Coming to any new construction project, it’s a bold claim for a stormwater attenuation company to say it will work out a system which promises to be the most cost-effective and practical solution of any on offer. But that is exactly what we do, sometimes to the surprise of the contractor and their engineers.
One of the key factors is the sheer versatility of our designs, which can be based on pipes with diameters from 0.3m to as large as 3.6m – a complete range of specifications to match any size, shape and condition of ground.
Better still, the invention of Twinstore, with its ability to create even greater volumes of storage within a reduced footprint, has put even greater options in the hands of our expert design team.
It’s that design versatility which is at the heart of our approach. For every project we are involved in, our designers will not only offer a solution which meets the specifications presented to us, but also look at alternatives to save further on materials, work and time.
The figures speak for themselves. Since we launched Twinstore in 2008 and patented its innovative method of attenuation, the use of the system has mushroomed. Last year it accounted for over 25% of all our stormwater systems, and has been growing at a double-digit annual rate.
Choosing the right type of attenuation depends on various criteria, and even when one appears to offer the most attractive solution in terms of system cost, including crate or concrete, the truly knowledgeable designer will also factor in installation overheads and time.
Every project needs to be reviewed in the round and from every angle. Take B&Q Tamworth, for example, where the best result was achieved by designing in two relatively small Twinstore tanks plus one of our soakaway tanks.
Going much further up the scale on size, at the new Mental Health Facility for NHS Dumfries and Galloway, our versatility of approach provided engineers WSP with a much improved solution to that first planned.
There were also constraints on space and layout, and access issues over the supply of services. But by changing the tank layout from L-shape to parallel legs, Twinstore compared favourably on cost with calculations for half a dozen other systems, and also saved on installation of a good number of manholes.
Limiting factors such as size and shape of workable area, available depth and compatibility with other pipework are all features which designers have to accommodate. But again, they repeatedly allow Twinstore to show its many advantages.
Working recently for a major car plant, our design team had to devise a system of providing surface water mitigation to prevent the increased discharge of rainwater from a partially Greenfield development. The solution was to provide suitable storage of the correct volume at the appropriate levels to allow the flow to be restricted off the site, whilst ensuring the development was free from flooding.
Three competing solutions were considered by the project engineers before deciding on Twinstore for a number of reasons – not least the smaller size and cost of tank. Our shallower design saved up to 20% in tank volume besides offering other benefits in terms of manageability and on-site use of space.
So the message to project engineers and contractors is clear – let our design team work their magic and seek the best and cost-conscious solution. With Twinstore as an option, we can do more to help than ever.