What Is a Drainage Gully?

A drainage gully is an important, yet often overlooked, part of a property’s drainage infrastructure. They’re found at ground level outside homes and commercial buildings alike, designed to collect surface water and grey water to be channelled away.

When working correctly, drainage gullies help prevent bad smells, slow drainage, damp issues and localised flooding. But if neglected, they can quickly overflow and cause costly damage.

In our guide at Express Drainage Surveys, we want to educate our readers on what a drainage gully is, how they work, where you’ll find them and how to spot early warning signs of a blockage. We’ll also highlight when you need the services of a professional drainage company to help prevent problems before they escalate.

Collecting water from outside areas and directing it to the underground drainage system, drainage gullies are the unsung heroes of ground-level drainage. For most properties in the UK, these gullies deal with rainfall and potentially grey water from household appliances.

You can usually spot a drainage gully due to the plastic or metal grating placed over the top, set into the ground. This is typically next to an external wall of a property, and the gully connects to parts of the wider drainage system.

They are different from manholes, which give access to underground drains, and soakaways, which disperse water into the surrounding ground. Instead, the gully is there to help control the flow of water and prevent debris from getting into the system.

What does a drainage gully do?

There are four main jobs of a drainage gully as part of its management of water:

They collect rainwater from your driveway, patio and other paved areas
They dispose of grey water from kitchens and utility rooms
They stop water from pooling around the foundations of your building
They reduce the risk of damp, mould and water ingress

Many gullies also prevent unpleasant odours from getting out of the sewer by holding water in a water trap, effectively sealing the channel.

Common Drainage Gully Types

There are plenty of different gully types, all with their different uses, found around UK properties. Knowing which one you have will help you maintain it more effectively.

Bottle gullies: A bottle gully is the most common gully type for homes, with a removable bottle-shaped trap to collect debris while still maintaining a water seal. This makes it great for odour control, and it’s easy to clean out.
Yard gullies: This type of gully is often used for patios, driveways and outdoor spaces. They have a larger capacity design to help tackle greater volumes than a bottle gully. A yard gully can often be found with a metal grid covering.
Road gullies: As you’d expect from the name, road gullies are typically used on public highways, and are therefore maintained by the local authorities.

Gully materials also vary, with plastic, clay and cast iron just a few of the common materials found, depending on the age of the property in question.

Common problems with drainage gullies

The biggest issue you might find with your gully if you don’t look after it is that it can become blocked. You’ll find the following symptoms if yours is blocked or poorly maintained:

Bad smells around your doors, windows and air vents
Water is draining away slowly or not going at all
Rainfall is causing the gully to overflow
Standing water around the gully

There are several culprits you can look out for with any of the above. The most common cause is leaves, moss and garden debris building up over and inside the gully. Food waste and grease can also create a blockage if poured directly into a gully or via the kitchen. Finally, silt and sediment, building up so gradually over time that it’s barely noticeable, can reduce your gully’s capacity to channel water efficiently.

Can homeowners maintain a drainage gully themselves?

Yes, in many cases it’s perfectly safe for homeowners to carry out basic maintenance themselves. Simple tasks, such as removing debris and flushing the gully out with clean water, should be enough to prevent minor blockages.

However, anything more complex than this, such as tasks involving underground pipework and the larger drainage system, may require more professional assistance. Health and safety is a concern in these instances, as you may become exposed to harmful bacteria and could damage your drains.

Here are some simple gully cleaning steps you can follow without needing to call in the professionals:

Carefully lift and remove the gully grate and set it to one side
Using protective gloves, scoop out leaves, silt and debris into a bucket
Flush the gully using clean water
Watch and check to ensure that the water flows freely through the gully
Ensure the water trap refills when most of the water has gone
Finally, replace the grate over the gully trench

Never use a high-pressure washer to clean out the gully and avoid chemical cleaners. These can damage the gully depending on the materials it is made from. Similarly, we do not recommend you use a drain rod on a gully.

How Express Drainage Surveys can help

While we don’t expect many homeowners to need our assistance after following the simple cleaning steps outlined above, we are always on hand if you suspect there are deeper issues within your drainage system.

Our use of the latest technology and equipment means we can produce clear, evidential reports. With recorded images, we can find the precise nature of any issues present within your drains.

Whether you’re dealing with a persistent drainage problem or have noticed something new and want peace of mind, take a look at our range of drainage services for more details on what our expert technicians can do for you:

Remember, regular DIY cleaning and sensible checks will keep your gully in top condition all year round. For anything more serious, such as blocked drains and sewage backing up into your property, contact our team today and book an appointment.