Historic floods in the Brazilian state of Rio Grande do Sul

20 May 2024 by The Water Diplomat

The state of Rio Grande do Sul in Brazil experienced very challenging times in the early days of May 2024, subjected to rainfall of unprecedented duration and intensity. In the space of a week, more than 300 mm of water fell in the region, and in some places the rainfall recorded was 150 mm in less than 24 hours. The region's main river, the Guaiba, recorded a once-in-100-year flood, reaching a maximum height of 5.33 meters, thereby surpassing the previous record from 1941 which measured 4.76 meters, according to the Brazilian National Institute of Meteorology. Some experts compared the phenomenon to that experienced by New Orleans during Hurricane Katrina in August 2005.

Numerous landslides occurred in the region, and the “14 de Julho” hydroelectric dam partially gave way, according to  authorities. The dam break generated a two-metre high wave which flooded large parts of the city of Porto Alegre, a city with 1.4 million inhabitants, as well as more than 350 municipalities in the region.  According to several sources, the death toll was close to 150, with around a hundred people still missing. In tota, 400,000 people were displaced, 75,000 of whom took refuge in shelters. The road network was paralysed and partly destroyed, bridges collapsed and the airport was closed indefinitely. Electricity was cut off and over 800,000 people had no access to drinking water, according to local utility CORSAN. These events followed several extreme events last year when, after more than 2 years of severe drought, the region was amongst others struck by a cyclone in September 2023 which killed around 50 people. According to specialists, this recent episode was mainly due to the El Niño phenomenon.

Brazil's President Lula visited the site twice to assess the damage and take emergency measures. He told the press that Brazil should develop a genuine culture of prevention and risk management in the face of the growing effects of climate change.

The Rio Grande do Sul region is one of the most prosperous in Brazil. Local authorities, faced with the scale of the devastation, have declared that it would take a veritable “Marshall Plan” to rebuild everything. Some local councillors even said they were considering moving their town to “rebuild at higher altitudes”. At this stage, the Brazilian government has already announced the release of the equivalent of 9 billion euros for reconstruction, while former Brazilian president Dilma Rousseff has also declared that she will make 1 billion euros of BRICS Development Bank funds available to disaster victims and the authorities to “rebuild urban and rural infrastructures”. For the time being, the Brazilian army has been mobilized to bring food, water and essential supplies to areas made inaccessible by the floods, while the UN Refugee Agency has sent emergency shelters, cooking utensils, blankets, solar lamps and hygiene kits from its stocks in northern Brazil and other parts of the region.