Northern South America: Annual rainy season underway in Colombia, Ecuador, Panama, and Venezuela through May 31

Event

The annual rainy season is underway across Colombia, Ecuador, Panama, and Venezuela through at least May 31, bringing an elevated potential for flooding and landslides/mudslides across the region.

As of April 7, the National Unit for Disaster Risk Management (UNGRD) in Colombia reported that since the beginning of the rainy season from March 15, 202 weather-related events have been recorded across 131 municipalities in 17 departments, the majority of which have been flooding and landslides. These events have affected 3,299 families and caused at least 21 fatalities. The severe weather has damaged at least 241 roads and 18 bridges across the country. The worst-affected departments include Antioquia, Caldas, Cauca, Cundinamarca, Huila, Narino, Quindio, Risaralda, Tolima, and Valle del Cauca. Authorities have warned that residents should be vigilant for potential flooding or landslides throughout the rainy season.

In Ecuador, heavy rainfall damaged the water supply infrastructure in El Oro and Manabi provinces early April; hundreds of thousands of people were without water supply.

Hazardous Conditions
Heavy downpours, flooding, and landslides could affect business, transport, and utility services in many areas. Localized disruptions could persist well after hazardous events have concluded; floodwaters may take days to subside, and debris from mudslides may take weeks to be cleared. Rural communities and informal settlements often sustain the greatest damage and casualties during such events due to poor infrastructure.

The risk of flooding is highest in low-lying communities near watercourses in recognized floodplains. Colombia, Ecuador, Panama, and Venezuela have several major rivers and lakes, including the Magdalena, Cauca, Caqueta, Putumayo, Guaviare, Meta, and Atrato rivers in Colombia, Amazon, Maranon, and Putumayo rivers in Ecuador, and Arauca, Apure, Caroni, Caura, Cuyuni, Guarico, Meta, Orinoco, Rio Negro, and Ventuari rivers in Venezuela as well as Chepo, Tuira, San Pablo, and Chagres rivers in Panama that could flood during periods of intense rainfall. Flash floods, which can occur with little to no warning, often threaten communities downstream of major rivers or dams in the event of structural failure. Urban flooding is possible in areas with poorly maintained or inadequate drainage systems, while storm surges may trigger flooding in coastal areas. Landslides and mudslides are possible in hilly and mountainous areas.

Transport
Floodwaters and debris flows may render some bridges, rail networks, or roadways impassable, impacting overland travel in and around affected areas, especially in rural areas, where infrastructure is already of a poor standard. 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.

Severe weather could trigger flight delays and cancellations at domestic and international airports. Authorities may temporarily suspend port operations along the Caribbean Sea and the Pacific Ocean if strong winds trigger hazardous sea conditions. Flooding could block regional rail lines; freight and passenger train delays and cancellations are likely in areas that see heavy rainfall and potential track inundation. Localized business disruptions may occur; some businesses might not operate at full capacity because of flood damage to facilities, possible evacuations, and some employees' inability to reach work sites.

Health
The threat of disease outbreaks is elevated during the rainy season. Backflow from drains that have 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 insect- and waterborne 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 updates and advisories on weather conditions. Confirm all transport reservations (air, ground, and maritime) prior to travel. Make allowances for possible supply chain disruptions throughout the rainy season, particularly in areas affected by flooding and or/landslide events.

Avoid low-lying areas near streams, rivers, and other bodies of water, such as reservoirs and coastlines, due to the threat of flooding. Do not drive on flooded roads. Exercise caution in elevated terrain due to the threat of landslides and mudslides. Charge battery-powered devices when electricity is available; restrict the use of cellphones to emergencies only during periods of severe weather. Take precautions against insect- and waterborne diseases. Keep any necessary medications in a waterproof container.

Resources

Colombia's Institute of Hydrology, Meteorology, and Environmental Studies (Spanish)
Ecuador's National Institute of Meteorology and Hydrology (INAMHI) (Spanish)
Panama's Hidrometeorologia (Spanish)
Venezuela's National Institute of Meteorology and Hydrology (Spanish)