SuDS must be introduced early on in the planning process to mitigate flood risk

Sustainable drainage mimics natural drainage processes by allowing rainfall to soak into the ground where possible or by delaying discharges. Reducing both the volume and rate of surface water run-off to sewers and watercourses, this helps to improve water quality, ecology and amenity value of watercourses. It is important, however, to remember that there is no single drainage solution for any one site.

Thanks to the wide range of methods available with a SuDS approach, designers and planners can consider local land use, future scenarios, and the needs of local people when undertaking the drainage design – helping to deliver the highest quality results. And, in the majority of cases, a combination of these techniques will result in best practice.

Urban solutions
As over 80% of the UK population now live in urban areas, there has been a huge reduction in the amount of land where rainfall can soak into the ground. The traditional approach of combining surface water with the foul sewage system is expensive, while separate surface water sewers that discharge directly into local watercourses pose environmental risks if misconnections occur between the two systems.

With both of these outdated systems already demonstrating key failings, they will also soon be overwhelmed by the intensity of rainfall which could cause widespread flooding. Furthermore, if building developments on flood plains continue to be approved in order to satisfy an ever growing demand for new houses, the need for proper flood risk management will surely reach an all-time high.

SuDS can help local authorities, planners, architects and developers meet the demands on them to deliver green infrastructure by creating green open spaces which encourage biodiversity and habitats. Effective early engagement with stakeholders could also help deliver SuDS in multi-functional spaces such as car parks, footpaths and verges, gardens, landscaped areas, driveways, courtyards or communal spaces – improving the cost-effectiveness and integration within the development resulting in better places to live.

A new generation of SuDS
Urban development, a changing climate and intensive rainfall has meant rainwater is an issue that just won’t dry up without proper investment and planning. It is also an issue that manufacturers of plumbing, rainwater and drainage systems must take very seriously indeed if they are to meet the growing demand for high performance, low maintenance solutions.

Faced with rising costs and stricter deadlines, modularisation is growing in popularity as contractors look to find the next generation of efficient and economical products and systems. Due to the numerous benefits, both on and off site, modular rainfall management has become an increasingly popular choice at every stage of the supply chain, from the architect and specifier to the contractor and client.

Easily assembled, geocellular units can simply be clipped together to form underground structures for the temporary storage of excessive rainwater. For additional strength, they can be designed and laid in a brick bonded format for enhanced stability – forming the required volume before being wrapped in either geotextile or membrane options. 

For pervious soils, a permeable geotextile option allows stored water to seep slowly back into the surrounding ground. And, where infiltration is not desirable, an impermeable geomembrane can be used to wrap the completed structure, allowing it to act as a reservoir and retain the stormwater until local drainage flows can accept it.

As concerns grow over climate change and urban development, geocellular stormwater management units are proving to be the number one choice at sites across the UK. From individual houses to large scale housing/commercial schemes, geocellular units can work in association with traditional SuDs solutions to provide the most effective flood protection possible for the long term.