The control of water for irrigation became even more important to newly arriving settlers who were allocated parcels of land or "chacras" issued by the Argentine government in the lower part of the valley.

In 1882, following a very bad harvest in 1881, a scheme of irrigation ditches from a new canal would ensure consistent watering of crops and deal with the vagaries of the flow of the Chubut.

The river flows eastwards for approximately 800 kilometres (500 mi), from the Andes to the Atlantic Ocean, emptying at Engaño Bay near Rawson.

The main arm of the Chubut originates in Carreras, Río Negro Province, and its basin covers a large area of the western Andean foothills between Bariloche and Esquel.

The many branches join some distance before the small town of Piedra Parada, where the terrain becomes the flat plain characteristic of Argentinian Patagonia.

It flows east and passes by the town of Paso del Sapo, where it turns southeast through relatively unpopulated central Chubut.

This dam, named after paleontologist Florentino Ameghino, was designed in 1943 by engineer Antonio Domingo Pronsato; work started on 19 April 1963.

The plant, which uses a 56-metre (184 ft) high waterfall with a flow of 150 cubic metres per second (5,300 cu ft/s) and three turbines, provides energy to Pico Truncado, Caleta Olivia, Comodoro Rivadavia, and the lower Chubut Valley.