Image taken while cruising along the mighty Murray River between Echuca and Swan Hill.
Camera Olympus E-30, Focal length 14.0,
Shutter speed 1/320s, f.3.5, ISO 200
The Murray River (River Murray in South Australia) is Australia’s longest river. At 2,375 kilometres (1,476 mi) in length, the Murray rises in the Australian Alps, draining the western side of Australia’s highest mountains and, for most of its length, meanders across Australia’s inland plains, forming the border between New South Wales and Victoria as it flows to the northwest, before turning south for its final 500 kilometres (310 mi) or so into South Australia, before emptying at Lake Alexandrina.
The waters of the Murray flow through several lakes that fluctuate in salinity (and were often fresh until recent decades) including Lake Alexandrina and The Coorong before emptying through the Murray Mouth into the southeastern portion of the Indian Ocean, often referenced on Australian maps as the Southern Ocean, near Goolwa. Despite discharging considerable volumes of water at times, particularly before the advent of large scale river regulation, the Mouth has always been comparatively small and shallow.
As of 2008, the Murray River only receives 36% of its natural flow, it is perhaps the most heavily irrigated and agriculturalised river in Australia.
The Murray River forms part of the 3,750 kilometre (2,300 miles) long combined Murray-Darling river system which drains most of inland Victoria, New South Wales, and southern Queensland. Overall the catchment area is one seventh of Australia’s land mass. The Murray carries 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 extreme drought, although that is extremely rare, with only two or three instances of this occurring since official record keeping began.
The Murray makes up much of the border of the Australian states of Victoria and New South Wales. The border is generally agreed upon to be the southern high water mark of the river (ie, none of the river itself is actually in Victoria). This boundary definition can be ambiguous, as the river has changed its course slightly since the boundary was defined in 1851.
West of the 141°E line of longitude, the river continues as the Victoria – South Australia border for 3.6 kilometres (2.2 mi), this being the only stretch where a state border runs down the middle of the river. This was due to a miscalculation in the 1840s when the border was originally surveyed. Past this point, the Murray River is entirely within the state of South Australia.
The Murray River (and associated tributaries) support a variety of unique river life adapted to its vagaries. This includes a variety of native fish such as the famous Murray cod, trout cod, golden perch, Macquarie perch, silver perch, eel-tailed catfish, Australian smelt and western carp gudgeon, to name a few, and other aquatic species like the Murray short-necked turtle, Murray River crayfish, broad-clawed yabbies and the large clawed Macrobrachium shrimp, as well as aquatic species more widely distributed through south-eastern Australia such as common long-necked turtles, common yabbies, the small claw-less Parataya shrimp, water rats and Platypus. The Murray River also supports fringing corridors and forests of the famous river red gum.
The health of the Murray River has declined significantly since European settlement, particularly due to river regulation, and much of its aquatic life including native fish are now declining, rare or endangered. Recent extreme droughts (2000–2007) have put significant stress on river red gum forests, with mounting concern over their long term survival. The Murray has also flooded on occasion, the most significant of which was the 1956 flood which inundated many towns on the lower Murray and lasted for up to six months.