Drain blockages - guidance to householders

Blocked household drains are inconvenient and can be a potential health hazard. Drain blockages are preventable.

Common causes

• pouring cooking fat, oils and grease down drains - these can solidify into the waste system and are difficult to remove
• detergent scaling, particularly in hard water areas
• flushing paper and cloth products such as disposable nappies, sanitary towels, cotton wool buds and newspapers down toilets - they can form a solid mass and eventually stop the flow of water.
• pouring cement and plaster down drains - these can set rock-hard in the drain
• pouring waste oil from motor vehicles into drains - it is illegal to do this
• collapsed or damaged pipes.

How can I get drains unblocked?

If your drains are blocked, contact Thames Water Authority on 0800 316 9800. They operate a 24-hour, 365 day a year, drain clearance service and may be able to assist you. 

Alternatively you can report blocked drains online at: Thameswater.co.uk.

Thames Water Authority (TWA) will be able to advise you if they are responsible for clearing the blockage or not. Where the blockage affects more than one house in a street they should be able to help.
TWA will assess the situation free of charge. If they are not responsible for clearing the blockage they will discuss this with you and explain why. 

If TWA cannot assist you, this will usually be because the blockage only affects a drain that serves a single house or flat. In that situation it is likely that responsibility rests with the private home owner. 

TWA do not offer a chargeable service to unblock private drains that serve only one property. They only provide the service for combined drainage which they have adopted and are responsible for maintaining.  For a private drain blockage, you would need to find a specialist contractor from the telephone directory or internet. Be sure to ask about hourly rates and call-out charges as these can be expensive, particularly at weekends.

Please note that if your home is a new build property, TWA do not adopt the combined drainage (drainage that serves more than one property) for the first two years following completion so you will need to go back to the contractor who constructed the building.  

What if drains keep blocking?

This may suggest that the pipes are faulty. Tree root penetration and subsidence are common causes of broken pipes.

If you are a property owner

You may want to have the drains surveyed using closed-circuit television (CCTV) equipment. The cost of a drain survey or repair to your house  might be covered by your home or buildings insurance.

If you rent your home

Your landlord is generally responsible and should arrange for remedial works to be carried out.

If you are a council tenant 

If your drain is blocked, contact our housing repairs service on 020 8726 6100.
 

Further help and advice

If you need further advice on privately rented household drainage issues contact the private sector housing team, details below.

Phone: 020 8760 5476 (answerphone is monitored)
Email: hsg-privatehousing@croydon.gov.uk          
Address: Environmental Health, Trading Standards & Licensing, Sustainable Communities, Regeneration & Economic Recovery, Floor 3 Zone B Bernard Weatherill House 8 Mint Walk Croydon CR0 1EA 

If you have an issue with flooding or drainage outside your property/on the highway, please contact the Lead Local Flood Authority (LLFA) on: Floodandwater@croydon.gov.uk