Work underway to cut storm overflows and protect Chichester Harbour
Our teams are making good progress on two major storm overflow reduction schemes on the Hampshire and West Sussex border.
Replumbing roads and finding solutions to reduce storm overflows
The projects, covering the communities of Bosham, Emsworth, Nutbourne, and Southbourne, are utilising a mix of innovative engineering solutions to reduce the amount of rainwater entering sewers.
This will help cut storm overflow releases and improve water quality in Chichester Harbour.
Teams are currently on the ground in Gordon Road, Emsworth, installing a new surface water sewer. This involves separating roof drainage from the foul sewer so that rainwater flows into the new surface water system instead.
By reducing the volume of water entering the combined sewer, these works will help prevent storm overflows. More than 40 homes at Gordon Road have already engaged with us and agreed to have this work carried out. We expect this work to be finished at the end of the month. Similar projects are planned across the area over the next two years.
Reducing Overflows at Chichester Harbour
Work in Bosham started in 2024, where investigations and initial improvements have already taken place. Now, work has just started in Emsworth as part of the wider Thornham storm overflow reduction scheme.
We are currently sealing public and private sewers in the Nutbourne area preventing ground water infiltration into the wastewater network reducing the impact on the school lane pumping station.
This investment forms part of our £1.5bn Clean Rivers and Seas Plan, which aims to drastically cut storm overflow releases and protect the environment across Hampshire, Kent, Sussex, and the Isle of Wight.
Efforts in Chichester Harbour are a key part of our role in the Three Harbours Partnership – alongside Langstone and Pagham – where organisations are working together to protect and enhance these precious environments, focusing on water quality, carbon capture, and biodiversity.
Other actions to help improve water quality in Chichester Harbour are our sewer sealing projects across the Lavant Valley, covering West Dean, East Dean, Singleton and Charlton and creating a wetlands at Lavant Wastewater Treatment Works and upgrading the works. The wetland at Lavant treats around 280 storm overflows per year.
Glenn McCubbin, Pathfinder engineer from Southern Water, said:
“We’re absolutely committed to reducing storm overflows and improving water quality at Chichester Harbour. These schemes in Bosham and Emsworth are a great example of how we’re implementing a range of solutions – from separating surface water from foul sewers to upgrading infrastructure – to make a real difference.
"Just as importantly, we’re keen to work closely with local communities throughout this process. Their engagement and support are vital, and we’ll continue to listen and collaborate to ensure these projects deliver long-term environmental benefits."