Laguna del Sauce
Laguna del Sauce is a subtropical shallow lake and the largest water body in the Maldonado Department of Uruguay. It is located west of Punta del Este. The lake is the only freshwater ecosystem in the country classified for drinking water as its principal use.
Originally a coastal lagoon, the lake was damned for military purposes in 1947. The closed ecosystem makes the lake prone to eutrophication, and has had regular algae blooms—one of which, in 2015, included cyanobacteria that disrupted water supplies.
Geography
The lagoon covers and is long and wide. The maximum depth of the lake is five meters. The lake is part of an interconnected lake system which includes Laguna de los Cisnes and Laguna del Potrero.The Pan de Azucar River discharges into the southwest of the lagoon, while the streams Arroyo del Sauce and Arroyo Mallorquina discharge in its north and northwest. A stream called Arroyo Potrero at the south end of the lagoon empties the water into the Río de la Plata at the beach of Chihuahua. The total input into the lake per year is approximately 285.4 mm3/year.
The catchment for the lake is largely grassland and native forest, with some forestry for paper and energy. Agricultural use for growing soy, wheat, and sorgum has increased in recent years, reaching 8216 hectares in 2015.