Interventions

The Commissioner Delegate had started up a series of operations, through the contractor Angelo Pepe, to channel the waters from the lakes and sources of water along the central part of the landslide, away from the landslide.
The purpose of these operations was to guarantee safe conditions for the work sites and to improve the overall conditions of the destabilized slope.
The works were carried out with the assistance of the DST-UNIFI, CNR-IRPI Operations Centres, Sannio University and the Foggia 11th Engineer Sapper Corps Regiment.

Job 1: altitude 500 m above sea level

At the altitude of 500 m above sea level the waters coming from the Schiamone River basin flowed directly into the central part of the landslide. A considerable part of the water in the central-terminal part of the landslide was eliminated by diverting these waters and channelling them valley-wards under controlled conditions. The works comprised: construction of an interception and retaining harness for the "Schiavone" stream waters, laying a water pipe (about 850m) to channel the waters towards River Cervaro and interception works to divert minor surface watercourses into the canal.
The typology of the works was established by the conditions of accessibility to the sites, time imposed by the events and above all by the necessity to avoid any interference between works at the work site and calamity in progress.
The works in fact served to mitigate the effects of the water circulating on the surface and just under the surface of the landslide to reduce the risk in the foot areas, where removal and profiling works were in progress to restore the communication network (railway and SS 90 main road).

Job 2: altitude 700 m above sea level
A drainage trench in gabions was dug to collect the waters from under the surface and those circulating on the surface and channel them towards the "Tre Confini" stream at a distance from the landslide.
The trench was positioned at an average depth of about 5 m from ground level and where the landslide canal has a reduced section, for geological reasons, and is at the right height for channelling the waters into the adjacent water basin. The water circulation above the landslide was partly restored and a considerable amount of the water flowing to feed the land on the move in the central-upper part of the slope was eliminated with these works.

Job 3: cleaning and repairing the "Laghetto delle rane" drainage canal
The works comprised deepening and re-profiling the canal, ablation of the pond and temporarily restoring the drainage canal to River Cervaro. The area also underwent forestry clearance works and dead vegetation was removed to allow the water to flow freely.
The waters coming from the water sources orographically to the left, which by running into a pond called "Laghetto delle rane" continually fed the land on the move, were deviated away from the landslide by these works

Job 4: Lake "Maggiore" siphon
To empty the landslide lake formed in a hollow (750 m above sea level) after the calamitous events, the Foggia 11th Engineer Sapper Corps Regiment built a system of siphons with light flyover pipes coming out in the "Tre confini" stream away from the landslide.

Job 5: horizontal drainage
Being impossible to use standard means for intercepting and draining the waters from the foot of the landslide in the area, sub-horizontal drainage holes were made with the “no-dig” method: through a drill leaving from undisturbed areas and crossing the central part of the landslide to connect up a special drain.