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Murray River

2007 Schools Wikipedia Selection. Related subjects: Geography of Oceania
(Australasia)

   Murray River
   Cliffs along the Murray River, near Younghusband, South Australia, with
   a houseboat on the right and an Australian pelican in the foreground

   Cliffs along the Murray River, near Younghusband, South Australia, with
    a houseboat on the right and an Australian pelican in the foreground

   Origin Australian Alps
   Mouth Goolwa, South Australia
   Basin countries Australia
   Length 2,575 km (1,600 mi)
   Avg. discharge 0.89 m³/s
   Basin area 1,061,469 km²

   The Murray River, or River Murray, is Australia's second-longest river
   in its own right (the longest being its tributary the Darling). At
   2,575 kilometres (1,600 miles) 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 or so into South Australia. The waters of the Murray flow
   through several lakes that fluctuate in salinity (and were often fresh
   in the 1800s) including Lake Alexandrina and The Coorong before
   emptying through the Murray mouth into the Indian Ocean (Southern Ocean
   according to Australian maps) near Goolwa. Despite discharging
   considerable volumes of water at times, particularly before the advent
   of large scale river regulation, the Murray mouth has always been
   comparatively small and shallow.

Geography

   The Murray River
   Enlarge
   The Murray River

   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.

   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. 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 km. 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.

River Life

   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 clawed Macrobrachium shrimp, as well as aquatic species more
   widely distributed through south-eastern Australia such as Common
   Long-necked Turtles, common Yabbies, 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 (2003-2004) have put significant
   stress on River Red Gum forests, with mounting concern over their long
   term survival.

   Introduced fish species such as Carp, Gambusia, Weather Loach, Redfin
   perch and Brown Trout and Rainbow Trout have also had serious negative
   effects on native fish, while Carp have contributed to environmental
   degradation of the Murray River and tributaries by destroying aquatic
   plants and permanently raising turbidity. In some segments of the
   Murray, Carp have been the only species found

Ancient History

Lake Bungunia

   Between 2.5 and 0.5 million years ago the Murray River terminated in a
   vast freshwater lake called Lake Bungunia. Lake Bungunnia was formed by
   earth movement that blocked the Murray River near Swan Reach during
   this period of time. At its maximum extent Lake Bungunia covered 33,000
   square kilometres, extending to near the Menindee Lakes in the north
   and to near Boundary Bend on the Murray in south. The draining of Lake
   Bungunnia approximately 0.5 million years ago must have been a dramatic
   event. Deep clays deposited by the lake are evident in cliffs around
   Chowilla in South Australia. Considerably higher rainfall would have
   been required to keep such a lake full; the draining of Lake Bungunnia
   appears to mark the end of a wet phase in the history of the
   Murray-Darling Basin and the onset of widespread arid conditions
   similar to today. A species of Neoceratodus lungfish existed in Lake
   Bungunnia; today Neoceratodus lungfish are only found in several
   Queensland rivers.

Cadell Fault and formation of the Barmah Red Gum Forests

   The famous Barmah Red Gum Forests owe their existence to the Cadell
   Fault. About 25,000 years BP, displacement occurred along the Cadell
   fault, raising the eastern edge of the fault (which runs north-south)
   8-12 metres above the floodplain. This created a complex series of
   events. A section of the original Murray River channel immediately
   behind the fault was abandoned, and exists today as an empty channel
   known as Green Gully. The Goulburn River was dammed by the southern end
   of the fault to create a natural lake. The Murray River flowed to the
   north around the Cadell Fault, creating the channel of the Edwards
   River which exists today and through which much of the Murray River's
   waters still flow. Then the natural dam on the Goulburn River failed,
   the lake drained, and the Murray River avulsed to the south and started
   to flow through the smaller Goulburn River channel, creating "The
   Barmah Choke" and "The Narrows" (where the river channel is unusually
   narrow), before entering into the proper Murray River channel again.

   This complex series of events however divert attention from the primary
   result of the Cadell Fault. The primary result of the Cadell Fault is
   that the west-flowing water of the Murray River strikes the north-south
   running fault and diverts both north and south around the fault in the
   two main channels (Edwards and ancestral Goulburn) as well as a fan of
   small streams, and regularly floods a large amount of low-lying country
   in the area. These conditions are perfect for River Red Gums, which
   rapidly formed forests in the area. Thus the displacement of the Cadell
   Fault 25,000 BP lead directly to the formation of the famous Barmah
   River Red Gum Forests

   The Barmah Choke and The Narrows mean the amount of water that can
   travel down this part of the Murray River is restricted. In times of
   flood and high irrigation flows the majority of the water, in addition
   to flooding the Red Gum forests, actually travels through the Edwards
   River channel. The Murray River has not had enough flow power to
   naturally enlarge The Barmah Choke and The Narrows to increase the
   amount of water they can carry.

   The town of Barmah, Victoria is unusual in that it is north of part of
   New South Wales, although everywhere else Victoria is south of New
   South Wales. Echuca on the map above is very close to Barmah.

   The Cadell Fault is quite noticeable as a continuous, low, earthen
   embankment as one drives into Barmah from the west, although to the
   untrained eye it may appear man-made.

Murray Mouth

   The Murray Mouth is the point at which the Murray river meets the
   Southern Ocean. Since the early 2000s, dredging machines have operated
   at the Murray Mouth, moving sand from the channel to maintain a minimal
   flow from the sea and into the Coorong's lagoon system. Without the 24
   hour dredging, the Mouth would silt up and close, cutting the supply of
   fresh sea-water into the Coorong, which would then warm up, stagnate
   and die.

Mythology

   Being one of the major river systems in one of the driest continents of
   Earth, the Murray has significant cultural relevance to Indigenous
   Australians. According to the peoples of Lake Alexandrina, the Murray
   was created by the tracks of the Great Ancestor, Ngurunderi, as he
   pursued Pondi, the Murray Cod. The chase originated in the interior of
   New South Wales. Ngurunderi pursued the fish (who, like many totem
   animals in Aboriginal myths, is often portrayed as a man) on rafts (or
   lala) made from red gums and continually launched spears at his target.
   But Ponde was a wily prey and carved a weaving path, carving out the
   river's various tributaries. Ngurundi was forced to beach his rafts,
   and often create new ones as he changed from reach to reach of the
   river.

   At Kobathatang, Ngurunderi finally got lucky, and struck Pondi in the
   tail with a spear. However, the shock to the fish was so great it
   launched him forward in a straight line to a place called Peindjalang,
   near Tailem Bend. Eager to rectify his failure to catch his prey, the
   hunter and his two wives (sometimes the escaped sibling wives of Waku
   and Kanu) hurried on, and took positions high on the cliff on which
   Tailem Bend now stands. They sprung an ambush on Ponde only to fail
   again. Ngurunderi set off in pursuit again, but lost his prey as Ponde
   dived into Lake Alexandrina. Ngurunderi and his women settled on the
   shore, only to suffer bad luck with fishing, being plagued by a water
   fiend known as Muldjewangk. They later moved to a more suitable spot at
   the site of present-day Ashville. The twin summits of Mount Misery are
   supposed to be the remnants of his rafts, they are known as
   Lalangengall or the two watercraft.

   Remarkably, this story of a hunter pursuing a fish that carved out the
   Murray persists in numerous forms in various language groups that
   inhabit the enormous area spanned by the Murray system. The Wotojobaluk
   people of Victoria tell of Totyerguil from the area now known as Swan
   Hill who ran out of spears while chasing Otchtout the cod.

Exploration

   The first Europeans to explore the river were Hamilton Hume and William
   Hovell, who crossed the river where Albury now stands in 1824: Hume
   named it the Hume River after his father. In 1830 Captain Charles Sturt
   reached the river after travelling down its tributary the Murrumbidgee
   River and named it the Murray River in honour of the then British
   Secretary of State for War and the Colonies Sir George Murray, not
   realising it was the same river that Hume and Hovell had encountered
   further upstream. Sturt continued down the remaining length of the
   Murray to finally reach Lake Alexandrina and the river's mouth. The
   area of the Murray Mouth was explored more thoroughly by Captain Collet
   Barker in 1831. In 1852 Francis Cadell built a canoe and set off to
   become the first European to travel the whole length of the river.

   In 1858 the Government Zoologist, William Blandowski, along with Gerard
   Krefft, explored the lower reaches of the Murray and Darling rivers,
   compiling a list of birds and mammals. During the expedition they
   accumulated 17,400 specimens and classified a number of newly
   discovered species.

River transport

   The PS Murray Princess is the largest paddlewheeler operating on the
   Murray river
   Enlarge
   The PS Murray Princess is the largest paddlewheeler operating on the
   Murray river

   The lack of an estuary means that shipping cannot enter the Murray from
   the sea. However in the 19th century the river used to support a
   substantial commercial trade using shallow-draft steamboats, the first
   trips being made by two boats from South Australia on the spring flood
   of 1853. One vessel, Lady Augusta reached Swan Hill while another, Mary
   Ann made it as far as Moama (near Echuca). In 1855 a steamer carrying
   gold-mining supplies reached Albury but Echuca was the usual
   turn-around point though small boats continued to link with up-river
   ports such as Tocumwal, Wahgunya and Albury.

   The arrival of steamboat transport was welcomed by pastoralists who had
   been suffering from a shortage of transport due to the demands of the
   gold fields. By 1860 a dozen steamers were operating in the high water
   season along the Murray and its tributaries. Once the railway reached
   Echuca in 1864, the bulk of the woolclip from the Riverina was
   transported via river to Echuca and then south to Melbourne. The Murray
   was plagued by "snags", fallen trees submerged in the water, and
   considerable efforts were made to clear the river of these threats to
   shipping by using barges equipped with steam-driven winches. In recent
   times, efforts have been made to restore many of these "snags" by
   placing dead gum trees back into the river. The primary purpose of this
   is to provide habitat for fish species whose breeding grounds and
   shelter were eradicated by the removal of "snags".
   Drawing of a paddle steamer travelling the Murray at night, c.1880
   Enlarge
   Drawing of a paddle steamer travelling the Murray at night, c. 1880

   The volume and value of river trade made Echuca Victoria's second port
   and in the decade from 1874 it underwent considerable expansion. By
   this time up to thirty steamers and a similar number of barges were
   working the river in season. River transport began to decline once the
   railways touched the Murray at numerous points. The unreliable levels
   made it impossible for boats to compete with the rail and later road
   transport. However, the river still carries pleasure boats along its
   entire length.

   Today, most traffic on the river is recreational. Small private boats
   are used for water skiing and fishing. Houseboats are common, both
   commercial for hire and privately owned. There are a number of both
   historic paddle steamers and newer boats offering cruises ranging from
   a half-hour to 5 days.

River crossings

   The Murray River has been a significant barrier to land-based travel
   and trade. Many of the ports for transport of goods along the Murray
   have also developed as places to cross the river, either by bridge or
   ferry.

Water storage and irrigation

   A branch of the Murray in its middle reaches, near Howlong, New South
   Wales
   A branch of the Murray in its middle reaches, near Howlong, New South
   Wales

   Small-scale pumping plants began drawing water from the Murray in the
   1850s and the first large-volume plant was constructed at Mildura in
   1887. The introduction of pumping stations along the river promoted an
   expansion of farming and led ultimately to the development of
   irrigation areas (including the Murrumbidgee Irrigation Area). In 1915
   the three Murray states — New South Wales, Victoria and South Australia
   — signed the River Murray Agreement which proposed the construction of
   storage reservoirs in the river's headwaters as well as at Lake
   Victoria near the South Australian border. Along the intervening
   stretch of the river a series of locks and weirs were built. These were
   originally proposed to support navigation even in times of low water,
   but river-borne transport was already declining due to improved road
   and rail systems.

Locks

   Lock 1 was completed near Blanchetown in 1922. Torrumbarry Weir
   downstream of Echuca began operating in December 1923. Of the numerous
   locks that were proposed, only thirteen were completed; Locks 1 to 11
   on the stretch downstream of Mildura, Lock 15 at Euston and Lock 26 at
   Torrumbarry. Construction of the remaining weirs purely for navigation
   purposes was abandoned in 1934. The last lock to be completed was Lock
   15, in 1937.

   Lock 11, just downstream of Mildura, creates a 100 kilometre long lock
   pool which aided irrigation pumping from Mildura and Red Cliffs. Each
   lock has a navigable passage next to it through the weir, which is
   opened during periods of high river flow, when there is too much water
   for the lock. The weirs can be completely removed, and the locks
   completely covered by water during flood conditions. Lock 11 is unique
   in that the lock was built inside a bend of the river, with the weir in
   the bend itself. A Channel was dug to the lock, creating an island
   between it and the weir. The weir is also of a different design, being
   dragged out of the river during high flow, rather than lifted out.

   Four large reservoirs were built along the Murray; in addition to Lake
   Victoria (completed late 1920s) is Lake Hume near Albury-Wodonga
   (completed 1936), Lake Mulwala at Yarrawonga (completed 1939) and Lake
   Dartmouth, which is actually on the Mitta Mitta River upstream of Lake
   Hume (completed 1979). The Murray also receives water from 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, run-off 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 will be unusably salty in the medium to long term — a
   serious problem given that the Murray supplies 40% of Adelaide's
   domestic water. Efforts to alleviate the problems proceed but political
   infighting between various interest groups stalls progress.

   Retrieved from " http://en.wikipedia.org/wiki/Murray_River"
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   with only minor checks and changes (see www.wikipedia.org for details
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