Tercero River

The Tercero River (Spanish, Río Tercero,[1] "third river"), also known as Ctalamochita, is the river of the Córdoba Province in Argentina with the most important water flow, 27.17 cubic metres per second (959 cu ft/s). It starts near the Calamuchita Valley, becomes navigable for boats of small to medium sizes as it flows through the plains, and flows 307 kilometres (191 mi) before reaching the Carcarañá River.

The Provincial Route 5 bridge over the Tercero River

It has its origin near the Champaquí hill, in an area of annual precipitation of between 600 and 1,000 millimetres (24 and 39 in), near the Calamuchita Valley. Leaving the valley, it reaches the plains where four dams there have been constructed, called Cerro Pelado Dam, Arroyo Corto Dam, Embalse Río Tercero—with 54.3 square kilometres (21.0 sq mi) built in 1936—and Piedras Moras, which serve as flow regulators, and hydroelectricity production. But the lakes of the dams are also used for tourism and recreation; water sports and fishing.

The river the incursions into the wet Pampas area, which has an average rainfall of 730 millimetres (29 in) per year. It joins the Saladillo River (also called the Cuarto River) to form the Carcarañá River, a tributary of the Paraná River.

Among the most important cities on the path of the Tercero are Río Tercero, Villa María, Villa Nueva, Bell Ville and Leones.

The word Ctalamochita (from which the term Calamuchita derives) seems to be a mixture of the Native American term ctala or tala, meaning "important tree", and a deformation of the Spanish mucho or muchito, finally meaning "area of many trees". The name Tercero became more common since the 18th century, being the third of five rivers counting from Córdoba city. Of them, the Tercero and the Cuarto (fourth) are the only ones to reach, indirectly, the Paraná River, being therefore tributaries to the Río de la Plata Basin.