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Preventing wastewater overflows

Most wastewater blockages are caused by people flushing things down the toilet or sink that they shouldn’t, like fats, oils and wet wipes. 

You can help to protect our wastewater network and the environment by following our practical tips to prevent blockages in your plumbing and in public pipes.

Your toilet

What you put down your toilet can affect your pipes and our network.

Remember – only flush the three Ps – pee, poo and paper. Keep a bin by your toilet and in your bathroom to dispose of anything else.

Wet wipes, sanitary items, cotton buds and many other commonly flushed items contain plastics. They don’t disintegrate like toilet paper. Even wet wipes labelled as ‘flushable’ or ‘biodegradable’ block pipes and increase the risk of polluting our oceans and beaches.

Fats, oil and grease

What you can do

  • Pour leftover cooled fat, oil and grease into a non-recyclable container or newspaper, then put it in the rubbish bin. 
  • Let the fat cool down then scrape pots and pans into your rubbish bin before washing.
  • Add a strainer to your sink to catch food scraps and other solids that can join with fats and create a blockage.

When you pour leftover fat oil and grease down the sink, it cools and turns hard. This can result in pipe blockages.

Running hot water afterwards just moves the problem further down the network. 

Trees and roots

As trees mature, their roots can reach pipes and damage them.

Tree roots collect debris, obstructing the flow and eventually causing a blockage or break. Roots can also displace water pipes, causing them to burst. 

Root damage from trees can also allow stormwater to enter the pipes. During heavy rain, this extra water can overload the wastewater network, causing it to overflow into waterways, streets or even your back yard. 

Tree roots find their way into the wastewater network through joints in the pipes (older pipes in particular). The roots cause blockages as they grow and restrict the flow in the pipe. This can result in the tree needing to be removed.

Before planting a tree, owners should consider the likelihood of that tree causing damage to underground pipes. Choose plant locations carefully and away from known pipes and gully traps.If the tree is on private land and is causing problems in the wastewater network, then the cost of tree removal may be charged to the landowner. 

Downpipes and gully traps

Downpipes carry rainwater from the roof of your house into the stormwater network. They should not enter the drain that is used for wastewater from inside your house (e.g. the kitchen, laundry or toilet).

What is a gully trap?

Gully traps are small drains, usually located beside your house’s foundations, outside your kitchen, bathroom or laundry. It may have a grate or cover over it to keep out leaves and other debris. A gully trap should be raised above the ground to prevent stormwater from the roof or ground draining into it. 

If rainwater can enter your gully traps, they need to be fixed. It is the landowner’s responsibility to do this. Rainwater entering gully traps is a major cause of wastewater overflows during heavy rain. Contact us for advice on how to inspect and fix your gully traps.

House gully trap

Illegal gully trap allowing rainwater to enter

Small stormwater drain (not to be confused with a gully trap)


Last Reviewed: 11/10/2018
 

 
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