Bristol Water is trialliing floating wetlands to help improve water quality at its reservoirs.
The water company is creating tiny floating islands to help improve the water quality and look after wildlife at its Chew Valley Lake.
Bristol Water said the innovative approach with floating platforms improves water quality naturally while also creating a wildlife habitat.
Chew Valley Lake faces a problem with pollution - rain can wash fertilisers and other nutrients from nearby farms and towns into the lake.
To tackle this, Bristol Water is already working with local farmers to reduce the nutrients entering the lake. However more solutions are needed which is why the company is testing floating wetlands.
The floating wetlands cosist of plants growing on top of a raft and their roots hang down into the water. The roots absorb nutrients like phosphorus from the water, cleaning it naturally.
In March 2024, Bristol Water set up its first floating wetland in March 2024 at a part of the lake called Herriotts Mill Pool. The small raft measures 4m x 7m, about the size of two parking spaces, planted with native wetland plants. The plants will grow and help soak up the nutrients over time.
A bird guard around the wetland protects the young plants - the company has also built a separate nesting platform for larger birds, so they still have a place to rest and nest.
After seeing how the first wetland worked, Bristol Water installed a second, larger wetland in November 2024 at another part of the lake called Villice Bay.
The wetland includes some clever technology in the form of a a solar-powered pump that moves water through special bags filled with a material that traps phosphorus. Once the bags are full, they can be replaced and reused in farming to help grow crops.
By combining plants and technology, this new wetland can clean the water even more effectively.
The water company is monitoring both wetlands, testing how much phosphorus they remove and how they benefit wildlife. If they work well, more might be added to Chew Valley Lake and other other locations.