Southern Water to spend £3m to seal sewers in two West Sussex villages

Southern Water teams will be carefully sealing sewers and manhole covers in Charlton and Singleton, in the Lavant Valley, to keep groundwater out of our wastewater pipes during rainy periods.

This £3.3m project follows the completion of a £1.1m project to seal sewers in the neighbouring village of East Dean in 2024, and is similar to work continuing in nearby Funtington and Bosham.

Historically, this area suffers badly with a build-up of groundwater during the wetter months of the year, and when this seeps into our network it can overload the system.

This can cause flash flooding locally, and also trigger storm overflows further down the valley and into Chichester Harbour when the influx of water is too much for our treatment sites and pumping stations to handle – requiring releases into the environment to prevent more homes and communities from flooding.

Once work is complete in Singleton and Charlton, Southern Water teams will continue to work their way down the Lavant Valley.

Joff Edevane, Pathfinder Delivery Lead for Southern Water, said:

“The work we have been doing across the Lavant Valley is already beginning to make a big difference in making sure our network is protected from the impacts of groundwater. We’re excited to begin work in two new villages which will help protect communities and also help to reduce storm overflows and reduce reliance on tankers when our network is under pressure.”

Customers in this area will notice an increase of activity over the coming weeks and we’re sorry for the disruption these works will cause.

What is groundwater?

Simply put, groundwater is water that is stored beneath the ground. When it rains, water runs into our streams and rivers and soaks into the soil, which acts like a big sponge. Some of this water is used up by plants and some is returned into the atmosphere through transpiration.

Some also makes its way further into the ground permeating through soil and rock and becomes groundwater and part of the water table. There it is stored underground in a layer of porous rock or sediment - known as an aquifer. How does groundwater affect our network?

When groundwater makes its way into the sewer network, we’re met with more challenges. Our sewers were only built to cope with wastewater and can quickly become overwhelmed. Excess groundwater can meander into private pipes, meaning less room for wastewater, leaving our network under immense amounts of pressure.

In the worst-case scenario when this happens, we use tankers to take excess water out of the sewers and treat it at our sites. This reduces the pressure on our network and the risk of foul sewer flooding. However, this is only a short-term, emergency solution.

To find out more about how groundwater impacts our network visit Groundwater Levels - Southern Water