it turns south, flowing through a deep-cut channel towards Lake Alexandrina, and then The Coorong. Only a tiny fraction of its water reaches the terminal lakes, however: the great bulk of it is extracted for irrigation and town water supply.
The Murray was the centre of an extensive Aboriginal civilisation for many thousands of years, but few records of it now remain.
Hume and Hovell were the first Europeans to explore the river, reaching it near present-day Albury in 1824, and naming it the "Hume River". Six years later, Charles Sturt reached the Murray after travelling down the Murrumbidgee and and renamed it in honour of the British Colonial Secretary, Sir George Murray. Sturt and his party continued downstream to the river mouth. The first biological exploration of the Murray took place in 1858 when William Blandowski and Gerard Krefft took over 17,000 specimens from the Murray and the lower Darling, including many previously undescribed species.
From the middle of the Nineteenth Century, the Murray became a major transport artery. Although the sandbars at the river mouth prevented direct access to the sea, river steamers made their way upstream on the spring floods as early as 1853. By 1860 there were 12 steamers carrying the wool clip downstream towards Adelaide, and supplies of all sorts in the opposite direction, usually to Echuca, but sometimes as far as Albury.
In 1864 the railway line from Melbourne reached the river, and the nature of the traffic changed: now the primary destination was the railhead at Echuca, but the influx of post-gold rush settlers saw steamer traffic continue growing, reaching a peak of about 30 steamers and as many barges by 1885. From that time on, as other railway lines reached the river, traffic declined.
The first major modifications to the river (beyond tree felling and fishing) were directed at the numerous underwater snags. To aid navigation, barges fitted with steam winches began removing sunken trees (and with them, valuable fish habitat). At this time, the river still retained its natural flow regime: floods in winter-spring, low flow or sometimes no flow at all in the summer months.
Steam pumps were first used to extract water from the river on a small scale during the 1850s, the first major pumping station was constructed at Mildura in 1887. Other stations soon followed. In 1915, after much interstate bickering, New South Wales, Victoria, and South Australia signed the River Murray Agreement and outlined ambitious plans to transform the river into a major economic resource.
To enable year-round navigation, many locks and weirs were proposed. The first, Lock 1 near Blanchetown, was completed in 1922 and construction of others continued until 1934 when the ongoing expansion of the railways and the rise of motor transport led to the program being abandoned with only 13 locks complete: these included Locks 1 to 11 (all downstream of Mildura), Torrumbarry Weir (downstream of Echuca), and Lock 15 at Euston, which was finished in 1937.
A series of massive water storages were constructed. Lake Victoria near the junction with the Darling river in far-western New South Wales was completed in the late 1920s; Lake Hume upstream of Albury in 1936, and Lake Mulwala near Yarrawonga in 1939. The Snowy Mountains Scheme began shortly after World War II, and the Dartmouth Dam (actually on the Mitta Mitta River, which supplies 40% of the Murray's water) was completed in 1979.
The overall result of the engineering works has been to invert the river's natural flow, and seriously disrupt the riverine ecosystem. Large scale irrigation has made the Murray Basin Australia's richest agricultural area, but has also let to serious problems with dryland salinity.