We designed a series of fifteen rain gardens to capture and treat stormwater at Eastcote Town Centre, an area where residents and businesses have suffered from frequent surface water flooding. As part of the wider Eastcote Town Centre Improvements for the London Borough of Hillingdon, the overall aim was to deliver a multifunctional scheme which would inject new life into a neglected public space and boost footfall at a time when high streets are struggling, whilst providing flood protection.
Delivering multiple benefits with SuDS
Instead of relying on traditional hard engineering, our Flood and Water Management Team opted for a Sustainable Drainage Systems (SuDS) approach utilising green infrastructure, to develop a scheme that was able to deliver multiple benefits, improving the area for residents, businesses and wildlife.
Dilapidated brick planters were replaced with rain gardens planted with shrubs, herbaceous perennials, bulbs and ornamental grasses. A below-ground gravel layer was installed with capacity to hold back up to fifty cubic metres of water, freeing up space in the local sewer system which would otherwise become overwhelmed during storms. Previously, the area would flood with 18mm of rain landing in one hour. Now, the site can accommodate up to 30mm of rainfall, increasing local flood resilience. Instead of businesses flooding each year, this may now occur once in a decade.
Water is filtered as it percolates through layers of soil, gravel and geotextile (a porous membrane which allows water through but prevent the flows of sediments or hydrocarbons), helping to remove harmful chemicals and sediments.
Completed in June 2019, the scheme is also helping to revitalise the area and improve Eastcote for both people and wildlife. The town centre had come to prominence following the tragic murder of a young resident in October 2015 and the scheme has helped to address negative perceptions and reposition Eastcote as a family friendly high street. The council has even organised school trips during storms and the rain gardens have done a superb job ‘performing’ in front of pupils, capturing polluted runoff from the road.
- Reducing flood risk by holding back up to 50m3 of water
- Revitalising the town centre for businesses, residents and visitors
- Improving water quality at the receiving watercourse, the Yeading Brook
- Creating a new green corridor for wildlife, including nectar-rich species for bees and other pollinators
- Supported by the community – 70% of consultation responses backed the scheme.