Project 668/2021. SP 216 (Melezet). Hydraulic arrangement works at the confluence of the Frejus–Melezet–Rochemolles streams, including demolition and construction of the new bridge in the Municipality of Bardonecchia.

Project objective

The purpose of the document was to identify and assess the technical and economic solutions best suited to address the critical issues that emerged following the flood events of 13 August 2023 and, more recently, 30 June 2025, which caused severe overbank flooding along the Frejus/Merdovine stream reach, with major impacts on the built-up area and on road infrastructures, in particular SP 216 and SS 335.

Main works

Alternative “A” (selected solution)
With the objective of improving the hydraulic efficiency of the entire system, it provides for the relocation of the current SP 216 alignment to the left (orographic) bank of the Frejus stream, with the construction of a new roadway alignment upstream of the current critical node (relocation of the roundabout Rest=15.5 m to the left (orographic) bank and raising of the roadway level at the node), and the rectification of the channel alignment brought back to its original bed (construction of new banks by means of diaphragm walls, with reprofiling of the flow sections and increased longitudinal slope). It also includes demolition of the bridges on Via Torino and Via Europa (the latter rebuilt in a new position, with a single 15 m span and a deck consisting of precast prestressed reinforced-concrete girders and a composite reinforced-concrete slab).

Alternative “B”
This corresponds to the Final Design prepared before the catastrophic events and, with the aim of improving flow conditions at the Via Torino bridge, located at the confluence between the Fréjus and Melezet streams, includes: widening of the hydraulic section with regularisation of the channel bed and replacement of the existing bridge with a new single-span structure (span 40.00 m between bearing axes), with soffit set at a higher elevation, and a composite steel–concrete section.

Alternative “C”
This option addresses the topic of the “third access to the town of Bardonecchia” already considered in the PRGC, achievable through a crossing L=120 m required to overpass both the Turin–Modane railway line and the Rochemolles stream, thereby providing a direct and functional connection between the A32 motorway and State Road SS 335 and the existing urban road network.