Snowy River (Bass Strait)

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Snowy River
The Snowy River between Orbost and Marlo, backwater from the sea

The Snowy River between Orbost and Marlo, backwater from the sea

Data
location New South Wales  / Victoria , Australia
River system Snowy River
source Snowy Mountains in the Great Dividing Range
36 ° 28 ′ 34 ″  S , 148 ° 16 ′ 52 ″  E
Source height 1840  m
muzzle At Marlo (near Orbost ) in the Bass Street coordinates: 37 ° 48 ′ 9 ″  S , 148 ° 32 ′ 45 ″  E 37 ° 48 ′ 9 ″  S , 148 ° 32 ′ 45 ″  E
Mouth height 0  m
Height difference 1840 m
Bottom slope 4.6 ‰
length 403 km
Catchment area 15,779 km²
Drain MQ
 517 m³ / s
Left tributaries Finns River , Tolbar Creek, Gungarlin River , Eucumbene River , Ironpot Creek, Wullwye Creek, Bobundara Creek, Lambing Creek, Ironmungy Creek, Kemps Creek, Brasseys Creek, Maclaughlin River , Delegate River , Minnehan Creek, Corrowong Creek, Little River , Black Jack Creek, Coe Creek, Right Hand Creek, Willis Biddi Creek, Joe Davis Creek, Sandy Creek, Guttamurh Creek, Jamb Creek, Deddick River , Mountain Creek, Rodger River , Raymond Creek, Double Bull Creek, Wibenduck Creek, Spring Creek, Brodribb River
Right tributaries Diggers Creek, Thredbo River , Cobbin Creek, Mowamba River , Beloka Creek, Blackburn Creek, Meadow Creek, Matong Creek, Snodgrass Creek, Toms Farm Creek, Stony Creek, Big Popong Creek, Reedy Creek, Tongaroo / Jacobs River , Moyangul / Pinch River , The Running Water, Menaak Creek, Tomcat Creek, Suggan Buggan River , Little River , Boundary Creek, Buchan River , Wall Creek, Stony Creek
Reservoirs flowed through Guthega Pondage , Island Bend Pondage , Lake Jindabyne
Medium-sized cities Jindabyne (NSW), Orbost (VIC)
Small towns Dalgety (NSW), Willis (VIC), Marlo (VIC)
Snowy River in Kosciuszko National Park in New South Wales

Snowy River in Kosciuszko National Park in New South Wales

Snowy River below McKillops Bridge in the state of Victoria

Snowy River below McKillops Bridge in the state of Victoria

The Snowy River at Suggan Buggan in the state of Victoria

The Snowy River at Suggan Buggan in the state of Victoria

Comparison of the water volume of the Snowy River before and after the construction of the Snowy Mountains System

Comparison of the water volume of the Snowy River before and after the construction of the Snowy Mountains System

The dry river bed just south of the New South Wales / Victoria border is a result of the 99% reduction in water volume

The dry river bed just south of the New South Wales / Victoria border is a result of the 99% reduction in water volume

The Snowy River is a 400 kilometer long river in southeast Australia .

It rises on the eastern slopes of Mount Kosciuszko in the Snowy Mountains in New South Wales and joins the Bass Strait at Marlo, near Orbost . Until the middle of the 20th century, the river was known for its large amount of water, its wide river bed and its large rapids.

Around 1950, the river was dammed up in several dams for energy production by the Snowy Mountains System , a water extraction project for the Australian capital Canberra . Large amounts of the water are now diverted into the Murray River system through pipes under the mountains , so that by 2002 the river only carried less than 1% of its natural water volume (measured in Jindabyne). 2002–2008 the amount rose again to 1–4%. The targets for 2009 were 15% and for 2012 21%, but will not be achieved.

geography

In 1986 Jennings and Mabutt recorded four geomorphic classes in the Snowy River system: (i) Australian Alps, (ii) Monaro Tableland, (iii) East Victorian Highlands, and (iv) Gippsland Plains. Each of these classes is very different from the others; a further description can be found in Erskine et al.

Tributaries (with confluence)

In New South Wales

  • Finns River - 1252 m
  • Diggers Creek - 1165 m
  • Tolbar Creek - 1137 m
  • Gungarlin River - 1052 m
  • Eucumbene River - 908 m
  • Thredbo River - 902 m
  • Cobbin Creek - 868 m
  • Mowamba River - 853 m
  • Ironpot Creek - 772 m
  • Beloka Creek - 770 m
  • Wullwye Creek - 746 m
  • Blackburn Creek - 745 m
  • Bobundara Creek - 736 m
  • Lambing Creek - 721 m
  • Ironmungy Creek - 719 m
  • Meadow Creek - 696 m
  • Kemps Creek - 663 m
  • Brasseys Creek - 597 m
  • Maclaughlin River - 533 m
  • Delegate River - 506 m
  • Matong Creek - 500 m
  • Snodgrass Creek - 424 m
  • Minnehan Creek - 423 m
  • Corrowong Creek - 421 m
  • Toms Farm Creek - 391 m
  • Little River - 365 m
  • Stony Creek - 345 m
  • Black Jack Creek - 334 m
  • Big Popong Creek - 305 m
  • Reedy Creek - 300 meters
  • Coe Creek - 291 m
  • Right Hand Creek - 284 m
  • Gulf Creek - 281 m
  • Willis Biddi Creek - 275 m
  • Tongaroo / Jacobs River - 266 m
  • Moyangul / Pinch River - 250 m
  • The Running Water - 240 m
  • Joe Davis Creek - 233 m
  • Sandy Creek - 228 m

In Victoria

Reservoirs

rainfalls

The rainfall in the catchment area of ​​the Snowy River varies greatly. In the Alps over 1500 m in the south-western part of the catchment area, the average annual rainfall is 1800 mm, in the north-eastern part of the catchment area in the rain shadow around Dalgety it is only 500 mm. In winter, especially with westerly winds, the rainfall is more productive than at other times of the year.

Hydrology

Melt-fed rivers in the Snowy Mountains typically carry the largest amount of water in the months of June – November, with the largest amount being in October. For example, the average monthly water volume in October from the Snowy River near Dalgety before the Snowy Mountains system was installed was 283,973 ML. In the first months of summer, mountain rivers also carry more water than rivers in lower regions, an effect that can be attributed to the groundwater, which is also fed by the snowmelt.

Most Australian rivers carry water volumes that vary greatly over the year. The mountain rivers of the Snowy Mountains, however, show fairly continuous amounts of water.

In the lower reaches of the Snowy River, the tributaries have a significantly different volume distribution than in the Alps. They carry a lot of water in the winter months and show the largest monthly amounts of water a few months earlier than the rivers fed by the snowmelt, i.e. mostly in June and July. In addition, the amount of water in the lower tributaries varies significantly more from month to month and is less predictable.

water falls

The Snowy River has four larger waterfalls below Jindabyne Lake:

  • Stone Bridge Falls
  • Corrowong Falls
  • Snowy Falls
  • Pinch Falls

Many of these waterfalls are believed to be barriers to fish migration in the Snowy River.

Surrounding mountains

The mountains through which the river winds are (listed downstream):

In New South Wales

In Victoria

  • Mt. Tingaringy
  • Mt. Deddick
  • Mt. Nunniong
  • Mt Bowen
  • Mt. Sardine
  • Mt. Tara
  • Mt Buck
  • Mt. Raymond

National parks and protected areas

Approx. 70-80% of the course of the Snowy River runs through national parks (classified downstream):

Settlements

There are only a few major settlements on the Snowy River, which are listed downstream here:

In New South Wales

In Victoria

  • Willis
  • Suggan Buggan (not directly on the river)
  • Buchan (not directly on the river)
  • Pray Bolong
  • Orbost
  • Marlo

bridges

In New South Wales

In Victoria

ecology

The aquatic flora and fauna of the snowmelt-fed rivers of the Snowy Mountains have adapted to the large amount of water of the snowmelt and the constant summer base volume. Many species are particularly suitable for the very cold water.

Habitat

The habitat in the river below Lake Jindabyne can be described as severely disturbed. Many properties of a typical highland river have been lost to the Snowy River. The substrate used to be characterized by large stones. Today the river bed is much narrower and the substrate forms a thick layer of sediment that covers the large stones.

The forest fires of 2002 and 2003 exacerbated this problem as they caused large amounts of sediment and organic matter to enter the Snowy River through its tributaries. As a result, the substrate became even finer. This pattern of increased silt content in the pools of the watercourses was observed throughout the Snowy Mountains after forest fires. These forest fires therefore have a long-term impact on watercourses.

Larger amounts of water should improve the conditions in the river bed. Quantities of 1000 ML / day begin to stir up the fine particles from the river bed. Quantities between 1000 and 3000 ML / day are necessary for a suitable running water habitat.

The current bad conditions in the river bed are a key factor for the lack of development of the aquatic fauna typical of meltwater rivers.

Water quality

Mountain rivers typically have few nutrients and poor electrical conductivity. The latter is mostly below 50 µS / cm.

Large dams can decisively influence the water quality downstream through two important mechanisms, namely (i) through the poor water quality in the lower outflow of the reservoir itself and (ii) through reduced mixing of the individual layers of the river water through lower flow velocities, which lead to anaerobic conditions at the bottom River pools leads.

Influence of the Jindabyne reservoir on water quality

Probably the biggest impact Lake Jindabyne has on water quality downstream is the increase in temperature. Unlike other reservoirs where cold water pollution is a problem because water is drained below the reservoir's thermocline (e.g. water from the bottom of the lake), Lake Jindabyne drains surface water. The water temperature of the Snowy River below this Strausee is often very different from that of other melt-fed rivers such as the Thredbo River and the Mowamba River. In winter the Snowy River is much warmer.

Flow velocity and temperature stratification in the Snowy River

The temperature stratification in the river sections below Lake Jindabyne is usually limited to a few larger and deeper pools. In general, the temperature stratification is localized to the pools, which are typically deeper than 4–5 m. Pools with a depth of less than 4 m show no temperature stratification.

The temperature stratification can be observed between October and March but generally does not last very long in the Snowy River in the Jindabyne Gorge. The breakdown of this temperature stratification is often initiated by the cooling of the air at night. The area through which the Snowy River flows shows very large temperature differences between day and night.

Seaweed

Algae are found on the bottom of the Snowy River as well as in the water above. The algae in the water are called 'phytoplankton', the bottom is called 'Periphyton' (deposited algae)

Algae on the river bottom

A large part of the river bed of the Snowy River below Lake Jindabyne is covered with deposited algae. These taxa are generally thread algae.

Large amounts of thread algae are uncommon in the rivers of the Snowy Mountains that are not affected by water discharge.

River bed in an unregulated section of the Snowy River above Guthega Pondage (left) and river bed in a regulated section of the Snowy River below Lake Jindabyne (right)

Algae in the water

In the summer of 2008/2009, blue-green algae were typically predominant in the river pools of Jindabyne Gorge and the Dalgety Highlands. Two types of blue-green algae, Aphanotheca spp. and Aphanocaspa spp. make up about 25% of the population. Nevertheless, this infestation is always below the limit values ​​and it is not clear whether it is only due to the regulation of the river or also to other influences in the catchment area of ​​the river.

The algae in unregulated snowmelt-fed rivers are usually mostly diatoms . Over 58% of the taxa are from this algae division; the most common species is Fragilaria spp.

Insects and worms

The insects and worms in the Snowy River are different from those in other melt-fed rivers. It has been shown that reservoirs have a negative impact on the insects and worms in the river.

Caenide mayflies (rapids) and little- bristle worms (at the pool edges) are generally typical of the regulated Snowy River in the highlands. Other studies have found larger concentrations of caenid mayflies in regulated rivers than in unregulated rivers. The decrease in the high flow areas and the increase in the low flow areas in the upper Snowy River has favored a larger population of worms through the build up of silt and organic matter in the pools. Nichols, et al. (2006), or Petts et al. (1993) also found a larger population of segmented worms in soft sediment and coarse organic debris that had formed as a result of regulation. Mosquitoes were also increasingly found in the rapids of the regulated Snowy River. These changes are also found in many other studies of regulated rivers and are attributed to the greater number of algae on the river floor in rapids areas, which has increased the corresponding habitat and increased food supply.

Conoesucide caddis flies (in the rapids), elidmide as larvae and fully grown (in the rapids), and Oniscigastrids (on the edge of the pools) are found in the regulated Snowy River but not in other rivers fed by the snowmelt. Marchant and Hehir (2002) stated that AUSRIVAS models had a 50% probability of predicting Conoesucidae and Elimids in the upper Snowy River, but these taxa were not found in their study. The larger populations of these taxa in other snowmelt-fed rivers compared to the Snowy River can be explained by river regulation.

Marchant and Hehir (2002) attribute the absence of these taxa to the fact that the dams act as a barrier to the drifting and resettlement of these taxa, and not to the regulation of the amount of water. The upper reaches of the Snowy River lies above the mouth of the Mowamba River, which provides a route for resettlement in the Snowy River. Therefore, the reduced amount of water and the changed flow behavior in contrast to the barrier effects of the Jindabyne Dam are probably the most important reasons for the lower frequency of these taxa in the upper Snowy River. Little information is available about the reaction of the Oniscigastriden to the reduced amount of water and the changed flow behavior, but it is very likely that the increased water temperature and the lack of sandy edges as habitat have reduced their frequency in the Snowy River.

fishes

The fish population in the Snowy River below Lake Jindabyne is clearly divided into two groups:

  • those in the upper catchment area (above Snowy Falls) and
  • those in the lower catchment area (below the Snowy Falls).

The big difference between the two zones was the small number or complete lack of migratory fish (with the exception of eels) and the higher number of short-fin eels ( Anguilla australis ) and trout in the upper range and the greater number of Australian smelts ( Retropinna semoni ) and long-fin eels ( Anguilla reinhardtii ) below the Snowy Falls. These differences between the upper and lower zones were greater than the differences between the unregulated tributaries and the highly regulated Snowy River in either zone. The river blackfish ( Gadopsis marmoratus ), the brown trout ( Salmo trutta ) and the short-fin eel were more common in the unregulated tributaries than in the upper reaches of the Snowy River, while the long-fin eel and goldfish were more common in the upper zone of the Snowy River. In the lower part of the Snowy River there were more gambus , the catadromous ice fish Pseudaphritis urvillii , long-fin eels, salmon and short-fin eels, while there were more galaxies and short-headed lampreys ( Mordacia mordax ) in the tributaries .

Water volume bumps in the Snowy River below Lake Jindabyne

Water scientists are currently conducting studies to determine the water volume thresholds for certain processes in the river. Some "preliminary thresholds" have already been identified:

Discharge [ML / day] Process in flux
~ 300 First wetting of the old river bed (Dalgety highlands)
850-1000 Collapse of the temperature stratification in the pools (Jindabyne Gorge)
1000 Lifting of the fine silt from the river bed and beginning of the movement in coarse sand that has not been deposited up to a grain size of 1.9 mm
1000-3000 Shear stress velocities over the rapids are significantly higher than in the pools (rapids)
10370 Permeability for adult Australian codfish (Pinch Falls)
13350 Permeability for young Australian codfish (Pinch Falls)

The determination of further ecological water quantity thresholds is currently in progress and will be achieved through model tests, field studies and flow tests.

History of water management

Early history

The Snowy River was used by the Aborigines as a sustainable source of food and water as early as 30,000–40,000 years before European settlement . Human habitation finds at Cloggs Cave near the Snowy River at Buchan are estimated to be 17,000 years old. Despite the cold climate in the upper reaches of the river, the natives of the Ngarigo tribe populated the land in the Australian Alps and the Snowy Mountains in what is now the state of New South Wales. On its way south through what is now Victoria, the river crossed the territory of the Kurnai of the Krauatungalung tribe .

1950–1990: Reduced amount of water

Main article: Snowy Mountains System

The Snowy River originally carried a huge amount of water at the time of the snowmelt in spring, which flowed directly into the sea. In the 1950s and 1960s, the Snowy Mountains System created a network of four reservoirs (Guthega Pondage, Island Bend Pondage, Lake Eucumbene, and Lake Jindabyne) as well as many smaller water drains that make up 99% of the Snowy River's water (according to measurements in Jindabyne) through the mountains into agricultural valleys of the Murray River and the Murrumbidgee River , mainly for land irrigation. A number of hydropower plants for generating electricity were also built. While there was public opposition to the discharge of river water in the early 1950s and 1960s, it was largely ignored because the system then created more water for agriculture and a large number of jobs.

1990–2000: Increased environmental awareness

In the 1990s, the decreased water flow from the Snowy River became a major environmental problem in Victoria, New South Wales and all of Australia. It became clear that the Snowy River was ecologically very sick.

This period of heightened awareness of the drawbacks of water drainage led to the Snowy Water Inquiry, which looked at ways to improve the health of the Snowy River. The most important result of this investigation was the agreement to discharge water (i) into the Snowy River below Lake Jindabyne and (ii) into the rivers of the Snowy Mountains to protect the environment.

This series of tiered water volume targets (up to 28% of mean annual runoff) was set for the Snowy River below Lake Jindabyne, depending on water savings in the Murray River and Murrumbidgee River basins. For 2009 the target was 15% and for 2012 it was 21%.

2002–2005: The first stage of water drainage for environmental reasons

From August 28, 2002 to January 2006, the first stage of water discharge into the Snowy River was realized via the Mowamba River. The Mowamba River Aqueduct was shut down so that no more water was diverted to Lake Jindabyne. As a result, a water volume of 80 ML / day was measured in Delgaty instead of just 40 ML / day in the Snowy River. In addition, a small maximum amount of water could be reached during the snowmelt time in September. Compared to the upper catchment area of ​​the Snowy River, only a small part of the catchment area of ​​the Mowamba River is covered with snow in winter. In addition, the drainage increased the difference in the amount of water during the day. The amount is now between 3 and 523 ML / day and also depends on the natural conditions in the catchment area. This small drainage also led to increased flow speed in the upper reaches, especially at the rapids, while in the rest of the river it decreased due to the prevailing current.

In this stage the amount of water was increased from 1% to approx. 4% of the average natural amount of water.

2006 – today: The second stage of water drainage for environmental reasons

After the completion of extensive works on the Jindabyne Dam, the drainage of water will essentially be carried out from Lake Jindabyne and no longer via the Mowamba River.

Political Aspects

A political campaign began with the aim of increasing the amount of water in the Snowy River from 1% to 28% of the natural amount of water below Lake Jindabyne. A non-party candidate for East Gippsland District , Craig Ingram , was elected to Parliament in Victoria in 1999, was re-elected in 2002 and 2006, and participated in a platform to increase the amount of water in the Snowy River.

After Ingram was elected, instead of worrying about increasing the amount of water in the Snowy River, he socialized the Snowy Mountains system and got the Victoria government to sign a bill. Although the governments of Victoria, New South Wales and the Australian Confederation assured that this socialization would not lead to privatization, it was announced in November 2005 that the new company would be sold in private free float . Community groups fought against the sale of the state company and in June 2006 the Australian Prime Minister withdrew his consent to the sale of the company's shares.

In music, literature, film and television

The river is also known from the 1890 ballad "The Man from Snowy River" by the Australian national poet Banjo Paterson (including Waltzing Matilda ).

Jules Verne describes the Snowy River in his novel " The Children of Captain Grant " as a raging river with extensive marshland, which becomes a major obstacle when crossing Australia.

The natural environment of the Snowy River inspired Paterson to write the poem. The river was immortalized by a silent film of the same name, which was made in 1920, as well as by another film of the same name, but better known, by 20th Century Fox from 1982. In 1988 Walt Disney Pictures also produced a film of the same name and a 64- part series on Australian television. All of these works are based on the poem by Banjo Paterson.

See also

Web links

Commons : Snowy River  - collection of images, videos and audio files

Individual evidence

  1. ↑ a b c Map of Snowy River . Bonzle.com
  2. ↑ Jennings & Mabutt: Physiographic Outlines and Regions in: DN Jeans (editor): Australia - A Geography: The Natural Environment . Volume 1. Sydney University Press. Sydney (1986)
  3. ↑ WD Erskine, N. Terrazolo, RF Warner: River Rehabilitation from Hydrogeomorphic Impacts if a Large Hydro-Electric Power Project: Snowy River, Australia . in Regulated Rivers: Research and Management , 15, 3-24
  4. ^ Tributaries of Snowy River . Bonzle.com
  5. ^ S. Morton, D. Green, S. Williams: Assessment of the Hydrological Changes Attributed to the First Stage of the Environmental Flow Release to the Snowy River 2002-2005 . Snowy Flow Response Monitoring and Modeling. NSW Office of Water. Sydney
  6. ^ D. Gilligan, S. Williams: Changes in Fish Assemblages after the first Flow Releases to the Snowy River Downstream of Jindabyne Dam . Snowy River Recovery: Snowy River Flow Response Monitoring, NSW Department of Water and Energy, Sydney (2008)
  7. ↑ T. Haeusler, R. Bevitt, R .: Hydraulic modeling of a fish barrier - Pinch Falls, Snowy River . Snowy River Recovery: Snowy River Flow Response Monitoring. NSW Department of Water and Energy. Sydney (2007)
  8. ↑ SO Brizga & BL Finlayson: The Snowy River Sediment Study: Investigation into the Distribution, Transport and Sources of Sand in the Snowy River between Lake Jindabyne and Jarrahmond . Report No. 81.Department of Water Resources, Victoria, Melbourne (1992)
  9. ^ GS Seddon: Saving the Throwaway River . Australian Geographical Studies. (1999). 37 (3). Pp. 314-321
  10. ^ T. Rose: Geomorphic Changes in the Snowy River Following the Stage Environment Release . Snowy River Flow Response Monitoring and Modeling. NSW Office of Water. Sydney (2010)
  11. ^ I. Reinfelds & S. Williams: Hydraulic Modeling to Estimate Threshold Discharges for Sediment Entrainment in the Snowy River, Australia . Snowy River Recovery: Snowy River Flow Response Monitoring, NSW Department of Water and Energy. Sydney (2008)
  12. ↑ L. Bowling, Z. Acaba, P. Whalley: Water Quality in the Snowy River Catchment Area, 1992/93 . Technical Services Division. NSW Department of Water Resources. Sydney (December 1993)
  13. ↑ R. Bevitt & H. Jones: Water Quality in the Snowy River before and after the first Environmental Flow Release from Mowamba River . Snowy River Flow Response Monitoring. NSW Department of Water and Energy. Sydney (2008)
  14. ↑ I. Growns, I. Rein field, G. Coade: Longitudinal Effects of a Water Supply Reservoir (Tallowa Dam) on Downstream Water Quality, and Riffle substrates Macroinvertebrate Assemblages in the Shoalhaven River, Australia . Marine and Freshwater Research 60. pp. 594-606
  15. ^ L. Turner & WD Erskine: Variability in the Development, Persistence and Breakdown of Thermal, Oxygen and Salt Stratification on Regulated Rivers of Southeastern Australia . River Research Application 21. pp. 151-168
  16. ↑ R. Bevitt & H. Jones: Water Quality in the Snowy River before and after the first Environmental Flow Release from the Mowamba River . Snowy River Flow Response Monitoring. NSW Department of Water and Energy. Sydney (2008)
  17. ^ A. Brooks, M. Russell, R. Bevitt: Response to Aquatic Macroinvertebrates to the First Environmental Flow Regime in the Snowy River . Snowy River Recovery: Snowy River Flow Response Monitoring. NSW Department of Water and Energy. Sydney (2007)
  18. ^ A b R. Marchant & G. Hehir: The Use of AUSRIVAS Predictive Models to Assess the Response of Lotic Macroinvertebrates to Dams in South-East Australia . Freshwater Biology 47. pp. 1033-1050
  19. ^ D. Gilligan & S. Williams: Changes in Fish Assemblages after the first Flow Releases to the Snowy River Downstream of Jindabyne Dam . Snowy River Recovery: Snowy River Flow Response Monitoring. NSW Department of Water and Energy. Sydney (2008)
  20. ^ P. Pendlebury, W. Erskine, S. Lake, P. Brown, J. Banks, I. Pulsford, J. Nixon: Expert Panel Environmental Flow Assessment of the Snowy River Below Jindabyne Dam . Government of New South Wales. Sydney (1996)