The project, which is being completed by Ward & Burke, will see the creation of 19.5m3 of additional storage in the sewer network upstream of the storm overflow by installing a weir chamber and box culvert.

The new storage and upstream pipework will hold almost 20,000 litres of wastewater during periods of heavy and prolonged rainfall, reducing the number of times this is discharged into the watercourse.

Once completed, the project will reduce discharges from Bleakley Lane combined sewer overflow, into Owler Beck, to less than 10 per year on average. Work is due to start on 20 July and is expected to be completed in December 2026.

Yorkshire Water project manager, Wayne Cocksedge, said:

“We’re currently investing £1.5bn across the region to reduce the number of sewage discharges into Yorkshire’s rivers and seas. This is vital work that we know is very important to our customers.

“We’re pleased to be getting underway with our work at the Bleakley Lane CSO as this will make a significant difference to the number of discharges into Owler Beck from this site.

The project follows a £4.8 million investment to reduce storm overflows into Applehaigh Beck and Hessle Beck from Notton CSO in 2025. The project, completed in mid 2025, reduced discharges by 50% in 2025 when compared to the previous year, with further reductions expected in 2026.