The Assam government has issued a state-wide high alert across several downstream districts following intense, torrential monsoon rainfall and flash floods in the upper catchment regions of Arunachal Pradesh.
Satellite data and regional meteorological centers confirmed that the Yazali station in Arunachal’s Lower Subansiri district recorded 72.8 mm of rainfall, a massive portion of which fell during a three-hour cloudburst window between 6:00 AM and 9:00 AM on Wednesday, June 24, 2026.
Emergency Dam Operations & Rising River Levels
The sudden water surge heavily impacted the upper catchments, triggering immediate crisis protocols at the Panyor Lower Hydroelectric Project (formerly known as the Ranganadi Hydroelectric Project).
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Spillway Release: To manage the massive inflow of water and debris, engineers were forced to open a spillway gate to discharge excess water.
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Downstream Surge: This controlled release, combined with ongoing run-off, is causing a rapid rise in water levels and river velocity along the Brahmaputra and its key northern tributaries.
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Target Districts: The initial flood wave is modeled to hit the districts of Dhemaji, Lakhimpur, Biswanath, and Sonitpur before traveling down to Dhubri over the next 48 hours.
Severe Infrastructure Damage and Missing Persons
The flash floods have caused severe structural damage across the border regions, disrupting critical transport and communication links:
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Keyi Panyor District (Arunachal): A massive landslide engulfed road stretches near the NEEPCO project area (KM 43). Deputy Commissioner Sweta Nagorkoti confirmed that 18 houses in the NEEPCO colony were entirely washed away and 3 people are currently reported missing. Furthermore, the local helipad has been rendered completely non-operational, temporarily blocking incoming Indian Army or IAF rescue choppers.
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National Highway 315 (A) Collapse (Assam): Continuous downpours triggered three massive landslides near the Kathalguri Beat Office inside the Dihing Patkai National Park. Nearly half of the newly reconstructed hillside roadway collapsed into a deep gorge, fracturing the primary transit route connecting Jeypore (Dibrugarh district) with Deomali and Khonsa in Tirap.
Government Response and Safety Directives
On the direct orders of Chief Minister Himanta Biswa Sarma, the Chief Secretary of Assam has mobilized the State Disaster Response Force (SDRF) and the National Disaster Response Force (NDRF) for immediate positioning at vulnerable river banks.
Official Advisory for Citizens:
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Evacuate Low-Lying Zones: Residents in low-lying, flood-prone areas are advised to immediately move toward designated higher ground or relief centers.
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Strict Boat Ban: Citizens must completely avoid traversing the Brahmaputra or its tributaries using small country boats or private vessels due to violent undercurrents.
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Night Traffic Prohibitions: Authorities have officially banned all vehicular movement between 6:00 PM and 6:00 AM along the unstable Jeypore-Kathalguri highway stretch.
