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Brazil: Nearly a million people live in the vicinity of dangerous dams

Brazil: Nearly a million people live in the vicinity of dangerous dams

Data visualization Brazilian dam safety population near dams EN

According to DW analysis, Brazil has around 1 million people living near a dam. The situation raises alarm bells about the possible consequences of yet another accident in the country, which has seen three large-scale dam disasters since 2009. 

The estimate includes all people that live in populated areas no more than a kilometer away from one of the 1220 dams that combine “high risk” and “high potential damage” classifications in Brazil’s National Dam Safety Information System (SNISB). 

High-risk dams have structural damage, design flaws, or are not properly maintained. This puts them at greater risk for organizational mishaps and safety incidents that could cause a rupture. High potential damage is a classification that indicates that such a failure would have significant economic, human and environmental costs. 

Data visualization Brazilian dam safety population near dams EN

 

A flawed governance system is contributing to the problem. Many dams do not have safety and emergency plans. 

According to SNISB data collected in February 2022, 39 of the dams classifed as high risk and high potential damage hold mining waste, which is considered particularly unstable. The recent disasters in the cities of Mariana in 2015 and Brumadinho in 2019 involved such dams. 

However, most of the most dangerous structures are water storage and irrigation Dams. They are mostly located in the Northeast region, which is a comparatively poor area that has suffered from water shortages in the past.  

Many reservoirs were created in the region to alleviate drought. They pose a threat to 600,000 people in the region if they are not properly maintained. 

Dams are part of a neglected infrastructure

Riacho da Cruz, a town of approximately 3,000 people, is located in semi-arid regions. It is a dry area, so it is not common for rain to fall.  

The dam is located in the middle of the town and almost everyone lives there. Built in 1957 to help keep water flowing during frequent droughts, the dam is a good example of the kind of structures found scattered across most of Brazil’s Northeast.

Data visualization Brazilian dam safety satellite image EN

Mariano Andrade da Silva is a researcher on health and disasters at Fiocruz, a leading Brazilian academic institution. He says, “In the 1960s & 70s the federal government tried promote water security in that region.” One of those efforts was the construction of water reservoirs for areas suffering from frequent drought.  

“Without proper maintenance, those structures have turned into a risk for the population,” adds da Silva. 

In addition to neglected state infrastructure, da Silva describes “orphan” dams. These dams are either not being maintained or the person responsible is unknown.   

As a result, 10 people out of every 1,000 in the Northeast lives close to a dangerous dam. This is the highest proportion in Brazil’s entire regions. About three out of every 1000 people in the Southeast, which is home wealthier states such Rio de Janeiro or Sao Paulo are in a similar position. 

The situation is made worse when there are not enough resources.

The problem is made worse by a lack of resources in areas where these dams are situated. According to a recent survey done by the Brazilian Institute for Geography and Statistics IBGE, 20% of Northeastern towns with at least one dam near them don’t have local civil defense systems.  

Civil defense services are responsible for implementing risk mitigation programs. This includes identifying vulnerable areas and creating contingency plans. They also coordinate rescue efforts in the event of disaster.  

“A disaster is unlikely to happen.” But it can lead to not only deaths, but also to the destruction these communities as a group,” says da Silva. He also adds that reservoirs provide important water sources for both agriculture and human consumption. He explained that a dam collapse can also threaten local food and water security. 

The consequences of such events can be seen in recent history. Cocal, a city of 25,000 people in the northeastern Piaui state, was hit by an anti-drought dam in 2009. The event resulted in the deaths of nine people, displacement of hundreds, and a serious threat to the local agricultural economy. 

Picture shows a man paying tribute to victims who died in the 2019 dam disaster in Brumadinho city, Minas Gerais state, Brazil.

One year after the disaster, a man gives tribute to the victims at the Brumadinho dam accident in January 2020

Brazil has seen numerous major dam disasters since then. The 2015 Mariana disaster and the 2019 Brumadinho catastrophe were two of the country’s most severe dam accidents. They are still fresh in the national mind. Together, they were responsible to nearly 300 deaths.

However, the structures that failed in these towns were quite different from those in the Northeast. These were tailing dams that were used to store mine waste.   

Half of all the disasters occurred in a mining state

Although tailing dams are significantly fewer in number, they are responsible for a disproportionate number of tragedies.  

Nine of the 18 large-scale dam disasters in Brazil that occurred between 1986 and 2019 were linked to mining operations. Eight of those, including Mariana’s and Brumadinho’s catastrophes, were in Minas Gerais. This state has been Brazil’s largest mining hub since the 1700s.

Data visualization Brazilian dam safety population failures map EN

“Tailing dams do not simply hold water like other dams. It’s completely different. The waste can contain elements such as starch, clay, starch, and iron. It’s much more hazardous, more unstable,” Evandro Morais da Gama, a professor in the mining engineering department of the State University of Minas Gerais, (UFMG) says. “There is no technique that can hold this in Brazil or anywhere else on the planet with 100% safety. 

Rafaela Baldi (a geotechnical engineer at Rio de Janeiro State University, UERJ) says most failures can be traced back towards poor management practices.  

Baldi says that mining companies are responsible for the lack in proper care as they try to increase extraction while reducing costs. She adds that the responsibility for this is also on institutions that monitor mining activities.  

Brumadinho is Brazil’s most fatal dam failure.  

Auditors from German company TV Sd and executives at Vale, the mine operator, have been accused of failing to address structural problems. 

“Unfortunately, this isn’t a rare occurrence. This is a common practice across Brazil. Bald says that consultants are often pressured by mining companies to write what is most convenient at the time. 

Turning a blind eye to danger

They weren’t publically classified as high-risk structures when the Mariana and Brumadinho dams collapsed. This is another aspect of Brazil’s dam problem: a lack information. The country doesn’t know how many dams are present on its territory or how well they are maintained. 

Since 2010, information about all dams in the nation has been centralized in the National Dam Safety Information System, maintained annually by the National Water Agency (ANA).  

However, the data is not complete as ANA’s annual reports highlight. The database currently records 22,000 dams. However, the agency estimates that the country has approximately 170,000 artificially crafted water reservoirs.  

For 57% of the dams in the system, no information exists to determine whether they are subject to legislation that outlines safety standards for structures above a certain size, risk level or potential damage classification.  

Most of the 6000 dams which are subject to national safety protocols have not been certified. 73% lack the necessary safety or emergency plans. They don’t provide basic guidance about what to do in the event of a disaster. 

Data visualization Brazilian dam safety dams by legal status EN

Fernanda Laus (dam safety coordinator at ANA), says that information gaps should be expected when implementing a new policy. The safety monitoring database was created 12 years ago. 

She also said that gaps could partly be attributed to the patchwork nature of the regulatory system. Data is collected by 44 government organizations with different levels of funding and staff.  

“Resources are limited. Laus says it’s natural to build larger dams first and then leave smaller ones for later. Laus also states that regulators are working quickly to collect missing data. “But this isn’t a reality for all agencies. Some agencies simply don’t have the ability to do this for now. 

Edited by Gianna Grn & Jennifer Collins

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