Demonte
The Stura di Demonte, an important tributary of the Tanaro
The Stura di Demonte is an 84-kilometer long river in Piedmont with a drainage basin of 1471.8 km² and a mean flow of 47 m³/s. It is entirely located in the province of Cuneo, and is the main left tributary of the Tanaro and the second largest after the Bormida. The river originates in the Italy-France border area near Colle della Maddalena from Lake Maddalena in the municipality of Argentera. The Stura has a torrential character until Vinadio, where it begins to appear as a river with an average flow of about 10 m³/s.
At Roccasparvera, there is a dam and near Cuneo, it is crossed by the impressive and beautiful Soleri Viaduct, after which it merges with its main tributary, the Gesso (stream) with an average flow of about 20 m³/s, thereby doubling its volume of water; it then continues towards Fossano, flowing several meters below the Cuneo plain in a wide pebbly bed. It then flows into the Tanaro from the left near Cherasco.
The main tributaries of the Stura di Demonte
Among its tributaries are:
- on the right side, the Puriac stream, the Rio Freddo, the Corborant, the Rio Sant'Anna, in addition to the aforementioned Gesso (stream);
- on the left side, the Neirassa and Cant (stream) or Kant streams.
The hydrological regime
The Stura di Demonte is a particularly water-rich river, with an average flow not very different from that of the Tanaro at the confluence point (47 m³/s compared to 41 m³/s for the Tanaro). In any case, the river's regime is predominantly torrential with particularly fierce and powerful floods, also due to the extremely capricious nature of its tributary, the Gesso (stream).
According to the Water Protection Plan, from 1951 to 1991, the monthly average flow of the Stura di Demonte at its confluence with the Tanaro is:
- January: 20.9 m³
- February: 20.7 m³
- March: 27.4 m³
- April: 39.1 m³
- May: 60.5 m³
- June: 65 m³
- July: 44 m³
- August: 30.4 m³
- September: 29.1 m³
- October: 31.4 m³
- November: 36.3 m³
- December: 25.4 m³
The history of the Stura di Demonte
The Stura di Demonte has been documented since the 10th century as Sturia, alternating with Sturea or even Stuira. Its name probably dates back to pre-Roman times. In 1992, it was included by the CIPRA (International Commission for the Protection of the Alps) among the only five watercourses in the entire Alpine arc with characteristics of natural integrity: for example, it was one of the last watercourses in the Po Valley to host the otter, which became extinct here in the early 1980s.
