Amazon investigation finds declining natural water across four river basins
The story at a glance
A cross-border investigation analysed satellite data from 722 micro-watersheds feeding the Beni, Caquetá, Madre de Dios and Caroní rivers between 2000 and 2024. It found that 393 had lost natural water, with nearly 33,000 hectares lost across the four catchments.12
Mapped water area increased in some places as artificial water bodies appeared, mainly associated by the investigation with mining in three basins. In the Madre de Dios basin, Arazaire residents report buying drinking water. The satellite analysis does not establish that these pressures caused the measured changes.12
The story in brief
What you need to know
- The investigation found natural-water losses in more than half of the 722 micro-watersheds it analysed. The result describes mapped surface area, not the amount of water available to communities.12
- The four basins show different reported pressures. Mining is identified as the main association with increased artificial water bodies in the Madre de Dios, Beni and Caroní basins, while livestock ranching is identified as a major pressure in the Caquetá basin.12
- More mapped water does not necessarily mean more usable water. In the Madre de Dios basin, the report says artificial water bodies increased substantially, but their surface area does not show whether the water is safe to drink.1
- Community accounts add a dimension that satellite mapping cannot provide: residents in Arazaire now buy drinking water. The reporting describes concerns about access to usable water, but does not quantify the change for communities across all four basins.1
- A separate peer-reviewed study found that tropical forest loss reduces regional rainfall. It supports a general forest-and-rainfall mechanism, but does not verify the investigation’s basin-level findings or establish the cause of particular water changes.4
Conservation context
Why this matters
The findings raise questions about how mapped changes in rivers and other water bodies relate to drinking-water access. The distinction between natural and artificial water is important: an increase in mapped water area does not show that communities have gained a reliable or drinkable supply.12
The developing story
What happens next
The reporting leaves the causes and community-level consequences unresolved. Field measurements of water quality, seasonal availability and drinking-water access, alongside further analysis of the satellite data, could help clarify the picture; the supplied reporting does not describe a specific follow-up plan.12
Established evidence
What we know
- The investigation covered 722 micro-watersheds in four river basins over 2000–2024; 393 showed a loss of natural water.12
- The investigation estimates that nearly 33,000 hectares of natural water were lost across the four catchments.12
- The project’s analysis uses satellite data and describes increased artificial water bodies in the Madre de Dios, Beni and Caroní basins, mainly associated with mining.12
- Arazaire residents in the Madre de Dios basin are reported to buy drinking water.1
Open questions
What we don't know
- The satellite analysis does not prove that mining, deforestation or other pressures caused the measured water changes.12
- Mapped surface area does not establish water volume, drinkability, seasonal availability or the level of access in each community.12
- The reporting identifies open questions about how robust basin-level estimates are to classification choices, satellite-data limitations and differences among national MapBiomas water datasets.2
- Further evidence is needed to clarify the relative contributions of mining, deforestation, livestock ranching, dams and climate variability.12
Source coverage
