South West Water has reduced storm overflow spills at a site near Lyme Regis after completing work to upgrade over 700 metres of sewer.
Uplyme Sewage Treatment Works saw storm overflow spills drop by 20% in 2025 compared to the previous year after engineers prevented groundwater that exists underground in cracks and spaces in soil, sand and rock from entering the sewers through pipe joints and manholes.
This water was flowing into the treatment works via the sewers, causing more water to enter the system than it was designed to take.
When wet weather hits villages like Uplyme, this water can overwhelm the sewer network, leading to spills from storm overflows.
South West Water’s engineers carried out CCTV surveys of the pipes to identify which sections were affected by this infiltration and installed a protective lining to 737 metres of sewer in the area.
This special lining is cured inside the sewer to create a watertight seal so no groundwater can enter the network.
Repairs were also carried out across the local network, including upgrades to 28 manholes.
Jenny Eamer, South West Water’s Operations Manager for Uplyme, said: “The work we’ve done in Uplyme is another great example of how targeted investment and the hard work of our teams is delivering real results in communities.
"Groundwater infiltration is something you can’t see on the surface but it has a real impact on our systems, especially during wet weather. By relining pipes and sealing manholes, we’re keeping groundwater out of the network, and as a result we’ve reduced spills and protected the environment."
Uplyme formed part of South West Water’s £16 million Infiltration Reduction Programme, which targeted 175 high-risk sites after reviewing performance across more than 1,600 storm overflows.
Further improvements are planned for Lyme Regis, with South West Water investing around £11m to install three new storm tanks in the area, to hold a combined 670,000 litres of additional storm storage.
Work is due to begin this September and will also include surface water separation works to further reduce the amount of rainwater entering the sewer network.
For more information about the work South West Water is doing in Lyme Regis visit www.southwestwater.co.uk/about-us/what-we-do/engineering-projects/wastewater/lyme-regis