Application of an innovative, low-maintenance weir to protect against debris flows and floods in Ottone, Italy

The need of a low-maintenance and easy-applicable apparatus against debris flow led Maccaferri Innovation Center and the Politecnico of Milan to a new hydraulic-based approach that was focused on the application of a special weir called Mini Skirt Check Dam (MSCD). After a three-years research on applicable equations, a construction site in Ottone (Italy) was identified to have been affected by destructive debris flow in the past years. The site is characterized by the presence of an underground pipe that collects the stream flow rate flowing under the village square. The purpose of this work is to design a MSCD, able to prevent a pressure driven flow in the underground pipe and to avoid the related risk for the inhabitant of the village. MSCD is a special weir, which consists in large wings to slow the flow and a ring net to block boulders and logs, as to become a sifting filter of the debris. As to design the best performing apparatus, materials and type of anchoring are crucial; for this reason, an analysis of the impact pressure was performed. The case study has considered several different aspects: hydrology, size of the material and its characteristics and previous events to have a complete analysis of what could happen in the next events. The result of this collaboration is the complete design of a MSCD, ready to be installed.