On November 5, 2015, the residents of Bento Rodrigues in Minas Gerais, Brazil, awoke to disaster. A mining dam, owned by Samarco—a joint venture between Brazilian mining giant Vale and Anglo-Australian powerhouse BHP Billiton—collapsed, unleashing a torrent of toxic iron ore waste that swept through the community, killing 19 people and contaminating the Doce River for nearly 600 kilometers before spilling into the Atlantic Ocean. For the Indigenous Krenak people, who have lived along the Doce River for generations, this catastrophe was more than a headline—it was, as they call it, “the death of the river.”
“It was the saddest day for my people,” said Shirley Djukurnã Krenak, an Indigenous leader whose community’s life, culture, and rituals have long revolved around the river. “We felt the death of the river before it arrived.” According to the Associated Press, the Krenak remember the days before the disaster with an eerie clarity: the birds stopped singing, the air turned heavy, and an unnatural silence settled over their village. Then, the mud came, and everything changed.
The Mariana dam collapse poured an estimated 40 million tons of mining waste into one of Brazil’s most ancient river systems. The Doce valley, which has shaped the landscape of Minas Gerais for millions of years, was left devastated. The environmental toll was immediate and immense, but for the Krenak and other local communities, the loss was also deeply spiritual. The river had provided food, water, and a sense of belonging. Now, it was poisoned—its fish contaminated, its waters dangerous, and its future uncertain.
Ten years on, as Brazil prepares to host the United Nations COP30 climate summit in Belém, the scars of the Mariana disaster remain raw. Reconstruction and reparations have dragged on through endless legal disputes, and the Doce River is still contaminated by heavy metals. Local residents, Indigenous leaders, and environmentalists warn that, despite Brazil’s aspirations to global climate leadership, little has changed for those living in the disaster’s shadow.
“For us, the fight isn’t about speeches at COP,” Shirley Krenak told the Associated Press. “It’s about survival.”
Brazilian President Luiz Inácio Lula da Silva has made no secret of his ambitions for COP30. With the summit set in the heart of the Amazon, Lula hopes to cement Brazil’s reputation as a global environmental leader. But the unresolved legacy of Mariana—and other recent policy moves—have cast a shadow over these ambitions. Maurício Guetta, legal policy director at the advocacy group Avaaz, put it bluntly: “It’s contradictory for a country that wants to lead on climate to keep approving laws that reduce protection for nature and Indigenous rights.”
Indeed, the years since the Mariana disaster have seen a troubling trend. After the 2015 collapse, the state of Minas Gerais weakened its environmental licensing laws—a move that, according to Guetta, directly contributed to the Brumadinho dam disaster in 2019, which killed 270 people. Nationally, Brazil’s Congress has approved laws restricting Indigenous land claims and, in 2025, passed what activists call the “devastation bill,” relaxing environmental licensing across the country. Environmentalists warn that these measures threaten to undermine Brazil’s commitments under the Paris Agreement, the 2015 global pact to curb greenhouse gas emissions and limit global warming.
“The Mariana disaster showed how fragile Brazil’s system of environmental control really is,” Guetta said. “Instead of learning from it, we’ve seen a process of deregulation.” He further warned that a new bill under consideration in Congress could “practically dismantle Brazil’s environmental licensing system.” Meanwhile, environmental agencies remain underfunded and understaffed, even as mining and agribusiness push deeper into fragile ecosystems.
For those who lost everything in the disaster, promises of justice have proved elusive. In October 2024, Brazil’s government and the states of Minas Gerais and Espirito Santo signed a 132 billion-reais ($23 billion) settlement with Samarco, Vale, and BHP to fund social and environmental repairs. The record deal—bringing total payments to 170 billion-reais ($30 billion)—was meant to provide aid for affected communities and restore the environment. Yet critics argue that, without deeper reforms, such settlements are little more than a bandage on a festering wound.
Indigenous congresswoman Célia Xakriabá, who represents Minas Gerais, described the tragedy as “a crime still in progress.” She told the Associated Press, “The Doce River is still sick. The fish are contaminated, the people are ill, and children still ask when the river will be healed. You can’t bring back 19 lives, and you can’t bring back a healthy river.” Xakriabá insisted that the lack of justice for Mariana’s victims undermines Brazil’s credibility ahead of COP30. “It’s hard to talk about climate leadership when the state where this crime happened hasn’t even recovered,” she said. “True environmental policy starts with justice for those living the consequences.”
As the world’s eyes turn to Brazil for the climate summit, skepticism among Indigenous communities is running high. The Krenak people, for one, have decided not to attend COP30. Shirley Krenak called the climate summit distant from the realities faced by Indigenous peoples and full of “greenwashing” and false promises. “If all the previous COPs had worked, we wouldn’t still be talking about crimes like this,” she said. For her, true climate action begins with protecting rivers and forests—and recognizing Indigenous territories.
Anthropologist Ana Magdalena Hurtado, a professor at Arizona State University who has spent decades working with Indigenous communities in South America, echoed these concerns. “My worry is, this all looks very pretty, but the people who will walk away feeling wonderful are the urban academics and policymakers—not those living in remote territories,” Hurtado told the Associated Press. She acknowledged that dedicating space to Indigenous voices at COP30 is a welcome step, but warned that inclusion without real follow-up can do more harm than good.
Despite the skepticism, hope lingers among some leaders. “I still believe change is possible,” Shirley Krenak said. “That one day, our children will be able to drink a glass of water without fear of dying.” But for now, the Doce River remains a symbol of both environmental devastation and the unfinished fight for justice in Brazil.
As COP30 unfolds, the world will be watching not just the speeches and pledges, but the lived realities of communities like the Krenak—those who know all too well what is at stake when rivers die and promises go unfulfilled.