£1-4m investment to further reduce storm overflows into river Wharfe

Yorkshire Water is planning to invest £1.4m in Ilkley and Ben Rhydding to reduce the number of discharges into the river, helping to improve water quality. 

The projects, which are being carried out by Mott MacDonald Bentley, are part of a £180m investment project across Yorkshire by the end of April 2025 to reduce discharges from storm overflows. 

Yorkshire Water’s projects will reduce discharges into the river Wharfe. They include: 

• £900k investment in Ben Rhydding to line 2.8km of sewer to prevent groundwater infiltration into the network to reduce flows in the sewers 
• £500k investment at Wyvil Crescent, Ilkley to separate surface water from wastewater to reduce the frequency and duration of overflows 

This work is separate to the accelerated investment in Ilkley and upstream of the bathing water which is due to commence later in 2024. 

The project in Ben Rhydding will begin in June, with 2.8km of sewer upstream of the treatment works being lined to reduce groundwater infiltration and reduce flows entering the sewer during periods of heavy and prolonged rainfall. Flow monitors have been used within the sewer network to identify the sections of sewer requiring additional lining work. 

By reducing groundwater infiltration, the flow of wastewater to Ben Rhydding wastewater treatment works will be reduced, cutting the frequency and duration of discharges to the river Wharfe. It is expected the project, once completed, will reduce discharges from the works by approximately 15%. 

Work will begin at Wyvil Crescent in July and Yorkshire Water’s partner Mott MacDonald Bentley will be installing five new manholes and constructing a new 300mm 130-metre surface water sewer. This will reduce the flows entering the storm overflow during periods of heavy or prolonged rainfall and enable surface water to be discharged to the Wharfe without entering the combined sewer network. It is expected that the surface water separation project will reduce discharges from the storm overflows by more than 50%. 

Mudassar Ahmed, senior project manager at Yorkshire Water, said: “Since the bathing water at Ilkley was designated, we have been working hard to play our part to improve water quality in the Wharfe. These projects will significantly reduce discharges into the river from Ben Rhydding wastewater treatment works and the overflow at Wyvil Crescent in Ilkley. 

“The projects follow work to construct a new sewer in Ilkley to reduce discharges from Rivadale storm overflow and the addition of UV treatment at Grassington, Beamsley and Draughton treatment works upstream of the bathing water. Further work is due to begin at Ilkley wastewater treatment works later this year as we continue to improve water quality in the Wharfe. 

“As well as this work, we are continuing to investigate storm overflows in the area and will be delivering further projects to reduce discharges into the Wharfe during periods of heavy and prolonged rainfall.”