Peru is home to 70% of the world’s tropical glaciers, but 40% of their surface area has disappeared since the 1970s. The glaciers are a crucial water source in Peru, so people must adapt as they disappear.

In a place like Peru, climate change adaptation begins in the mountains. And alpine communities are scrambling to find ways of adjusting to a new reality.

According to Peru’s Natural Institute of Natural Resources all of the country’s 200 glaciers are under threat. It is feared that by 2025, all of them will be gone.

When the poisoned rivers ran red with heavy metals, people from nearby communities didn’t believe at first that climate change was to blame. In this small village nestled in the Cordillera Blanca, a majestic mountain range that contains several of the highest peaks in South America, the glaciers melted and metal-rich rocks were exposed to the air for the first time in thousands of years.
The glacial meltwater washing over the exposed rocks carried metals such as lead, arsenic, cadmium and iron into area waterways, turning rivers like the Rio Negro a rust red. This contaminated both soil and water and posed a significant health risk.
Over time, people, wildlife and livestock who drank the water became sick, and crop productivity plummeted. As headlines of global climate change become more alarming, it’s easy to forget that climate change is also an intensely local problem.

In the remote mountain villages around the Rio Negro, that adaptation effort took a curious and innovative form. To restore the poisoned river water and contaminated landscape around it, villagers collaborated with scientists from the Mountain Institute and with academic specialists. With training, they built a water purification system that collects the acidic river water in small ponds.
Then, using local traditional knowledge, they planted native plant species that could absorb metals from the water.

The water management systems developed in ancient Peru involved a set of technologies designed to slow or retain water in high alpine territories. The purpose was to keep water available for use as long as possible in the dry season. These ancient systems included dams and reservoirs of different sizes, irrigation canals and large silt traps that kept soil from being eroded in years of intense rain.
They also encouraged wetlands to develop. The excess soil in these silt traps could be “harvested” and used in terraces in warm valleys below the puna. Pre-Inca civilizations in the Andes maintained highland pastures with water technologies that slowed the movement of water through grasses and soils and provided a buffer against flooding and drought. Local wildlife flourished. A steady supply of water supported lush pastures and livestock, who in turn provided manure, used as fertilizer for corn, tubers, hard grains and the hundreds of potato varieties that are native to mountain valleys in the Andes.
Over the centuries, most of this infrastructure was abandoned. Today, older villagers only remember some of the locations and uses. The social and demographic collapse of indigenous cultures after the Spanish conquest of Peru in 1532 helps explain why these ancient socio-technological systems decayed. In more recent times, glacier retreat, changes in precipitation, loss of local labor and shifts away from traditional herding and farming practices have all contributed to the abandonment of this infrastructure and the degradation of the puna ecosystem.
But that’s starting to change. Villagers and scientists worked together to restore some of the ancient canals, and the wetlands began coming back to life. Cattle and sheep graze once again in revitalized highland pastures. The approach once again produced a strong sense of pride that traditional knowledge was being used to enable the community to become more resilient to the impacts of climate change.

In the rural community of Miraflores, a 700-year-old pre-Inca water storage and distribution system was rehabilitated. Adapting this old technology to the current context made it possible to reorganize the cattle grazing system in more than 6,000 hectares of grasslands that were in very poor condition and are now in the process of recovery. These changes have made it possible to improve the economy of the families in the community, reduce their risk in the face of climate impacts and improve the water regulation capacity of the ecosystem, for the benefit of the community itself and also of the low-lying areas. This solution has just been recognized as a cultural landscape in the World Monuments Watch 2022 and will help draw international and national attention to the ancestral water management network of Yanacancha-Huaquis.