Oct 17, 2023 - Energy & Environment

Extreme drought drives Amazon River port to lowest level on record

Floating houses that are not longer floating on the Negro River near Manaus, Brazil, on Oct. 16.

Floating houses that are not longer floating on the Negro River near Manaus, Brazil, on Oct. 16. Photo: Michael Dantas/AFP via Getty Images

Amid extreme drought across South America exacerbated by climate-change related heat extremes and El Niño, major tributaries of the Amazon River are reporting record-low water levels.

Why it matters: The measurements warn that parts of the Amazon Basin, the largest watershed in the world, are being stressed and the deterioration of the one of the most biodiverse places on Earth may be accelerating.

  • The drought is also driving extensive wildfires and human-caused fires that are smothering Brazilian cities with smoke.

By the numbers: The water level of the Negro River dropped to 44.3 feet on Tuesday — the lowest since measurements began there 121 years ago.

  • The measurement was taken near Manaus, the capital and largest city of the Brazilian state of Amazonas situated on the confluence of the Negro and Amazon Rivers.
  • Around 10% of the water in the Amazon basin drains through the Negro River, which is considered the world's sixth largest river by water volume.
  • The Madeira River, another vital tributary of the Amazon, also recorded historically low levels, according to AP.

Over 11,500 fires were detected through the Amazon during the first 16 days of October, according to Brazil's National Institute for Space Research.

  • Amazonas, which is almost entirely covered by the Amazon rainforest, has so far seen almost 3,000 fires — making it the worst October since records began 25 years ago.

Of note: Air quality in Manaus hit "very unhealthy" levels last week and only dropped back down to "moderate" values in recent days, according to the Swiss air technology company IQAir.

Before and after animation of satellite images along a tributary of the Amazon River, with the most recent NASA image taken Oct. 3.
Comparison between images on Oct. 8, 2022 and Oct. 3 this year of the Rio Negro River in the Brazilian state of Amazonas near the city of Manaus. Images: NASA Earth Observatory

Threat level: The low water levels have isolated riverine communities that rely on boats for transportation, disrupting their access to drinkable water and other supplies.

  • Indigenous peoples asked the Brazilian government last week to declare a climate emergency in response to the drought, Reuters notes.
  • Brazil's fourth-largest hydroelectric dam had to halt operations earlier this month because of Madeira River's record low flow, while shipping companies have warned that low depths on the Amazon River have impeded operations.
  • The drought and high water temperatures are also likely affecting the endangered pink river dolphin. Over 1oo of them have been found dead in recent weeks.
  • The governor of Amazonas has declared a state of emergency for more than 50 cities and towns across the state over the drought and wildfires, FT reports.

The big picture: This year, all-time winter heat records were set in multiple locations in South America, including Brazil, per Axios' Andrew Freedman.

  • Several regions of South America are experiencing drought, but exceptional conditions currently affect a large swath of Brazil, French Guiana, Suriname and Guyana.
  • Research out earlier this year shows that over a third of the Amazon rainforest has been degraded and may be approaching a dangerous tipping point, beyond which it may not be able to support the abundance of life it currently can.
  • Large parts of the rainforest losing is losing resilience from wildfires, droughts and human-caused disturbances, like logging, and risk eventually transforming into dry savannah, another study found.
  • Researchers in 2021 also discovered that segments of the Amazon were emitting more carbon dioxide than they can sequester, suggesting that the region's effectiveness as a climate change buffer has been depleted.

Go deeper: Global warming may be accelerating, data shows

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