- Project plans
- Project activities
- Legislation and standards
- Industry context
Last edited 25 Nov 2019
A gulley is a fitting with a chamber which is designed to collect rainwater, wastewater and groundwater, conveying it to an underground surface-water sewer. Gullies can be used to drain waste water and rainfall from buildings, large paved areas and roadsides, pedestrian areas, parking areas, pavements, roofs and so on.
Usually buried in the ground, the gulley’s configuration typically involves a chamber and a trap (sometimes referred to as a trapped gulley), while its top surface often has a grille over which a waste or rainwater pipe can discharge. Trapped gullies can also be used to take waste water from household sinks and baths. Thus, gullies can collect rainwater from roofs, impervious surfaces and waste water from buildings. When used to drain large areas, they are frequently called yard gullies or road gullies.
The gulley’s top grille is usually designed to prevent leaves, litter and large objects from blocking the system, while the trap – which can be a P-, Q- or S-type – prevents odours from escaping into the environment and can make it difficult for rats to reach the surface. Over time, the level of sediment collecting in a trap can cause blockages which may require manual removal or mechanical suction.
When a trapped gulley features a below-ground inlet coming from another gulley or water source, it is termed a back-inlet gulley. The horizontal inlet is typically located below the top grille but above the level of the water seal. Many gulley types provide the facility to rod the system when a blockage occurs down the line.
 Related articles on Designing Buildings Wiki
- Approved Document H.
- Difference between drains and sewers.
- Drainage stack.
- Grease management.
- Groundwater control in urban areas.
- Highway drainage.
- Public sewer.
- Rain gutter.
- Rainwater downpipe.
- Safe working in drains and sewers.
- Sewer construction.
- Soil vent pipe.
- Waste water.
- Water transfers and interconnections.
Featured articles and news
Robotics and the construction industry.
ECA comments on CLC's three-phase recovery plan.
Their diplomatic and architectural history.
The origins of the six volume series.
Built to defend British waters, only to serve as pirate radio stations later.
Wellbeing to influence mix of home and office based working.
An introduction to cobotics.
Survey reports on outlook for the engineering sector.
A simple path to possible error avoidance.
Construction + technology = ConTech.
New low and high tech tools enter the marketplace.
Report looks at mental health in the built environment.
Radiant wall heating method to control rising damp.
What future infrastructure provision might look like.
Highlighting the health benefits of home improvement.
Pavilions for music, entertainment, and leisure. Book review.