A £2 million project to reduce the flooding risk to homes in Chippenham and protect the River Avon running through the town has been completed.
The work, which saw a 10-metre-deep storage tank sunk below ground on land in the east of the town to add extra capacity to the sewer network, has been wrapped up, preventing the system from being overwhelmed and potentially discharging on to nearby properties.
Testing and commissioning of the 250,000-litre tank, which is sited next to Long Close and will play a vital role towards reducing times when high volumes of rainwater cause storm overflows to operate automatically to relieve pressure on the system, will continue to the end of the month.
More than 200 metres of gravity sewer and nearly 300 metres of rising main were also installed within roads in the area, including London Road, Black Cross and Long Close during the project, which got under way last July.
Project manager Paul Delves said: “This was an important project to help diminish the threat of sewers becoming overloaded in this area of Chippenham and potentially flooding nearby properties.
“The additional storage will help the sewer network’s ability to withstand the arrival of large volumes of water in a short space of time, such as during a heavy storm.
“This stormwater mixes in the sewer with the foul water from homes and businesses and can also cause overflows to operate, but by retaining it in the tank, it can be returned to the sewer later, prior to being piped to a water recycling centre for treatment.’’
The project team worked closely with the local community before and during the work, sending thousands of letters to local customers and meeting them face-to-face at community drop-in session in the town.
The company also met and liaised with local businesses, councillors, schools and organisations, as well as working closely with Wiltshire Council to manage the programme of road closures and traffic measures associated with the project.
“We worked hard to minimise the impact on the local community and we would like to thank them for their patience, co-operation and understanding while we completed this essential scheme,’’ added project manager Paul Delves.
The Long Close project continues Wessex Water’s commitment towards reducing the impact of storm overflows on the environment, with similar River Avon work having taken place in Hanham near Bristol, Bradford on Avon in Wiltshire and Lambridge, in the east of Bath, as well as Saltford.
Wessex Water’s work to progressively and substantially reduce the discharge of untreated wastewater is continuing over the coming years too, with plans for 2025-30 outlining a £580 million investment – more than double the current figure – to reduce the operation of storm overflows, introducing more nature-based solutions and promoting better rainwater management.
The company has asked the Competition and Markets Authority (CMA) to review how much it can invest in vital water and sewerage improvements over the next five years.
This comes after the industry regulator Ofwat’s final determination on Wessex Water’s five-year business plan allowed for £4.2 billion of total expenditure – 17% short of what the company’s own calculations have shown are required to meet its obligations and customers’ expectations, and support growth in the region.
