Providing strategic solutions for a collection of innovative collaborative projects trialing new ways to reduce storm overflows

Clean Rivers and Seas Task Force – Pathfinder Projects

During heavy rain, sewer networks can be overwhelmed by the amount of water entering the system. When the tanks fill up, water companies use pressure relief valves known as storm overflows to stop homes and businesses from flooding. These overflows release excess water into rivers and the sea. Urbanisation and the effects of climate change are increasing the use of storm overflows, and this is becoming the focus of public scrutiny.

Southern Water, which provides clean water and wastewater services across Hampshire, Isle of Wight, Sussex, and Kent, recognised that to significantly reduce storm overflows they must develop local partnerships to identify and implement innovative infrastructure solutions. In response, Southern Water set up the Clean Rivers and Seas Task Force (with us as their strategic solutions partner) to deliver at least six Pathfinder projects by 2030. What’s a Pathfinder project? A framework to trial solutions that could significantly reduce storm overflows in communities. We provided catchment modelling and insight, programme and delivery support, regulatory engagement, and wetland strategy.

The partnership works to reduce the use of storm overflows and support a programme which helps reduce flooding and increase biodiversity. Other benefits of this programme include tree planting and the creation of more green spaces for residents. Southern Water is now applying lessons learned from the Pathfinder projects across new projects in each catchment.