Indonesia: Flooding ongoing across parts of West Sumatra Province May 14 /update 1

Flood-related disruptions are ongoing across parts of Agam, Tanah Datar, Padang Panjang, Padang Pariaman, and Solok regencies, West Sumatra Province, as of May 14. Heavy rainfall has been ongoing in the region since May 11, triggering widespread flooding and cold lava flow from volcano-hit areas. Authorities have declared an emergency response status.

Authorities have reported at least 50 fatalities and 37 injuries, with at least 27 people still missing and more than 3,300 others displaced. The death toll is likely to rise as search and rescue operations continue. Flooding and cold lava flow have cut off some road access in the worst-hit areas, hindering rescue and repair operations. Floods have damaged at least 71 houses and 16 bridges.

The Indonesian Agency for Meteorology, Climatology, and Geophysics (BMKG) has forecast further showers across the West Sumatra Province. As of May 14, the BMKG is maintaining yellow (lowest level on a three-tier scale) thunderstorm, heavy rain, and flood warnings across the province.

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 stormwater drainage systems. Sites located 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 rain has saturated the soil. Power outages could occur throughout the affected area.

Floodwaters and debris flows may render some bridges, rail networks, or roadways impassable, impacting overland travel in and around affected areas. Ponding on road surfaces could also cause hazardous driving conditions on regional highways. Authorities could temporarily close some low-lying routes that become inundated by floodwaters.

The disruptive weather may cause delays and cancellations at regional airports. Flooding could block regional rail lines; freight and passenger train delays and cancellations are possible in areas with heavy rainfall and track blockages.

Disruptions triggered by inclement weather and resultant hazards, such as flooding, could persist well after conditions have improved—it could take days before floodwaters recede and/or officials clear debris. Repair or reconstruction efforts may result in residual disruptions if there is severe damage to infrastructure.

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.