Changing landscapes – Water

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Watering sheep in the interior: relying on underground supplies

Watering sheep in the interior: relying on underground supplies
Watering sheep in the interior: relying on underground supplies

Until the 1880s sheep could only be grazed in areas where there was lots of surface water – in rivers and dams, for example.

The first of many bores was sunk into the Great Artesian Basin near Bourke in 1878. It tapped a reliable, underground source of water and so opened up the arid north-west of NSW to graziers.

By bringing water to the surface, settlers provided water for wildlife as well.

As a result, kangaroo populations in some arid regions are very much higher today than they were 100 years ago.

Questions

  1. Is this a photo of a wet or dry environment?
  2. How have humans changed this environment?
  3. What impact can large numbers of kangaroos have on an environment?
  4. What impact can large numbers of sheep have on an environment?

Washing wool: Enngonia bore near Bourke

Washing wool: Enngonia bore near Bourke
Washing wool: Enngonia bore near Bourke

In the dusty outback of NSW, dirt can make up more than half the weight of a sheep’s fleece.

Farmers once washed sheep in rivers and pools before shearing them. Without the dirt, the fleece became more attractive to buyers and cheaper to transport.

By 1840, wool was being washed after it was removed from the sheep.

Many inland sheep stations used warm water from artesian bores to scour their wool. The wool was spread out on boards to dry before being pressed and baled for market.

Questions

  1. What is an artesian bore?
  2. Where does water enter the Great Artesian Basin that lies under much of Queensland, NSW and South Australia?
  3. Why is artesian water precious?
  4. How is wool washed (scoured) today?

The Snowy River at Jindabyne: once a mighty river

The Snowy River at Jindabyne: once a mighty river
The Snowy River at Jindabyne: once a mighty river

When this photo was taken over 100 years ago, the meltwaters of the NSW snowfields still flowed east to the coast via the Snowy River.

In the 1950s the river was turned west to irrigate food-growing areas inland. As a bonus, the flowing water generated electricity.

The Snowy Mountains Hydro-Electric Scheme was one of Australia’s greatest engineering triumphs but it was a disaster for ecosystems and people living on the river east of Jindabyne.

When the river was dammed, it became a weed-infested trickle. Protests raged for years, leading to a plan in 2001 to return 27% of the river’s original flow.

Questions

  1. How has damming the river changed many environments?
  2. List the advantages and disadvantages of hydro-electric schemes.
  3. How were Indigenous people affected by the damming of rivers for the Snowy Mountains Hydro-Electric Scheme?
  4. How were people who lived in Jindabyne and Adaminaby affected by the damming of rivers for the Scheme?

River gums dying for a drink

River gums grow along most NSW water courses and can survive drought if they are flooded every few years.

Over the last 100 years, flood prevention measures and use of water for irrigation have meant that the rivers seldom flood any more.

When the drought took hold in 2002, thousands of river redgums died.

The entire ecosystem along a river relies on a sufficient flow of fresh water. Without it, native plants and animals can’t survive.

If the biodiversity of the region drops, the productivity of nearby farms falls too.

Questions

  1. How have humans changed the environment in this photo?
  2. What is the impact of that change?
  3. How are nearby farms affected by the biodiversity of a river ecosystem?
  4. How old can a river gum grow if it receives enough water?

Belalie Bore: tapping the Artesian Basin near Bourke

The Great Artesian Basin is a giant porous sandstone aquifer – a kind of massive underground storage tank – that underlies a fifth of Australia.

It can hold an estimated 8700 million megalitres of water, which enters the basin in the Great Dividing Range and takes two million years to travel to Lake Eyre! On its journey it can be tapped by bores from the surface.

When bores were sunk in the 1880s, water was forced out under enormous pressure. That pressure dropped when thousands more bores were sunk.

Unfortunately, many bores remain uncapped today and the pressure continues to drop as much of the precious water is wasted.

Questions

  1. How far below the ground at Bourke is the Great Artesian Basin?
  2. Find a map showing the location of the Great Artesian Basin.
  3. List ways to reduce the waste of artesian water on a farm.
  4. What are some ways you can conserve water at home?

Barringun irrigation farm: an oasis in the desert

Artesian water is the primary source of water in north-western NSW.

Irrigation farms and orchards sprang up around bores in the 1890s. Corn, grapes and citrus fruit were all grown around Barringun Artesian Bore, 128km north of Bourke.

The farm supplied people in Barringun, which was once a thriving border town.

It was a stopover for travellers between western NSW and the Darling Downs of Queensland, so there was a ready market for produce.

Questions

  1. Where does artesian water come from?
  2. What are other sources of water for people living near Bourke, NSW?
  3. How did Indigenous people manage water shortages before artesian bores were sunk?
  4. Why is it good to eat food crops that are grown locally?

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