Major Stabilisation Works Delivered at Dillavaird Following Landslide

MAM Contracting is pleased to announce the successful completion and handover of the retaining wall reconstruction project on the C421, adjacent to the historic Bridge of Dillavaird. The works follow the failure of a masonry retaining wall caused by a landslide in 2023 at this environmentally sensitive and heritage-rich location on the boundary between Perth and Kinross Council and Angus Council.

The Bridge of Dillavaird, constructed around 1850 and recognised as a listed structure, spans the River Isla approximately 23 miles north-east of Perth. While the bridge itself remained unaffected by the landslip, the adjacent retaining wall required a full reconstruction to restore stability to the road corridor and safeguard the long-term condition of the surrounding landscape.

The completed works involved the construction of a new retaining structure immediately beside the bridge to replace the failed wall. MAM Contracting undertook a carefully planned sequence of engineering operations, including the installation of piled foundations, a reinforced concrete capping beam, ground anchors and a reinforced soil retaining wall. This modern, engineered solution has been designed to provide long-term resilience while respecting the site's historical significance.

Before construction, extensive ecological surveys were carried out to identify breeding birds, otters and beavers. Where necessary, environmental protection measures were implemented and maintained throughout the works. Pollution prevention controls and surface water management systems were also established from the outset to ensure the River Isla and its surrounding habitats were fully protected.

Temporary works, including a batter slope and construction bench, were installed to safely facilitate the build process. With the new retaining wall now in place, the surrounding slope has been reinstated to align with the natural topography. The C421 road surface and drainage gully have also been fully reinstated, and a new vehicle restraint system has been installed along the route to enhance road-user safety.

Upon completion of the main engineering activities, MAM Contracting undertook the full reinstatement and revegetation of the works area, including the removal of ecological and pollution protection systems. The project has now been formally handed over to the client.

The Dillavaird project showcases MAM Contracting’s expertise in delivering complex engineering works in environmentally sensitive locations and near heritage assets. Through a combination of technical precision, environmental stewardship and collaborative project management, the company has restored stability to this important section of the C421 while preserving the historic character of the Bridge of Dillavaird.