Yorkshire Water’s storm overflow programme kicks off in York (1)

Yorkshire Water has begun its first storm overflow project in York to reduce discharges into watercourses in the area, as part of a £1.5bn wider programme of investment by April 2030. 

The £870,000 project at York Landing Lane combined sewer overflow (CSO) includes the replacement of the existing storm overflow chamber with a larger one, as well as the installation of screens to reduce the likelihood of sewer debris entering the river during a discharge. 

Once completed, the project will reduce discharges to the River Ouse from York Landing Lane CSO by 49%, helping to improve the water quality in the river. 

The additional capacity will enable more excess wastewater to be held back during periods of bad weather, preventing it from being discharged. Flows will be sent for treatment when capacity in the network has returned to normal levels. 

Yorkshire Water is currently planning several further storm overflow projects in the York area. 

Louise Wright, project manager at Yorkshire Water, said: “Our storm overflows are operating more than we, and our customers, would like, and we’re committed to reducing the number of discharges taking place. We’re happy to be getting underway with our York programme, which will see the number of discharges from York Landing Lane reduced by 49%.” 

Contract partners Ward and Burke are expected to take around ten months to complete the project at York Landing Lane, which is taking place on Yorkshire Water land. 

The £1.5bn Yorkshire-wide storm overflow investment programme, which will see improvements at over 450 overflows, follows a £180m investment over the previous two years that helped reduce discharges to watercourses by 12% in 2024 from 2023, and by a further 24.5% in 2025. 

Whilst York Landing Lane marks the first scheme in York, there are already many schemes taking place in Leeds, Bradford, Calderdale, Sheffield, Barnsley, and across North Yorkshire. 

Storm overflows are designed to act 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 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 £8.3bn investment into its services and the environment over the next five years.