Yorkshire Water has begun digging under the A65 using a remote-controlled tunnelling machine as part of a scheme to reduce sewage discharges into the river Wharfe during periods of bad weather.

Once completed in January 2024, the new sewer will reduce the frequency of discharges from Rivadale CSO by 40% and halve the volume of discharges.

Trenchless technology will be used 5-8 metres underground, with boring machinery controlled remotely to keep disruption to a minimum while laying 800 metres of new sewer.

This reduces the need to close the road as it lays pipework behind it and sends the earth back to the staging site where it is cleaned and recycled for use in other projects in the area.

Ben Roche, director of wastewater at Yorkshire Water, said:

“This project, which forms a major part of our investment in Ilkley, is progressing well and we’re pleased to begin tunnelling today.

“Using trenchless technology will enable us to bore under the A65 and lay the sewer remotely, significantly reducing disruption in Ilkley. For most of the project, there will be limited signs of our activity underground.

“Laying a new sewer to accommodate higher flows of wastewater during periods of heavy and prolonged rainfall will ultimately reduce the number and volume of discharges from Rivadale CSO, helping to improve water quality in the Wharfe.

The water company, which serves over 5 million customers and 140,000 businesses, said the project is expected to be completed in January 2024.