SAHARA TO SAVE WATER
Melbourne Water will trial a new inspection device, which has the potential to save many millions of litres of precious water annually from the city and metropolitan areas dwindling supply, in Ringwood tomorrow evening.
Aptly called Sahara, this leak detection system has been imported from the UK by Melbourne Water and is also being trialled by two of the water retailers.
In the United Kingdom Thames Water reported that the use of Sahara reduced trunk-mains losses by a staggering 76,500 litres per day.
“Every year leaks in Melbourne Water mains and other piping alone deprive us of up to 200 million litres (or 0.04%) of water supplied annually for consumption,” said the Managing Director of Melbourne Water, Rob Skinner.
“The challenge is to trace these leaks before they surface as wet patches by which time significant amounts of water could be lost.
“Finding these leaks is both expensive and difficult because accurate identification is often almost impossible on large transmission mains,” Mr Skinner said.
“This means not only do many leaks remain undetected, but there is often unnecessarily large excavation required in order to reach the problem. The undetected leaks eventually become major problems by which time large amounts of water are lost.”
Melbourne Water and the other water retailers have been trialling Sahara over the past three weeks on pipes that are easier to access.
The Ringwood operation involves two major pipelines - parallel mains known as Olinda Mitcham Number One and Olinda Mitcham Number Two.
The operation, which includes the shutting down of two lanes of the Maroondah Highway will cost over $40,000.
Melbourne Water hopes that if the trials are successful Sahara can be used as an additional tool to test the mains system.
“Sahara can not only pinpoint the exact location to within a few millimetres, but can also estimate the magnitude of the leak. This will allow Melbourne Water and the other utilities to accurately plot which leaks need urgent attention,” Mr Skinner said.
“By using the Sahara system to pinpoint leaks in trunk mains, we will be able to selectively replace or repair individual pipes. This could avoid the cost of a complete pipeline replacement and will effectively extend the life of a pipeline.”
“The dollar savings of this alone will be significant,” Mr Skinner said.
The Sahara system is part of a mobile unit – fitted to a large van and is relatively simple to operate.
It uses a highly sensitive detector unit that is inserted into a pipeline at a tapping point. At all times the water main remains in service without any effect to water quality or supply.
This unit is carried along the pipe by the flow of water and any leaks are identified immediately by a processor inside the van. The magnitude of the leak is measured by an acoustic system.
Depending on the configuration of the pipe up to 2,000 metres can be surveyed in one pass and a leak as small as a few litres per hour can be detected.