Chile's official water authority has warned that the Echaurren glacier near Santiago, which supplies the capital with 70 per cent of its water needs, could disappear in the next half century.

In a new report on Chile's glaciers the main water company - Direccion General de Aguas de Chile (DGA) - said the ice fields of Echaurren are receding up to 12 metres per year.

"These glaciers are vanishing," said Antonio Vergara of the DGA, who has worked on glacier research on the fields for 35 years.

At the current rate of decline, Echaurren and other smaller glaciers near Santiago could disappear over the next 50 years.

The river Maipo and its smaller tributaries, key water sources for Santiago, its environs and agriculture in region, all flow from Echaurren.

The water shortage would force Chileans to seek new sources of water and would cause "large-scale population displacement in central Chile," Mr Vergara said.

Located 50 kilometres east of Santiago, on the western slopes of the Andes mountain range, the Echaurren glacier is one of the 10 most studied ice fields in the world, and is considered a "landmark in the global studies of climate change," DGA director Rodrigo Weisner said.

- AFP