A series of catastrophic flash floods triggered by a glacial collapse in the Trishuli River basin has dealt a severe blow to Nepal's energy infrastructure, destroying or severely damaging 12 hydropower plants and knocking out more than 10% of the country's total power generation capacity. More than 1,200 people have been confirmed dead, with thousands still unaccounted for, and potentially hundreds of hydropower workers and engineers are feared trapped inside mud-filled tunnels at the damaged facilities. The disaster has forced a reckoning with Nepal's near-total dependence on hydropower — a strategy that brought the country remarkable progress but that critics say carries increasingly dangerous risks in a warming climate.

Nepal, a landlocked Himalayan nation wedged between India and China, generates almost 100% of its electricity from hydropower and earns nearly $200 million annually by exporting electricity to India and Bangladesh. The country's 225 operational plants represent over 3,900 megawatts of installed capacity, and hundreds more facilities are under construction or planned. This expansion transformed the country: as recently as 2010, only two-thirds of Nepalis had access to electricity, and even connected households endured power cuts of up to 16 hours a day. By 2018, most of the country had 24-hour supply. The Upper Trishuli-1 project — among the plants all but destroyed by the floods — was valued at approximately $647 million and was backed by the Asian Development Bank and the International Finance Corporation. A neighbouring project, the Upper Trishuli 3A, was funded by China's Export-Import Bank. Critics of international lenders argue that disaster risks in the Trishuli basin were well documented, pointing to flood events in 2024 and a glacial lake outburst from Tibet's Gyirong county in July 2025 that killed at least 11 people and shut the Nepal-China border for nearly six months.

The disaster has exposed a structural vulnerability in how most of Nepal's plants are designed. Built high in the mountains to exploit fast-flowing currents, most require little or no water storage — meaning they are highly exposed to sudden glacial events and have no buffer capacity. Preliminary investigations suggest last week's flood was triggered by a collapsed glacier and its bedrock. The high-altitude zones of the Himalayas are warming approximately 50% faster than the global average, and Nepal's own Disaster Risk Reduction and Management Authority has recorded that more than nine in ten disaster events between 2018 and 2024 were climate-related. The Nepal Electricity Authority has acknowledged that even where climate risk assessments were conducted, plant designs may not have reflected their findings.

The question now is what comes next. Nepal's former energy minister Kulman Ghising has called the floods a "once-in-a-century" event and urged stronger plant design, better site selection, and robust early-warning and evacuation systems. Officials at the Nepal Electricity Authority are weighing a shift toward reservoir-based plants at lower altitudes, which could store and release water more flexibly, though such projects carry significant economic and environmental costs of their own. Renewable energy expert Kushal Gurung, founder of clean-tech firm WindPower Nepal, argues that the country must urgently diversify, noting that solar potential in Nepal is estimated to be roughly ten times larger than its hydropower potential. Researchers at Columbia University echo this view, describing wind and solar additions as a resilience strategy that limits the risk of cascading electricity system failures. Others, however, caution that diversification has limits: hydropower remains Nepal's single most competitive energy advantage relative to its South Asian neighbours and cannot simply be replaced. Meanwhile, private plant operators are already feeling the financial pressure, with insurers having paid out around $40 million in flood-related claims over the past three years and premiums rising to levels that some in the industry describe as making business "unfeasible."

The floods have made plain that the very geography that makes Nepal one of the world's most promising hydropower producers also makes it acutely vulnerable to the consequences of a changing climate. Dr Arun Bhakta Shrestha, an expert on Himalayan environment and risk management, has noted that detecting glacier movements in advance remains extremely difficult with current technology — a sobering reminder that engineering ambition in the region must be matched by investment in monitoring, early warning, and genuine disaster preparedness. Whether Nepal and its international backers will translate that lesson into policy remains an open question.