Learn about sewerage

Why are sewerage systems important?

Melbourne enjoys a world class sewerage system that is central to preserving the health of our community and environment. Water authorities like South East Water operate and maintain reliable sewerage systems that safely collect and transfer sewage to treatment plants.

South East Water manages a sewerage network that is made up of 9,868 kilometres of pipeline, 259 sewage pump stations and nine water recycling plants.

Our pipes and yours – who is responsible?​

We manage and maintain the sewer up to the connection point with your property, often near the property boundary. This connection point is called the inspection opening and any pipes or fittings upstream of this is the responsibility of the property owner. There are generally two types of house connection drain arrangements: a boundary trap and an inspection shaft. These are shown in the diagrams below, as are the connection points.

It is important that the property owner maintains and keeps the boundary trap and inspection shaft accessible and uncovered at all times. If there is a blocked pipe in your home, this is the first place sewage should spill.

Sewer connection with inspection shaft
South East Water’s sewer and the property connection point on a property with an inspection shaft drain arrangement.
Sewer connection with trap
South East Water’s sewer and the property connection point on a property with a boundary trap drain arrangement.

How can I prevent blocked sewers?

There are some easy ways you can help look after your pipes, and ours too. From planting the right tree near a sewer pipe, to knowing what you shouldn’t pour down the sink or flush down the toilet – there is plenty you can do.

Learn more about preventing blocked sewers.

What should I do if I have a blocked sewer or pipe?

Some blockages may cause your outlets to drain slowly while others can cause wastewater or sewage to spill outside from your boundary trap/inspection shaft or inside from your toilet or basin. It is important to try to determine where the blockage is caused:

  • If sewage is spilling continuously or you hear a bubbling sound from your fixtures and no internal fixtures are being used, the blockage could be in our sewer. Call us on 132 812. If the blockage is in our pipes, we will fix it at our cost.
  • If you have a slowly draining toilet, sink or shower, it may be a blockage in your internal drain. This would be the property owner’s responsibility. Please contact your plumber to diagnose the problem. You can also engage South East Water’s plumbing service Priority Plumbing on 1300 760 306.

Learn more about what to do if you have a blocked sewer or pipe.

What should I expect from my plumber?

If your plumber identifies that the blocked sewer is in South East Water’s system, they are required to call us on 132 812 to report the blockage. Our crew will then attend to investigate and repair the blockage, and your plumber may receive a spotter’s fee of $74+ GST for correctly reporting the issue. As only South East Water and its approved contractors are allowed to access and carry out repairs on our assets and pipes, your plumber should not perform any work on a blockage that is our responsibility.

If the plumber also invoices you for the time spent to diagnose the cause of the blockage, we may reimburse the reasonable costs associated with the call out (typically between $200 and $300).

The sewerage system and extreme rainfall events


In Australia, we maintain separate stormwater and sewerage systems. In Melbourne, water authorities like South East Water manage the sewerage network while Melbourne Water is responsible for the stormwater system.

We know that during heavy rain events, stormwater can enter the sewerage network which is why they are built to cope with daily peaks and inflows from significant rainfall flows of 25mm of rain in one hour. This reflects the typical rainfall for a one in five year storm event and is in line with the Environment Protection Authority requirement.

Despite this, during extreme storm events (beyond a one in five year storm) the sewerage system may reach capacity. When this happens we may need to discharge diluted sewage at specific overflow locations, which are generally into creeks or low lying areas away from likely human contact. We report the action to EPA Victoria and notify relevant local councils. There is no impact on drinking water quality from this type of action.

It's important to note that heavy rain can also wash other pollutants such as dog droppings, oil, nutrients and litter into Melbourne's rivers and creeks. This impacts water quality and as a precaution you should avoid contact with rivers and creeks for 48 hours after heavy rain.