Deforestation and unscientific hill cutting in neighbouring upstream states like Nagaland and Arunachal Pradesh accelerate surface runoff and soil erosion. This unleashes massive volumes of water and sediment down a natural geographical funnel into the flat plains of Assam, rapidly overwhelming river channels and breaching local embankments.
On July 19, 2026, floodwater tore through Sivasagar, Charaideo, Jorhat and Golaghat districts in Upper Assam. By July 31, the death toll stood at 80, according to the Assam State Disaster Management Authority (ASDMA). More than 2.12 lakh people remained affected, and over 17,000 hectares of cropland lay underwater. Sivasagar, the worst-hit district, accounted for the largest share of the affected population, while neighbouring Charaideo remained among the hardest hit. Thousands of displaced people were still living in relief camps, with many more relying on relief distribution centres, according to the ASDMA's July 31 report.
Critically, Chief Minister Himanta Biswa Sarma said Friday that the government has yet to reach around 30% of areas in the Nazira Assembly constituency and around 20% in the Sivasagar constituency, both in Sivasagar district, even after water levels have come down.
He said this is because receding floodwaters have left behind layers of sediment several feet high, making it difficult to access these areas on foot or by vehicle.
Over the course of the week, the Brahmaputra tributaries that flow through this belt have been flowing well above their “danger levels”. As of Friday, the rivers Dikhow in Sivasagar, Disang at Nanglamoraghat and Dhansiri at Numaligarh were all flowing in a “severe flood situation”.
The unpredictable Brahmaputra River shapes Assam's flood landscape, originating in the Tibetan plateau, and flows through Arunachal Pradesh and Assam before emptying into the Bay of Bengal. The river is joined by substantial tributaries from neighbouring states and countries. This river system is vital for the region's ecology and economy but makes Assam susceptible to annual flooding.
According to the Rashtriya Barh Ayog, almost 40% of Assam's land is flood-prone, nearly four times the national average. According to the ASDMA, major floods have occurred in Assam in 1972, 1974, 1978, 1983, 1986, 1988, 1996, 1998, 2000, 2004, and 2012. Since then, there have been annual flash floods and long-term inundations in 2018, 2020, 2021, 2022, and 2024.
Historical data show a troubling trend of rising flood impacts. From the 1950s to the early 2000s, the average annual flooded area and affected cropland increased. The number of affected people surged from 860,000 to over 4.5 million in the early 2000s. The economic damages increased more than 120-fold annually. According to the Assam State Disaster Management Authority (ASDMA), 838 people died in floods from 2013 to 2022. The toll peaked in 2022 at 181 flood-related deaths - the highest in a decade.
Assam is used to the annual floods, but the authorities and the inhabitants of three historically near-untouched districts — Charaideo, Jorhat, and Sivasagar — have borne the brunt this time. The Assam government told the 126-member Assembly on July 23 that the situation has been the worst in 60 years. Scientists say climatic uncertainty is the “new normal” and no part of Assam or the rest of the northeastern region can or hope to stay unaffected.
The deluge that mainly hit the state's eastern districts of Sivasagar, Charaideo and Jorhat caused massive destruction, leading to over 60 deaths and impacting over seven lakh people in just four days, between July 21 and 24 July.
What makes 2026 different is that this wasn't the Brahmaputra overflowing as usual; it was flash floods from south bank tributaries like the Dikhow and Disang, fed by extreme rainfall in Nagaland's hills, hitting Upper Assam, a region that doesn't usually see this scale of damage. Floodwaters are receding in parts, relief and compensation are underway, but IMD has flagged more heavy rain through August 1, so the crisis isn't fully closed yet.
To combat downstream flooding aggravated by hill deforestation and unscientific land use, the Government of India and the state governments have shifted from traditional, isolated flood protection to transboundary basin governance, nature-based engineering, and technology-driven resilience.
Even as the flood situation gradually improves in parts of Upper Assam, thousands of families are still struggling to return to normal life. While government agencies continue rescue and rehabilitation work, citizens, social media influencers, student bodies, NGOs and community organisations have stepped in to support people in villages that remain cut off or are receiving limited assistance.
According to official figures, the floods have claimed more than 75 lives so far and affected over 3.3 lakh people across the state. Relief operations are continuing through 81 relief camps and 34 relief distribution centres. Personnel from the Army, Air Force, NDRF, SDRF and the civil administration remain deployed in the worst-affected districts.
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