Brazil: Disruptions following severe weather ongoing across parts of Rio Grande do Sul and Santa Catarina states as of Sept. 5 /update 1

Event

Flooding and other weather-related disruptions are ongoing across parts of Rio Grande do Sul and Santa Catarina states as of Sept. 5 following the passing of a storm system over the region. The system brought strong winds, heavy rainfall, and hail Sept. 3-4, with Rio Grande do Sul State being the worst affected. Rainfall totals of more than 20 cm (8 inches) have been recorded in some areas, triggering flooding across 67 municipalities in Rio Grande do Sul State, including Bento Goncalves, Caxuias do Sul, Ibiraiaras, Lajeado do Bugre, Nova Bossano, Santo Expedito, and Sao Jorge municipalities. River levels are continuing to rise, and authorities have issued flood warnings for communities along the Antas, Cai, and Taquari rivers. The Taquari River has overflowed, flooding Estrela and Lajeado municipalities in Rio Grande do Sul State on either side of the river.

As of late Sept. 5, authorities have reported at least 21 storm-related fatalities across Rio Grande do Sul State, with the majority in Mucum Municipality. Access to the municipality has also been disrupted since Sept. 4. More than 1,650 people have lost their homes, and almost 3,000 have been displaced. More than 200 homes have been damaged and hundreds of people are uncontactable. Flooding and landslides have blocked roads in at least ten locations across Rio Grande do Sul. Parts of the BR-386 Federal Highway, which connects Porto Alegre, the capital of Rio Grande do Sul State, to the north of the state, are impassable due to the flooding of the Taquari River. Parts of the BR 116, 285, 290, and 470 highways are also closed. The Sao Jose Hospital in Arroio do Meio Municipality is without electricity and water; officials have suspended all elective consultations and surgeries Sept. 5-6.

In Santa Catarina State, one fatality occurred in Jupia Municipality due to a falling tree. Reports indicate more than 3,500 power outages in Chapeco Municipality in the state.

Calmer weather conditions are forecast in the region Sept. 5 before another low-pressure system is expected to bring further unstable weather conditions Sept. 6-8. Additional heavy rainfall will likely exacerbate the situation due to high river levels and saturated soil, as well as hamper ongoing recovery efforts.

Hazardous Conditions
Further sustained heavy rainfall could trigger additional flooding in low-lying communities near rivers, streams, and creeks. Urban flooding is also possible in developed areas with easily overwhelmed or a lack of stormwater drainage systems. Sites downstream from large reservoirs or rivers may be subject to flash flooding after relatively short periods of intense rainfall. Landslides are possible in hilly or mountainous areas, especially where heavy rainfall has saturated the soil. Disruptions to electricity and telecommunications services are likely where significant flooding, landslides, or strong winds impact utility networks.

Transport
Floodwaters and debris flows could render some bridges, rail networks, or roadways impassable, impacting overland travel around affected areas. Ponding on road surfaces could cause hazardous driving conditions on regional highways. Authorities could temporarily close some low-lying routes that become inundated by floodwaters. Flooding could block regional rail lines; freight and passenger train delays and cancellations are possible in areas that see heavy rainfall and potential track inundation. Localized business disruptions may occur in low-lying and riverine areas.

Health
Flooding could heighten the threat of disease outbreaks. Backflow from drains mixed with floodwaters can become trapped in open areas when inundations recede. These stagnant pools often become a breeding ground for mosquitoes and bacteria, increasing the incidence of insect- and water-borne diseases. Exposure to contaminated water from inundated industrial sites, sewer systems, and septic tanks also poses a significant health threat.

Advice

Monitor local media for updated emergency and weather information. Seek updated information on weather and road conditions before driving or routing shipments through areas where severe weather is forecast. Plan accordingly for potential delivery delays if routing shipments by truck through the affected area. Stay away from elevated streams, creeks, and other watercourses that are prone to flash flooding. Do not attempt to navigate flooded roadways. Exercise caution in elevated terrain due to the threat of landslides, as well as mountainous regions where avalanches pose a threat. Keep important documents and necessary medications in waterproof containers.

Observe strict food and water precautions, as municipalities could issue boil water advisories following flooding events. Take precautions against insect- and waterborne diseases in the coming days. Review contingency plans and be prepared to move quickly to shelters if evacuation orders are issued. Charge battery-powered devices in the case of prolonged electricity outages.

Resources

National Institute of Meteorology