Norte Energia, operator of the Belo Monte Dam on the Xingu River in the eastern Amazon rainforest, has begun diverting about 85% of the river's water to the dam's turbines in order to boost electricity production. Scientists say the resulting drop in water levels will disrupt flood-dependent ecosystems and adversely affect the Indigenous peoples along the river.
Brazil has built more than 200 large hydroelectric dams as a way to produce energy for a growing economy, and Norte Energia's Belo Monte Dam has been one of the most controversial. Aside from its effect on local people and wildlife that rely on the river's natural rise and fall, flooding behind dams can add to climate change by killing trees and other vegetation, which decompose and release methane, a potent greenhouse gas.
Annual flooding naturally occurs on the Volta Grande (Big Bend) branch of the Xingu River, explains Tiffany Higgins, who reported on the story for Mongabay. The water level rises and the river moves rapidly, up to 25,000 cubic meters per second. The water swells beyond the banks of the river and floods the adjacent forest, where special trees grow that have adapted to being seasonally flooded. Around February, the turtles and the fish catch this river wave and ride it into the flooded forest.
“It's an amazing synchrony, developed over millennia, between the trees that are fruiting and maturing just at this time of year and the fish and turtles who come along."
“It's an amazing synchrony,” Higgins says, “developed over millennia, between the trees that are fruiting and maturing just at this time of year and the fish and turtles who come along."
The trees drop their ripening guavas, figs, tucum, cashew fruits, and golosa fruits into the water and then the fish and turtles scoop them up. The fruits give them the essential calories which provide the energy that allows them to reproduce, Higgins explains.
“This is the exact time of year when they're reproducing,” she says. “It’s called the piracema, which is from the Tupi native words. It's something that all the fisherfolk communities are totally oriented to.”
But beginning in February of this year, Norte Energia diverted about 85% of the water that would have flowed into the Volta Grande so they could use it for the Belo Monte Dam. This was written into the original plan back in 2009, as something the company calls Hydrogram B, Higgins says.
At the time, the technical team of IBAMA, Brazil’s environmental agency of specifically criticized Hydrogram B. Essentially, Hydrogram B indicates that the largest amount of water released to the Volta Grande will be 8,000-cubic-meters-per-second in April, which is always the river’s peak, Higgins explains. About 20,000-cubic meters-per-second is the historical average in April on the Volta Grande.
The company signed an agreement more than a decade ago which said that its license was dependent upon them maintaining life on the Volta Grande. In December 2019, IBAMA's technical team said that Norte Energia had not proven scientifically that their plan could maintain the ecosystem on the Volta Grande and told them to conduct additional studies to prove that it could.
Instead, Higgins says, the president of IBAMA, Eduardo Fortunato Bim, stepped in and made an agreement with the president of Norte Energia that allowed them to implement Hydrogram B.
“The president didn't defend it,” Higgins says. “He simply said, ‘Go ahead, you can implement this Hydrogram B for a whole year.’ But there was no scientific evidence given for it. The experts I talked with, as well as the people on the Volta Grande, say this is a politically motivated decision.”
El Niño of 2016 provided a kind of natural test for what 2021 is going to look like on the Volta Grande, Higgins notes.
The Juruna, a local Indigenous tribe, say fish that year were "very skinny,” she explains. “They’re supposed to have scales on them, [but] some were smooth. … They would cut them open and see that their eggs were dry or their eggs had been reabsorbed into their bodies. … They saw many turtles who were only bone, they had very little flesh on them. And when they cut the turtles open, they found that where there should be eggs, there was foam instead. The Juruna also noticed a clear change in the taste to acidic, bitter, and they weren't able to eat them.”
In April of 2016, the river flowed at 10,000-cubic-meters-per-second. “But now we're going to have 8,000-cubic-meters-per-second in April in 2021, so we can expect even more disastrous effects on the animals,” Higgins says.
People Higgins spoke with said Norte Energia’s hydrogram violates a wide range of national and international laws.
“Article 231 of the Brazilian Constitution says that hydroelectric dams cannot interfere with Indigenous territories. But this is exactly what's happening."
“Article 231 of the Brazilian Constitution says that hydroelectric dams cannot interfere with Indigenous territories,” she notes. “But this is exactly what's happening. Other conventions safeguard the fishing stock of Indigenous communities. In essence, you can't remove the food basis of a community.”
In a video that Higgins filmed as part of her investigation, an Indigenous woman named Bel Juruna says, “This will be a cemetery of trees; this will be a cemetery of fish.” She adds, "And so we Juruna, we will be here fighting so that we, too, won't become a cemetery in our village."
“She's being quite literal,” says Higgins. According to a local scientist, Jansen Zuanon, the trees in the forest that are adapted to seasonally flooding will “experience functional death if they are not able to be flooded,” she says.
An ornithologist named Camila Ribas told Higgins that 60% of the birds in the area are adapted only to the flooded forest. “So when the forest dies, these special kinds of birds are going to die off, as well,” Higgins adds. “It'll create a wide patch of deforestation in this forest that will cut off the biological continuity [in] this wildlife corridor between what's called the upper Xingu River and the lower Xingu River.”
When Higgins contacted Norte Energia for her story, the company stated that “there is no technical, scientific proof that the company's hydrogram, i.e. Hydrogram B, will cause any harms to the animals, the fish and turtles of the Volta Grande,” Higgins reports. “In addition, they said, ‘We have robust scientific monitoring.’”
This is “perverse logic,” Higgins says, because Norte Energia is doing the monitoring itself while claiming there’s no proof their actions are going to harm any animals.