Brett Martin has provided its new StormCrate55 modular crates for an underground attenuation tank designed to control stormwater and address surface water run-off as part of the redevelopment of a business park in Cheshire.
Located in Wincham near Northwich, the Blue Group site at the New Cheshire Business Park features offices, a workshop and space for up to 20 waste handling machines. In order to manage surface water on the site during periods of heavy rainfall, Engineering Services, working on behalf of Blue Group, collaborated with Brett Martin on a design which incorporated the StormCrate55 system – an engineered Sustainable Drainage System (SuDS), to create a 325m³ storage tank below a parking area.
Due to space limitations and drainage layouts on site, Engineering Services found the dimensions of the StormCrate55 perfect for this project. With each crate capable of storing up to 237.5 litres of water, Brett Martin’s technical experts were able to offer technical guidance for the design of an attenuation tank and underground storm drainage pipe layout to suit both the site landscaping and tank storage requirements and allow stormwater to be managed on an area where staff cars and light goods vehicles are to be parked.
With Brett Martin offering a complete package, the attenuation tank was installed in a short timescale by contractor Catalogue Engineering. As each crate weighs only 15.5kg they were easy to lift by hand and simple to connect together using connectors and shear pins in a brick bond pattern and at three layers deep in parts.
As with the application at the Blue Group site, one option is to surround the StormCrate55 system with an impermeable geomembrane to create a sealed underground attenuation tank. The outlet from this tank is then controlled to facilitate a slow release of the stored water back into the drainage system. StormCrate55 can also be wrapped in a permeable geotextile material to create an infiltration system which allows stored water to slowly seep into the surrounding ground and back into the water table over a period of time.