In urban landscapes, concrete and other impermeable surfaces, together with the removal of vegetation, result in increased surface water run off. The growing trend to pave our driveways and front gardens allows rainwater to be quickly directed into the drainage system, which during heavy rain and storms can cause local flooding.
First developed in the United States in the 1990s, rain gardens are a popular flood prevention approach. They comprise landscaped areas, designed to help slow down surface water run off, reducing the rate at which it enters the surface water drainage system. In turn, this helps to reduce the risk of flooding. As well as helping to prevent flooding, rain gardens can make attractive features in front or rear gardens that can also benefit wildlife and attract bees and other pollinating insects.
Woking Borough Council is working in partnership with Surrey County Council and Highways to install rain gardens as part of a pilot project across the Borough in areas that are susceptible to flooding. The first rain garden was installed in Blackdown Close, Sheerwater in February 2019. The existing roundabout was converted to a rain garden incorporating a range of plants that are also good for pollinating insects. The garden has been a great success and is working efficiently during heavy rain and storm events to successfully manage surface water run off in the location. It has also added amenity value for the local residents through the provision of an attractive perennial garden. The project team is actively identifying further locations across the Borough that have suffered from past flood events that will benefit from the installation of rain gardens.