Southern Water is progressing work on £170 million investment in a storm overflow reduction scheme to improve water quality in Portsmouth Harbour.

The water company’s Clean Rivers and Seas Task Force is surveying sewers across Portsmouth city, Gosport and Fareham for improvements.

The major scheme is part of Southern Water’s £1.5 billion Clean Rivers and Seas Plan to tackle storm overflows and follows on from other projects going live in locations across Hampshire, Kent, Sussex and the Isle of Wight – but on a much larger scale.

The work that Southern Water is focusing on for Portsmouth Harbour includes:

• Introducing a range of sustainable drainage schemes (known as SuDS), like raingardens, swales and permeable surfaces to slow the flow of rain into sewers
• Installing hundreds of slow draining and smart water butts on homes, businesses and public buildings
• Tackling the impact of surface water run-off from roofs, through disconnecting downpipes which are incorrectly plumbed into sewers
• Upgrading pumping stations and treatment works so they can better cope with high volumes of flows
• Teaming up with partner organisations, groups, businesses and schools to come up with solutions, including the ‘greening’ of roads

Project manager Keith Herbert from Southern Water’s Task Force, said:

“This is a big moment for our Task Force as we embark on one of our biggest storm overflow reduction projects anywhere in the UK - to cut storm overflows into Portsmouth Harbour, and work with our partners to overhaul how our sewer network is viewed and how it works in this area.

“If water companies only had to treat wastewater, there would not be the need for storm overflows at all. Our strategy is to stop this extra water from getting into our pipes, or use nature-based solutions to slow down the flow, so that we can keep our sewers moving and protect our precious coastline.”