Dam on the Secchia near Campogalliano.
|- location||Tuscan-Emilian Apennines, Alpe di Succiso|
|- elevation||2,017 m (6,617 ft)|
|- location||Po, south of Mantova|
|Length||172 km (107 mi)|
|- average||42 m3/s (1,500 cu ft/s)|
|Basin size||2,292 km2 (885 sq mi)|
It is 172 kilometres (107 mi) long, and has a drainage basin with a catchment area of 2,292 square kilometres (885 sq mi), alternating between aridity in the dry summer months and higher flows during the wet spring and autumn periods. It originates at Alpe di Succiso at an elevation of 2,017 metres (6,617 ft), close to the pass of Cerreto in the Tuscan-Emilian Apennines, then it heads north, touching on the territory of Frignano, passing into the territory of the commune of Pavullo nel Frignano and reaching the Po Valley close to Sassuolo (in the province of Modena). Here it touches on the city of Modena and, with its riverbank protected by embankments, runs into the Po just south of Mantua, close to the mouth of the Mincio.
North of the Via Aemilia, the course of the river suffered many alterations; it is believed that in Roman times it flowed further west of its current location, in the direction of Cavezzo, and shifted suddenly its course eastwards, flowing into the Po at Bondeno. In 1288–1360 it was deviated to its present course, after an agreement made by the cities of Parma, Reggio Emilia, Modena, Mantua and Ferrara, which baptized, in honour of this alliance, the city located on the shores of the Secchia as Concordia sulla Secchia.
- Naturalis Historia, Book 3, chap. xvi.