Signs you need external drain unblocking help
- Water pooling around an outside gully
- A manhole full of standing water
- A bad smell in the yard or garden
- Several fittings inside draining slowly at once
External Drain Unblocking: what the job involves
Outside drains take waste from your home to the public sewer. They include gullies under your downpipes, drain runs under the ground and the manholes along them. While each part is simple, a blockage in any one can back water up into the yard or house. Leaves, silt, fat and tree roots cause most of these blockages.
The engineer starts by lifting the manhole covers, since the chambers show where the water stops. They then clear it with drain rods or a jetter. Finally, they flush the run and check each chamber flows.
Not every outside drain is yours to fix. Citizens Advice explains that you look after the drains within your boundary that only serve your home. However, a lateral drain you share with a neighbour belongs to the water company. Around Wolverhampton, that is Severn Trent.
How the job goes
- 1. Lift the covers The engineer checks each manhole to see where the water stops.
- 2. Clear the run They clear the blockage with rods or a jetter.
- 3. Flush and check They flush the run and check every chamber flows.
Typical costs
MyJobQuote puts clearing an outside drain at about £80 to £150 (2026). Other UK guides put drain unblocking in general at about £80 to £250 outside London. Jetting a long or greasy run costs more. These are typical ranges, and you can ask your engineer to confirm the price before they start.
Around Wolverhampton
Many terraced streets around Wolverhampton share a drain run behind the houses. Because of that, a blockage can back up into a neighbour's yard before it reaches yours. City of Wolverhampton Council looks after the road gullies in the street, not the drains on your property. You can report a blocked road gully to the council through its Love Clean Streets app.
External Drain Unblocking: frequently asked questions
Who is responsible for a blocked drain outside my house?
You look after drains inside your boundary that only serve your home. However, shared lateral drains and public sewers belong to the water company, says Citizens Advice. Road gullies in the street are the council's job.
How do I know if the blockage is mine or the sewer's?
Lift your manhole covers and look, because the water level tells you a lot. If your chamber is full but the next one down is empty, the blockage is probably in your drain. If the public sewer chamber is also full, report it to the water company.
Can tree roots block an outside drain?
Yes, roots grow into old clay pipes through cracked joints. They then catch waste and form a blockage. Jetting can clear them, although a repair stops them coming back.
Will the council unblock my drain?
While the council clears road gullies in the street, it does not clear drains on your property. For shared drains and sewers, contact the water company instead. For your own drain, you need a drain engineer.