Gandak River Sets Record High, Breaches Embankments in Bihar

The Gandak River reached a historical record water level of 91.25 metres at Bagaha on September 29, 2026, following intense rainfall in Nepal. The surge exceeded the previous record set in 2024 by 0.35 metres, triggering multiple embankment breaches across Bihar's West Champaran district and threatening widespread inundation across multiple states.

Heavy precipitation in Nepal's catchment area caused a massive discharge of 5,43,500 cusecs at the Valmikinagar barrage—slightly below the 2024 record of 562,500 cusecs but sustained above 500,000 cusecs for 13 hours and above 400,000 cusecs for 32 hours. This exceptional flow placed unprecedented pressure on river embankments throughout the region. Water Resources Department teams identified and repaired 169 seepage and piping points through emergency measures, but critical breaches still occurred during the night of September 28–29.

Two major breaches were recorded on the left bank of the Champaran embankment in West Champaran: a roughly 10-metre breach at the 4 km mark near Khairatwa village in Bagaha-1 block (with reports suggesting expansion to 30 metres), and a second breach at Phuliyakhar village in Bairia block. A third breach was reported on the right bank in Kushinagar district, Uttar Pradesh. Floodwaters surged through downstream districts including West Champaran, East Champaran, Gopalganj, Saran, Muzaffarpur, and Vaishali, entering agricultural fields and low-lying settlements in villages including Agastya, Khairatwa, Chandrapur, and Nautan, with water reaching National Highway 727 in some areas.

The West Champaran district administration and Water Resources Department mobilized four executive-engineer-led response teams to Bagaha, Bettiah, Motihari, and Gopalganj for breach repairs and embankment protection. In Gopalganj, around 5 lakh cusecs of water from the barrage flooded multiple villages, with water entering homes across five panchayats. By 8 am on September 30, discharge at Valmikinagar had reduced to 1,86,200 cusecs, indicating a receding trend, though downstream reaches continued to experience temporary water level rises as the surge progressed.

The flooding occurred amid broader precipitation across border districts between September 26–27, which had already elevated water levels prior to the main surge. Other river systems in Bihar remained under pressure: the Bagmati stood at 37.4 metres (1.5 metres below its High Flood Level) in Khagaria, while the Kosi measured 35.24 metres (1.16 metres below HFL). The Khagaria district administration deployed 10 boats, identified 66 community kitchens, and established seven relief camps, with approximately 2,000 people affected by disrupted mobility.