Southern Water launches new storm overflow reduction pilot for Chichester Harbour

The West Sussex village of Bosham has been announced as Southern Water’s latest pilot project in rolling out innovative nature-based and engineering solutions to cut storm overflows.

It is now the seventh scheme led by the company’s Clean Rivers and Seas Task Force, taking learning from existing successful pilots in Kent, Hampshire and the Isle of Wight.

Bosham, looking out onto Chichester Harbour, is heavily impacted by groundwater in wetter months, and this can lead to private pipes and Southern Water’s network being overloaded.

This new pilot project will seek to address that challenge by using tried-and-tested techniques used in the Pan Parishes of Hampshire, near Andover.

The project will include:

• Relining and sealing up to 9.9km of sewer in nearby Funtington – with more than 1.5km of this to be completed over the next year
• Building a new wetland scheme close to Bosham Wastewater Treatment Works by summer 2027
• Sealing private pipes where required to reduce infiltration into our sewer network 

The announcement of this new pilot comes after Southern Water received government backing for an extra £10 million of spending over the next year to tackle storm overflows, before the company plans to enact its £1.5bn Clean Rivers and Seas Plan from 2025, with some of this money contributing to the project.

Task Force Delivery Lead for Bosham, Joff Edevane, said: “We’re really excited to begin work on another pilot that will make a real difference to reducing storm overflows in and around Chichester Harbour.

“We know that this area of our region suffers with significant groundwater challenges, so we are keen to employ a mixture of approaches that have proven successful elsewhere to tackle this problem and reduce storm overflows. We are looking forward to working closely with the local community during these efforts, for the benefit of customers and the local environment.”