In the case of the Lake Poopo in Bolivia, the Andean nation's formerly second largest after the famed Titicaca, the answer is nothing short of devastation.
The saltwater Lake Poopo was located in the Bolivian altiplano at an altitude of 3,700 metres in the western department of Oruro.
. Poopo Lake, BOLIVIA. Reuters/David Mercado
Fisherman Rene Valero, from the Urus ethnic group, stands in his boat on the dried Poopo lakebed.
The area has long been populated by mining outfits, which depended on the lake. For their part, members of local communities like Untavi historically made a living from fishing and other activities dependent on the body of water.
With the water gone, animals have died off in the millions, according to studies. And the local families, having lost much of their sustenance, have been forced to migrate.
. Poopo Lake, BOLIVIA. Reuters/David Mercado
The government has declared the area a "disaster zone," but many say not enough has been done to make the area sustainable again.
Valerio Calle Rojas is one of 150 fishermen from the Untavi community.
"Just 40 days ago there was water, and flamingos were there. There was some water, where there's now those small, dark patches," he said.
He explained Lake Poopo's gradual water loss.
"In the 90's there was at least 2,000 square kilometres of water. After that, the water level began going down,” he said. “In 1995, 1996, there was a drought as well, and the water dried up, but it came back quickly. (…) There should be some rain. But that's not happening.”
. Poopo Lake, BOLIVIA. Reuters/David Mercado
Milton Perez, a professor at the Oruro Technical University, noted changing climate patterns.
"The El Nino phenomenon used to show itself every ten years,” he said. “So you have it one year and then another, and the Lake Poopo had eight years of normal climate behaviour with regards to precipitation and temperature so maintained its normal status.”
. Poopo Lake, BOLIVIA. Reuters/David Mercado
“But now because of global warming, and the currents of the Pacific Ocean, the El Nino phenomenon occurs every three years,” Perez said. “So, one year of El Nino, one year La Nina, and in the best of cases one normal year. One year is not sufficient for the lake to recover. And it's only going to get worse.”
The crisis came to a head in late 2014 with a massive loss of local animal life. Deaths among fish have been estimated in the millions. Some 500 or so birds, including flamingoes and ducks, also died.
. Poopo Lake, BOLIVIA. Reuters/David Mercado
Bolivian lawmakers in late 2014 declared the lake a "disaster area," meaning the area must be cleaned up. The situation has been made more acute by the buildup of metres-high sediment from local mining that has no water to combine with, leaving much of the local land full of a reddish sand.
Local non-government organisations have tried to help, facilitating the construction of wells, replacement farms or selling clay that has developed from the sediment.
. Poopo Lake, BOLIVIA. Reuters/David Mercado
"There's no water, no fish,” said Norma Mollo, of the Centre of Ecology and Andean Villages. “This is definitely affecting the local communities. They now have no way of surviving.”
Local fisherman Calle Rojas, who has five children, said he is mulling the same decision that roughly two thirds of his community of some 500 families have taken - picking up and moving to Bolivia, Argentina or Chile.