It originates in the Sierras de Córdoba near Cerro Champaquí and Calamuchita Valley, in an area of annual precipitation of between 600 and 1,000 millimetres (24 and 39 in).

The reservoirs created by the dams are also used for tourism and recreation, including water sports and fishing.

It flows eastward into the Humid Pampas, which has an average rainfall of 730 millimetres (29 in) per year.

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".

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.