A blocked drain outside the house can look alarming. Water pools in the gully, or a manhole cover stays wet. However, a few simple checks tell you more before you call anyone. They also help you describe the problem clearly.
This guide covers what to look at and what to leave alone. It also explains who deals with each part of the drain system.
What you may see outside
Most outside blockages show up in a few ways. Some are easy to spot, while others only appear after rain.
- A gully that fills with water and empties slowly
- Water that sits around a manhole cover
- A bad smell near the drain
- Waste water that backs up in a ground floor sink or toilet
Plymouth City Council lists similar signs on its blocked drains and sewers page. Waste stops going away when you flush, and gullies outside overflow. A smell is likely too. If you see more than one sign, treat it as a stronger warning.
Check the simple things first
Start with the gully grid. Leaves, silt and rubbish often sit on top. Wear gloves, because drain waste can carry germs. Lift the grid only if it is safe, and clear what you can reach by hand.
Next, run a tap and watch the gully. If the water leaves quickly, that pipe is flowing. If it backs up, the blockage lies further along. Then flush the toilet and look again, since each test narrows down where the problem sits.
Leave heavy manhole covers alone. They are awkward to lift, and the chamber below may be deep. A drainage engineer has the tools to open them safely.
What to avoid
Do not use strong chemicals without reading the label. Some can harm old pipes, and they can splash on skin. Never push a stiff rod into a drain you cannot see, because you may damage the pipe.
Keep children and pets away while the area is wet. Dirty water may carry germs, so wash your hands afterwards. Wet ground can also be slippery, which is another reason to take care.
Whose drain is it?
The answer depends on where the pipe runs. Plymouth City Council explains that a drain carries waste from a single property. A sewer carries waste from more than one property. You look after the drain until it crosses your boundary, and South West Water looks after the lateral drains and sewers beyond that point.
Street drains are different again. The council deals with flooded roads and blocked street drains, so report those to it. In Cornwall, the council's guidance sends blocked road gullies to a company called CORMAC Solutions. Our guide on who is responsible for a blocked drain goes into more detail.
When to ask an engineer for help
Ask for help if the water keeps coming back. The same goes for a smell that will not fade, or a drain that overflows after rain. These signs suggest a blockage deeper in the pipe, and it will not clear by itself.
A drainage engineer can clear a blocked pipe from outside the house. Our pages on blocked drains and external drain unblocking explain what the work involves. Ask for a written quote before work starts. Also ask what the engineer will do if the first method fails.
Take a photo of the gully and note when it last cleared. This helps an engineer judge the problem, so it can save time on the visit.
Help in your area
These pages cover outside drain problems for nearby areas. Each one lists the drain services you can ask about.
- Blocked drains in Plymouth
- Blocked drains in Plymstock
- Blocked drains in Plympton
- Drain unblocking in Torpoint
- Emergency drain help in Saltash
You can also browse every drain service in one place. Pick the one that matches what you can see.
Related guides
If water floods a path or road, read about flooding from a drain or manhole. Clean water from a pipe is different, so see burst pipe first steps. A drain that blocks again and again may need a camera. See when to book a drainage investigation for the signs.
Cost matters too. Our guide to CCTV drain survey cost factors explains what changes a quote. A cracked pipe may need pipe relining or excavation, while what drain jetting is covers a common way to clear a pipe.