Sewerage

Greater Melbourne's sewerage has provided Melburnians with world-class sanitation for over 100 years, protecting public health and the environment. Find out why.

What is sewerage?

WTP covers
Anaerobic lagoons at the Western Treatment Plant

Our sewerage (also known as a 'sewerage network' or 'sewerage system') is vital to Melbourne's health. It is a network of over 3,000 km of pipes and pumps that safely transfers sewage from homes and businesses to our treatment plans for processing, including:

  • 400 kilometres of sewers
  • 3 main trunk sewers
  • 9 pumping stations.

Who does what, and where?

Check out this map, which shows Greater Melbourne's sewerage and the water corporation boundaries.

Greater Melbourne sewerage map

Maintaining our sewerage

Although Melbourne has world-class sewerage, sewage can still overflow sometimes.

This happens when sewer pipes are blocked or broken by tree roots, fats or oils – or when sewers are too full after heavy rain.

We constantly monitor and maintain our sewerage to keep it in good working condition. This involves:

  • inspecting sewers through closed circuit TV
  • cleaning sewers
  • trimming tree roots to prevent blockages, using high-pressure water jets
  • major works and projects to replace aging pipes or increase their capacity.

How you can help

  • Don’t flush fats, oils or other dangerous chemicals down the sink or toilet.
  • Don't flush wet wipes or disposable nappies down the toilet either – visit Yarra Valley Water to learn about 'fatbergs'.
  • Check your stormwater plumbing isn’t connected to sewerage.
  • Install a water tank to capture rainwater.

Watch this video for an overview

OK, so what is sewage then?

Melbourne Water sign saying 'Recycled Water in Use'

Sewage, comprised of 98% water, is the wastewater that leaves our kitchens, bathrooms, laundries and toilets, as well as from industry and businesses.

It is treated to Class A, the highest quality of recycled water, before being released into the environment. Receiving environments include Port Phillip Bay, Bass Strait and many inland waterways, such as Yarra River, Jacksons Creek and Merri Creek.

Recycled water
How Melbourne Water produces recycled water, following strict regulatory guidelines – and how it is a key initiative in securing our water supply.
Read more

How sewerage works, from flush to treatment

Melbourne Main Sewage Replacement Project (MMSR), Flinders Wharf, Wurundjerri Way bypass
Site progress works, from Melbourne Main Sewerage Replacement Project (MMSR).

First, disposal

Each year, more than 320,000 million litres of sewage enters Greater Melbourne's sewerage through a network of underground pipes.

This sewage comes from homes as well as businesses. Businesses need permission to use the sewers because their trade waste is more contaminated.

Then transfer

Sewage then enters one of three larger trunk sewers. These slope downwards so gravity helps the sewage flow.

Eventually, pumping stations push it up to ground level to be processed at a treatment plant or to continue its journey through our sewerage, which can take up to 12 hours.

Finally, treatment

Melbourne has two big treatment plants: the Western Treatment Plant in Werribee and the Eastern Treatment Plant in Carrum. 

There are lots of smaller treatment plants all around Melbourne too.

The treatment plants process sewage in different ways, removing rubbish, organic matter and chemicals. After water is treated, it can be released into the environment or disinfected to supply as recycled water.

Western Treatment Plant lagoons


Western Treatment Plant 

Find out about the sewage treatment process at the Western Treatment Plant, which produces 40 billion litres of recycled water.
Read more

 

Eastern Treatment Plant, birdlife in the lagoon

Eastern Treatment Plant
The Eastern Treatment Plant is one-tenth the size of the Western Treatment Plant, but treats nearly half of Melbourne's sewage: 330 million litres a day.  
Read more

 

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Swimming pool at Cocoroc township

Visit our sewerage past

Want to see Melbourne's sewerage history? Check out our sewerage history, including how sewage was previously treated, or go straight to historic sewerage sites Cocoroc and Werribee Farm.

 

Our sewerage history

Looking down the Maribynong River

Envisage our sewerage future

To maintain Melbourne as a liveable city, we need to manage our resources wisely, enhance liveability and support the economy: all while ensuring that sewerage remains affordable to the broader community.

Read the Melbourne Sewerage Strategy: a collaboration between Melbourne Water and Melbourne's water retailers.
 

Read the strategy

Last updated:
17 September 2019