Gullies & Headwalls

At Cotterill Civils, we provide a reliable range of gullies and headwalls to support effective surface water drainage and reduce erosion at the point of discharge. Whether you’re working on a yard, roadway, or open watercourse, our products are designed to perform in demanding environments and support long-term infrastructure integrity.

Our range includes lightweight HDPE gullies, durable concrete gullies, and customisable precast headwalls, suitable for civil engineering, agricultural, commercial, and residential drainage projects. With trusted brands, expert support, and fast UK delivery, we make it easier to get the right drainage solution for your site.

Gullies for Effective Surface Water Management

Gullies play a vital role in safely collecting surface water and directing it into underground drainage systems. Our product range includes both trapped and untrapped gullies, available in HDPE or concrete, offering flexibility for a variety of site requirements.

HDPE gullies are lightweight and easy to install, while concrete gullies provide added durability for heavy-duty settings.

View our Concrete Gullies | Browse HDPE Gullies

Precast Headwalls to Protect Watercourses

Headwalls are essential for controlling discharge at pipe outfalls and reducing erosion around watercourse embankments. As a cost-effective alternative to in-situ concrete, our precast headwalls are available in a wide range of sizes and configurations.

We offer:

  • Adjustable toe-pieces for uneven terrain
  • Custom openings (square, round, multiple pipe entries)
  • Optional pre-installed features including gratings, railings, and flap valves

View our Headwall Collection

Trusted Brands We Stock

We stock products from leading manufacturers, including:

Our carefully selected brands meet UK standards for durability, performance, and ease of installation.

Need Help Choosing the Right Product?

Whether you’re building a new drainage network or upgrading an existing system, our team can help you select the right solution for your project.

Call us on 0121 351 3230 or contact us online through our quick enquiry form — we’d be happy to help.

1 of 21 products

Filter and sort

Filter and sort

1 of 21 products

Product type
Brand
Colour
Diameter
Inlet Invert
To suit
Width
Length
Clear opening (mm)
Drainage area (m2)
Load / Load Rating

1 of 21 products

Filter:

Product type
0 selected Reset
Brand
1 selected Reset
Colour
0 selected Reset
Diameter
0 selected Reset
Inlet Invert
0 selected Reset
To suit
0 selected Reset
Width
0 selected Reset
Length
0 selected Reset
Clear opening (mm)
0 selected Reset
Drainage area (m2)
0 selected Reset
Load / Load Rating
0 selected Reset

Frequently Asked Questions

What is a drainage gully used for? A drainage gully collects surface water and directs it into underground drainage systems. It’s commonly installed in yards, roads, driveways, and hardstanding areas to manage rainfall runoff, reduce flooding, and keep surfaces clear.

What is the difference between a trapped and untrapped gully? A trapped gully includes a built-in water seal that prevents unpleasant odours from escaping the drain. It’s typically used in combined storm and foul water systems, or where there’s a risk of oil runoff.

An untrapped gully has a straight outlet, is lighter in weight, and is used where odour control isn’t a concern—making it suitable for simpler surface water-only drainage.

What is a headwall and why is it important? A headwall is a pre-cast concrete structure installed at the outlet of a drainage pipe. It helps control water discharge into open watercourses and prevents erosion of embankments. Headwalls improve stability at the outfall point and can include features like gratings, flap valves, and toe pieces for added functionality.

When should I use a headwall in a drainage system? Use a headwall whenever a pipe discharges into a ditch, stream, culvert, or open watercourse. It’s especially important in areas where erosion or ground movement could threaten the stability of the bank. Headwalls also make inspection and maintenance easier by clearly marking pipe exits.

What are gullies made from? Our gullies are available in both HDPE (plastic) and concrete options.
HDPE gullies are lightweight, easy to install, and ideal for most yard and surface water applications.
Concrete gullies are more robust and suited for heavier loads or longer-term installations.
View our concrete gully options

Do gullies prevent odours and blockages? Yes. Trapped gullies are specifically designed to block odours from foul water systems. Many models also feature rodding access and silt traps, which help prevent blockages and reduce the need for maintenance.

How do I maintain or unblock a drainage gully? Routine maintenance involves removing built-up debris from the sump and using rodding access to clear the outlet.
Read our guide on how to clear a blocked gully

Where can I get technical advice or help choosing a product? Our expert team is here to help. We can advise on gully types, headwall sizing, custom features, and more. Contact us online or call 0121 351 3230 to speak with our team.

Can't find what you're looking for?

Let Us Know