When a drain blocks or sewage begins backing up, one of the first questions is usually straightforward: who is responsible for fixing it? In some cases, the responsibility sits with the homeowner or landlord. In others, the blockage is within a shared drain or public sewer maintained by Severn Trent Water.
Understanding the difference can help you report the problem to the right organisation and avoid unnecessary delays.
Ofwat Takes Action Over Wastewater Failures
In October 2026, Ofwat announced a proposed £280,000 enforcement package involving Hafren Dyfrdwy, a Welsh water company owned by Severn Trent.
The regulator found that the company had failed to meet its legal obligations when managing parts of its wastewater treatment and sewerage network. The failures contributed to excessive spills from storm overflows.
Although Hafren Dyfrdwy operates in Wales rather than the English Severn Trent region, the case has placed further attention on how water companies manage public sewers and wastewater infrastructure.
Ofwat had also found Severn Trent Water in breach of its wastewater obligations earlier in 2026. The company had already started a £98 million shareholder-funded improvement programme, including additional treatment capacity, storm storage and improvements to wastewater sites.
For homeowners, however, the practical question remains the same. If a drain blocks outside your home, is it yours to clear or does it belong to Severn Trent?
What Is the Difference Between a Drain and a Sewer?
A drain normally carries wastewater away from a single property. This can include water from toilets, sinks, baths, showers, washing machines and other household facilities.
A sewer receives wastewater from more than one property. Sewers form part of a larger network that carries wastewater towards treatment facilities.
The distinction matters because it usually determines who is responsible for maintenance, blockage clearance and repairs.
When Is the Homeowner Responsible?
Homeowners are normally responsible for private drains within their property boundary when those drains serve only their property.
For example, if a drainage pipe runs from your house through your garden and only carries wastewater from your home, it will usually be considered a private drain. Any blockage or damage within that section is likely to be your responsibility.
This can include:
- External drains and gullies serving your property
- Drainage pipes beneath your garden or driveway
- Private inspection chambers
- Waste pipes serving only your home
- Internal toilets, sinks, baths and showers
- Roof drainage, downpipes and soakaways
- Privately owned septic tanks and treatment systems
If a private drain becomes blocked, you can choose an independent drainage contractor to investigate and clear it.
Drainage 2000 provides professional domestic blocked drain clearance across Chesterfield, Derbyshire, South Yorkshire and the surrounding areas.
When Is Severn Trent Responsible?
Severn Trent Water is generally responsible for public sewers, shared drainage pipes and lateral drains connected to its network.
A shared drain carries wastewater from more than one property. Even when that pipe passes beneath your garden or driveway, it may still be the responsibility of the water company.
A lateral drain normally carries wastewater from a single property after the pipe has passed beyond the property boundary. These drains are also generally maintained by the water company.
Severn Trent may therefore be responsible when:
- Several neighbouring properties are affected
- The blockage is within a shared drainage pipe
- Sewage is backing up from a public sewer
- The problem is outside your property boundary
- A lateral drain has become blocked or damaged
- A public manhole is overflowing
The location of the pipe alone does not always establish ownership. A public or shared sewer can run through privately owned land.
What About Road Gullies and Highway Drains?
Blocked road gullies are generally the responsibility of the relevant local authority or highways authority, rather than Severn Trent Water.
These gullies collect rainwater from public roads and direct it into the wider drainage network. If a blocked road gully is causing standing water or flooding on a public highway, the problem should normally be reported to the local council.
Severn Trent may become involved if the highway drainage system is flowing into a public sewer and that sewer is unable to carry the water away correctly.
How Can You Tell Where the Blockage Is?
It is not always obvious whether a blockage is within your private drain or the public sewer network. However, there are a few useful signs.
If only your property is affected, the blockage is more likely to be within your private drainage system. Slow toilets, gurgling sinks and an overflowing external drain within your boundary can all indicate a private blockage.
If several neighbouring properties are experiencing the same problem, the blockage may be within a shared drain or public sewer. An overflowing manhole in the road can also point towards a problem with the public network.
These signs provide a useful starting point, but they do not always confirm the exact location or cause.
When Should You Call Drainage 2000?
If the problem appears to affect only your property, Drainage 2000 can investigate the drainage system and identify the most appropriate solution.
Our experienced engineers can help with:
- Blocked toilets, sinks and external drains
- Overflowing gullies and inspection chambers
- Slow-draining pipework
- Recurring drain blockages
- High-pressure water jetting
- CCTV drain surveys
- Root ingress and damaged pipework
- Drain repairs and pipe relining
- Emergency drainage problems
Our vehicles carry specialist drainage equipment, allowing many blockages to be identified and cleared during the initial visit.
If our investigation shows that the problem is within a shared drain or public sewer, you can then report it to Severn Trent with a clearer understanding of the issue.
Can a CCTV Drain Survey Confirm Responsibility?
A CCTV drain survey can help establish where a blockage is located and what is causing it.
A specialist camera is passed through the accessible drainage pipework, providing a clear view of the internal condition of the system. This can reveal blockages, cracks, displaced joints, root intrusion and collapsed sections.
The survey may also help trace the direction of the pipework and identify where a private drain connects with a shared or public sewer.
This is particularly useful when blockages keep returning or when responsibility for the affected section is unclear.
Who Is Responsible at a Rented Property?
At a rented property, the landlord is normally responsible for maintaining the drainage system and arranging repairs caused by age, damage or normal use.
However, a tenant may be held responsible if the blockage was caused by something they placed into the drainage system. Common examples include wet wipes, sanitary products, cooking fat and other unsuitable materials.
Where the blockage is within a public sewer or shared drain, responsibility will normally remain with the water company regardless of whether the property is rented or owner-occupied.
What Should You Do When a Drain Blocks?
Start by checking whether neighbouring properties are experiencing similar problems. If several homes are affected, report the issue to Severn Trent Water.
If the problem only affects your property, contact an independent drainage contractor. Avoid repeatedly flushing toilets or running additional water into the system, as this could cause further backing up or flooding.
Do not remove heavy inspection chamber covers or attempt to enter any drainage system yourself.
Need Help With a Blocked Private Drain?
At Drainage 2000, we have been helping homeowners, landlords and businesses resolve drainage problems for more than 25 years.
From straightforward blockages to recurring problems requiring CCTV investigation, our experienced team can identify the cause and recommend the right solution.
If you are unsure whether a blockage is within your private drainage system, contact Drainage 2000 or call 01246 456 300 to discuss the problem.
