Main contractor Knight Build faced a difficult challenge when developing an old private school into luxury apartments; in order to manage surface water run-off from the hard standing areas of the development, a below-ground SuDS solution was required to fit within the development footprint. However, the undulation of the landscaped areas of the site required the drainage application to be installed on a slope. This translated to varying burial depths across a large area which had a significant impact on the type of drainage application that could be installed.
Following in-depth consultation and technical input from Polypipe CGU, a bespoke hybrid solution integrating Polystorm and Polystorm Lite cells was designed.
Over 14,000 Polystorm and Polystorm Lite cells were installed on site as part of the attenuation solution, providing 2,700m³ of capacity.
Polystorm can be installed at a maximum burial depth of 3.7 metres, meaning that a modular cell structure could be constructed using Polystorm as the base layer, with Polystorm Lite cells placed nearer to the surface of the application.
Polypipe CGU were able to design a structure that offered Knight Build the most viable and adaptable solution and, installed in July 2006, the modular attenuation tank is capable of storing over 2.5 million litres of water run-off from the roof, car park and roadway of the development.
Over 1,800 metres of Ridgidrain piping was also supplied to connect the hard standing areas to the attenuation structure. Whilst Polystorm, Polystorm Lite and Ridgidrain can all be used effectively as standalone solutions, it was the adaptability of the products that offered Knight Build the most viable solution.
“We have worked with Polypipe CGU on a number of occasions and are well aware of the performance of their products and their technical proficiency,” John Durcan, Knight Build’s Project Manager, said, “On such a large scale project, we needed a solution that was sustainable yet flexible enough to accommodate the challenges we faced on site, and we’ve been thoroughly impressed with the contribution of Polypipe CGU. Their input into this particular project has been greatly appreciated.”
Jason Shingleton, Marketing and Development Director for Polypipe CGU, said: “This has been a fantastic project for us to work on, not only in terms of size, but also the challenges it has created. This is the first time we’ve integrated our Polystorm and Polystorm Lite products together as part of a single solution, and the adaptability of our SuDS range enables us to create bespoke applications to accommodate modern site constraints such as those found on this project.”