Water Supply and Sanitation in Peru - Water Resources and Impact of Climate Change

Water Resources and Impact of Climate Change

On average, surface water in Peru is abundant. Nevertheless, it is unequally distributed in space and time. Especially the coastal area, where the country's major cities are located and two thirds of the population live, is very dry. Lima with 8 million people, is the world's second largest city located on a desert (after Cairo).

Peru contains over two-thirds of all tropical glaciers which provide important water sources for the dry western half of the country. These glaciers are rapidly melting as a result of climate change, making the flow of rivers more irregular, leading to more droughts and floods. A report by a team from the World Bank published in June 2007 in the bulletin of the American Geophysical Union (AGU) predicts that many of the lower glaciers in the Andes will be gone in the next decade or so, and that glacial runoff may dry up altogether within 20 years. The last comprehensive satellite survey by Peru's National Environmental Council, carried out in 1997, found that the area covered by glaciers had shrunk by 22% since the early 1960s. Partial surveys by geologists suggest that the rate at which the glaciers are melting has speeded up over the past decade.

For example, the Quelccaya Glacier, the largest ice cap in the Peruvian Andes, has shrunk by 30% in the last 33 years. The streams fed by the glacier provide water to irrigation canals built by the Incas and, further downstream, for the city of Lima.