Causes of sewer flooding

A blockage in a sewer pipe can lead to flooding in or around your home. Our sewers are only designed to take away the normal contents of sinks, baths, showers and toilets, so all other waste should go in the bin.   

75% of all our sewer blockages are caused by the wrong items being flushed down the loo or washed down the sink. These blockages, often known as fatbergs, contain many unflushable items including:

These items get stuck and build up in private drains and public sewers. Over time, more items get caught in the blockage. It gets bigger and bigger until it totally blocks the pipe and stops wastewater flowing to our treatment sites.  

You can help prevent sewer flooding and avoid blockages by putting wet wipes, nappies and sanitary items in the bin, not down the loo; and binning leftover food waste, cooking oil and sauces before washing up.

While we look after the public waste and water network, you are responsible for maintaining drains and wastewater pipes within your home’s boundary.

We’re responsible for looking after the public sewer network. 

Most of our sewer pipes are underground, so it can be hard to tell if they’re damaged until there’s a problem. Sewers can be over 100 years old.

They can be broken or damaged by tree roots and soil movement caused by extreme freezing and thawing.

We always work hard to check our pipes and keep them all in good condition, but you can help us find and fix problems quickly by reporting issues with your waste services. 

During long periods of heavy rain, sewers can become overwhelmed. 

The sheer volume of rain can sometimes make it impossible for the sewers to cope with the extra water. When sewers are unable to take the water away quickly enough, this can cause flooding.

Climate change is making extreme weather such as heavy rain cause sewers to be unable to quickly take the water away. This type of flooding is becoming more common.

You can reduce the impact of this type of flooding by installing items like flood gates to protect your home.

If flooding like this affects many properties in your area, your local council or the Environment Agency may have to help to find long term solutions.

As the population grows, more of our green spaces are being built on. 

This means that we lose some of the natural drainage we have, making it harder for heavy rain to be absorbed into the soil.

This can lead to more cases of sewer flooding. 

If you replace grassed areas around your property with hard, impermeable surfaces, it's important to think about how rainwater will drain away from that area.

It's also important to keep gutters and drains free from leaves and debris so surface water can flow away freely.