Andre Street Rain Garden, London - light case study

Where

The site is a triangular island bounded by Andre Street to the east, south and west, with Downs Park Road to the north. The railway line is located to the east and residential properties to the south beyond Andre Street.

The site has a number of mature cherry trees lined to the north and east of the island and further bounded by a footway. The trees are mature in size but went largely unnoticed due to the ground condition of the island. Cherry trees have a tendency to root at quite a high level which can lead to serious ground disruption without root protection which occurred on this site. This had led to severe deformation and cracking of the slabs covering the island surface creating an uninviting space with trip hazards. The island was unattractive and had limited amenity value despite the presence of the mature trees.

The site was first brought to the attention of the SuDS team by Hackney’s arboricultural officer in regard to the condition of the island. The area would have to be repaved to address the trip hazard but consideration was given to investigate whether it was an option to depave the entire area for the benefit of the existing trees.

The location was not initially considered as being suitable for SuDS as the island sits approximately 300mm above the adjacent carriageway level, which makes it difficult to direct runoff from the carriageway into the island. Further investigation and design consideration concluded that an innovative design could overcome this challenge.

The construction of a rain garden at the location was welcomed by the arboricultural officer and local users. This was a much-needed improvement to the public space and was able to provide an attractive amenity space for local residents. Furthermore, the rain garden would be able to reduce the volume of carriageway run-off into the sewers and therefore decrease the subsequent risk of surface water flooding in an area shown to have a ‘high’ risk of surface water flooding.