Increasing Severity of Floods in Arunachal Pradesh: A Growing Concern

Gangtok, India Jul 21, 2026 ALN: All photos by Marina Dai

After hours of heavy rain, a flash flood swept through Possa village and the North Eastern Electric Power Corporation (NEEPCO) colony in Yazali Circle of Arunachal Pradesh’s Keyi Panyor district on the morning of 24 June, destroying homes, damaging infrastructure, and forcing residents to flee with little warning.

“We never imagined the water would come this way,” recalled a resident who has lived in the NEEPCO colony for nearly 35 years.

“It had been raining since early morning. When I woke up around 7 a.m., the river looked normal. We saw people moving their vehicles because they thought the water level might rise. Even then, no one expected the flood to come from this direction.”

According to her, the main river remained within its course. Instead, a smaller stream that usually flowed quietly through the settlement suddenly turned into a raging torrent.

“We had never seen anything like this. People ran with only the clothes they were wearing. Some didn’t even have time to put on slippers.”

For many residents, it was unlike anything they had experienced in decades. The suddenness and intensity of the flood left families scrambling to save their lives and belongings, highlighting the vulnerability of communities in this region to extreme weather events.

However, Keyi Panyor was not an isolated tragedy. It became one of the clearest reminders of how destructive this year’s monsoon has been across Arunachal Pradesh. The state has a history of heavy rainfall and flooding, but the recent events have raised alarms about the increasing severity and frequency of such disasters.

According to the Department of Disaster Management’s Daily Situation Report dated July 20, the state recorded 173 landslides, 104 flood incidents, 80 heavy rainfall events, and eight flash floods during the season. These disasters affected 594 villages across 337 administrative circles, impacting nearly 1.49 lakh people. Fifteen people lost their lives, including four in flash floods, while roads, bridges, drinking water systems, power lines, and other critical infrastructure suffered extensive damage.

Districts from East Kameng, Changlang, Lower Dibang Valley, Upper Subansiri, and East Siang also reported repeated floods, landslides, and damaged infrastructure. The cumulative effect of these disasters has disrupted livelihoods, forced families to evacuate, and strained local resources, raising concerns about the resilience of communities in the face of climate change.

Scientists point to both rainfall and the landscape it fell on.

According to the India Meteorological Department (IMD), rainfall over Arunachal Pradesh between 1 June and 10 July was characterised by short-duration, high-intensity spells rather than being evenly distributed throughout the season. This pattern of rainfall is particularly concerning as it can overwhelm local drainage systems and lead to rapid flooding.

During this period, the state recorded 22 heavy rainfall events, nine very heavy rainfall events, and two extremely heavy rainfall events. Dr A. Sandeep, head of the IMD’s Meteorological Centre in Itanagar, said the monsoon exhibited pronounced intra-seasonal variability, with intense downpours interspersed with comparatively dry periods.

While a single season is insufficient to establish a long-term climatic trend, he said, such concentrated rainfall substantially increases the likelihood of flash floods and landslides in mountainous regions. The unique topography of Arunachal Pradesh, characterised by steep hills and narrow valleys, exacerbates the impacts of heavy rainfall, making the region particularly vulnerable to flash floods.

The intense rainfall created the conditions for flooding, but Arunachal’s steep terrain and small river catchments made the flood more severe. Gyati Gyuth, a scientist in the Division of River Basin at the Centre for Earth Sciences and Himalayan Studies, explains that what happens after the rain falls is equally important.

In the Yazali–NEEPCO catchment, which covers only about 17 square kilometres, intense rainfall can quickly generate rapid surface runoff, causing rivers to swell within a short period and leaving communities with very little time to react. “A state like Arunachal has steep terrain that is inherently unstable and highly susceptible to landslides and flash floods,” Gyuth explained. “If rainfall intensity exceeds the soil’s infiltration capacity, rapid surface runoff increases peak discharge and the likelihood of flash floods. At the same time, increased soil moisture raises pore-water pressure, reducing soil strength and triggering landslides.”

According to Gyuth, his analysis also suggests that while the state’s overall rainfall may be decreasing, high-intensity rainfall events are becoming more frequent, accompanied by increasing maximum and minimum temperatures. This trend is concerning, as it implies a shift in the region's climate that could have long-term implications for water security, agriculture, and biodiversity.

Although he says these observations require continued long-term monitoring, they point to the need for closer scientific assessment of how mountain river basins are responding to changing climatic conditions. The interplay between climate change and local geography necessitates a comprehensive approach to disaster risk management.

Research Officer (Wildlife) Tajum Yomcha from the Office of the Principal Chief Conservator of Forests (Wildlife & Biodiversity), Itanagar, highlights the crucial role of forests in mitigating flood risks. He states that forests act as natural flood-control systems by absorbing rainfall, reducing surface runoff, limiting soil erosion, and slowing the movement of sediment into rivers. Healthy forests also recharge groundwater and sustain springs and streams during dry periods.

“Any change in forest cover will definitely have an impact on local weather and water security,” he said. “Healthy forests are not just important for biodiversity; they are essential for maintaining resilient mountain watersheds.” The loss of forest cover due to deforestation, agriculture, and urbanization poses a significant threat to the region's ecological balance and increases the risk of flooding.

According to Keyi Panyor Additional Deputy Commissioner Likha Tejj, Arunachal Pradesh needs a more institutionalised approach to disaster risk reduction. He called for greater public awareness, catchment restoration, scientific hazard mapping, better road planning in vulnerable areas, and stronger investment in research and early-warning systems. “This is not only a Keyi Panyor-centric disaster,” he said. “The state needs long-term research and an institutionalised approach to prevent such situations in the future.”

The call for a more structured response to disasters reflects a growing recognition of the need to adapt to changing climatic conditions. As extreme weather events become more frequent, it is imperative for local governments and communities to implement strategies that enhance resilience and reduce vulnerability.

For the families who witnessed the events of that morning, the river will never look quite the same again. Whether this flood remains an exception or becomes a warning for the future will depend on how Arunachal prepares for the seasons ahead. The challenge lies not only in immediate disaster response but also in long-term planning and adaptation to a rapidly changing climate.

As the region grapples with the implications of these floods, it serves as a reminder that proactive measures, community engagement, and scientific research are essential in building resilience against future disasters. The experiences of Keyi Panyor and similar communities can inform broader strategies for disaster risk management across the region, ensuring that lessons learned contribute to safer and more sustainable living conditions for all residents.

The author is a mentee of the Climate Change Media Hub at the Asian College of Journalism, Chennai. The programme is supported by Interlink Academy, Germany.

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