Murray RiverMurray River is Australia's second-longest river in its own right (the longest being its tributary the Darling). The 3370 kilometre long combined Murray-Darling river system drains most of inland Victoria, New South Wales, and southern Queensland. The 2500-kilometer Murray proper rises in the Australian Alps, draining the western side of Australia's highest mountains. Carrying only a small fraction of the water of comparably-sized rivers in other parts of the world, and with a great annual variability of its flow, in its natural state it has even been known to dry up completely in drought years. For most of its length, the Murray meanders its way across Autralia's inland plains, forming the border between New South Wales and Victoria as it wanders to the northwest, before turning south for its final 500 kilometres or so into South Australia. It supplies much of Adelaide's domestic water supply.
In the 19th century the river used to support a substantial commercial steamboat trade, but the unreliable levels made it impossible for boats to compete with the railways and later road transport. However, the river still carries pleasure boats along its entire length. During the 20th century a large number of dams were constructed in the river's headwaters, including the Hume Dam, Dartmouth Dam, and the complex dam and pipeline system of the Snowy Mountains Scheme. These dams inverted the patterns of the river's natural flow from the original winter-spring flood and summer-autumn dry to the present low level through winter and higher during summer. These changes ensured the availability of water for irrigation and made the Murray Valley Australia's most productive agricultural region, but have seriously disrupted the life cycles of many ecosystems both inside and outside the river, and the irrigation has led to dryland salinity that now threatens the agricultural industries.
The disruption of the river's natural flow, runoff from agriculture, and the introduction of pest species like the European Carp has led to serious environmental damage along the river's length and to concerns that the river (and thus Adelaide's water and the irrigation water) will be unusably salty in the medium to long term. Efforts to alleviate the problems proceed but political infighting between various interest groups stalls progress.
- Lake Hume
- Lake Dartmouth
- Snowy Mountains Scheme
- Yarrawonga Weir