Kenmont Gardens, London
DescriptionThe College Park area of North London grew around the transport links, starting with the Paddington arm of the Grand Junction Canal, and later the expansion of the railway lines. Bordered in the south by the Kensal Green Cemetery, most of the development was along the Harrow Road running approximately East/West. Numerous smaller bay fronted houses were built during the last 25 years of the 19th Century, and the infrastructure followed quickly, with the Kenmont Primary School being constructed in 1883. Nearby in Letchford Gardens a library was opened to allow residents of this new area known as Kensal Rise access to reading material.
During the 1990’s, the roads within this small area of Kenmont Gardens, Letchford Gardens and Trenmar Gardens had become a rat-run to dodge the traffic at the top of Scrubs Lane, so one-way streets and emergency access bollards were installed, returning these principally residential streets to their more tranquil state with a 20mph speed limit.
In 2010 the community requested that an area should be provided to serve as a focal point for the neighbourhood, and following extensive consultations, it was decided to close the carriageway outside the Kenmont School and make the area an informal gathering area, or “pocket park”, to be used by all the public, and in particular the parents of children at the school. Various designs were proposed, and with the advice from the London Borough of Hammersmith and Fulham, and in partnership with Thames Water, it was decided to provide a landscaped area including a Sustainable Urban Drainage System (SuDS) system as well as benches and general landscaping.
This area of London has a combined foul sewage and storm water sewer system. This, whilst adequate for the demand when installed, has become incapable of dealing with the increase in sewage from growing population, and from the more frequent storm water events. These are of course exacerbated by the decrease in permeable surfacing such as gardens and pervious paving, which means a High Risk of surface water flooding in this area.
So back in 2014 the street design included the removal of road gully drains and replacement with rain gardens, tree planting in GreenBlue Urban Soil Cell Systems, rain gardens and a dished central area to hold exceedance flow.
Now storm water is diverted into the rain gardens and Strata Cell tree pits and filtered through a soil medium - AborSoil Hydro (removing much of the pollutant loading) slowly returning to the combined sewer via a control orifice.
This means that for up to a one in ten-year rainfall event, the water returns to the combined sewer at a greenfield runoff rate, massively helping the sewer network.
In the event of a greater rainfall event, some can be stored above ground in the dished area, and some can pass over to alternative inlets to cope with the exceedance flow. Interestingly, typically only 50% of the water that enters this sort of SuDS system ever reaches the sewer system, as the planting and trees retain a lot of the water and use it for their own requirements.
There are many other benefits though; This area is not well served with street trees and has become an outdoor classroom for the primary school pupils. It is also bringing bio-diversity to the area and is encouraging healthy behaviour with walking and cycling in becoming popular.
Working extensively with streetscape designers Project Centre from concept, design through to implementation along with strong relations with installers FM Conway this was another great GreenBlue Urban installation which is improving the quality of life for all those who live, work and play in our urban areas. So much so we were invited to the Kenmont Primary School to support LBHF to provide an overview of the scheme and how it was reducing flood risk to the local community.