This reservoir was originally a natural depressed area, possibly excavated by wind erosion, which was later filled with water brought by a derivation channel from the nearby Neuquén River, in order to regulate its flow (since the river had no natural lakes that would fulfill this function).

The lake is employed for commercial fishing of trucha criolla (Percichthys trucha, a species of temperate perch) and pejerrey (Odontesthes microlepidotus, a neotropical silverside), as well as sport fishing, recreation and tourism.

The tourism can make a little detour of 14 km from the National Route 151, which travels to and from the South region.

Pellegrini lake is an important water mirror, which is part of the irrigation work of the Alto Valle of Rio Negro, that is fed from the canal that rises from the imponent dam, Dique Ingeniero Ballester.

At the Pellegrini lake you can do the most diverse watersports such as swimming, windsurfing, canoeing and sailing.