Plastic Yard and Road Gullies

A road gully is a robust drainage system that is installed along roadsides. It is normally installed at the kerb as it’s well-positioned to collect surface water. A road gully’s primary function is to channel surface water into the underground drainage network while trapping debris such as silt, leaves and litter in a gully pot. The metal grating design is also useful for allowing water, while preventing large debris from entering. 

A yard gully is a drainage outlet typically installed in private areas. It performs a similar function to a road gully by managing surface water runoff and preventing debris from entering the drainage system, but it is most commonly located in gardens and around buildings.

The depth of a road gully can vary depending on the design and installation requirements. Generally, they can vary between 600mm and 900mm, though in special instances such as motorways, they can reach up to 1050mm in depth. This depth allows sufficient space for a sump to collect silt and debris while maintaining efficient water flow into the drainage network. Here at Drainfast, we stock 750mm and 900mm road gullies.

Road gullies are used to manage surface water on roads and motorways. Their primary function is to prevent water from pooling on the road surface, reducing the risk of flooding and improving safety for vehicles and pedestrians. Their metal grating and design also help keep debris from entering a drainage network. 

A trapped gully includes a water seal that prevents foul gases from the drainage system from escaping. An untrapped gully does not have this feature and is typically used for surface water drainage only. Trapped gullies are better suited for environments where foul smells may escape from the drainage system, particularly in areas close to buildings or public environments where people are regularly present.

The size of a road gully depends on factors such as the expected volume of surface water, the area being drained and the load rating needed for traffic conditions. Larger gullies with higher capacities are typically used on busy roads or areas prone to heavy rainfall, while smaller units may be suitable for lighter applications.

Choosing the right silt capacity is essential for maintaining long-term drainage performance. A larger silt capacity allows the gully to capture more debris before it needs emptying, reducing maintenance frequency and the risk of blockages. This is particularly important in areas with high levels of debris or heavy traffic.