Siphon tunnel under the Secchia river

A siphon tunnel is a hydraulic mechanism that enables two waterways to cross. The tunnel under the River Secchia carries the main canal of the Agro Mantovano-Reggiano under the Apennine river through a siphon tunnel and then, by means of a sluiceway, conveys the water from the Oltrepò on the left bank of the River Secchia to the Moglia di Sermide pumping station, 23 km to the east on the bank of the River Po.

The tunnel was built between 1903 and 1907. At that time it was a colossal work, dry built in the vicinity of a narrow meander of the river, the course of which was diverted to complete work on the tunnel itself. The complex consists of the tunnel under the Secchia and two sluiceways (Controchiavica di San Siro, Controchiavica di Saliceti) to defend the land in case the siphon malfunctions. The tunnel belongs to the Consorzio di Bonifica Terre dei Gonzaga in Destra Po.