Ground conditions, ground movement and any changes to groundwater levels associated with tunnelling will be monitored using real-time TBM data, specialised equipment and visual inspections of excavated material.

Extra checks will be completed ahead of tunnelling where potentially poorer ground conditions are identified, surveys will be completed to inspect the condition of the tunnel lining, and there will be monitoring points on nearby footpaths and buildings using specialised equipment.

By continuously monitoring conditions, potential issues will be quickly addressed to ensure the surrounding area is safe.