Murray

Principal river of Australia, which rises in the Snowy Mountains of the Australian Alps near Mount Kosciusko, in New South Wales; length 2,540 km/1,578 mi. The Murray flows west and northwest, for most of its length forming the boundary between New South Wales and Victoria, then turns south to reach the Southern Ocean at Encounter Bay, southeast of Adelaide in South Australia. The River Murray is an important source of hydroelectric power and water for irrigation which supports farming in over 4,000 ha/1,000,000 acres. With its main tributary, the Darling, it is 3,750 km/2,330 mi long. Together the basins of these rivers produce 40% of the country's agricultural wealth, including wheat, fruit, and wine, as well as the products of pastoral farming, especially of sheep and cattle.

The main towns on the Murray's course are Albury-Wodonga, Echuca, Mildura, and Murraybridge.

Course The Murray is joined by the Darling 640 km/400 mi from its mouth, at Wentworth. Its other tributaries include the Lachlan and the Murrumbidgee. Before entering the Southern Ocean at Encounter Bay, the Murray flows through the shallow Lake Alexandrina. In conjunction with the Darling, the Murray drains almost the entire southeast quarter of the continent. The river is navigable to Albury-Wodonga.

Irrigation and hydroelectric power The water of the Murray is used to provide irrigation and hydroelectric power. It is dammed at the Hume Reservoir, near Albury-Wodonga, where the Mitta Mitta joins it. The reservoir stores water which runs off a catchment area of about 15,540 sq km/6,000 sq mi of mountainous country on the border of Victoria and New South Wales. The large volume of water stored in the reservoir ensures an adequate flow of water in the irrigated areas in the lower reaches of the River Murray. In 1949 the governments of New South Wales and Victoria agreed on a scheme for the diversion of the headwaters of the Snowy River across the Australian Alps into the upper Murray and Tumut rivers, in connection with a vast hydroelectric irrigation project, constructed by the Snowy Mountains Hydroelectric Authority and opened in 1972. The Dartmouth Dam (1979) in the Great Dividing Range supplies hydroelectric power and has drought-proofed the Murray river system, but irrigation (for grapes, citrus, and stone fruits) and navigation schemes have led to soil salinization, which is a serious problem both for cultivation and for the supply of drinking water. Adelaide, for example, relies mainly on the Murray for its drinking water, which in some recent years has been found not to meet the standards prescribed by the World Health Organization.

Recreation The river is used for fishing, swimming, and houseboats; three paddlesteamers based in Echuca, the Pevensey (1911), the Adelaide (1866), and the Canberra (1912), make tourist trips along the Murray.

History In 1830 the explorers Charles Sturt and William Hovell sailed up the Murray in a whaleboat, and Sturt named the river after Sir George Murray, the secretary of state for the colonies. Following on from their exploration, the interior of the continent was opened up, and from 1938 the Murray was used by drovers to take sheep and cattle to Adelaide. The first paddle steamer was launched in 1853, increasing the use of the river for transportation of goods.

Environmental concern An Australian government study found, in November 1999, that some of Australia's major rivers, including the Murray, are likely to be poisonous to humans and crops within 50 years because of high levels of salt. The salinity problem is due to the clearance of native vegetation and the widespread use of irrigation, which have led to a rise in the water table; this in turn causes naturally occurring salt in the subsoil to rise to the surface, contaminating rivers and topsoil.