Wessex Water starts up nature-based storm protection plan for Salisbury waterways

Wessex Water has embarked on a £500,000 series of projects in Wiltshire to expand nature-based methods used in protecting some of the most precious waterways near the city of Salisbury from storm impacts.

The water company is trialling small projects to support the drive to reduce the knock-on impact of excessive groundwater on the nearby environment. It has dug so-called bio-swales of varying sizes at four rural water recycling centres around the city, then lined them to prevent contamination and split into cells.

Wessex has layered the Swales with soil and planted them with species accustomed to growing in water to improve the quality of the water before it discharges into a watercourse. After a storm, any overflows from the storm storage tanks at the sites will pass through the swales, where the plants and micro-organisms in the soil get to work to improve the water quality.

Three sites have already been planted, with a fourth currently being completed this month.The bio-swales will be fully commissioned once the plants have been allowed to mature for several months to ensure their roots are strong enough to deal with storm water overflows.

Senior environmental scientist, Lorraine Isgar said: “We’re hopeful that all of these will specifically address storm water overflows in areas where there is high groundwater infiltration and sample monitoring of them will continue to help with the design of future projects.

“Wetlands schemes are also being planned in collaboration with Wiltshire Wildlife Trust and other community groups.”