Disappearing Glaciers: Exposing Vulnerabilities in the Rio Santa Basin Water Supply

Climate change drastically impacts regions worldwide, with some being more vulnerable to changing climatic conditions than others. The Rio Santa Basin contains the largest glaciated mountain range in Peru, the Cordillera Blanca, and these glaciers are experiencing rapid retreat. The glacierized mountains are the main water source for the basin by providing meltwater for agriculture, industrial, and domestic use throughout the year.

Climate projections consider both high and low emissions and population scenarios. Each case estimates significant warming in the tropical Andes between three and four degrees Celsius. With significant warming in the region, the high mountains may be increasingly vulnerable due to the ice-albedo feedback loop, therefore increasing the rate of glacial melt in the area. Most glaciers in the Cordillera Blanca have passed or are near the “peak meltwater” stage, meaning decreased flows are predicted into the future and, depending on the extent of glacier recession, annual flows in the Santa River may decrease by up to 30%. The impact during the dry season would be more severe, with estimated flow reductions ranging from 50 to 84%. A downward trend in water supply has already been reported in the basin, along with increased seasonality.

Consequently, the Rio Santa Basin should focus on transitioning away from water-intensive crops such as mangos, artichokes, asparagus, and avocados and switch to low water use options. Furthermore, government support in educating and funding smaller-scale farmers to install efficient infrastructure or learn better irrigation methods will effectively reduce unnecessary water usage.