Channel Drainage

Channel drainage is a solution used for managing surface water in paved areas susceptible to flooding. The pre-formed U-shaped trough features protective grating and sits flush with the ground surface to efficiently manage surface water run-off by diverting it to locations such as stormwater drains and nearby watercourses. Its long and narrow design helps catch water before it begins to accumulate and directs it safely to a discharge point.

The different types of channel drains include slot drains with no grating, pre-sloped channel drains designed to assist with water transport and standard linear drains with different ratings based on load class requirements set in BS EN 124:2015. These ratings range in everything from A15 for light domestic use to F900 for heavy-duty environments such as airports.

• Extracts water from across a much greater surface area.
• Decreases the risk of flooding due to insufficient capacity.
• Avoids the accumulation of silt in one area.
• Channel drains with removable grating are easy to clean and maintain.
• Alternatives such as gullies are not designed to handle severe rainfall.

A drainage channel’s destination will depend on several factors. For example, if it is being used to remove stormwater from a driveway, road or car park, it can be connected to a nearby main stormwater drain. If this isn’t possible, it may be either diverted to a nearby watercourse or a soakaway system.

Stormwater can also be harvested to provide non-potable water for domestic, agricultural or industrial use, to reduce demand on the mains water supply. In this case, the channel drain will be connected to a stormwater harvesting system which treats and stores it for reuse.

If the channel drain collects water that contains chemicals, run-off from car washes or industrial processes, it will be connected to a wastewater treatment system.

1. Plan where the channel drain will go and where the water will discharge. It’s important to have a safe designated discharge point, such as somewhere permeable or a storm drain. 
2. Excavate a trench that’s wide enough and deep enough for the drain bedding. The drain bedding is essential, as the drain should not be placed directly into the soil.
3. Create a solid base for the channel drain using concrete.
4. If your drain isn’t pre-sloped, check the level and ensure there’s a slight slope for water to flow and not remain stagnant.
5. Install grating to keep debris out and protect the drain. Grating is also necessary to provide a safe walking and driving surface for channel drains in busy areas.

Both channel drains and slot drains are designed to manage the accumulation of surface water, but they have a few notable differences in their appearance and the way they way function. Slot drains lack grating and have a sleek, discreet appearance. However, their water flow capacity is lower than that of channel drains, making them more susceptible to clogging and flooding. Channel drains are easier to maintain, as you simply need to remove the grating to access the trough. Both systems are effective, but you should consider the intended application and demand before deciding between the two.

There’s no difference between a trench drain and a channel drain, both refer to long narrow drains installed at ground level designed to transport water away from areas prone to pooling. ‘Trench drains’ are how they’re often referred to in the US, whilst in the UK the term ‘channel drain’ is more widely used by product manufacturers.

Yes, as long as it’s safely connected, you can run a downpipe into a channel drain. However, it’s important to be certain the drainage system can handle the water flow amount.

Yes, channel drainage can prevent flooding by directing the flow of water from non-permeable areas. This creates a safer environment for vehicles and pedestrians while keeping water from pooling and causing damage to surfaces and structures.

In most cases, channel drains need to be cemented to remain stable and support heavy loads. Cementing channel drains also supports the longevity and performance of the troughs, helping to ensure they can perform their functions without constant maintenance and replacements.

Many channel drains have a built-in slope to manage the transfer of water. In situations where channel drains do not come with a pre-slope, it’s important to ensure the cement beneath it is laid at a slight angle to guide water towards the discharge point to prevent water from stagnating.