Indonesia: Disruptions due to flooding ongoing across parts of Central Java Province as of March 18

Flood-related disruptions are ongoing across much of Central Java Province as of March 18. Heavy rainfall has been ongoing in the region since March 13 and has caused rivers in the area to overflow and some embankments to collapse, triggering widespread flooding. Authorities have confirmed at least five fatalities across the province, and two others remain missing. More than 420,000 people have been affected, and around 17,000 have been displaced across various cities and regencies, including Pekalongan City, Pati, Semarang City, Kendal, Pekalongan, Grobogan, Demak, Jepara, and Kudus. More than 103,000 homes and hundreds of other buildings have been damaged by floodwaters. Many roads across the province have been blocked by floodwaters and landslides.

The Indonesian Agency for Meteorology, Climatology, and Geophysics (BMKG) has forecast further showers across the region over the coming days. As of March 18, the BMKG is maintaining an early warning for moderate-to-heavy rainfall, which may be accompanied by lightning, strong winds, and flooding, across Central Java 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 any 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.