A Welsh Government-owned business park in Offa’s Dyke, Welshpool, has turned to ACO’s innovative StormBrixx HD stormwater management crate system to deliver flexible flood relief in a tight footprint, and protect against a one-in-a-hundred-year rainfall event.
The system was designed by consultant engineers, Bradley Associates, as part of the construction of a new 5,500m2 facility for electro-mechanical variable speed drives manufacturer, Invertek.
A key challenge for the engineers was delivering the hydraulic capacity using Sustainable Drainage System (SuDS) design principals, ‘BREEAM’ maintenance requirements in line with Welsh Government policy, and within a limited footprint.
The finished system would also need to ensure surface water flooding would be minimised in the event of a one-in-a-hundred-year rainfall event, and take into account a projected 30 percent increase in rainfall intensity attributed to climate change over the course of the development’s design life.
Paul Bradley, of Bradley Associates, commented: “The construction of the new production facility, coupled with other site expansions at the business park, meant that a significant supplementary stormwater soakaway attenuation strategy was required to accommodate the reduction in naturally-infiltrating land. The main challenge was designing a system that would offer the required storage capacity in line with the Welsh Government SuDS policy, while fitting into the space available.”
To find a high-capacity infiltration system that would not only offer the flexibility of design, but also embrace SuDS best practice, Bradley Associates worked alongside the site’s appointed contractors, PaveAways, and specified ACO Water Management’s StormBrixx HD system.
StormBrixx HD is a patented plastic geocellular stormwater management system with a high void ratio of 95 per cent thanks to its unique pillar configuration. This minimises the excavation required to achieve a specified storage capacity, reduces the aggregate needed for backfilling, and improves the flow characteristics of runoff through the installed tank.
Martin Smith, business development manager at ACO, worked closely with Bradley Associates throughout the project: “The flexibility of the StormBrixx system allowed a variety of configurations to be factored into the design, including a number of highly innovative ‘P’ shaped soakaways. This enabled a crate-free zone to be included in the eye of the ‘P’, leading to a greater surface area in contact with the soil to maximise infiltration rates in a limited site footprint.
For more detailed information on the configurations used in the Offa’s Dyke Business Park project and how ACO StormBrixx helped support achieving a BREEAM ‘excellent’ rating please visit: https://www.aco.co.uk/stormbrixx-configurations.