South Benfleet, Essex
Much of the UK coastline is low-lying, and with the predicted rise in sea levels, is liable to become flooded in the not-very-distant future. Many local authorities and water companies are concerned about this. They are putting in place contingency measures to cope with this potentially massive alteration to the available land for residential purposes, and to retrofit protection where possible.
Whilst large flood protection schemes are those that hit the headlines, it is often the small interventions that when added up, can make a big difference in how resilient our communities are to climate change. Whilst properties higher up a hill may not be at risk of sea rise flooding, the ability of their drainage systems may become compromised as a result of the inundation of wastewater treatment works, which are often situated on low ground near watercourses, so the whole water use and treatment cycle need to be taken into consideration.
One such local authority, Castle Point Borough Council, in Essex has been promoting Sustainable Drainage Systems (SuDS) in new developments for a considerable time. Recognising that the borough is possibly one of the most at risk in the UK, the local authority SuDS and Drainage officer has been insisting on provision for Sustainable Drainage features to be made on new developments.
One such development, in Hill Road, South Benfleet, consisting of seven new executive houses, used the GreenBlue Urban HydroPlanter to mitigate the flow of stormwater. As the land had previously mostly been a large garden, the development would have had a significant impact on the drainage network with the increase in impermeable area, so some form of attenuation was required.
The site constraints meant that an extensive attenuation crate system as has been often used was not appropriate, so the drainage engineers, Civil Engineering Solutions of Dolgellau, Gwent specified the modular HydroPlanter rain garden solution, in series with a small attenuation tank, one per downpipe. This use of MicroSuds, sustainable drainage features incorporated at a property level led to a massive saving in space, as well as allowing additional biodiversity to each property.
This intelligent use of different nature-based drainage features installed in a “SuDS train” ensures that peak flows are smoothed out, and maximum evapotranspiration is achieved. This water uptake by plants is the best way of reducing the volume of water being discharged into the sewer system, as well as slowing down (attenuation) the water flow. As an added benefit, the interaction between the micro-biological and fungal activity and the pollutants can achieve contaminant removal to levels acceptable for discharge to water courses under Environment Agency guidelines – a major positive when seeking to develop in areas with combined sewers at capacity.
These HydroPlanter units come with a high-level overflow for extreme rainfall events, making sure that there can be no flood issues, even in exceedance flow scenarios, these have been designed for the future, creating resilient places.
These installed drainage features once planted up, become an attractive visual enhancement to the gardens of these properties; quietly getting on assisting the drainage from the house roof they blend into the quality landscape provided by the developers, and will continue to do so without any special maintenance for years to come.
GreenBlue Urban can support with any drainage, green, or blue infrastructure enquiry that you may have, with a wealth of resources and guidance. GreenBlue Urban – creating places for the future, in harmony with nature.