Robin Hood meets new drainage regs |
Our traditional markets for Civils Products have been surface water drainage, service ducting and sewer pipes for both foul water and rainwater. Due to recent flooding events across the UK the Government introduced new regulations which meant that conventional drainage away from site was no longer a preferred option.
Instead stormwater must now be controlled on site as far as possible using storage systems to allow water to soak into the ground or trickle away without the risk of causing flooding. We developed and launched the Polystorm system just a year ago. Polystorm units form a huge underground storage structure capable of taking loads of up to 40 tonnes per square metre – suitable for use under gardens or car parks.
We have recently completed one of the largest soakaways in the country using Polystorm cells at the new Robin Hood Airport, near Doncaster – on the site of the old RAF Finningley airbase.
As part of the conversion into a civil airport, parking spaces for over 3,000 cars plus another 200 disabled bays were required. With a hard-standing area of two main car parks and one for staff, totalling 100,000 sq.m, plus the rainwater run-off from the Terminal Building roof, drainage was an obvious problem.
The Hewlett Group, subcontracting to Main Contractor Bovis Lend Lease and expert in environmental planning, was responsible for the car parking areas. Polystorm Modular Storage Units were chosen as the most effective drainage solution. Manufacturer Polypipe Civils Ltd. worked closely with Hewlett from the birth of the project to produce a design that was practical and simple to install.
The Polystorm System consists of units one metre long x 0.5 metre wide x 0.4 metre. With a weight of only 9 kilograms but a storage capacity of around 190 litres and a 95% void ratio, they offer a truly remarkable drainage capability.
The units can be interlinked in any shape or size required. At Robin Hood Airport, three pits – 1,100, 1,900 and 270 sq.m respectively – contain well over 17,000 Polystorm units. The pits are comparatively shallow thanks to Polystorm’s weight bearing capability, so groundwork and installation were relatively simple and quick.
