ACO provides sustainable drainage to supermarket

A Waitrose store in Stratford-upon-Avon has utilised ACO Water Management’s Qmax slot drainage system and KerbDrain, a combined kerb and drainage system, to effectively manage surface water on the new car park and the approach to the store.   

ACO worked closely with structural engineers BJB Consultancy and highways contractors Fitzgerald to help create an effective solution, in line with the scheme requirements.  

Retailer Waitrose, part of the John Lewis Partnership, is committed to promoting good practice and doing everything possible to ensure its environmental impacts are minimised. By putting in place agendas such as the Responsible Development Framework, the company is dedicated to future proofing Waitrose against the impacts of climate change.

Large supermarket car parks pose a particular problem when it comes to surface water run off and for this Waitrose project, structural engineers BJB Consultancy designed a system which utilised both permeable paving, to deal with primary rainfall and ACO’s Qmaxm slot drainage to manage heavy downpours and exceedance, due to its high-flow inlet and channel capacity.  

ACO worked closely with BJB and contractors McLaren to deliver the most effective solution, hydraulically checking the area first – treating the paving as if it had become impermeable - to establish the parameters and necessary requirements.

ACO’s Qmax 225 was selected, as the slot drainage can be easily integrated into a SuDS application and allows for the fast, efficient removal of water from the surface, as well as eliminating carry over in storm conditions. As a back up solution for the permeable paving, the Waitrose site required a high capacity attenuation system. Qmax was perfectly suited – water can be stored at source within the product, allowing for a much slower and more controlled discharge of water to surrounding drainage networks, so that they do not become overwhelmed, leading to possible flooding.  

Commenting on the project, Barry Coney, Associate at BJB Consulting said: “It was of the utmost importance that the surface water management system installed on this site would work alongside the design and provide support to the car park’s permeable paving. ACO was able to provide a high-quality solution that met this requirement, but was also discreet and did not detract from the aesthetics.”  

To accommodate increased traffic volumes generated by the store, it was essential to build a new road and roundabout system as part of the scheme. Highways contractors Fitzgerald approached ACO to provide a surface water management system that would suit the application.  ACO’s KerbDrain system was selected; a one-piece combined kerb and drainage solution specifically developed to form an integral part of any modern, sustainable surface water management scheme. The versatility of KerbDrain, including its selection of depths– from 255mm to 480mm – allows engineers and designers to create a solution to optimise the specific hydraulic and performance requirements of a road’s drainage scheme, making it much more efficient.

Rob King of ACO commented: “When designing a surface water management scheme it is crucial that all the individual requirements of the site are taken into account. For example, with this project it was important that there was a proven system in place that could intercept and attenuate high volumes of surface runoff, in the event of the permeable paving being overwhelmed.

"For this, Qmax was the perfect product for the job; providing reliable performance as part of the wider SuDS system and can easily cope with the design requirements of this scheme.  In addition, the company’s KerbDrain® is ideal for the highways infrastructure.”