Nepal: Heavy rainfall, consequent flooding and landslides leave at least 193 people dead across country as of early Sept. 30 /update 1

Monsoon-related heavy rainfall has affected much of Nepal since Sept. 27, causing flooding and landslides that had killed at least 193 people, injured some 100 others, and left at least another 31 missing across the country as of early Sept. 30. Authorities have reduced more than 4,000 people. Most of the reported deaths are from the Kathmandu Valley. As search and rescue operations continue, the casualty count will likely rise over the coming days.

The rainfall, flooding, and landslides have inundated thousands of homes, blocked roads and highways across the country, and caused electricity and internet disruptions in some areas, including Kathmandu. At least 23 highways across the country have been affected, and landslides and flooding have damaged several bridges. Most major motorways connecting Kathmandu with the rest of the country remain blocked due to landslides. Many domestic flights were delayed or canceled Sept. 27-28; most flights resumed early Sept. 29. Around 22 hydroelectric power plants and nine transmission lines have been damaged, resulting in power disruptions. Authorities have closed schools through at least Oct. 2.

Officials have discouraged nonessential vehicular travel and banned buses from traveling on highways at night, as well as nighttime road travel in Kathmandu Valley. Officials have mobilized thousands of members of the country's security forces, including police officers and military personnel, to assist in search and rescue operations.

As of early Sept. 30, Nepal's Department of Hydrology and Meteorology has forecast that the heavy rain will ease over the coming days but light to moderate rainfall is possible. Authorities will likely issue new alerts or update/rescind existing advisories as weather conditions change over the coming days.

Further sustained heavy rainfall could trigger additional flooding in low-lying communities near rivers, streams, and creeks. Further urban flooding is also possible in developed areas with easily overwhelmed stormwater drainage systems. Sites downstream from large reservoirs or rivers may be subject to flash flooding after relatively short periods of intense rainfall. Additional landslides are possible in hilly or mountainous areas, especially where heavy rain has saturated the soil.

Authorities could issue mandatory evacuation orders for flood-prone communities over the coming days. Disruptions to electricity and telecommunications services are possible where significant flooding or landslides impact utility networks.

Floodwaters and debris flows will likely render additional bridges, rail networks, or roadways impassable, impacting overland travel in and around affected areas. Ponding on road surfaces will probably cause hazardous driving conditions on regional highways. Authorities will likely temporarily close additional routes that become inundated by floodwaters. Flooding will probably block regional rail lines; freight and passenger train delays and cancellations are likely in areas with heavy rainfall and track inundation. Severe weather will also trigger further flight delays and cancellations at regional airports.

Significant business disruptions will likely occur in low-lying areas; some businesses might not operate at full capacity because of flood damage to facilities, possible evacuations, and some employees' inability to reach work sites.

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 breeding grounds for mosquitoes and bacteria, increasing the incidence of insect- and waterborne diseases. Exposure to contaminated water from inundated industrial sites, sewer systems, and septic tanks also poses a significant health threat.