Chapter 3
I Background
II Early European Settlements
III Assessment Of Available Water Resources
IV Water Supplies For Goldmining Development
V Irrigation Development
VI Farm And Stock Water Supplies
VII Urban Water Supplies
i Reticulation systems
ii Water treatment
iii Water saving techniques
iv Desalination
v Conjunctive use - West Pilbara water supply
vi Conjunctive use - Newcastle and district water supply scheme
vii Olympic Dam mining project - water supply
viii Urban water supply dams in South Australia
ix Multi-purpose schemes - the Wivenhoe project
VIII Wastewater Management And Treatment
IX Water Quality Management
X Limnological And Water Quality Research
XI New Techniques In Water Resource Planning And Management
XII Legislation
XIII Conclusion
XIV List Of Abbreviations
XV Acknowledgements
XVI Plantations-high Productivity Resources
References
Index
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Reticulation systems
The low availability and high cost of the conventional materials used for the construction of pipes and other water conveyors in the early years led to the development of ingenious local alteratives. These included wood stave pipes, for which Australian timbers were particularly suitable, some of which were still in use in recent years; and spun concrete pipes, cast either in horizontal or vertical moulds. The vertically spun pipe was first developed in Australia and the technique is in use around the world, with progressively larger pipes still being produced for ever-increasing pressures. Another Australian adaptation was the galvanized iron water-flume, using the ubiquitous Australian corrugated galvanized iron, with prefabricated supports. Australia was among the first countries to use PVC piping for domestic reticulation and many improvements in the quality of this pipe and its utilization were pioneered here. Galvanized iron was, and still is, used extensively to construct rainwater tanks for house supplies in remote and in urban areas, its portability, low weight and high strength making it ideal for the outback in comparison to other materials.Interesting Australian technology was developed in recent years to cope with the problems caused in water reticulation systems by the electrolytic corrosion of ferrous pipes. There are two major sources of the problem. The first arises when electric traction systems using earth returns are installed. Leakage of strong traction currents through underground mild steel water pipes may make the pipes unserviceable in a very short time unless counter measures are taken. The second major source of corrosion is the bimetallic cell effect caused by tapping copper house services directly into cast iron water mains, compounded by the effect of multiple-earthed-neutral (MEN) electric supply systems used in a wide range of domestic appliances.
Australian engineers have developed a wide range of measures to cope with these problems, including:
- Electrical drainage bonds, devised in the 1920s during the growth of electric traction public transport systems
- Cathodic protection
- The laying of pipes in a non-cohesive sleeve such as polythene
- The use of ductile iron in lieu of cast iron
- The insulation of service pipes from the main, or the use of plastic service pipes
The use of these anti-corrosion techniques, developed to a significant extent in Australia, has raised the life expectancy of ferrous water mains to the order of 100 years, even in highly adverse conditions.
In the early 1920s, the vexed question of cleaning the inside of deteriorating cast iron water mains and re-lining them with cement mortar in situ was solved by a process developed in Sydney. The Tate process provided a simple and effective means of removing corrosion products and placing a new lining in pipes, by pulling a baffle through them without having to pull up the pipes and relay them. This inexpensive process was adopted in many other countries, including Great Britain, USA, Ireland and Uganda, and was used for over fifty years before being superseded recently.
As major cities grew, the difference in water availability between city and rural settlement became evident, both as to quantity and quality. This led to a decision by governments in some States to improve water supplies to small settlements by providing financial subsidies when necessary. The Victorian Government, for example, adopted an objective of providing a reticulated water supply to every town with a population of over 1,000 within a reasonable period. Such policies, whilst raising the local quality of life, generally left the question of water quality untouched, but this has been tackled in more recent years by further Government subsidies encouraging the development of low-cost treatment facilities with many unique features which are described later in this chapter.
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Australian Academy of Technological Sciences and Engineering |  |
© 1988 Print Edition pages 171 - 172, Online Edition 2000
Published by Australian Science and Technology Heritage Centre, using the Web Academic Resource Publisher
http://www.austehc.unimelb.edu.au/tia/173.html