- Brazil has committed to dredge major Amazon rivers in response to record drought that has lowered water levels and made ship passage, a key transportation lifeline, difficult or impossible.
- The dredging is aimed at supporting local communities, who rely on river navigation to get supplies in from outside, and producers, who need to ship their commodities out.
- But experts question whether dredging is a sustainable solution, raising concerns about long-term ecological impacts and advocating for community involvement and innovative technology for better outcomes.
- The environmental risks of dredging include ecosystem disruption, increased erosion, water contamination, and harm to aquatic species such as manatees and river dolphins.
For the second year in a row, record-breaking drought in the Amazon has caused environmental havoc and left entire communities stranded. Water levels in the major Amazonian rivers have dropped to historical lows. And because they serve as the main transport conduit in the region, the consequences of critically low water levels that prevent boat traffic are far-reaching for all segments of the population.
This year’s calamity had long been foretold. The Brazilian government announced in mid-June an investment of 505 million reais ($90 million) in licenses for dredging stretches of the Amazon River and two of its main tributaries, the Solimões and Madeira, over the next five years. That amount is almost four times what was spent in emergency response to 2023’s drought.
The move came as a result of months of negotiations between the federal government and the state of Amazonas, where industries’ economic output dropped by 16.6% because they couldn’t get supplies in or commodities out by boat during the last drought.
Brazil’s Ministry of Ports and Airports has called the proposed dredging operation “the largest volume of dredging in the history of the Amazon.” The National Department of Transport Infrastructure, DNIT, told Mongabay in an email that it would collect sediment from the riverbed using a suction mechanism, and then pump it to a different location to increase water levels in a particular channel.
A dredger at work in the Madeira River. The Brazilian government announced an investment of 505 million reais ($90 million) for dredging stretches of the Amazon, Solimões and Madeira rivers. Image courtesy of DNIT.
The plan “takes into account the vessels navigating the river, the characteristics of the riverbed, the river levels throughout the year, and the amount of silt accumulated,” DNIT wrote. “In addition to dredging, the installation of nautical signs is being planned for the sections included in the contract, to guide navigators and mark the navigation channel.”
In addition to helping producers move their goods, dredging rivers also helps vulnerable populations that are disproportionately affected by the drought, Robert Muggah, chief innovation officer at the Igarapé Institute, a think tank, told Mongabay by email. These populations “depend on rivers for everything from subsistence fishing to trading goods,” he said.