Lake Salto Grande is an artificial lake built on the Uruguay River, which forms the boundary between Argentina and Uruguay, at about 450 km from Buenos Aires and about 500 km from Montevideo. The reservoir is 144 km long and about 9 km wide, covering an area of 783 km². Its western shore belongs to the Province of Entre Rios of Argentina, and the eastern shore is shared by two provinces of Uruguay. The catchment area covers 224,000 km² extending over the territories of the two countries.

The impoundment was initiated in 1973 after a long period of negotiation between the two countries since 1964. The reservoir was constructed and managed by the Comision Tecnica Mixta de Salto Grande in which Argentina and Uruguay participate evenly in both operational and financial aspects. The creation of the reservoir resulted in the submergence of a town with 22,000 inhabitants, though the town has been relocated at some distance from the dam site. The produced electricity is supplied to both countries. The supply to Uruguay side very often surpasses the whole consumption in Montevideo.

Because of its proximity to such cities as Concordia (Argentina) and Salto (Uruguay), L. Salto Grande is an important recreational center. The surrounding area made a public park with various facilities (an airport, harbors, auditoria and camping sites) soon after the reservoir was formed. Since there are vast flat plain with many residential areas in the upstream of the reservoir, accelerated soil erosion in the rainy season and resultant siltation offer a prevailing problem in spite of the afforestation efforts around the reservoir (Q, 1, 2).