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How to prevent blockages

Learn more about blockages, how to report and prevent them, and how our blockbusting team help prevent flooding

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How do blockages happen?

At just 4 inches (10cm) wide, the average sewer is smaller than you think and so we all need to be careful what we put down the drain. The things people put down their toilets and sinks would blow your mind and when it mixes with fat and oil poured down the sink, it starts to cause a smelly blockage. 

These blockages build up and can create one large 'fatberg' that can cause wastewater to back up and flood your home, business or local neighbourhood.

These blockages can also damage pipes causing bursts and can even cause blockages at our sites, causing flooding and increasing the risk of pollution in local streams and bathing waters.  

Our blockbusting team in action

We have a dedicated blockbusting team who work around the clock to clear blockages and help people understand on what they should and shouldn't put down their loo. Since 2016 our team have:

  • had 175,000 face-to-face conversations with customers
  • surveyed 23,000 manholes
  • found 1,050 blockages
  • cleared 610 blockages themselves
  • prevented 127 internal floods
  • prevented 62 external floods
  • delivered 523 presentations
  • attended 124 public events.

Recently they discovered and removed a 50kg fatberg in Horsham.

A Southern Water engineer talks to a customer in their garden with another employee visible in the background

What to do if you have a blocked drain?

If you think you have a blockage, please tell us as quickly as possible and we'll do our best to find out if the problem is in one of your pipes or one of ours. If it turns out that the blockage is in one of your pipes, we recommend contacting a drain specialist who can help you clear it. 

If  it's something we can help with, our blockbusting team will be sent out to investigate or jet the sewer. We'll ask you to sign a consent form if this involves working on your private drain.

Did you know?

Every year, blockages cause huge problems throughout our network and we spend over £90 million clearing them. If we all become a blockbuster, we can easily avoid blocked drains.

20,000 blockages

occur in our sewers from fats and oils. Over 60% are preventable

4.5 million

period products make their way into the sewer every day

3,000 homes

are flooded in the UK each year because of blockages

Did you know?

Every year, blockages cause huge problems throughout our network and we spend over £90 million clearing them. If we all become a blockbuster, we can easily avoid blocked drains.

20,000 blockages

occur in our sewers from fats and oils. Over 60% are preventable

4.5 million

period products make their way into the sewer every day

3,000 homes

are flooded in the UK each year because of blockages

True or false

There are a lot of myths when it comes to blockages. Some of the most common can be found below. How do you score?

Washing up liquid and hot water breaks down fat and oil

False 

When fat and oil mix with washing up liquid there is a chemical reaction between it, the washing up liquid and calcium in the water. This causes the fat and oil to solidify into a soap-like substance when it cools. It binds together everything else in the sewer and overtime, causes blockages.

 

solid fats, oil, grease found in a sewer

Coffee grounds should go down the sink

False 

It's easy to forget to scrape coffee grounds into the bin, especially before your first coffee of the day. Unlike most foods, coffee grounds clump together in water rather than breaking down. This causes blockages in pipes and sewers, especially when fat, oil and grease cause them to stick onto other objects. 

coffee grounds

There's no such thing as flushable wet wipes

True

Even plastic-free flushable wipes shouldn’t go down the toilet, as essentially they are thick tissue, which doesn’t break up quickly enough. Reusable products are cheaper, better for the environment and help prevent blockages. 

wet wipes blocking a sewer

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