Sewage flooding and blockages can occur during a flood and is a health hazard. Sewers and drains can also become blocked at any time.

Sewage flooding

Intense rainfall can cause sewage flooding, if the flood water finds its way into the sewers. Flood water can then become contaminated with sewage which is hazardous to health and should be managed carefully.

Contact your GP immediately or call NHS 111 if you have diarrhoea or vomiting after a flood.

Following basic hygiene procedures can help reduce the health risk from sewage flooding

  • Wash hands and disinfect footwear after any contact with the sewage
  • Keep children and pets out of any area affected by sewage flooding
  • Whilst cleaning up after flooding, protect cuts and grazes with waterproof dressings and wear protective clothing such as rubber gloves
  • Do not eat any fruit or vegetables growing in the garden if it has flooded, and do not plant any more for at least six months after sewer flooding. In the six months after this period you can plant new crops, provided that you do not harvest them for at least two months


Thames Water is responsible for maintaining, repairing and clearing sewers and drains. If you suspect that a sewer or drain is blocked, call Thames Water on 0845 9200 800 who will clear the blockage free of charge. If the blockage is not Thames Water's responsibility they will advise at the time.

If there is a blocked gully in the road contact Surrey County Council (Highways)

If there is a blockage at a property that you are renting, you should contact Thames Water as well as informing your landlord as soon as possible. A blockage inside a property is the responsibility of the owner/occupier. In a private block of flats it is normally the managing company's responsibility.

Blockage on neighbouring property

If you suspect a blockage on your neighbour's property, advise them to contact Thames Water on 0800 316 9800. If a neighbour is refusing to remove a blockage, you can ask for our engineering team to investigate the issue. They can be contacted by emailing If necessary, we can serve a legal notice on the property owner or occupier requiring the unblocking of the drain or sewer.


Drains and sewers are generally designed to be self-cleaning however careful maintenance is still important.


  • Periodically examine the system to identify any necessary repairs, paying particular attention to manholes
  • Check for water overflowing from gullies or manhole covers
  • Clear any blockages, including partial blockages

Do not

  • Damage drains and obstruct access to manhole covers
  • Put potentially blocking items down the toilet, such as nappies
  • Pour cooking fat or oil into the sink or drains, as it will solidify and cause blockages