The £2.6 million scheme to build a new 460m³ storage tank at Butterthwaite Road, in the Ecclesfield area will build additional storage capacity to the network, holding excess water during periods of prolonged and heavy rainfall.

Flows will be sent for treatment when the network capacity has returned to normal levels. On completion it should result an 83% reduction or fewer than 10 storm spills a year, going into Blackburn Brook from Butterthwaite Road combined Sewer overflow (CSO).

Lexie Thubron, project manager, said:

“Project partners Ward & Burke will be delivering the scheme starting on site on Monday 2 February. This project is one of 92 storm discharge reduction projects across South Yorkshire over the next five years, including seven identified in Sheffield.

“We know that reducing the reducing the number of storm discharges going into local watercourses after heavy rainfall is a really important matter to our customers and Yorkshire Water is investing over £1.5bn to tackle this over the next five years. This follows a £180m investment over the previous two years, which helped reduce discharges to watercourses by 12% in 2024, compared to 2023.

Storm overflows are designed to function as a relief valve for the combined sewer network, which carries both wastewater and surface water, during periods of heavy or prolonged rainfall. They discharge when the system is at capacity to prevent flows backing up and flooding homes and gardens.

Across Yorkshire, the water company said the need for storm overflows to operate will be reduced by building new:

Surface water sewers, to separate surface water and wastewater so that wastewater networks aren’t impacted by bad weather

Underground storage tanks, to build additional capacity into the network

Nature-based solutions, to build additional capacity into the network

Sustainable drainage systems, to slow the flow of surface water into the combined network

The storm overflow project is part of Yorkshire Water’s £8.3 billion AMP8 investment in its services and the environment over the next five years.

Construction starts on site in February 2026 and is expected to take up to 12 months to complete.