India: Disruptions due to flooding ongoing across parts of Bihar State as of Sept. 27

Disruptions due to flooding are ongoing across parts of Bihar State as of Sept. 27. Heavy rainfall in recent days amid the current monsoon season has caused water levels to swell along the Ganges River and its tributaries, triggering widespread flooding. The National Emergency Response Center of the Ministry of Home Affairs Disaster Management Division has reported 45 flood-related fatalities across Bihar Sept. 25-26. Around 1.35 million people have been affected by flooding across the state, with districts along the Ganges and other major rivers the worst affected, including Bhagalpur, Munger, Lakhisarai, Katihar, and Khagaria districts. Homes have been flooded in hundreds of villages and many roads and bridges have been damaged, leaving some communities isolated. Dozens of schools across the state have been closed due to the flooding.

Although water levels are receding in places, further adverse weather is forecast across the region over the coming days, and additional downpours will likely exacerbate the flood situation. The India Meteorological Department has issued red heavy rainfall and thunderstorm warnings (the highest level on a three-tier scale) across Bihar Sept. 27 and yellow warnings Sept. 28. 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. 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. Landslides are possible in hilly or mountainous areas, especially where the soil has become saturated by heavy rainfall.

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 may render some bridges, rail networks, or roadways impassable, impacting overland travel in and 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 likely in areas that see heavy rainfall and potential track inundation. Severe weather will also probably trigger flight delays and cancellations at airports in the region.

Localized business disruptions may 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 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.