Walking on water
The availability of groundwater has always been taken for granted by Australians. Groundwater supplies have in prior times been perceived as a resource of infinite bounds - the prevailing mindset was “out of sight out of mind”. This has all changed with the modern epoch. Persistent neglect has resulted in numerous complications for groundwater users and many interest groups have great stake in its management and allocation. Over-allocation of surface water and persistent water shortages mean that reliance of groundwater supplies is expected to swell.
The main point of concern now is whether or not a groundwater source can deliver a sustainable yield. This relies on a proper management of discharge (outflow) and recharge (inflow) rates. Discharge occurs when humans extract water as well as through vegetation and evaporation into the atmosphere. Sustainable use therefore depends on more than keeping within the recharge rate: if humans use water at precisely the recharge rate, discharge through other ways can be adversely affected.
Queensland has been one of the most active states in managing groundwater supplies. This is because the territory sits atop the Great Artesian Basin (GAB) an expansive underwater aquifer that covers nearly one-fifth of the Australian continent. This resource has long been used by indigenous people and outback communities, particularly in times of drought (when surface water could dry up for hundreds of kilometres on end). Since farmers at Kerribee pioneered the use of bores in the country, the number has spiralled beyond sustainable levels and caused water pressure and flow rates across the region to decline. Furthermore, estimates indicate that 80% of GAB outflow is wasted because of inefficient and out-dated delivery systems. Open drains used to keep livestock hydrated are a particular scourge - much water is lost due to seepage and evaporation.
A number of initiatives have been undertaken to help stem this problem. The Queensland government declared in 2005 a moratorium on issuing new licences for water extraction from GAB. A strategy group known as the Great Artesian Basin Consultative Council has also published a management plan that involved capping some bores (to prevent further declines in pressure) and rehabilitating hundreds of other bores and bore drains with troughs and polyester piping (to prevent water seeping into the earth).
It is now also apparent that corruption of groundwater supplies by humans is going to be an issue to contend with. In 2006, thousands of Sydney residents had their groundwater usage curtailed due to industrial pollution of the Botany Stands aquifer. Bore water for any domestic purposes has since been off limits due to chemical seepage from an estimated 8 industrial sites.
Nevertheless, groundwater plans continue apace. Development of a controversial desalination plant has been postponed indefinitely while the feasibility of exploiting two aquifers near Sydney is explored. Authorities intend to use the aquifers to provide up to 30 gigalitres of water a year during dry spells and then leave them alone to replenish during higher rainfall years. But the proposed scheme it riddled with difficulties: low flow rates are hampering extraction: replenishment rates are lower than expected, and salinity imbalances caused by the procedure could wreak havoc on efforts to preserve wetland flora and fauna ecosystems that rely on a plentiful, clean and steady supply of water from the aquifers.
It is not too late to turn groundwater into a sustainable resource. Groundwater is renewable through surface runoff (and, at a much slower rate, in organic springs where it is literally drip fed through rock on its way to aquifers). At present however, experts believe excessive amounts of groundwater are being squandered on aesthetic projects such as keeping parks, gardens and golf courses green.
Aside from more judicious use of groundwater, many experts also believe that we need to look at harnessing other potential sources in order to meet our water needs. During rainy seasons for example urban areas are inundated with storm water and flash flooding that can bring cities to a standstill. Better storm water control mechanisms could potentially capture and preserve this rainwater for use at a later date.
Questions 28-31
Which FOUR of the following uses are mentioned by the writer of the text?
Choose FOUR letters A-J for the answer and write them after the numbers.
List of Uses
A. maintaining recreational areas
B. helping sewer systems function
C. providing opportunities for underground adventure sports
D. supporting wildlife habitats
E. storing excess amounts of surface water in cities
F. naturally removing salt content from water
G. personal household use
H. forming hot springs for bathing
I. providing water for animals
J. dumping toxic waste products
- .....
- ...
- ...
- ...
Questions 32-35
Define the statement
TRUE if the statement agrees with the information
FALSE if the statement contradicts the information
NOT GIVEN if there is no information on this statement
Statements
32. Australians have always seen groundwater as a precious resource.
33. Use of groundwater is predicted to increase.
34. Humans cannot alter the recharge rate of groundwater.
35. Using water at the recharge rate or lower will ensure sustainable use.
Questions 36-40
Complete the words or phrases
Choose the correct ending, A-I, to fill the blanks.
List of Endings
A. took action to stop more people from being able to use groundwater
B. released a plan to improve bores and lessen wasted water
C. used groundwater to create artificial rivers
D. began a formal register to control access to groundwater
E. decreased the amount of water in movement
F. used their bore holes to dispose of waste products
G. were prevented from using groundwater due to contamination
H. relied on groundwater during long periods of dry weather
I. were the first to use a bore in Australia
- Outback communities
- Farmers at Kerribee station
- In 2005, Queensland authorities
- The Great Artesian Basin Consultative Committee
- Some residents in Sydney
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- A
- D
- G
- I
- FALSE
- TRUE
- NOT GIVEN
- FALSE
- H
- I
- A
- B
- G