Bath-based Wessex Water has unveiled plans to triple its investment in storm overflows as part of the water sector’s largest overhaul of the sewerage network since the Victorian era.
The water recycling centre at Saltford | Photo © Wessex Water
Wessex Water invested £69 million in the past year as part of efforts to protect rivers and beaches in the region.
This significant investment was part of measures to address the challenges posed by heavy rainfall and to mitigate the impact of storm overflows.
Currently, the water company spends approximately £3 million per month on improving storm overflows, which are designed to activate during or after heavy rain to prevent flooding of properties.
Wessex Water has also made substantial investments in advanced treatment methods at water recycling centres to remove phosphorus and other nutrients, thereby further enhancing river ecology.
However, the company aims to go even further by proposing to triple its investment, with plans to spend £9 million per month on additional improvements to storm overflows from 2025, subject to regulatory approval.
Matt Wheeldon, Wessex Water’s Director of Infrastructure Development, said: “We know our customers care passionately about protecting watercourses, whether or not they use them for swimming or recreation, and we share their passion.
“That’s why we’re investing unprecedented amounts to help improve river and coastal water quality, including reducing how often storm overflows operate and minimising the environmental impact of our treatment processes.”
Data from the Environment Agency indicates that storm overflows account for less than 1% of the factors contributing to rivers in the Wessex Water region not achieving good ecological status.
This is due to the heavy dilution of discharged water by rain or groundwater.
Progress has already been made, as overflow discharges decreased considerably in 2022 due to prolonged dry weather and the company’s investment in infrastructure upgrades.
Wessex Water says it recognises that water quality can be influenced by various sources, including wildlife and agricultural run-off.
In response, the company has collaborated with farmers on catchment partnerships to develop cost-effective solutions.
Mr Wheeldon said: “We would love to stop all storm overflow discharges immediately but unfortunately there is no quick fix – eliminating them completely would mean re-plumbing a sewerage system which has been built in this way for over 150 years.
“The solutions we’re rolling out include separating out rainwater to stop it entering sewers and constructing large storage tanks to contain the combined rain and sewage for later treatment.
“Beyond this, we have further plans for nature-based solutions such as natural wetlands and reed beds.
“It is vital that regulators support these schemes to help reduce carbon impacts, minimise bill rises for customers and greatly improve river water quality.”
To enhance transparency and meet the demand for more information from river users, Wessex Water developed an Artificial Intelligence (AI)-powered mobile application.
The app utilises data from sensors installed in bathing and recreational waters to predict bacteria levels, providing real-time water quality information to the public.
The company has already implemented the AI app at locations such as Warleigh Weir near Bath and Baltic Wharf in Bristol, where water quality forecasts are provided for shellfishery and recreational businesses.
Wessex Water is also working with local authorities and community groups to extend the app’s coverage to more than 50 other popular river locations across the region.
This collaborative effort aims to provide comprehensive information on water quality, temperature, and river flow.
Over the past two decades, Wessex Water has upgraded nearly 600 storm overflows, and its ongoing investments are expected to reduce the operational hours of storm overflows by approximately 25% by 2025.
