The level of the Madeira River, at the height of Porto Velho, continues to fall in an unprecedented way. The level reached 79 cm. With 1.02 m, a week earlier, it was already the lowest in the last 57 years.

Riverside dwellers who rely on fishing and small-scale agriculture are now facing immense sandbanks.

Those who have always lived by the Madeira’s banks consider the situation to be the result of a series of factors, including the lack of rain. Another problem is the rampant mining by dredges that navigate the main tributary of the Amazon River.

These archaic structures disturb the riverbed in search of gold. The illegal activity has been part of the Madeira's landscape for decades, and giant dredges—equipped with machinery for suctioning and grinding rocks and banks—aggressively alter the riverbed, especially during the dry season.

Folha visited the region of Humaitá (AM), 200 km from Porto Velho, and traveled a 100 km stretch of the Madeira River. Along the way, it observed the operation of 25 large dredges.

Their activity in the Madeira, during the worst drought period in the region, occurred 15 days after a Federal Police operation to destroy the structures used in illegal mining.