The Oglio (; or ; , ) is a left-bank tributary of the river Po in Lombardy, Italy. It is long. In the hierarchy of the Po's tributaries, with its of length, it occupies the 2nd place by length (after the river Adda), while it is the 4th per basin surface (after Tanaro, Adda and Ticino), and the 3rd per average discharge at the mouth (after Ticino and Adda).

Overview

The Oglio is formed from the confluence of two mountain streams, the Narcanello branch from the Presena Glacier, in the Adamello group and the Frigidolfo branch, in the Corno dei Tre Signori, part of the Stelvio National Park. The two streams that merge near Pezzo di Ponte di Legno have an average discharge of . The Frigidolfo branch, before merging with the Narcanello branch, receives the Arcanello branch, which have an average discharge of , which receives a minor branch originating from Lake Ercavallo. The Ogliolo stream, with an average discharge of and a length of (similar to the length of the main branch between the Frigidolfo-Narcanello merge at Ponte Di Legno and the Oglio-Ogliolo merge at Edolo) is sometimes considered a de facto fourth branch of the Oglio river.

It flows in a southwest direction, through Valcamonica and enters into the Lake Iseo at Costa Volpino. It leaves Lake Iseo at Sarnico and, after traveling a zone of moraine deposits, it joins the Po river at Torredoglio, not far from Cesole and Scorzarolo, in the province of Mantua. Its drainage basin, which corresponds to the region of Valle Camonica, covers . It is part of the larger Po-Adige basin.

Course of the river's main branch

Val CamonicaCamonica Valley section

The river in the Camonica Valley flows almost exclusively in the province of Brescia, entering in the province of Bergamo only at , on the border between Artogne, Brescia and Rogno, Bergamo.

The following is a list (incomplete) of the tributaries in the Camonica Valley:

• Frigidolfo and Narcanello branches, also known as Oglio Frigidolfo and Oglio Narcanello, respectively, in Ponte di Legno at merge forming the main branch

• Valpaghera, at Vezza d'Oglio

• Valgrande, at Vezza d'Oglio

• Ogliolo branch, at Edolo

• Rabbia, at Sonico

• Remulo, at the border between Sonico and Malonno

• Allione, at the border between Malonno and Berzo Demo

• Poia river, at Cedegolo

• Re, at Sellero

• Re, at Capo di Ponte

• Clegna, at Capo di Ponte

• Figna, at municipal border between Nadro, Ceto and Ono San Pietro

• Blé stream, at municipal border between Cerveno and Ceto

• Palobbia creek, at municipal border between Ceto and Braone, near the quadruple municipal border with Losine and Cerveno

• Poia creek, at Losine

• Re, at Losine, near the municipal border between with Niardo

• Lanico stream, at the municipal border between Malegno and Cividate Camuno

• Trobiolo, at Cividate Camuno, near the municipal border with Cogno, Piancogno

• Grigna stream, Esine near the municipal border with Piancogno

• Resio, at Esine

• Davine river, at Darfo Boario Terme

• Budrio stream, at Erbanno, Darfo Boario Terme

  Dezzo river, at Darfo Boario Terme

  Gleno, at the triple municipal border between Vilminore di Scalve, Colere and Azzone

  Re stream, at Darfo Boario Terme

• Orso creek, at Rogno

• Supine creek, at Costa Volpino

Lake IseoLake Iseo section

At Costa Volpino, the Oglio river enters the Iseo lake with a mixed delta-estuary mouth.

Po ValleyPo Valley section

The Oglio main branch leaves the lake at the provincial border between Sarnico, Bergamo and Paratico, Brescia and begins to follow (approximately) this provincial border. At the triple provincial border between Torre Pallavicina (Bergamo), Roccafranca (Brescia) and Soncino (Cremona) the Oglio begins to follow (approximately) the provincial border between the Brescia-Cremona provincial border.

The major tributaries in the Po valley are the following:

• Cherio river, at the provincial border between Palosco, Bergamo and Pontoglio, Brescia

• Mella river, at the provincial border and triple municipal border between Seniga (Brescia), Ostiano (Brescia), and Gabbioneta-Binanuova (Cremona)

• Chiese river, at the triple provincial border between Canneto sull'Oglio (Brescia), Acquanegra sul Chiese (Mantua) and Calvatone (Cremona)

At this triple provincial border the Oglio river begins following the Mantua-Cremona provincial border, which leaves at the triple municipal border between Acquanegra sul Chiese (Mantua), Calvatone (Cremona) and Bozzolo (Mantua) where the river enters entirely in the Mantua province.

At the municipal border between Marcaria and Viadana , the Oglio river enters the Po river.

External links