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Sleek  |  Modern  |  Straightforward  |  Competitive  |  D400/F900
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​Swarm Aqua®


Designed for areas of heavy loading
requirements up to D400kN, where a
robust iron top is required. The finish
matches the F900kN system.


Available Channel Sizes: 150mm,

225mm, 300mm, 375mm

The Swarm Aqua® System

Swarm Aqua® is a hybrid surface water drainage system that combines the benefits of proven materials and robust manufacturing techniques to create an exceptional surface water drainage product for external use. With a focus on strength, rigidity and lighter weight, Swarm Aqua® provides the perfect solution.

A strong, durable ductile iron top section (with an option of steel for pedestrian use), combined with steel side walls and Twinwall conduit ensures that the product is ideal for external drainage applications.

Swarm Aqua® Cast is designed to cater for up to F900kN applications. With a strong, precision engineered cast iron top this is the perfect solution for applications where both aesthetics and functionality are required.

Also available with a steel or stainless steel top, Swarm Aqua® can be utilised in paved areas up to D400kN loading where it is important to achieve a superior aesthetic finish whilst still providing a functional drainage system.

Swarm Aqua® is designed to work with all standard twinwall fittings so that connection to exterior drainage networks is quick and simple.

Design Benefits


  • 100% recyclable materials

  • Full range of sizes from 150 – 375mm wide

  • Channel manufactured to SN6

  • Predicted design life over 60 years

  • Steel throat section

  • Smooth bore

  • Longer lengths, fewer joints

  • Reduced weight

  • Custom lengths available

  • Easily specifiable with a dedicated design service.

  • Ease of installation with interlocking sections

  • From loading A15 to F900kN

Superior aesthetic finish

With a choice of cast iron, steel or stainless steel tops, you can achieve a far superior finish.

Simple to install

Push-fit connections with a range of easy to use accessories, it is quicker and simpler to install than other drainage systems.

Ideal in heavy traffic areas

The strong, durable design of Swarm Aqua® means that when installed with a full concrete surround, it can be used in areas of heavy loading traffic up to F900.

Long design life

Manufactured from 100% recyclable material (HDPE plastic), resistant to chemicals, with a predicted design life of over 60 years.

Ideal in pedestrian areas

With only two 10mm openings visible at the surface level of Swarm Aqua®, this system is safe to use in areas of high pedestrian traffic.

Cost effective

Swarm Aqua® works out as a cost-effective drainage solution. The light-weight nature of the product also saves transport and installation costs.

Product Downloads

Technical Brochure

Version: Feb 24

Download Size: <10mb

O&M Manual

Version: Feb 24

Download Size: <10mb

Installation Guide

Version: July 2023

Download Size: <10mb


Swarm Aqua® D400kN Product Table

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What size channel do I need?
150mm - (max volume 17.67l/m)

225mm - (max volume 39.76/m)
300mm - (max volume 70.69/m)
375mm - (max volume 110.45l/m)


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Why Choose Swarm Aqua®
​The Swarm Aqua® slot drain system is a revolutionary hybrid surface water drainage system that is taking the market by storm. The system offers cost savings, is quick and simple to install and has a superior aesthetic finish. Despite its light-weight design, it’s also ideal for use in areas of heavy loading traffic (up to F900kN).

With a strong, durable ductile iron top section (option of steel for pedestrian use), this slot drain system combines steel side walls and HDPE Twinwall (plastic) conduit to make it the perfect solution for all external drainage applications.

Sleek  |  Modern  |  Straightforward  |  Competitive  |  D400/F900


Our Accessories are universal and work with both D400 and F900kN Swarm Aqua® systems.

These include:

End Caps, Combined Access/Outet Units, Chamber Connectors & Transition Pieces.

We can also provide F900kN gratings to suit our boxes on request, boxes are supplied with D400kN gratings.

Typical Installation

Swarm Aqua D400kN in Concrete

What is a slot drain system?

A slot drain is a linear drain that is installed in the ground and is used to filter off groundwater. The main difference between a slot drain and other more traditional channel drainage systems is that a slot drain does not include any type of grating. Fundamentally, the slot drain is another type of trench drain or channel drain system.

Did You Know?
Surface water drainage is an important part of water management on every project. EJ are the sole manufacturers of the Swarm Aqua® system. If your project requires surface water drainage, linear drainage or any other type of drainage then let our team of experts help you by saving you time and money on-site.Swarm Aqua® is a hybrid linear slot type drainage system with a wide range of applications from small residential sites to the largest industrial plots.

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