The constructed wetland at Cromhall Water Recycling Centre offers a prime habitat for birds, invertebrates and other wildlife – while also providing a sustainable method of treating waste water by removing phosphorus.
We're taking action to reduce phosphate levels, which come from sewage treatment as well as other sources like agriculture and urban run-off, and the Cromhall project offers a natural approach that delivers wider environmental benefits.
Connected to Tortworth Brook, it was built over 12 months and offers thousands of native wetland plants to numerous species of birds, amphibians, insects and more.
The project was highly commended in the RTPI Awards for Planning Excellence and is being monitored by a research team at the University of Bristol, while Wessex Water is trialling similar wetlands and woodlands across its region as part of the government’s green recovery initiative.
Ruth Barden, Wessex Water’s director of environmental strategy, explained: “Too much phosphorus in rivers can lead to excessive algae growth and reduced oxygen levels, upsetting the delicate balance of life and primarily affecting invertebrates and fish.
“Instead of using expensive chemical treatment and excess energy to remove it, our wetland acts as a filter by using plants in cells which will preferentially use phosphorus in their growth.
“The Cromhall Water Recycling Centre integrated constructed wetland project also involves the Wildfowl and Wetlands Trust, Environment Agency, Tortworth Estate and Bristol Avon Rivers Trust.”
Wessex Water is investing record amounts in upgrading its treatment works to improve river water quality, as well as reducing the amount of water it extracts from rivers and catchments to keep flows sufficient for ecology and habitats to thrive.
The company is also monitoring three quarters of storm overflows in its region, rising to 100 percent by 2023, to gain a better understanding of when they operate and their impact on river water quality.