Flooding and climate change are combining to create a concerning rise in floodwater damage to commercial and residential buildings alike. To protect against the potentially catastrophic damage caused by excess water over-capacitating standard drainage systems, developers are turning to SuDS.
Adequately protecting from potential flood damage was a key concern of the developers of a 202-bed student accommodation in Cambridge for Anglia Ruskin University, as they enlisted the support and expertise of Stephenson Construction in installing an integrated drainage system within a tight timeframe.
With over 200 students set to descend on the halls upon its completion in January 2019, the developer needed a solution that could not only be installed quickly but could fit into the tight space left by a derelict car dealership on the corner of Newmarket Road and River Lane.
Doing the homework
After careful consideration of the size and situ of the site, it was clear that traditional stormwater solutions which direct water into pipe systems to be carried away by a local watercourse would not be sufficient. Such systems fail to mitigate the impact of such high levels of surface water – rather, moving it elsewhere. The challenge with this is that it can make flooding worse in other parts of the local area, as water is directed away from access points.
To overcome this issue, Stephenson Construction worked with specialist experts from Wavin, who recommended the use of an engineered solution specifically designed to support the infiltration and attenuation of stormwater. The installation of such a system would help provide a place to store excessive groundwater away from the halls for later controlled release, supporting floodwater attenuation.
The system would also need to be somewhat flexible to make the best use of the limited space of the site. This meant the developers were in need of a modular system that they could, in effect, mould to the shape and size of the space they were able to use.
Sitting the exam
To meet the brief, Wavin’s Q-Bic Plus infiltration system, with integrated and bespoke Wavin Vortex valves, was selected for the student halls site. This is a specialist SuDS consisting of a series of tanks buried underground.
Designed to mimic mother nature by managing stormwater at source, the system works by collecting excess stormwater from across a site, and storing it until it can be released in a controlled manner back into the surrounding soil or into the local sewerage network. Working in tandem with existing management systems, it can help significantly reduce the risk of flooding.
The modular nature of the Q-Bic Plus system – with integrated connectors incorporated into each unit – meant that the engineers working on the design for the new halls had considerable freedom to devise the most appropriate drainage solution for the needs of the site.
The result was a network of more than 140 Q-Bic Plus units installed beneath the halls, arranged into five different tank configurations of units optimising storage capacity. The system will be connected to the guttering on the final build, as well as the drains for the local area, ready to collect excess groundwater during extreme weather events.
2:1 with honours
The new Q-Bic Plus SuDS system with Vortex valves has now been installed beneath the ground of the development – the second site with this system in place in the UK – with work on the halls themselves still ongoing.
For Stephenson Construction, the company leading the drainage system installation, the Q-Bic Plus system offered benefits beyond ensuring the site remains dry and accessible during bad weather.
The project manager of Stephenson Construction said: “Wavin’s first-class customer service and products far outstripped our other supplier options as they provided bespoke solutions that addressed our need for speed, maximising the use of the small space we had.
“We were able to work efficiently, saving time and costs, by having a 3D model from Wavin of the full attenuation system – Vortex valves included – meaning we were able to plan with minute accuracy. The products themselves solved the issue of our space restrictions, with Q-Bic Plus allowing both regular- and irregular-shaped tanks to be constructed. Wavin helped us to make what could have been a near-impossible task straightforward, quick and effective.”
Martin Lambley, Product Manager at Wavin UK, concluded: “When choosing stormwater management equipment, it’s important not just to think about capacity alone, there are other considerations as well. These include issues like health and safety for workers, as well as installation efficiency. Taking all of these factors into account during the selection process, it’s possible to ensure that the construction process runs as smoothly as possible, while providing the finished site with the protection it needs from the harmful impacts of extreme weather.”