Southern Water says early progress has been made in reducing storm overflow releases as part of its £1.5billion Clean Rivers and Seas Plan, with significant investment already delivered across Hampshire and the Isle of Wight.
The water company says more than 700 storm overflow releases have been prevented in the past 12 months through a combination of infrastructure upgrades, sustainable drainage schemes and new technology.
Across Hampshire and the Isle of Wight, Southern Water plans to invest £341million over the next 5 years to reduce discharges from almost 100 storm overflows.
More than £70million has already been spent on a range of improvements, including environmentally focused projects and the use of artificial intelligence to better manage the sewer network. According to the company, work has already been carried out at 95 of the most environmentally sensitive overflows, with 29 projects brought forward ahead of schedule.
Several projects have already been completed or are underway on the Isle of Wight, aimed at preventing storm overflows and increasing the capacity of the sewer network.
In Cowes, pipework upgrades and the installation of smart sewer gates have prevented 57 storm overflow releases. Meanwhile in Newport, unused storm ditches have been brought back into use to provide temporary storage during periods of heavy rainfall.
Upgrades have also been carried out at Appley Pumping Station in Ryde, where the facility has been reconfigured to significantly increase its storage and processing capacity. Storage has increased from around 900 cubic metres to more than 4,000 cubic metres, while the station’s ability to process wastewater has more than doubled from around 110 litres per second to over 240 litres per second.
Elsewhere on the Isle of Wight, sustainable drainage measures have been introduced including a SuDS ‘safari’ at Wildheart Animal Sanctuary, designed to process around 475,000 litres of water each year.
Southern Water has also installed more than 4,000 water butts, 200 rain garden planters and 6 permeable paving driveways. The company says it has also stopped rainwater entering the combined sewer system from 175 large roofs, including at 6 schools and businesses.
Further investigations are due to begin across the Isle of Wight from April 2026 as the company looks to identify additional improvements to help meet regulatory targets set for 2035. These could include separating surface water from sewers, sealing groundwater and tidal infiltration and upgrading treatment works.
Nick Mills, Director of Environment and Innovation at Southern Water, has said:
“We’re on a really exciting journey to create cleaner rivers and seas for everyone in our region. Preventing more than 700 releases in the first year is a clear sign that our approach is working – and we’re now scaling up resources, accelerating projects and expanding our partnerships to go even further, faster.
“This is one of the most complex environmental challenges of our time, made harder by climate change, heavier rainfall and a growing population. But we’re determined to meet it head-on. By working closely with local authorities, communities and partners across the South, we can deliver the healthier waterways and coastal environments our customers expect and deserve.”
Southern Water says its Clean Rivers and Seas Plan builds on 2 years of £45million Pathfinder Projects, including work on the Isle of Wight, which tested methods such as sustainable drainage and network optimisation to reduce storm overflows.
These improvements should have been done years ago !