Requirement

A series of gabion walls lining Bonaly Burn below the Edinburgh ring road had progressively failed due to scour below the baskets and growth of vegetation, including small trees through the installation.

A greened solution was sought by the local council and, with the support of Greenfix the designers, Amey, specified Envirolok® MSE vegetated bags as the preferred option.

The South bank was replaced over Christmas 2018 as the adjacent footpath needed to be closed to the public and the Burn diverted during the course of the works.

Project details

The existing gabions and loose stone were removed, and the bed levelled and prepared for the Envirolok bags. The initial layers comprised of gravel-filled bags to provide a strong base for the wall. The upper courses were a mix of soil/sand and seeded internally. A double row of bags was employed to support the footpath and a wooden rail fence added for security.

The Envirolok bags were specified as access to the site was restricted with all plant and materials being craned from the Edinburgh ring road above. They also conformed to the bend in the watercourse and to the variable angles of the embankment.

Outcome

The contractor, using the product for the first time, described the installation as smooth and hitch-free with works completed on time. The North bank will be replaced during the summer of 2019.