# Flooding and river maintenance in southern Brazil > Live situation record from CLSTR: https://clstr.news/situations/flooding-and-river-maintenance-in-southern-brazil > Updated: 2026-09-09T19:47:42.000Z. Sources: 12. Developments: 3. In late August 2026, authorities in southern Brazil initiated preventative measures to mitigate flooding risks. In Santa Catarina, the CT SATC technological center identified 590 points of obstruction in the Urussanga River across nine municipalities. Concurrently, the local government in São João Batista began dredging the Tijucas River to remove an estimated 360,000 cubic meters of sediment and stones, aiming to counter the effects of heavy rainfall and El Niño. By early September, heavy rainfall led to active flooding in the region. In Rio Negro, Paraná, the Rio Negro river exceeded 8 meters, displacing 122 people. In Santa Catarina, the Rio Canoas reached a flood alert level of 6.17 meters in Otacílio Costa, flooding streets and local facilities. Civil Defense officials reported that saturated soil and difficult drainage in the river basin maintained critical conditions despite pauses in precipitation. On September 9, severe weather conditions intensified due to the formation of an extratropical cyclone in the ocean between the coasts of Santa Catarina and Rio Grande do Sul. The Civil Defense issued high to very high risk alerts for flooding, flash floods, roof damage, power outages, and falling trees across the Grand West, Itajaí Valley, North Plateau, and North Coast. In the northern region, the Rio Canoinhas and Rio Negro reached critical levels, with the Rio Negro hitting 8 meters. This has displaced over 100 people into shelters in Três Barras. Consequently, the Public Ministry of Santa Catarina launched a formal proceeding to monitor municipal assistance and ensure the rights of affected populations. Additionally, the National Institute of Meteorology (INMET) issued a red alert for Western Santa Catarina, warning of intense storms, hail, and potential isolated tornadoes. ## Claims - An extratropical cyclone forming between the coasts of Santa Catarina and Rio Grande do Sul has created a high to very high risk of flooding, wind damage, and flash floods. (corroborated by 3 sources) - Wind gusts may exceed 90 km/h in certain regions of Santa Catarina. (single source) - Over 100 people in Três Barras were displaced due to the rising levels of the Canoinhas River. (single source) - The Public Ministry of Santa Catarina has opened a formal proceeding to monitor municipal responses and assistance to the population in the northern region. (single source) - The Rio do Peixe has seen rising water levels in Caçador. (single source) - The Itajaí-Açu River reached 3.52 meters in Blumenau following recent rainfall. (single source) ## Timeline ### 2026-09-09: Santa Catarina faces severe storms and flooding from extratropical cyclone An extratropical cyclone in Santa Catarina has triggered severe weather alerts, causing river flooding in the north, displacing over 100 people, and raising risks of intense storms and wind damage. 9 sources. https://clstr.news/cluster/santa-catarina-rivers-rise-amid-heavy-rainfall-and-flooding ### 2026-09-04: Flooding impacts southern Brazil as river levels rise Rising river levels in Rio Negro, Paraná, and Otacílio Costa, Santa Catarina, have caused flooding and displaced residents in southern Brazil despite varying rainfall patterns. 2 sources. https://clstr.news/cluster/flooding-impacts-southern-brazil-as-river-levels-rise ### 2026-08-26: River maintenance and dredging operations underway in Santa Catarina River maintenance and dredging operations are being implemented in Santa Catarina, Brazil, to prevent flooding by clearing obstructions and removing sediment from the Urussanga and Tijucas rivers. 2 sources. https://clstr.news/cluster/river-maintenance-and-dredging-operations-underway-in-santa-catarina --- Cite as: Flooding and river maintenance in southern Brazil. CLSTR, https://clstr.news/situations/flooding-and-river-maintenance-in-southern-brazil