Can Nepal’s hydropower boom withstand a changing Himalaya?

At Rasuwagadhi, a rock-ice avalanche on Langtang Lirung triggered a flood that sent mud, water, and rocks into a power tunnel. Bal Bahadur Majhi and three co-workers were trapped for two days and two nights without food or water. The incident matters because hydropower is central to Nepal’s plans for economic transformation.

Rasuwagadhi suffered three floods in 15 months. A glacier lake outburst flood came first, followed by a sediment-laden flood and then the August 2026 avalanche-triggered flood. These events damaged tunnel walls, pillars, pipes, power projects, and transmission lines. The disasters show how hazards can cascade through connected systems.

Nepal wants 30,000 megawatts by 2035, but the damage has prompted questions about safety, sustainability, and planning. Water expert Ajaya Dixit says institutions still rely on an older understanding of rivers. Some experts call the disaster exceptional; others say Nepal must pause and reconsider business as usual.

Hydropower generates electricity from moving water. A plant directs some river water through a tunnel, pipe, or channel toward a lower point. As the water falls, gravity gives it energy. That moving water spins turbines, and generators convert the turbines’ motion into electricity. The article describes this as catching the river’s elevation difference.

At Rasuwagadhi, the plant diverts part of the river into a tunnel. The tunnel carries water through a steep drop, allowing the plant to produce electricity. Energy expert Satish Joshi says shorter distances over which a drop occurs can make a site better economically. The plant therefore depends on both the river’s flow and the landscape’s shape.

This design also creates risks. Tunnels, pipes, walls, and other structures sit close to powerful rivers and unstable mountain slopes. Floods carrying mud, rocks, ice, or sediment can block or destroy them. Hydropower can produce large amounts of electricity, but its safety depends on understanding changing river and mountain conditions.

The August 2026 disasters caused damage far beyond one power plant. More than 6,700 people were killed or left missing. The disasters damaged 12 operating hydropower projects, 15 projects still under construction, and transmission lines. This scale shows that river disasters can affect people, electricity infrastructure, and future investment simultaneously.

Rasuwagadhi was among the most visible sites. A rock-ice avalanche on Langtang Lirung triggered a flood that struck the project in August. It followed a glacier lake outburst flood in July 2025 and a sediment-laden flood in July 2026. The repeated events demonstrate how several hazards can compound within a short period.

Estimated losses reached Rs150 billion. The article compares that amount with more than 90 percent of Nepal Electricity Authority revenue in the previous fiscal year. Such losses can strain public finances, delay construction, disrupt electricity networks, and increase pressure to improve project safety before expanding further.

A glacier lake outburst flood occurs when water suddenly escapes from a lake formed by melting glacier ice or unstable natural barriers. A sediment-laden flood carries unusually large amounts of loose soil, sand, and rock. A rock-ice avalanche is a rapid collapse of rock and ice down a mountain slope. These definitions use established scientific knowledge; the article names the hazards but does not define them.

The article records all three hazards around Rasuwagadhi. A glacier lake outburst flood struck in July 2025. A sediment-laden flood followed in July 2026. In August, a rock-ice avalanche on Langtang Lirung triggered another flood. The resulting slurry entered the project tunnel and destroyed walls, pillars, and pipes.

They are dangerous because they combine speed, mass, and force. Mountain valleys concentrate water and debris toward infrastructure and settlements. The article reports that the August disaster damaged projects and transmission lines across Nepal. It also shows that repeated events can leave little time for recovery between disasters.

Nepal sees hydropower as “white gold,” a source of wealth and a pillar of economic transformation. The country also experienced severe power cuts, with loadshedding reaching up to 18 hours a day. These conditions encouraged investment and helped create support for a 30,000-megawatt generation target by 2035. Hydropower is therefore both an energy plan and a development strategy.

The benefits are spread across several groups. Citizens were encouraged to buy hydropower shares through the “Nepal’s waters, people’s investments” campaign. Private investors could recover money by selling shares, while power purchase agreements with the Nepal Electricity Authority offered a predictable market. The state expected more electricity and economic activity.

The article does not identify a specific electricity export market or say exactly how the target’s power will be divided. It does show that licensing rose from 79 projects in 2024 to 241 in 2026. That rapid expansion increases the importance of deciding who gains and who carries the risks.

The consequences begin with people. At Rasuwagadhi, workers were trapped underground for two days and two nights after floodwaters destroyed tunnel structures. Nearby communities can face deaths, missing people, damaged infrastructure, and disrupted livelihoods. The article reports more than 6,700 people killed or missing in the August 2026 disasters.

Projects can stop operating when floods damage tunnels, pipes, plants, or transmission lines. That can reduce electricity generation and make it harder to move power through the network. Investors also face delays and losses. Nepal encouraged citizens to buy hydropower shares, while private companies invested heavily in projects built around power purchase agreements.

The wider economy absorbs the damage through reconstruction costs and lost revenue. The August disasters affected 12 operating projects and 15 under construction. Losses reached Rs150 billion, more than 90 percent of Nepal Electricity Authority revenue in the previous fiscal year. Repeated disasters could make expansion more costly and risky.

The article does not identify alternative power sources or a detailed risk-reduction programme. Based on established energy practice, Nepal could diversify with solar and wind generation, battery or pumped storage, and stronger regional electricity connections. A broader mix would reduce reliance on any single mountain river system, although each option has its own costs and environmental effects.

Risk reduction should begin with better information and planning. Nepal could map flood, landslide, avalanche, and glacier-lake hazards before approving projects. It could strengthen monitoring, warning systems, evacuation plans, tunnels, barriers, and emergency communication. Workers also need clear, practiced procedures. At Rasuwagadhi, workers had received instructions, but the disaster still trapped them underground.

The article’s strongest proposal is institutional change. Ajaya Dixit says hydropower has been designed in silos and that rivers have changed through diversion and dam building. Nepal could assess projects across whole river systems, update design standards, and pause expansion where risks are poorly understood. These strategies are broader knowledge beyond the article.