The Biobio River (Also known as Bio Bio or Bio-Bio) is the second largest river in Chile. It originates from Icalma and Galletue lakes in the Andes and flows 380 km to the Gulf of Arauco on the Pacific Ocean.
The major tributaries of the river are the Malleco and the Laja. The river is Chile's second-longest river (the longest being Loa River) and Biobio basin is Chile's third largest watershed, after Loa and Baker basins. The river is also the widest river in Chile, with an average width of 1 km. In the Metropolitan area of Concepcion, the river is crossed by four bridges: Biobio Railroad Bridge (1889), Biobio Bridge (1942), Juan Pablo II Bridge (1973) and Llacolen Bridge (2000).
The Biobio river originates at the west shore of Galletue Lake, within the national reserve that bears the same name. The river flows east for a few kilometers to the point where it receives the waters of the near Icalma Lake, through a short stream. Then, it turns its course northwestward, meandering through Andean valleys and receiving the discharges from some minor tributaries, as are the Lonquimay and the Rahue. The Lonquimay is fed by some glaciers of Sierra Nevada and passes close to the town of the same name. Just downstream from the confluence with the Rahue, the upper course of the river, locally known as Alto Biobio, begins to run rapidly through narrow canyon.
After reaching the Intermediate Depression, the river flows through a predominantly flat area, increasing its width between 60 to 120 meters and reducing its speed, which allows the navigation in some zones. In the middle course, the Vergara River joins the Biobio in the vicinity of Nacimiento, draining a great part of southern river basin after receiving the waters of rivers such as the Malleco and the Renaico, which constitute a northwest-oriented and parallel network of drainage to the Biobio of a great part of the northern Andean portion of the Araucania Region.
To the east of Chilean Coastal Range, near the cities of San Rosendo and La Laja, Biobio River is joined by the Laja River, its major tributary in terms of volume of water. From here, the river follows its course increasing its width considerably, reaching 2 km wide at its mouth on Pacific Ocean, near San Pedro de la Paz, Gran Concepcion.
It was the traditional borderline during the War of Arauco between southern Mapuche self-ruled areas and northern Spanish-ruled Chile. The territory south of the river was not incorporated into the Chilean state until the 1880s after the campaigns of the "Pacification of the Araucania".
In the early 1980s it was renowned as being one of world's best whitewater rafting venues with a trip that lasted seven days through some of Chile's wilderness areas. Endesa, the Chilean state-run power company at that time, constructed the Pangue dam, despite strong protests by environmentalists. With the loss of the whitewater rafting venue, there was also the displacement of indigenous Pehuenche people, who had lived in the area for centuries.
This article draws partially on the [[:es:Rio Biobio|corresponding article]] in the [[:es:Portada|Spanish-language Wikipedia]], accessed July 10, 2007.
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article Biobio River