For a new housing development in Coventry, surface water management was a key consideration to prevent any future flooding. As part of the design strategy for the site, Brett Martin’s lightweight and easy to install StormCrates have been used to create an underground attenuation tank for the temporary storage of stormwater, reducing the demand on built drainage.
The development of 15 new homes – a mixture of 2, 3 and 4 bed semi-detached, terraced and detached houses – has been built on an area which is susceptible to flooding. In order to manage rainwater within the site and prevent flooding during periods of bad weather, the contractor O’Flanagan Homes required a drainage solution that could be integrated within the site and found the solution in StormCrate, an engineered Sustainable Drainage System (SuDS).
Brett Martin provided O’Flanagan Homes with 180 StormCrates which were used to create a 54.5m3 underground storage tank, constructed in three layers at a depth of 2 metres beneath the entrance road, to offset stormwater run-off from the developed area.
Commenting on the installation, Danny O‘Flanagan of O’Flanagan Homes commented:
“We have used StormCrates on other projects and they are an ideal solution for managing stormwater run-off. Lightweight, easy to move and incredibly strong, we used them to create an underground tank beneath the permeable paving in the entrance road of the development.”
Weighing in at only 18kg per module and measuring 1200mm x 600mm x 420mm, the StormCrate modular units can be easily lifted by hand and then laid or stacked in rows. The units are suitable for a range of applications including residential, commercial and industrial projects.
StormCrates can either be wrapped in a geotextile which allows stored water to slowly seep into the surrounding ground and back into the water table or a more common practice, wrapped in an impermeable geomembrane to create a sealed underground tank. The sealed tank approach was adopted in the housing development school, with the outlet from the tank then controlled to facilitate a slow release of the stored water back into the drainage system over a longer period.
Manufactured from recycled plastic, StormCrates have a high void ratio of 95% which means that each crate is capable of storing up to 300 litres of water in the event of heavy rain. If inspection is required for future maintenance, then Brett Martin can offer StormCrate Inspect Crates.
There are no limits on the use and design of the surface over the system and StormCrates may be successfully installed under parking areas, driveways and landscaped areas. Ideal for domestic soakaways, only 250mm* of cover is required above the crates in light traffic applications which results in less dig and site spoil. For more challenging applications the lorry bearing design ensures extreme load capacity due to StormCrate’s stable column structure. This provides a SLW 60-bearability with a 500mm* covering which represents a vehicle of up to 60t.
The use of StormCrates from Brett Martin Plumbing and Drainage has ensured this new housing development will have a proven rainwater attenuation solution which will reduce demand on built drainage and the sewerage infrastructure.
To find out more about StormCrate or for more information visit www.brettmartin.com.
*subject to load calculations