Fixing a blocked sewer

You may have a blocked sewer if:

• your toilet isn’t flushing properly, or is draining slowly
• your drains are gurgling
• you notice a bad smell coming from your drains
• sewage is spilling from your pipes.

What to do when you have a blocked sewer

You need to work out whether the blockage is in your property’s pipes or within our service network. 

We only service blockages within our network. 

If the blockage is in your property, you’ll have to call a plumber to get it fixed. 

Determine where the blockage is

Find the overflow relief gully and inspection shaft. These are usually in your backyard near the laundry, kitchen or bathroom. 

The overflow relief gully is a vertical pipe with an open vent set in the ground.

The inspection shaft is a vertical pipe set in concrete with a heavy metal lid marked ‘IS’. Some older homes may not have an inspection shaft.

A photo showing an "Inspection shaft" at left, and a "overflow relief gully" at right.

The blockage is likely in your property if: 

• water is overflowing from the overflow relief gully and inspection shaft when taps, toilets or showers are being used in your house
• your toilet, sink or shower is draining slowly.

The blockage is likely in our network if: 

• water is continuously overflowing from the overflow relief gully and inspection shaft even when water isn’t being used in your house
• the inspection shaft is full of water.

Always stay away from sewage spills

If there’s live sewage spilling, avoid any contact with it and call our Faults and Emergencies team on 13 44 99. They will be able to advise you what to do next.

Who to call when you have a blocked sewer

If the blockage is in our network, call our Faults and Emergencies team on 13 44 99.

If the blockage is in your property, you will need to call a plumber. 

If your plumber finds the problem is in our service network, they’ll need to contact our Faults and Emergencies team.

If this happens, you may be eligible for a full reimbursement of the plumber’s fee (up to $500). 

While the blockage is being fixed, limit the amount of water that you use. Try not to flush toilets and avoid using appliances that require water, such as washing machines and dishwashers. 

Avoid sewer blockages

When the wrong things are flushed down the toilet or washed down the sink, they can cause blockages. These blockages can damage your property, the service network and the environment. 

You can prevent blockages by being careful about what you flush down the toilet or wash down the drain.

What you can flush 

Only flush the 3Ps down your toilet: 

• pee
• poo 
• (toilet) paper.

Anything else can cause a blockage, so put these in the bin.

Look for the flushable symbol on products. If there’s no symbol on the packaging, or if you’re unsure, put it in the bin.

What not to flush

• fats, oils or food scraps
• motor oils
• nappies
• underwear
• condoms
• non-biodegradable products
• paints
• pesticides
• plastics
• tissues
• tampons, pads and their wrappers
• solvents, aerosols or disinfectants
• cotton buds.

You can safely dispose of household chemicals at a free Detox Your Home event near you.

Prevent food going down the kitchen sink

Use a sink strainer to catch food scraps.

Wipe greasy pots and pans with paper towel before washing them.

Cooking oils shouldn’t go down your kitchen sink. 

You can put small amounts of cooking oil in your home compost. But check with your council before you put in your food and garden waste bin.

You can collect cooking oils and take them to a local recycling facility.

Tree roots and blockages

Trees can also cause blockages. 

Consider what trees you’re planting and where to avoid future damage to pipes on your property.