If you're a little puzzled about the recent enthusiasm for creating small rain gardens (the latest being in the middle of Betstyle Circus), bringing culverted streams back to the surface, asking householders not to completely pave over their front gardens, slowing down streams by planting vegetation, creating "wetlands" and deliberately flooding selected areas after heavy rain, then a new short animated film gives the clearest explanation that I've seen so far.
The film is mostly about reducing flood risk - not necessarily threatening areas anywhere near where the measures are being taken. For instance, the extensive work that was carried out a few years ago to dam the Salmons Brook at Cheyne Walk open space was designed to prevent flooding in areas further east, in Edmonton. The work has reduced the flood risk to more than 2,500 homes. And because of climate change, the frequency of extremely heavy rain is increasing. But the same measures also clean the water - see below.
While the Cheyne Walk open space project involved civil engineering and concrete, Thames 21 and its partners are about to start work on a new "natural flood management" scheme to further reduce problems downstream along the Salmons Brook. This involves working with nature rather than trying to overcome it - using and enhancing the natural landscape’s ability to store and slow flood waters. Depending on the local area, that could involve planting trees, reducing soil compaction, creating wetlands or leaky dams. The Salmons Brook NFM project will concentrate on the upper, higher area of the Salmons Brook catchment: north of Enfield Road, through Trent Park and as far as the Ridgeway Road, where there is a large amount of agricultural and park land. This includes the Merryhills Brook and the Leeging Beech Gutter.
Why "Thames 21"? Because we're in the 21st century and because another advantage of slowing down and filtering water flow is that it helps remove impurities, such as the particles of rubber from tyres and diesel exhausts that cars leave behind on roads and is washed into drains and streams. The water in the Salmons Brook, Pymmes Brook and other local streams goes into the Lee and eventually into the Thames at Limehouse, taking with it pollution picked up along the way. So Thames 21's ultimate role is to clean up the Thames.
You can read about this in more detail at the links below and help with the work yourself, since much of the work will be small-scale and carried out using volunteers.
