The western side of Calabria, in southern Italy, is characterized by strongly altered orthogneiss outcrops, which give rise to fine and coarse sands. With heavy rainfalls, they are brought down to the valley and channeled into the famous "fiumare".
This phenomenon is particularly intense in the area of Favazzina, along the River Scirò. There it threatens the railway network, the national highway SS18, and the local road network.
A series of Geobrugg barriers have been installed to limit the risk of debris flows . This deterrent system for debris flows was developed by Geobrugg with the Swiss research institute WSL in Birmensdorf, part of the Swiss Federal Institute of Technology Zurich (ETH), following the field trials in Illgraben, Switzerland. Also check Illgraben on YouTube.
The system consists of 19 barriers of various types: UX180, UX100 and VX100 of varying height from 4 to 6 meters, for a total of 970 square meters. All Geobrugg barriers are CE marked.
The week after the installation of the first barriers, a debris flow occurred. It was completely held back by the highest situated barrier, and thus saved and protected the downstream site. Subsequent events have filled the other barriers. After inspection, it was decided not to proceed with emptying in order not to trigger further landslide movements. The retained debris flow material stabilizes the banks of the channel and thus reduces the formation of further debris flow. Inspections also revealed the excellent condition of the post-event structure: no intervention on the barriers was necessary. Only some anchorages were slightly damaged. The braking system showed no deterioration.