Response from Southern Water
Our dedicated Clean Rivers and Seas Task Force are now in the final phase of our Pathfinder programme, which has determined the most effective ways to reduce storm overflow releases, and make sure we get the best results from our next investment cycle (2025-2030).
This year we’ll be scaling up our storm overflow reduction programme considerably, rolling out the most effective solutions from our pilots, including:
Optimisation: working on both public and private infrastructure to reduce infiltration and ensure it’s working as effectively as possible, as well as reconfiguring our permits and existing sites to help us manage more stormwater
Misconnections: redirecting surface water that’s been misconnected into the foul/combined sewer, which causes the system to become overwhelmed leading to storm overflow releases
Household sustainable drainage systems (SuDS): rolling out ‘slow the flow’ measures at scale on properties across our region to manage roof run-off
Non-household SuDS: targeting large roof areas and car parks with sustainable ‘slow the flow’ measures to significantly reduce surface water run-off
Highway schemes: large amounts of surface water come from public highways, so we’re working with local authorities to influence future designs and improvements to reduce their impact
Early results have been positive. Our sealing work in the Pan Parishes has put an end to noisy and disruptive tankers and over pumping, and a dual-approach upgrade in Cowes on the Isle of Wight has completely stopped storm overflow releases from the local outfall. We’ve optimised our Swalecliffe site to work more effectively, which has reduced storm overflow releases by 36%.
In another example, we’ve worked with the Department of Education to install SuDS, such as raingarden planters and swale drains in nearly 100 schools across the south, removing tonnes of rainwater from school sites every time it rains. The SuDS have managed over 117 million litres of rainwater and groundwater so far.
For further examples and to find out what the Task Force has been up to, please visit our Task Force webpage.
We can’t do it alone
With so much of the network being private and out of our jurisdiction, partnerships are vital for our planned improvements. We need our regulators, the Government, local authorities, and community groups to work together to better manage water in towns and cities. We’ll also need to work closely with customers and business owners, to install ‘slow the flow’ measures on their land.
If you want to find out how you can help slow the flow of rainwater getting into the system, please visit the how can I get involved pages on our website.