In the high Andes of Peru, glacial retreat poses a complex set of challenges related to water supply.
But in the high Andes of Peru, glacial retreat poses a different and complex set of challenges related to water supply. These challenges have far-reaching implications for Peruvian society, from water quality and agriculture to development and the risk of catastrophic flooding.
The Peruvian Andes are home to 70 percent of the world’s tropical glaciers, many of which are concentrated in the “Cordillera Blanca” or “White Range”. Located in high mountain ranges around the equator, tropical glaciers are especially sensitive to climate change and, like other glaciers throughout the world, are retreating at an alarming pace. Peru’s glaciers have lost some 40 percent of their surface area since the 1970s.
During the dry season, glacial meltwater is an important water source for communities from the high Andes to the coast. In recent decades, the rapid melting of Peru’s glaciers has resulted in increased water flow across the region. This water boon has fueled large-scale agricultural production in arid lands and spurred development: new communities sprang up, hydroelectric plants began to supply power to thousands of consumers, and Peruvian blueberries and asparagus were exported to lucrative markets abroad.But the abundance of water also brought complications. The water quality in rivers and streams declined as they became contaminated with heavy metals like lead and cadmium from newly exposed rocks and mining sites. These minerals also began to accumulate in croplands, impacting soil quality and agricultural productivity. Meltwater lakes at the foot of glaciers became swollen, threatening towns and cities with catastrophic flood events. An estimated 25,000 people have been killed by outburst floods and avalanches in the Santa River valley since the 1940s.Perhaps most worrisome is the likelihood that Peru’s glaciers, and the water they provide, will continue to decline in the years to come. A recent study found that seven out of nine watersheds in the Cordillera Blanca are already experiencing decreased water flow rates during the dry season. Once Peru’s glaciers are gone, annual streamflow may fall by as much as 30 percent in some watersheds. Conflicts over strained water resources may then reshape life in the Ancash region once again