Assam is witnessing one of its worst floods in recent years. At least 80 people have died, lakhs have been affected, and extensive damage has been caused to homes, roads, bridges and farmland. Thick layers of silt have buried houses, vehicles and livestock in several districts. Even as relief and rescue operations continue, many families have lost their homes, crops and livelihoods.
Floods are an annual phenomenon in Assam, but a combination of geography, heavy monsoon rainfall, silt-laden rivers, deforestation and riverbank erosion has made the state especially vulnerable. Here’s why the floods recur almost every year and why this year’s devastation has been so severe.
TIMELINE
1950: The Assam-Tibet earthquake triggers massive landslides across the eastern Himalayas, sending enormous quantities of sediment into the Brahmaputra and permanently altering the river system.
1950s onwards: Riverbank erosion becomes a chronic problem. Assam has since lost over 4.27 lakh hectares of land to erosion.
2001-2025: The state loses about 3,600 sq km of tree cover, accelerating soil erosion and increasing the amount of silt entering rivers.
2016: Floods claim 64 lives.
2017: 160 deaths.
2018: 45 deaths.
2019: 101 deaths.
2020: 124 deaths.
2021: 8 deaths.
2022: The deadliest flood year in recent times, with 181 deaths.
2023: 18 deaths.
2024: 110 deaths.
2025: 25 deaths.
2026: At least 80 people have died, lakhs have been affected and widespread damage has been reported across the state.
What causes floods in Assam?
Assam is surrounded by the Himalayas and the Patkai, Naga, Khasi and Garo hills. It receives intense monsoon rainfall every year, while nearly 40% of its land lies in the floodplains of the Brahmaputra and its 33 major tributaries. During the monsoon, these rivers swell rapidly and pour enormous volumes of water into the Brahmaputra, often causing it to overflow.
Why is Assam so vulnerable?
The Brahmaputra carries massive volumes of water and sediment from the Himalayas. Rivers such as the Siang, Dibang and Lohit descend steeply from Arunachal Pradesh before joining to form the Brahmaputra. As they enter the plains, the flow slows and the silt settles on the riverbed. Over time, this raises the riverbed, reduces its carrying capacity and significantly increases the risk of flooding.
What makes the floods worse?
Experts point to two major factors: shrinking forest cover and heavy siltation. Forests help bind the soil and slow rainwater runoff. As vegetation declines, runoff accelerates, increasing soil erosion and depositing larger quantities of silt in rivers. The accumulated sediment reduces the rivers’ capacity to carry floodwaters during heavy rains.
How did the 1950 earthquake change the Brahmaputra?
The Assam-Tibet earthquake triggered thousands of landslides across the eastern Himalayas, dumping huge quantities of sediment into the Brahmaputra. Over the decades, this has raised sections of the riverbed, reduced the river’s carrying capacity and contributed to recurring floods.
What role does riverbank erosion play?
Flooding and erosion are closely linked. Fast-flowing rivers erode riverbanks every year, washing away villages, farmland and roads. According to government data, Assam has lost more than 4.27 lakh hectares of land to riverbank erosion since the 1950s.
What measures are being taken?
The Assam government has built embankments, undertaken river-training works and strengthened early warning systems. Its Hydro Informatics Unit uses scientific data and real-time forecasting to improve flood monitoring and issue advance warnings.
How is Nagaland linked to the floods?
Nagaland also received prolonged heavy rainfall during the monsoon. In Assam, there is a perception that runoff from denuded hills in Nagaland, where mining has altered parts of the landscape, aggravated flooding downstream. While this has not been conclusively established, Assam government officials say greater afforestation in neighbouring hill states could reduce soil erosion and the amount of silt entering rivers as part of a long-term flood mitigation strategy.
Why were Sivasagar and Charaideo worst affected this year?
According to the Assam government, extremely heavy rainfall upstream, coupled with local rainfall that was 436% above normal, triggered severe flooding in Sivasagar and Charaideo. The swollen Dikhow River inundated vast areas, while thick deposits of silt buried agricultural land and settlements, causing widespread damage.
Has Assam sought a permanent solution?
Yes. Successive governments and several political and social organisations have repeatedly urged the Centre to declare Assam’s recurring flood and erosion crisis a “national problem” and implement a comprehensive long-term strategy.
What relief has been announced?
The Assam government has announced ₹9 lakh for the families of those who died in the floods and ₹15,000 as interim cash assistance for more than one lakh severely affected families. Relief distribution and rehabilitation efforts are continuing across the affected districts.
What lies ahead?
Once the floodwaters recede, the immediate priorities will be restoring agriculture, rebuilding homes, reviving livelihoods and ensuring access to healthcare. Beyond immediate relief, long-term flood mitigation will require sustained planning, better watershed management and close coordination between the Centre and the Assam government.