Construction on a £2 million project will help enhance the health of the River Avon in the UK, by reducing the impact of excessive rainwater entering sewers and unavoidably spilling into the river.

Installation of a large below-ground storage tank in the centre of Bradford on Avon has been completed, and was part of a seven-month scheme to reduce instances of diluted untreated wastewater being released into the river automatically through storm overflow channels. More than 160,000 litres of additional subterranean storage has been added.

The extra capacity will reduce the times the combined sewer system - which transfers both foul water from people’s homes and rainwater to a nearby water recycling centre for treatment - from overflowing to the river when there is a heavy storm. Instead, the new tank will store the water, allowing it to safely return to the sewer system and onwards for treatment once the storm has receded.

Teams from Wessex Water began the project in September 2023. It is one of 13 being prioritised by the company to tackle overflows that discharge into rivers most frequently, or that carry the most significant environmental impact.

Additional improvements saw a mechanical screen installed to prevent any larger solid material from being discharged without having first gone through treatment.

Wessex Water project manager Alex Aulds said, “We’re pleased to have completed construction work on time as part of our £3 million a month investment towards reducing the instances of storm overflows operating across our region.

"The main construction work has been finished and while our teams will continue to commission and test the new system throughout the summer.

The Bradford on Avon scheme is one of several similar projects in progress or in planning to help improve the health of the River Avon and reduce the discharge of untreated wastewater. A storage tank project in Hanham near Bristol is nearly complete, with one already in place near the city of Bath that was finished last year.

Nearly 100 improvement projects are taking place across in Bath, Bristol, Dorset, Somerset, South Gloucestershire and Wiltshire before 2025 as part of the company’s Storm Overflows Improvement Plan. Proposals to invest a record £400 million towards the goal of reducing overflow operation in its next five-year investment period between 2025 and 2030, subject to approval by industry regulators, have also been unveiled, with a decision expected later this year.