Multimillion pound investment to tackle storm overflows

Wessex Water is investing £3 million a month to tackle storm overflows and reduce how often they operate.

  • Wessex Water is investing £3 million a month to tackle storm overflows, with work already underway.
  • Sewage treatment upgrades at 42 water recycling centres to increase capacity and with more nature-based, low carbon methods introduced.
  • A 25% reduction in the number of hours of storm overflow discharges by 2025.
  • Increased environmental and public health monitoring at key locations.
  • Use of artificial intelligence to manage sewerage network and provide real time bathing water information.

The company’s Storm Overflows Improvement Plan will see every overflow in the region monitored by 2023, while the number of hours storm overflows discharge will be reduced by 25%.

New storm tanks will be built; nature-based solutions, like wetlands and reed-beds in rural locations introduced; and work will be carried out to separate rainwater from the sewer system. There will also be continuing investment in artificial intelligence monitoring at wild swimming sites to provide near real time information. A WebApp for Warleigh Weir, near Bath, is already being tested.

Capacity is being increased at the company’s two largest water recycling centres, serving Bristol and Bournemouth, to enable more stormwater to be stored and treated, with work due to start early next year.

Storm overflows have always been part of the UK’s sewerage network because most sewers carry both rainwater and foul sewage. The overflows prevent contaminated rainwater backing up and flooding people’s homes. Published river water quality data shows their impact on the water environment is minimal because of the significant dilution during rainfall. All overflows are licensed by the Environment Agency and rarely cause pollution.

Matt Wheeldon, Director of Asset Strategy and Compliance said: “We understand the concerns about storm overflows and agree they should have no place in a 21st century sewerage system. This major investment is the start of decisive action to tackle storm overflows, and our longer-term improvement plan sets out the further progress we will make over the coming years.

“We have 1,300 overflows across the Wessex Water region, so it will take time and significant resources to eliminate them. By committing to spend £3 million every month on overflows, starting with those that discharge most frequently and those that have any environmental impact, we will make a good start.”

The Storm Overflows Improvement Plan has been shared with water industry regulator Ofwat and regional environmental groups.