First kilometer of the “idropolitana” completed from Parco dell’Arrivore to Via Gottardo
14/11/2025 - 14:31
On November 13, the tunnel boring machine named “Gaia” reached the first kilometer of progress in the construction of the main tunnel of the Collettore Mediano di Torino — a strategic infrastructure serving the city of Turin and the municipalities of the Metropolitan Area. The TBM will excavate a 9.5 km tunnel, passing through heterogeneous soil layers more than 10 meters below the groundwater level.
The Mayor of Turin and the Metropolitan City, Stefano Lo Russo, descended into the tunnel to reach the excavation front, accompanied by SMAT’s top management — Paolo Romano (President) and Armando Quazzo (Chief Executive Officer) — together with representatives of the construction companies Ghella and Itinera, members of the COLMETO S.c.a.r.l. consortium.
“It is fascinating to witness the progress of an excavation for a project that is scarcely visible on the surface yet so crucial for Turin and twenty metropolitan municipalities,” explained Stefano Lo Russo, Mayor of the Metropolitan City and the City of Turin. “The works are proceeding according to schedule and will provide the Turin area with a more modern and safer infrastructure, which will also help mitigate the impact of the most extreme weather events.”
“We are particularly pleased with this first milestone, which confirms that we have overcome the initial challenges of the project and allows us to continue, as planned, with the construction of this new infrastructure — designed to protect the environment without causing significant disruption to traffic or commercial activities above ground,” emphasized SMAT President Paolo Romano.
SMAT’s CEO, Armando Quazzo, also expressed pride in the achievement, noting: “The project management has been entrusted to Risorse Idriche, the Group’s engineering company, demonstrating our expertise, synergy, and ability to tackle complex technological challenges.”
The collector is being built through mechanized excavation using a Mix Shield TBM with a diameter of 4.08 meters. The machine is designed to install a ring lining composed of six reinforced concrete segments, and its cutterhead is equipped with 18 disc cutters.
The TBM, which began excavation on June 3, has been advancing steadily. It was assembled at a depth of 20 meters and measures 163 meters in length. Operating in three shifts, it completes about 20 meters of tunnel per day. More than 400 people are involved in the project, including operators, staff, and related personnel.
The infrastructure not only serves the city of Turin but also benefits 20 municipalities in the southern and western metropolitan areas: Beinasco, Bruino, Cambiano, Candiolo, Chieri Pessione, La Loggia, Moncalieri, Nichelino, Orbassano, Piobesi, Piossasco, Poirino, Riva di Chieri, Rivalta di Torino, Sangano, Santena, Trana, Trofarello, Villastellone, and Vinovo.