A breakdown of the Brumadinho dam filmed
The failure of the Brumadinho dam in Brazil is not only a human tragedy: it is also an environmental disaster. On January 25, 2019, the collapse of this dam caused 259 deaths and 11 disappearances.
And since this construction serves as a holding tank for toxic substances from mining, its collapse engulfed the mining site in a torrent of mud and waste.
According to the investigations carried out, the joint responsibility of the executives of the mining company Vale, which operated the dam, was not in doubt. The reports indicated the complete recklessness of company executives for the environmental and safety issue.
The executive director of the region was thus pointed out. The same goes for the mine geologist and the environmental engineer.
But the evil is deeper
The Brumadinho disaster would never have happened, if the lessons of previous tragedies had been learned. Indeed, a similar accident occurred in Minas Geiras in 2015.
Due to the carelessness of the managers of the Samarco company, the Mariana dam had collapsed. And this by releasing a flow of toxic mud that engulfed the village of Bento Rodrigues, causing the death of 19 people.
In addition, it should be borne in mind that dam accidents are rare. Indeed, since the 20 th century, only 1% of existing dams were broken throughout the world. The causes of these catastrophes are either human, in the case of technical negligence or bad maintenance; or natural, in the case of erosion, earthquakes and bad weather.
However, the dams are generally very resistant. Like the Chilean dams which have held up despite several earthquakes.
Dam failures always result in a powerful, out-of-control spill of the water and mud contained in the reservoirs. This results in the sudden inundation of spaces and dwellings that are located downstream of these dams.
The Ituango dam
Located in northwestern Colombia, on the Cauca River, the Ituango Dam plunged residents of the surrounding region into deep anguish in 2018, when the threat of its collapse was at its height.
The construction of this huge hydroelectric structure began in 2011 and it was to be operational in 2018, without a host of disturbing events that could have put the lives of 100,000 people at risk.
A great threat to the population
Indeed, in April 2018, international experts sounded the alarm signals. And this by noting that the materials used for the construction of the dam did not meet the international standards in force. And that the construction was on the verge of collapse.
In addition, the rains had caused three landslides in the mountain. This had the effect of obstructing the tunnel which was used to divert water from the river during construction. But the power of the water had opened another tunnel, causing an increase in the river flow. And a serious threat to the surrounding communities.
Indeed, the flow of the river had almost tripled, and the torrent was so powerful that several bridges had collapsed. Firefighters, police, the Red Cross and even the army had been mobilized.
The collapse of the Edenville dams
In May 2020, torrential rains caused the double collapse of the Edenville and Sanford dams. This resulted in a massive evacuation of the population, and a serious risk of pollution due to the proximity of a chemical plant.
The failure of the first dam had propelled floodwaters into Sanford Lake where another dam was located. Which ended up giving way to the pressure of the waves, before being completely submerged.
In all, 11,000 people had to be evacuated, threatening an even more dire situation. All this in the midst of the coronavirus pandemic.
The other worrying element was the proximity to the large industrial plant Dow Chemical. It is a multinational established along the river, and where there is a small nuclear reactor.
The water had invaded the retention basins which were used to contain the brine. Which is a chemical toxic to animals and vegetation. Luckily, no major incidents have been reported since! And we can conclude that the management of this critical situation has been effective.
When the dam gate collapsed at Dunlap Lake
Let’s go to Texas now, where there was a dam crash in 2019, on Lake Dunlap. As can be seen in the police’s images, part of the structure was lifted, then returned by the thrust of the water, giving free rein to the waves.
In a few hours, this failure of the weir, on the one hand, lowered the level of the lake by nearly 2 meters. And on the other hand, it increased the Guadalupe River flow, which reached nearly 300 cubic meters per second.
Ultimately, Dunlap Lake was almost completely drained, revealing bridge structures. Although this accident did not require an evacuation, the authorities warned the local population by advising him not to get too close to the river.
This dam was nearly a century old when it collapsed. And detailed reports since then indicate that this dysfunction is due to the obsolescence of structural steel.