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We clean water and sewer mains regularly to maintain and deliver quality services to our customers. This may cause some disruption to service and traffic.

See our planned works and interruptions page for the latest information on planned works in our region.

Customers affected by planned works will be notified 7 days in advance.


Why mains need cleaning

The ongoing maintenance of our water and sewer network:

  • helps prevent blockages
  • improves the efficiency and reliability of our service
  • ensures we deliver safe drinking water and meet Australian Drinking Water Guidelines.
  • helps prevent issues such as sewer overflows or leaks.


How we clean water mains

We use the latest mains cleaning techniques to maintain the quality of our drinking water.

  • Flushing – hydrants are opened and water is flushed through at high speed to remove the natural build up of sediments.
  • Air scouring – a mixture of water and compressed air is forced into the mains to remove sediment and maintain disinfection levels within the water supply network.
  • Ice pigging – a thick ice slurry (mixture of semi-solid ice and water) is pushed through the main and removed from a hydrant. This method uses minimal water and is environmentally friendly.
  • Swabbing – a large ‘sponge’ is propelled by water pressure and pushed through the main to remove sediment and debris.


How we clean sewer mains

We assess sewer mains using CCTV and acoustic sensing technology so we can use the cleaning technique that's best suited to its condition.


A high-pressure hose with a cleaning nozzle is pushed through the main. The most common form of cleaning, jetting takes place in a section of sewer main between two manholes and is often used before inspecting or renewing mains.

Chemical tree root treatment

Tree roots cause more than 70 per cent of sewer main blockages in our region. To prevent further structural damage, we use a foam herbicide to remove roots within and very close to the pipe. Trees and shrubs immediately above ground are not harmed.

Last updated on 08 Feb 2020
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