M25 Drainage Improvements

Gill Civil delivered drainage improvement works on the M25 between Junction 23 and Junction 22 in the Catherine Bourne area. The project focused on increasing drainage outlet capacity by upgrading existing gully infrastructure. At each selected location, the existing single gully arrangement was replaced with a triple gully system, significantly increasing the capacity of surface water drainage. In total, 10 locations were upgraded along this section of the motorway.

All works were carried out during restricted night-time closures to minimise disruption to motorway users. Operational working hours were limited to a four-hour window from Monday to Friday nights, with the carriageway safely reopened to traffic each morning. The project required careful planning to manage potential risks including adverse weather conditions, complex existing infrastructure, buried utilities, and other adjacent highway assets. Detailed coordination and efficient sequencing ensured all activities were completed within the limited working windows.

Despite the operational constraints, the works were delivered safely and within budget. The upgraded triple gullies drainage systems significantly improved the surface water capacity of the carriageway, enhancing resilience during heavy rainfall and reducing the risk of water accumulation. The scheme was successfully completed ahead of schedule and within the agreed budget while maintaining safe and reliable motorway operations throughout the project.