What is an outside drain?
An outside drain carries water away from your property, so a blockage can flood the ground. It includes gullies, which catch rainwater, and the pipes that join them. Inspection chambers let you reach the pipes.
Some drains take waste from the toilet and sink, while others take only rainwater. Know which is which, because the fix may differ. See our guide to foul and surface water drains.
Immediate steps when an outside drain is blocked
Stop using water in the house if the drain also takes waste, because it has nowhere to go. Clear leaves and debris from the gully with gloves on. Check the chamber nearby, as a full chamber shows where the problem lies.
Do not climb into a chamber. Keep covers on when you are not working, since open chambers are a danger. Keep children and pets away.
When to call a professional
Call a drainage engineer if clearing the gully does not help, since the blockage may be deeper. Call one too if water rises in a chamber or sewage smells appear. These signs point to a blockage in the pipe.
Our sewer smell guide explains related problems. You can also ask for a free quote on our site, and we will pass it to a local engineer.
Common causes of outside drain blockages
Leaves, silt and moss block gullies, while fat and wipes block foul drains. Fat, wipes and other waste block foul drains. Roots and broken pipes cause blockages deeper down.
Building debris can also end up in drains after work on a house. Because each cause needs a different fix, find out what you are dealing with first.
Who is responsible for the blocked drain?
Responsibility depends on where the pipe sits, because the law splits it by boundary. In England and Wales, many shared drains and pipes outside your boundary became the water company’s on 1 October 2011. Pipes that serve only your home, inside your boundary, are usually yours.
Scotland and Northern Ireland have different rules. If you are unsure, ask your water company to check. They can tell you who must clear it.
How to prevent outside drain blockages
Clear gullies often, especially in autumn, because leaves fall fast. Keep fat and wipes out of drains. Keep plants and soil away from gullies.
A yearly check helps. Because small habits keep pipes clear, a short routine pays off.
If you share a drain with neighbours, tell them about any problem. A blockage on one side can affect everyone. Talking early helps, since the cost and the work are often shared.
Related guides and local help
If you want to know more, read 10 Plumbing Myths That Cost UK Homeowners Serious Money. You can also read Kitchen Drain Problems: Causes, Fixes and Easy Prevention and Sewer Smell in the House: Causes and How to Fix Each One, because they cover closely related problems.
These guides help too: How to Unblock a Toilet: Safe Methods and When to Stop, Shower Not Draining: What You Need to Know to Fix It, How to Unblock a Drain: A Simple Step-by-Step UK Guide, 10 Signs Your Drain Needs a Professional, Not Just a Plunger and Drain Maintenance: How to Keep Your Drains Clear All Year. Each one explains a related topic in plain English.
Need help near you? Read our blocked drain guide first, or see Blocked Drains in Wolverhampton and Blocked Drains in Southampton. You can also see Blocked Toilets in Blaydon, since every service page has a free quote form. We pass each request to a local drainage engineer.
