Holder of one-fifth of the world’s fresh water, the Amazon is beginning the dry season with many of its rivers already at critically low levels, prompting governments to anticipate contingency measures to address issues ranging from disrupted navigation to increasing forest fires.

“The Amazon Basin is facing one of the most severe droughts in recent years in 2024, with significant impacts on several member countries,” stated a technical note issued Wednesday by the Amazon Cooperation Treaty Organization, which includes Bolivia, Brazil, Colombia, Ecuador, Guyana, Peru, Suriname and Venezuela.

In several rivers in the southwestern Amazon, water levels are the lowest on record for this time of year. Historically, the driest months are August and September, when fire and deforestation peak. So far, the most affected countries are Bolivia, Peru and Brazil, according to ACTO.

On Monday, Brazil’s federal water agency decreed a water shortage in two major basins, Madeira and Purus, which cover an area nearly the size of Mexico. The next day, Acre state declared an emergency amid an impending water shortage in its main city. In June, neighboring Amazonas state adopted the same measure in 20 of its 62 municipalities that are mostly only accessed by water or air, even in normal times.