Polypipe's Permavoid Keeps Coronation Street Cobbles Flood Free

Working closely with construction company, The Carey Group Plc, and international consultancy and construction company Mace, Polypipe’s supply and install partner, SEL, undertook an evaluation of the site and its ground conditions, recommending a Permavoid system to provide a shallow solution, due to the site being on Brownfield land, having a high water table and a shallow outfall. The shallow depth of the solution not only negated the need for pumping stations it also reduced the need for temporary works, which in turn reduced installation and labour costs as well as health and safety risks.

The project, undertaken at the popular ITV soap’s new home at MediaCityUK in Trafford, has seen 28 separate Permavoid attenuation tanks installed throughout the site. 

With a combined storage capability of 420,000 litres Polypipe’s high strength geocellular Permavoid solution, combined with Permachannel and Permavoid Biomat cells have been strategically located for the capture, treatment, storage and controlled discharge of rainwater at source.

Permachannel acts as both a surface water collection point and a treatment system that intercepts silt and oil with a zero gradient at pavement level. Water is then discharged from the side of each Permachannel into the Permavoid cells, complete with Permavoid Biomat and Permafilter for further treatment and storage, allowing only treated water to be discharged into the local watercourse.

The system incorporates a unique jointing mechanism that forms an interlocking ‘raft’ that will support structural loads across the most heavily trafficked areas, such as those found at the Coronation Street set.

Sean Robinson, Permavoid Project Manager at Polypipe, said: “Creating a drainage system on Brownfield land is a problematic exercise, with the excavation, disposal and remediation of contaminated soil being a costly and time-consuming process. Permavoid proved to be fit for purpose and was an ideal choice for The Carey Group as it allowed the team to work at much shallower depths whilst achieving an appropriate level of water storage and dispersal.

“As well as capturing the surface water, we were also able to incorporate a treatment process at source through the use of our Permachannel, Permavoid Biomat and Permafilter products.” 

The Permavoid system is both a practical and cost-effective solution in such applications, installed in areas to facilitate enhanced water treatment prior to dispersal into the storage aggregate compared to a traditional aggregate sub-base, Permavoid maintains structural integrity and reliability of the sub base, while providing greater storage volumes and a more sustainable solution to traditional methods.