Brazil: Disruptions due to flooding ongoing across Maranhao State as of early April 9

Event

Heavy rainfall has resulted in flooding and damage across parts of Maranhao State as of early April 9. The floods have especially affected communities near Trizidela do Vale. Around 7,700 people were reportedly displaced, and 35,900 were affected by rising levels of water following heavy rainfall. Six casualties have been reported. This is the second heavy flooding episode in Maranhao following a similar event in late March.

The National Institute of Meteorology (Inmet) has issued orange (the middle level on a three-tier scale) heavy rainfall warnings for most of the coastline, including the states of Para, Marahao, Piaui, Ceara, Rio Grande de Norte, Paraiba and Pernambuco in the North, as well as the states of Rio de Janeiro, Espirito Santo, Minas Gerais and Sao Paulo in the South, through the remainder of April 9. Further downpours are likely during the remainder of the monsoon season through April 2023. Additional rainfall will likely lead to further rise in river levels and could trigger flooding in areas where the ground is saturated. Power outages and damage to infrastructure are likely. Increased security is likely ahead of the president's visit on April 9.

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