Extreme drought has reduced Lake Titicaca, South America’s largest freshwater lake, to its lowest levels since 1949, threatening flora and fauna and the livelihoods of hundreds of thousands of people who inhabit its shores.

Water levels in Titicaca, shared by Bolivia and Peru, have dropped by 32 inches (81 cm) since April. If they continue to fall another foot (30 cm), water shortages could put at risk irrigation for tens of thousands of Bolivian farmers producing wheat, barley and potatoes around the lake, according to Bolivian authorities.

Some 200,000 Peruvian fishermen who depend on the lake’s fish, waterfowl and reeds for their subsistence and that of their livestock also would be affected, Peruvian officials say.

Numerous species of commercially important fish such as trout, karachi (Orestia sp) and suche (Trichomycterus rivulatus)—already reduced in numbers because of this year’s drought—could begin dying off in greater numbers because of warming waters and extinction of algae where they spawn.

So could a key plant—totora (Schoenoplectus californicus), a giant bulrush sedge subspecies that is used for nesting by aquatic birds and to feed cattle and other animals belonging to local inhabitants—authorities in both nations say.

Covering 8,400 square kilometers (3,240 square miles) of the southern province of Puno in Peru and the western department of La Paz in Bolivia, Lake Titicaca sits 3,800 meters (12,493 feet) above sea level in the arid altiplano, or highlands, and is fed almost entirely by rainfall. About 45% of its surface area belongs to Bolivia and the rest to Peru.

The Binational Autonomous Authority of Lake Titicaca, which administers the lake for both Bolivia and Peru, warned in a November report that if water levels continue to drop it would have to “begin to apply restrictions on the use of the lake’s water resources.”

The authority suggested that should the pattern of scant rainfall and high evaporation continue, such restrictions would be needed to avoid a reduction in “socio-economic activities” and a resulting human migration away from the region.

“The lake this year has dropped more than two meters from its average,” says Félix Trujillo, head of forecasting for Bolivia’s National Meteorological and Hydrological Service (Senamhi). “If its water level continues to descend, authorities are going to have to close floodgates on the border between Bolivia and Peru, potentially affecting thousands of Bolivian families living on the lake’s edge.”

Other nations affected

While there have been cyclical variations in the levels of Lake Titicaca, the long-term prognosis for the lake, a home to the Incas and previous civilizations stretching back thousands of years, has appeared gloomier this year as a result of one of the most severe droughts to afflict Latin America in decades.

In Guatemala, some 500 people have died of drought-related hunger, and in Venezuela, the production of maize, rice and sorghum are way down.

Drinking water and electricity are being rationed. Argentina has not been spared. Searing temperatures there have sparked wildfires that have destroyed tens of thousands of hectares of land.

The impact on Bolivia has been particularly severe.

With zero precipitation between August and October in the southern lowlands of Chaco, more than 11,000 head of cattle have died and thousands of farmers now face potential food shortages as a result of a planting season that had to be delayed from late September to late November when the first rains began.

Climate experts blame the devastating climate on El Niño, the seasonal warming of Pacific waters that warps normal weather patterns and occurs on average every three to eight years. But experts on Titicaca worry that the sustained decline in the lake’s water level is more a function of long-term global warming.

The water level has fallen steadily in recent years, descending a total of three meters since 2003, according to Bolivian authorities. And that is likely to only get worse, they say. The Friends of Nature Foundation (Fan), a Bolivian green group in Santa Cruz de la Sierra, forecasts that the temperature around Lake Titicaca will increase by 2 degrees centigrade by 2030 and six degrees by 2100.

Water-supply concerns

Moreover, some parts of the lake might even dry up altogether, separating the lake into fragments, the organization says.

“There could be real problems in water availability for agriculture around the lake and around the Desaguadero River, which drains some of the lake’s waters in the south (of the river basin),” says Humbero Gómez, Fan’s scientific director.

Bolivian officials argue they need to invest heavily in more efficient systems of irrigation as well as reservoirs that can store water in dry times. Bolivian Environment Minister René Orellana talks of investing US$1 billion over the next seven years for such reservoirs both around Titicaca and in the rest of the country.

In Peru, where precipitation around Lake Titicaca this year was 30% below average levels, authorities have been promoting drought-resistant crops such as alfalfa and oats.

Moreover, they are working to finish the irrigation channels of the Lagunillas Dam—which is fed by the Ramis River and was built in 1996 to supply water to some 31,000 hectares of farmland—as well as planning another major dam in the local Huenque River.

But “investment in dams is a risk,” says David Aranibar, the head of the National Reserve of Titicaca (RCN), which was established to preserve the natural resources of the lake. “These dams are ultimately fed by glaciers in the Western Mountain Range, which are melting because of global warming.”