Nepal’s Catastrophic Floods Spark Debate Over Himalayan Hydropower Risks

KATHMANDU — In the wake of deadly flash floods and mudslides that struck Nepal’s Rasuwa district in late August, families of missing workers are demanding urgent government action while experts warn that the disaster may signal a dangerous trend for hydropower development across the Himalayas.

Sumana Shrestha Amatya joined protesters in the Nepali capital recently, urging officials to expedite searches for loved ones trapped inside hydropower facilities. Her husband, Sunil, a geologist, has not been heard from since the disaster. Describing the event, Amatya recalled, “It was like a Himalayan tsunami.”

The tragedy unfolded on August 26 when a glacier and its bedrock, spanning more than 3,800 feet, collapsed into a valley roughly 4,000 feet below. The impact generated 30-foot waves of boulders, water, and ice that surged downstream, destroying a multistory border building, approximately 70 bridges, and miles of highway. Twelve hydropower plants along the Trishuli River were buried under debris.

As of mid-September, authorities had recovered 1,400 bodies, with more than 5,000 still unaccounted for. According to Brigadier General Subas Jung Thapa of the Nepali Army, which is leading rescue operations, 121 of the dead or missing were trapped inside hydropower plants. Only three individuals have been rescued alive since efforts began.

Arnold Dix, an Australian tunneling expert assisting with the rescue, described the scene as resembling the aftermath of an explosion. “It’s removed the power stations from the surface, like they’re just not there,” Dix said. He noted that while the plants were constructed properly, the glacier collapse represented an unforeseen threat that will necessitate changes to future design standards.

The disaster has reignited scrutiny over the safety of hydropower projects in seismically active and glacially vulnerable regions. C.P. Rajendran, an Indian geoscientist critical of large-scale construction in the Himalayas, emphasized that the conditions leading to this tragedy could recur elsewhere in the region.

Critics have pointed to the role of international lenders, particularly the World Bank, which financed some of the affected projects. The Upper Trishuli-1 plant, one of the largest in the basin, cost Nepal more than $500 million and received approximately $300 million in loans and equity from World Bank groups. As of early September, an estimated 50 people were believed trapped there, though only five bodies had been recovered by mid-month.

Parineeta Dandekar, a river expert with the advocacy group South Asia Network on Dams, Rivers and People, accused the World Bank of producing flawed risk assessments that ignored the cumulative impact of building multiple projects in the same river system. The Trishuli basin now hosts 36 hydropower projects.

While initial analyses suggest global warming accelerated the glacier melt that triggered the collapse, experts debate the extent to which construction contributed. Dipak Gyawali, a hydropower engineer at the Nepal Academy of Science and Technology, argued that dynamiting is negligible compared to tectonic forces. However, he acknowledged that developers failed to adequately assess the compounded risks of concentrating so many projects in a single zone.

Austin Lord of the Stimson Center highlighted that the Trishuli basin has experienced deadly flooding for three consecutive years: extreme rainfall in 2024, a glacial lake outburst in 2025, and the recent glacier collapse. Lord and colleagues had published a warning just days before the flood, noting the area’s vulnerability to glacial lake bursts and landslides.

In response to inquiries, the World Bank stated that the Upper Trishuli-1 design was based on risk assessments using data available in 2018. The bank added that it would review any new implications for risk assessment and emergency response as information about the floods becomes available.

The Asian Development Bank, which provided a $60 million loan for the project, faced criticism after independent experts in 2024 reported that no climate resilience assessment had been conducted. The bank did not immediately respond to requests for comment on whether such an assessment was later completed.

Retired Indian ambassador Shyam Saran noted that while individual projects may appear safe in isolation, a cumulative environmental impact assessment of an entire river system reveals a different reality. He described the Trishuli as a high-risk area for dam construction.

The incident has prompted calls for a broader reevaluation of hydropower strategies in the region. According to Reuters, China and India have built 68 major dams in the Himalayas, with 101 more in development. China is currently constructing one of the world’s largest dams in Tibet, estimated to cost $170 billion and power 300 million people, despite concerns raised by Chinese geologists about its location over an active fault line.

As rescue efforts continue, advocates hope the tragedy will lead to stricter safety standards and a more comprehensive understanding of climate risks in Himalayan energy projects.