Preventing sewer blockages

Our team of sewage inspectors work to help keep our sewerage network clear. But sometimes blockages occur and can stop, or reduce, the flow of sewage through sewer pipes.

If this happens then there is a possibility that sewage can back up in the underground pipe network and overflow from manholes in roads, in gardens, or on private land. Blockages can also lead to pollution of a river, or can even cause your toilet to overflow and flood your house. But most blockages are avoidable. Welsh Water’s ‘Let’s Stop the Block’ campaign helps reduce the cost, bad smell, stress and impact on the environmental caused by blockages by raising awareness around what to flush and what not to.

How do I know if I have a blockage?

If you notice a strong unusual smell around sewer pipe covers, or that water is very slow to drain from your toilet, then you might have a blockage. Other possible symptoms might be water seeping from chambers or manholes in your garden or overflowing from gullies next to your house.

If the blockage is on your private pipes, we recommend that you contact a reputable drainage contractor, who will be able to help you. The costs of fixing any faults on this pipework will fall to you or your home insurers.

If the blockage is on public lines then it is the responsibility of Welsh Water. Call us on 0800 085 3968 to report the blockage, or if you would prefer you can chat to us online. If you are unsure, contact us and we will investigate.

What you can do?

If you are able to, lift any lightweight Inspection Chamber covers, but only those on your property. Check if the underground pipe work is clear and water is free flowing. Inspection Chamber covers can usually be found close to the house, in a driveway or in the garden.

If the underground pipe work is clear then the problem is probably on your private sewage pipe (known as a drain) and it will be your responsibility to remove the blockage. You can call a plumber or a private contractor to fix this for you. The costs of fixing any faults on this pipework will be yours or your home insurers.

Check any house or buildings insurance policies you hold first, as you might be covered for the cost of clearing blockages.

If more than one property is affected, there is flooding outside the boundary of your property (e.g. in the road), or you know that sewer pipes on your property take sewage from more than one household, then the problem may be on the public sewer network. If so this is our responsibility, please call us on 0800 085 3968

What we will do?

If the problem is on Welsh Water’s pipes, then we aim to a have jetting crew with you within 24 hours of being contacted. However during busy periods (eg during heavy rain) there may be a delay which we will tell you the time of calling.

If things change after we have spoken to you, or we are going to be late we will always try to let you know.

Once a jetting crew arrives we will investigate to identify the blockage location. Our regulatory responsibility is to clear blockages in public sewers and transferred assets If the blockage is on our sewer network, we will clear it for you free of charge.

If we attend a blockage that is found to be on the private sewage pipe we can offer a service to clear the blockage for a charge of £86 + VAT or you can use a private drainage contractor to clear the blockage. Our charge covers up to an hour's work and if we are unable to clear the blockage, you will not be charged.

I’ve dropped something into my drain

Every year we pull countless screw drivers, chair legs, drain rods and other items out of sewers that people have used to try and clear a blockage. If you try to clear a blockage yourself but drop something into the sewer please let us know.

It is highly likely that any item lost down a sewer pipe will cause a blockage and may cause flooding to you, or your neighbours’ property.

If you inform us that you have lost an item down the sewer we will come and remove it from the sewer free of charge.

Please be aware that it would be impossible for us to locate and retrieve small items, such as rings or other jewellery, which may have been accidentally flushed down the toilet.