The Flood Hub

This blog has been written by The Flood Hub People.

Thousands of sewer blockages happen every year in the UK, increasing the risk of flooding that could often be avoided. By following simple actions at home, everyone can help reduce sewer blockages, improve drainage and lessen the chance of flooding.

 

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Why Do Sewers Get Blocked?

Every year, around 22,000 sewer blockages and 7,000 sewer flooding incidents occur across the North West from 49,000 miles of underground sewers. These are mostly caused by flushing unsuitable items like wet wipes, cotton buds and sanitary products down the toilet, or disposing of fats, oils and grease (FOGs) down the kitchen sink.

The build-up of these items can form a fatberg, a rock-hard blockage that restricts sewage flow. This can cause sewage to back up into homes, gardens, or public spaces, creating flood hazards and health risks from harmful microbes.

Studies show that wet wipes account for around 93% of sewer blockages, and even wipes labelled as ‘flushable’ often fail to break down.

In 2019, United Utilities removed the North West’s largest fatberg in Liverpool, measuring 250 metres long and weighing 400 tonnes. The fatberg consisted of fats, oils, wet wipes, and other materials that don’t belong in sewers, and clearing it took two weeks. Watch how the fatberg is being tackled here.

 

 

Who Is Responsible for Sewer Maintenance?

• Property owners are responsible for private drains that take wastewater away from their property to the point where it connects with shared pipes.
• Water companies manage public sewers and drains outside the boundary of private properties. Blockages in these areas are the water company’s responsibility.

To find out more about responsibilities for general flooding, see our ‘Who is responsible for flood water?’ resource here.

 

What Are Water Companies Doing to Reduce Blockages?

Water companies across the UK run campaigns to raise awareness of sewer blockages and encourage careful disposal of waste:

• United Utilities urges the public to “stop the block“
• Yorkshire Water reminds people that “flushing wipes blocks pipes”
• Thames Water, handling 85,000 blockages a year, encourages people to “bin it – don’t block it”

 

How to Prevent Sewer Blockages at Home

The easiest way to prevent blocked drains is to flush only the three P’s: pee, poo, and toilet paper.

Other top tips include:

• Place a bin in your bathroom for wet wipes, cotton buds, and sanitary products
• Collect leftover cooking fats and oils in a heat-resistant pot or ‘fat trap’ and dispose of them with household waste
• Wipe up grease and food scraps before washing dishes and bin them
• Use a sink strainer to catch food scraps
• Wrap coffee grounds in newspaper and put them in the bin

We can also increase the use of Sustainable Drainage Systems (SuDS) in homes and new developments. SuDS help manage rainwater, reduce water entering sewers, and store water safely in temporary areas or the surrounding land. You can read more on our SUDs page here.

 

Why Sewer Blockages Matter

Sewer blockages are not just a local issue. They can:

• Cost millions to clear and repair
• Cause disruption and damage homes and businesses
• Pollute rivers and harm wildlife
• Increase flood risk, especially during heavy rainfall, which is becoming more frequent due to climate change

By preventing blocked drains, we not only protect homes and communities but also support healthy waterways and a more resilient drainage system.

 

Download our resource on The Flood Hub for more info on sewers, blockages and flooding here.

 

 

 

Sources: United Utilities, Thames Water, The Guardian, The Rivers Trust, Severn Trent, Unblocktober