A Stormwater Attenuation Tank

Stormwater Attenuation

Rated 5.00 out of 5 based on 1 customer rating
(1 customer review)

Biocell Water offers a comprehensive range of attenuation solutions for every application. Solutions for shallow or deep installations, capable of dealing with HGV loadings of up to 80 tonnes. Full project assistance from initial design through to installation supervision. Highly cost effective solutions and bespoke designs available. Tank based, pipe based and geocellular solutions.


Biocell Water offers a range of attenuation solutions to cater for a variety of site spatial and loading constraints. These range from tank based attenuation solutions, to pipe based and geocellular solutions. By offering a range of products, it allows us to offer a competitive solution for every application.

In addition to attenuation storage, we also offer a range of ancillary products such as flow control devices and oil interceptors.

Tank Attenuation

Providing storage in tanks offers a very reliable and simple attenuation tank solution. Tanks are simple to install and connect, and they offer excellent access for maintenance. From an installation viewpoint, there is minimal work for the contractor onsite excluding excavation and backfilling. There is no requirement for geotextiles or geomembranes, or welding of geomembrane joints.

Our tanks can also be factory fitted with discharge pumps. This may be necessary where there is a remote discharge point if the site levels do not facilitate a gravity discharge.

Our tank based systems are available in precast concrete tanks or in twin wall HDPE tanks.

a Stormwater attenuation tank

Pipe Attenuation

Pipe-based twinstore attenuation is an innovative attenuation solution using a combination of gravel and tank storage similar to plastic tunnel based attenuation systems. The twinstore solution is a highly competitive stormwater management system. Twinstore works by using a system of lightweight, helically wound pipes in a range of diameters (0.6m to 3.6m) installed within a lined excavation and backfilled. Instead of being sealed, the pipe joints are designed to pass water into the granular fill. This balances water freely between the pipes and the backfill contained within an impermeable membrane. Twinstore reduces the overall footprint of the pipe system – a critical factor in many applications – by balancing the void ratio between the tank and the granular fill. The excavation is lined with either an impermeable membrane (GCL or fully welded liner) or a geotextile liner, depending on the site requirements. Water is cleaned as it passes in and out of the tank.

Don’t be limited by the size or shape of concrete or cellular systems; work with our design team to create a stormwater system that really meets your site brief. We can offer an infinite number of layouts using pipes from 0.3m to 3.6m diameter. Solutions are available regardless of site spatial constraints, access requirements, installation depths or budgets.

Some pipe attenuation tanks

Chamber Attenuation

Chamber or crate based attenuation offers a viable alternative to tank or pipe based systems where there are site access restrictions or where there is a very small footprint available.

Modular geocellular systems are designed to withstand vertical loads of up to 80 tonnes, which makes them ideal for attenuation or soakaway applications in heavily trafficked areas. They can also be used very effectively in installations which require shallow burial depths.

Modular cells are assembled together to form a structure of any shape or size to hold water from roofs, gutters or surface drains. The modular structure can then be wrapped in an impermeable membrane (for attenuation) or permeable membrane (for infiltration) to control the surface water entering the tank.

Our geocellular units are lightweight and easy to handle and have unique rounded corners to prevent punctures to the membrane during the installation process.

With the use of a silt trap, sediments can be removed before entering the tanks and then discharged at a set rate.

attenuation crates at a site

Product certification

All of our attenuation solutions have the appropriate certifications for every jurisdiction. These include BBA certification and  WRC approval, in addition to designs in accordance with Highways Agency standard BD12.

BBA attenuation logo

1 review for Stormwater Attenuation

  1. Rated 5 out of 5

    Tricky site. Was great to deal with a company with a range of options. All installed now on budget so happy.

Add a review

Your email address will not be published. Required fields are marked *