If you have discovered a blocked drain outside your home, it can be difficult to know whether you should deal with it yourself or call the water company. This confusion is incredibly common. Many people assume that anything outside the house is someone else’s problem, while others end up paying for work they did not need to. In reality, responsibility depends on where the blockage sits in the system and which part of the UK you live in. This guide explains the rules clearly, using everyday examples so you can work out who is responsible and what to do next.
To work out liability for a blocked drain, you first need to know how the system is arranged underground, and what these terms mean.
A drain carries wastewater from your property to the point where it meets another property’s drain or the lateral drain. It sits within your property boundary and normally only serves your home.
Example:
If your kitchen sink starts gurgling and you notice water pooling around a drain cover in your garden, the issue is almost certainly on your private drain.
Some homes, especially terraces or semis, have shared pipes connecting several properties before they reach the lateral drain.
Example:
If both you and your neighbour’s toilets are backing up, the blockage may be in a shared section before the lateral drain.
A lateral drain sits outside your property boundary and carries wastewater to the public sewer. It often runs under pavements or shared access routes.
These are the main sewers serving multiple streets and are the responsibility of the local water authority.
You can view sewer maps from:
England and Wales: https://www.dwrcymru.com or your regional water company’s website.
Scotland: https://www.scottishwater.co.uk
Northern Ireland: https://www.niwater.com
If the blockage is on pipework located inside your boundary and serving only your home, you are responsible for the repair and you will need to contact a company such as Drain Division to clear it for you.
Things that cause this include:
• Grease and food buildup from kitchen sinks
• Tree roots damaging private pipes
• Collapsed or ageing pipework on your land
• Wipes or sanitary items causing blockages
Example:
If you lift a drain cover on your driveway and it is full of wastewater but your neighbour’s drain is clear, the issue is almost certainly on your section of pipe.
Although many shared drains became the water company’s responsibility after the 2011 transfer in England and Wales, some private shared systems still exist.
If the shared drain remains private, maintenance costs are almost always divided between the connected properties, unless there’s another contractual reason why this isn’t the case.
In rented homes and flats, legally speaking:
• Landlords must repair drains that form part of the building’s structure.
• Tenants must report issues promptly and avoid blockages caused by improper use.
Example:
A tenant reports that the outdoor drain keeps overflowing after showers. A landlord has responsibility to fix the drain, unless the cause is proven misuse (for example, flushing nappies or wipes). If the drain blockage is caused by misuse, the landlord can charge the tenant for the cost of clearing it.
In England and Wales, the water company is responsible for most lateral drains.
If the blockage is located:
• Under the pavement
• Under a road
• Beyond your property line
…it usually falls under the relevant water authority.
Public sewers are always the responsibility of the water company. The company responsible for the sewer is different depending on what region you are in.
Example:
If multiple gardens on your street are flooding from manholes at the same time, it is almost certainly a public sewer issue.
Water companies are responsible for:
• Most lateral drains
• Most shared drains
• All public sewers
Homeowners only handle drains within their own boundaries.
The rules differ:
• Scottish Water only deals with public sewers
• Homeowners must maintain private drains AND lateral drains, even outside the property boundary
• Shared private drains must be jointly maintained by all connected properties
Example:
In Scotland, a blocked pipe under a shared driveway is usually the responsibility of the homeowners using it rather than Scottish Water.
NI Water handles:
• Public sewers
• Some shared drainage systems
Homeowners remain responsible for private drains.
Some blocked drains outside need urgent action.
A blocked drain becomes an urgent emergency if you notice:
• Wastewater backing into toilets or sinks
• A strong sewage smell around your home
• Flooding across gardens or driveways
• Sewage escaping onto public footpaths or roads
• Water company: if the problem is clearly on a lateral drain or public sewer
• Drain Division: if the problem is on your property or if you are unsure and need fast diagnosis
Emergency services should only be contacted if there is a danger to life, such as:
• Raw sewage flooding in a public place or otherwise posing a health hazard
• Wastewater reaching live electrical systems
• Electrical shorting or fire risk
Remember raw sewage is a serious risk to health and must be dealt with as soon as possible.
Blocked drains on farms can cause:
• Slurry tank overflow
• Contaminated run-off entering watercourses
• Disruption to livestock water systems
• Environmental breaches that risk fines
Urgent professional help is needed if there is any pollution risk. Quick action prevents costly damage and protects animal welfare.
Checking drainage plans can show which pipes are private and which are public.
A CCTV survey provides:
• Exact blockage location
• Confirmation of whether the pipe is private, shared or public
• Evidence needed for cost sharing or insurance claims
Drain Division offers surveys that identify responsibility clearly and prevent unnecessary charges.
Responsibility for blocked drains outside depends on whether the pipe sits inside your boundary, in a lateral drain or in a public sewer. Acting quickly prevents significant damage and avoids the cost of incorrect repairs. When the issue sits within your responsibility, or when you need help identifying ownership, Drain Division offers expert advice, full drain surveys and rapid callouts.
If you need support with a blocked drain outside your property, contact Drain Division today for clear guidance and fast, professional assistance.
Contact our team of experts today. Our offices are open 6am to midnight 7 days a week.
