A 5,600 m2 living biofilter in the form of 31 Floating Ecosystems is being installed across three lakes at Witches Oak in Derbyshire. The project is a part of Severn Trent Water’s Green recovery programme, under the decarbonising water resources workstream.  The 31 Floating Ecosystems are installed in an array across the gravel pit lakes, which will form a nature-based solution to help pre-treat flows of average 65 million m3/day (65ML/d). The water then heads for the new Witches Oak Water Treatment Works, where it will receive further treatment with ceramic membranes. This combined approach represents an innovative and eco-friendly model focused on reducing energy consumption and chemical usage in the water treatment process. It is the first time a UK company has used this type of nature-based floating pre-treatment.

Water will be drawn from the River Trent through the three lakes in series. The lakes are disused gravel pits and currently have limited existing shallow wetland areas. The new Biomatrix Floating Ecosystems have been planted with over 60,000 native aquatic plants to form a living biofilter powered by photosynthesis and the natural complex biological food chains that wetland ecosystems provide. The project is being delivered for Severn Trent Water with  Mott McDonald Bentley as the principal contractor and Biomatrix Water as the specialist Floating Ecosystem provider.

The 31 new ecosystems are designed in natural islands shapes of three sizes, 33m*10.5m, 27m*8m and 21m*8m. They utilise Biomatrix Water’s patented 5D Floating Ecosystem technology, which biomimics natural riparian substrates to form a robust infrastructure grade floating ecosystem structure, supporting nature to do what it does best.

As we seek a more symbiotic relationship with nature, projects like this one help to advance our scientific understanding of ecological process and their capacity to benefit people by restoring and enhancing natural systems. We observe that Floating Ecosystems, and the unique suspended root zone habitat they provide, have the capacity to effect larger water bodies beyond the direct area of the wetlands themselves. The high surface areas of plant roots, which are naturally adapted to absorb nutrients and to form beneficial relationships with micro-animals like zooplankton, support complex food chains with an increased biological metabolism and ability to transform nutrients and other pollutants in the water body.