In My Area

Causes of sewer flooding

Sewer flooding is often caused by blocked drains and sewers.

Here’s what you can do to avoid blockages and stop sewer flooding affecting you and your neighbours.


Blocked drains or sewers  |  Damaged pipes  |  Heavy rain  |  Urban development

Blocked drains or sewers

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:

  • wet wipes
  • nappies
  • tampons and sanitary pads
  • fat, grease and oil from cooking
  • leftover food
  • sauces, gravies and custards

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
  • binning leftover food waste, cooking oil and sauces before washing up

Responsibility for drains

It's important to note, while we look after the public waste and water network, you are responsible for maintaining drains and wastewater pipes within your home’s boundary.


Simple steps you can take to help prevent flooding

You can help to stop sewer flooding in your community.

  • Be aware of the flood risk in your area
  • Know where to find and check weather forecasts
  • Clear leaves and debris from your gutters and drains
  • Make sure you include enough drainage if you pave over your garden
  • Install flood gates or doors if you live in a high flood risk area
  • Check your flood gates and doors regularly
  • Close your flood gates and doors if heavy rain is forecast
  • Only flush pee, paper and poo
  • Bin used cooking fat, oils, and leftover food