Heavy rainfall has triggered landslides, flash floods, and infrastructure damage across Arunachal Pradesh, creating downstream flood threats in Assam. A major landslide in Lower Siang district blocked the Siji River, while a railway bridge collapsed in Dhemaji district due to severe erosion.

Key Highlights

• A massive landslide blocked the Siji River at Siji–Magi Block Point in Lower Siang district, creating an artificial lake and increasing the risk of a sudden flash flood if the debris dam collapses.
• The Siji River flows into Assam as the Gai River, putting Likabali and downstream areas of Dhemaji district on high alert.
• Heavy rainfall (over 110 mm in 24 hours in parts of Arunachal and Assam) caused severe flooding, landslides and riverbank erosion.
• A railway bridge over the Simen River in Dhemaji, built in 1965, collapsed after riverbank erosion destabilised one of its piers, disrupting rail services between Murkongselek and Silapathar.
• The India Meteorological Department issued Red Alerts for several districts of Arunachal Pradesh, forecasting more than 200 mm rainfall within 24 hours.
• The Assam State Disaster Management Authority reported that over 22,000 people were affected by floods, including more than 15,000 people in Dhemaji district.

Disaster Response

• The Arunachal Pradesh State Disaster Management Authority advised residents to avoid riverbanks, evacuate vulnerable areas if required, and remain alert for sudden flash floods.
• The Border Roads Organisation restored the crucial Kimin–Potin Road within 36 hours, reconnecting several remote districts.
• The National Disaster Management Authority, State Disaster Management Authorities, and district administrations continue to monitor the situation through early warning systems and emergency response measures.

One-Line Wrap

The Arunachal landslides highlight the urgent need for integrated river basin management, early warning systems, and climate-resilient infrastructure across the Eastern Himalayan region.