Water returns to Amazon rivers amid historic drought

The Amazon River and its tributaries, which make up the largest freshwater basin in the world, are showing signs of recovery after dropping to record-low levels between September and November 2024.

Abnormally low rainfall and high temperatures across the Amazon caused water levels to plummet, shutting down river transport, isolating communities and leaving industries without supplies. Indigenous children were forced to drink water contaminated with mercury, and fishers faced a mass fish die-off likely due to high water temperatures.

The Madeira River in Rondônia state in northwest Brazil, responsible for 15% of the water in the Amazon Basin, was 6.7 meters (22 feet) high on Dec. 9, marking a significant improvement over the 25 centimeters (9.8  inches) measured Oct. 12.

Farther east, on the Negro River near Amazonas state’s capital, Manaus, large grain barges owned by Cargill, Louis Dreyfus and Bunge, among others, resumed shipping soy and corn at full capacity following a 70-day hiatus. The river there is rising at an average of 3 cm (1 in) a day.

More than 118,000 hectares (291,000 acres) of the Amazon Rainforest were cleared between 2009 to 2019 to make way for large-scale soy farms, according to a recent investigation.

Deforestation is one of the leading causes of climate change in the region, which has led to the devastating droughts that have gripped the Amazon over the past two years.

Some relief has reached the region’s residents as the drought begins to ease. Water levels are now rising, but 16 of the 18 monitoring stations across the Amazon Basin in Brazil remain below normal.

“It’s very good to see that the rivers are returning,” Ane Alencar, the science director at the Amazon Environmental Research Institute, told Mongabay in an audio message. “What we don’t know yet are the long-term impacts of this severe drought,” Alencar added.

The incoming rain poses a paradox, she said. Too much rain all at once and there will be flooding, which can cause houses to collapse and plantations to fail. But at the same time, much more rain is needed to get back to previous water levels.

“Anything is possible. The climate is very unstable, and the tendency is for these events to become more frequent and intense,” Alencar said. “Unfortunately, it’s always the most vulnerable communities that are hardest hit.”

Banner image: Rivers in the Brazilian Amazon are recovering following historic lows. Image courtesy of João Dejacy/Rios de Notícias.