How climate change is reshaping a river

From the Andes to the Amazon: climate change is reshaping the Mayo-Chinchipe River 

Climate change across the Amazon Basin 

Across the Amazon Basin, climate change is already driving transformations in water systems, ecosystems, and daily life. Severe droughts, such as those in 2005, 2010, and 2023-2024, have led to record-low river levels, disrupting transportation, isolating communities, and leading to large-scale wildlife deaths. Meanwhile, widespread deforestation and erosion in the western Amazon have increased sediment discharge into rivers, destabilizing aquatic ecosystems and compromising water quality across entire watersheds. These interconnected impacts show how water-related stress is no longer isolated to remote areas but is affecting both urban areas and rural communities across the basin.  

From the Amazon to Mayo-Chinchipe: A shared climate reality 

The Mayo-Chinchipe River is one of the many tributaries that flow into the Amazon through the Marañón River. Although relatively small in size, it reflects many of the same water-related vulnerabilities observed throughout the broader basin. This binational river, rich in biodiversity and water resources, is facing growing climate stress, impacting the communities that depend on its ecosystem services.  

Protos Andes’ field experience with communities in the Mayo-Chinchipe watershed provides valuable insight into how climate change is impacting the local level. Three key climate impacts have emerged as particularly pressing in this Andean region: (1) disrupted rainfall patterns, (2) rising temperatures, and (3) declining water quality affecting nature and public health.  

1. Disrupted rainfall patterns

In the Mayo-Chinchipe Basin, seasonal rainfall patterns have become increasingly unpredictable. Communities working with Protos Andes report that the once-predictable rainy and dry seasons are becoming increasingly unreliable. This unpredictability poses serious challenges for smallholder farmers in the basin, many of whom depend on rainfall for maize and other crops and lack access to irrigation systems. In 2024, the region experienced over 100 consecutive dry days, a historic event that strained livestock, damaged crops, and pushed local water systems to the brink of rationing. 

This mirrors broader drought trends across the Amazon. In Brazil, the droughts of 2005, 2010, and 2023 caused months of abnormally low river levels, isolating thousands of communities and cutting access to essential goods and services. These events reveal how climate change is not only shifting the hydrological cycle but also deepening vulnerabilities in regions where rivers serve as the main lifeline. 

2. Rising temperatures

Average temperatures in the Mayo-Chinchipe Basin now range from 19°C to 23°C, but communities have observed notable warming in recent years, particularly during the hotter months of November and December. Lower-elevation zones feel increasingly tropical, while highland areas like Palanda and Valladolid remain cooler. These shifts are disrupting local ecosystems, especially species sensitive to microclimatic conditions. Some crops are harder to grow in their traditional zones. For example, coffee farmers are now moving to higher elevations in the mountains to find suitable climate conditions for growing coffee. 

Across the Amazon, these trends are accelerating. Rising temperatures are pushing ecosystems toward critical tipping points. Studies show that in regions like the central Amazon and the eastern Andes, prolonged heat waves and erratic rainfall are causing shifts in forest composition, weakening biodiversity and carbon absorption. Together with altered rainfall and erosion, warming is reshaping how communities interact with their environment, from crop choices to forest-based livelihoods.  

3. Water quality: the importance of rivers health on public health

Water quality of the Mayo-Chinchipe River has deteriorated noticeably in recent years. Betwe 017 and 2021, Peru’s Autoridad Nacional del Agua monitored 27 locations in the watershed. None were rated “excellent,” and over 70% were ranked as either “regular” or “poor.” This can be attributed to a combination of upstream deforestation, livestock farming, and the lack of sanitation infrastructure, all of which contribute to organic waste, sedimentation, and bacterial contamination. 

These challenges are not unique to Mayo-Chinchipe. In Santarém, unregulated urban growth and stormwater runoff have caused contaminant levels in Amazonian’s sub-watersheds to spike. Seasonal rainfall intensifies the problem, washing pollutants into rivers and accelerating erosion. Sediment overload not only clouds water and degrades habitat, but also shifts river morphology, threatening aquatic life across the basin. 

In the Mayo-Chinchipe Basin, declining water quality is impacting human health. Parasitic infections are among the most common health concerns in the region, especially during floods or extended dry periods when clean water is harder to access. The 2024 drought exacerbated these risks, concentrating pollutants and nearly triggering water rationing in some communities. 

This pattern is echoed throughout the Amazon. In urban and peri-urban areas, water pollution from sewage, sediment, and agricultural runoff has led to unsafe drinking water and rising health costs. This highlights how the health of rivers is closely linked to the communities’ health.  

A local basin, a shared responsibility 

The Mayo-Chinchipe River is more than a local water source, it is part of a much larger hydrological system that feeds the Amazon River and supports life across South America. As climate change continues to disrupt rainfall, raise temperatures, and degrade water quality, this binational basin reveals the human face of a broader environmental crisis. What happens in the Mayo-Chinchipe River does not stay in the Andes. The water flowing through its forests, farms, and villages carries the challenges, and the potential, for building a more resilient future for the entire Amazon. 

That is why Join For Water and Protos Andes together with 4 other partners are implementing the CUIDAR project (Proyecto CUIDAR) that aims to strengthen the socio-ecological resilience of communities to climate shocks by defending the right to water, promoting cross-border collaboration, protecting water sources and restoring water-related ecosystems.