17. Tottenham Floating Reedbeds
Themes: Water quality; Biodiversity
Objectives:
- Reduce the frequency and severity of pollution
- Improve riverine and riparian habitat
Project description
Floating ecosystem designed to reduce pollution and provide habitat.
In 2012 Thames21 commissioned a report to identify sites on the Lea Navigation where new reedbeds could be installed. Reedbeds are important habitats for wildlife and a refuge for fish. Furthermore they breakdown pollutants in a watercourse, thereby improving water quality.
This site on the Lea Navigation near Tottenham Lock is considered the most polluted section of the Lea Navigation; at this point the Pymmes Brook enters the Lea Navigation, various studies undertaken by the Environment Agency, a number of Universities and Thames21 have identified this water to contain a very high nutrient load and has a history of severe pollution incidents.
At this location the water is very deep, making it unsuitable to install a traditional reedbed. A 70 metre floating ecosystemhas been chosen for this site; this installation will float on top of the fluctuating water levels and has been built to last at least 25 years and is able to withstand impacts from boats. Below the surface the root mass will hang into the water providing maximum surface area for pollution to be broken down. Additionally media (that looks like a feather duster!)will be attached to the underside to provide further surface area for microbes to colonise, for these too break down pollutants.