In construction and civil engineering projects, surface water drainage is essential for keeping surfaces and roads dry, ensuring projects are safe, accessible and long-lasting. 

Without it, there would be a very high risk of flooding and soil erosion, and it could even threaten the structural integrity of the infrastructure.

What are the different types of surface water drainage?

There are lots of different types of surface water drainage for civil engineering projects, whether it’s for roads, yards, airfields or paved areas.

Channel drains

A channel drain is designed to drain surface water away from areas like patios, driveways and car parks. Sometimes called trench drains or linear drains, they usually work based on gravity, being placed in a position where surface water runs towards – like the bottom of a slope.

Combined drainage kerbing

Combined drainage kerbs are kerbs that have small gaps in them, to allow surface water to drain through the kerb and under the road surface. They’re usually used on streets, carriageways, roundabouts and car parks and have two purposes – to mark the edge of the road and to lead surface water off the road. 

Swales

Swales are shallow, grassy channels that collect surface water and the water then drains through the grass underground. As well as having a drainage function, they also enhance the natural landscape, have both aesthetic and biodiversity benefits and can help to remove pollutants.  

Fin drains

Fin drains are pipes that are laid under the ground which allow water to flow away into a traditional piped drainage system. They’re commonly used to provide drainage at pavement edges, to ensure the sub-base and capping layers of the carriageway aren’t affected by excess surface water.

Gullies

A rainwater gully helps to discharge surface water from the road into the main drainage pipe, where it then goes to a watercourse, storm drain or soakaway. These are commonly used in the UK, particularly in urban and embankment conditions. 

What is the best type of water drainage?

The type of drainage system that will work best totally depends on the setting and the project – for example using a channel drain on a totally flat surface probably won’t be the most effective, as they work best when positioned on a slight incline.

At Minster, we are experts in surface water drainage, so are well positioned to advise on and install the best drainage for your project. This can include permeable surfaces where rainwater can soak through to the soil, or underground drainage channels where large volumes of water can be transported quickly. 

We are an approved Anglian Water contractor, capable of installing and maintaining foul and surface water drainage to an adoptable standard. Even when harmful or hazardous chemicals, fuels or oils are involved – like on industrial yards and airfields – we ensure spillages are drained effectively and responsibly without damaging the environment.

What are the benefits of surface water drainage?

Drainage is an important safety consideration for any construction and civil engineering project and is essential for accessibility and usability. 

Not only this, but it’s also an important environmental consideration – responsible water management can alleviate flood risk, prevent environmental contamination and support a balanced water table.

It can also help to make road surfaces last longer, as excess water causes damage to roads over time – especially in the colder months. For example, potholes are created when water seeps into cracks in the road surface and then freezes. As it freezes, the water expands and pushes against the cracks, which widens them. 

When the water melts back down, it leaves behind a larger crack called a divot. When cars drive over divots, the weight pushes the top layer of the road into the space created by the divot, leaving a pothole in the surface. 

Therefore, having good surface water drainage in place on road surfaces lowers the chances of potholes forming and increases the lifespan of the road. 

If you’d like to learn more about how we can support with drainage on your project, then visit our service page or get in touch with our team of experts.