Race against time to find workers missing in Nepal’s hydropower tunnels. Here’s what we know

Nepal’s Flood-Buried Power Tunnels: A Desperate Search for Hundreds of Trapped Workers

Activelifezero.com – Flash floods that tore through Nepal’s mountain corridors last week have swallowed entire sections of hydropower infrastructure, leaving at least 933 workers unaccounted for across multiple projects threaded along the Trishuli river. The country’s disaster management agency confirmed the figure as rescue teams, foreign geological specialists, and military units converged on the affected districts in one of the largest coordinated search-and-rescue operations the Himalayan nation has ever mounted.

The Trishuli, a fast-flowing tributary of the Gandaki system, carves through some of the most remote and rugged terrain in southern Asia. Hydropower stations built along its course over the past two decades were designed to convert the river’s enormous kinetic energy into electricity for Nepal and its neighbors. Now those same tunnels and chambers sit buried under meters of mud and debris, and the question haunting every rescuer on site is simple and terrifying: how many of the missing workers are still breathing inside?

Scale of the Loss and the Geography of the Problem

A tally assembled by Nepal’s Independent Power Producers’ Association (IPPAN) on Saturday placed roughly 900 workers missing across eleven separate hydro facilities struck by the flooding. Each installation presents a distinct layout, depth profile, and access challenge, meaning no single rescue playbook applies to all sites simultaneously. Internal passages in several plants stretch several kilometers, so a worker caught inside could be separated from the nearest portal by a vast distance of reinforced concrete and steel.

Survival odds depend heavily on what remains intact within those sealed spaces. Storage rooms, kitchens, and cached supplies could theoretically sustain trapped individuals for days or even weeks. The more immediate threat is oxygen: without ventilation, air in a sealed chamber depletes quickly, and the window for rescue narrows with every passing hour. Compounding the difficulty, the floods destroyed roads and bridges that normally provide access, while persistent poor weather grounded many aerial assets and slowed ground teams to a crawl.

Trishuli 3A: Drilling Into a Four-Kilometer Dark

At the Trishuli 3A hydropower plant, forty-two workers were listed as missing when the flood struck. The tunnel connecting the surface portal to the underground powerhouse, where dozens of personnel were on shift at the moment of impact, extends more than four kilometers (2.5 miles) into the mountainside. Arnold Dix, an Australian geologist advising the rescue operation at that site, explained the uncertainty facing crews attempting to bore through the tunnel’s roof.

“So, we might only have to dig 10 meters, or we might have to dig 100 meters.”

Dix noted that if the plant’s emergency shutdown systems failed during the flood, the turbine room itself could have filled with water, drowning anyone still inside. Worse, that accumulated water could be released suddenly by the very drilling meant to create an access shaft, endangering the rescuers working above. Breaking through the heavily fortified structure surrounding the turbine room demands specialized cutting equipment capable of penetrating multiple layers of steel and reinforced concrete.

“We need special equipment to get through the steel and everything that’s surrounding the turbine room. So, it’s layer upon layer of technical difficulties.”

Despite those obstacles, crews at Trishuli 3A managed to open a hole large enough to rappel personnel inside using ropes and harnesses. They called out into the darkness. No answer came. In earlier attempts, teams pumped fresh air into the tunnel and lowered food supplies through the shaft, buying time for workers who might still be alive below.

Chilime: Chest-Deep Mud and a 130-Meter Standstill

At the Chilime Hydropower Plant, six workers are believed trapped. Jenjen Lama, a mountain guide participating in the search-and-rescue effort, described the facility’s layout to reporters on Monday: a 250-meter (820-foot) tunnel descending before joining a larger complex that houses a service bay, control room, and the main transformer.

On Sunday, teams entered the tunnel and found it “completely blocked by deep, muddy sediment and sludge,” with the debris reaching up to their chests. They advanced only 130 meters before conditions forced them to halt. Lama added that damaged infrastructure in the surrounding area made helicopter landings extremely difficult, limiting aerial resupply and extraction options.

“There is the kitchen, there is some food … but I don’t know about the oxygen.”

International Reinforcement and the Broader Toll

Nepal’s army engineers and police search-and-rescue units were joined over the weekend by specialist teams dispatched by India and China, both of which have invested heavily in Himalayan hydropower development alongside Nepal. Together, the combined forces deployed thermal-imaging cameras mounted on drones to scan for heat signatures of survivors, located tunnel entrances obscured by debris, and cleared mud from access routes. Simultaneously, ground crews drilled through the reinforced roofs of the tunnels to create vertical access points.

Dix estimated that as many as twenty-seven hydropower plants sustained damage in the floods, with approximately twelve rendered all but destroyed. The scale of infrastructure loss underscores how concentrated Nepal’s energy ambitions have become in a handful of river corridors, and how vulnerable that concentration is to a single extreme weather event.

Survivors and What Comes Next

At least 279 hydropower workers have been rescued or have managed to walk their way out of the mud- and silt-choked tunnels. Each survivor carries a harrowing account of hours spent in darkness, wading through debris, or clinging to equipment while floodwater rose around them. Their testimonies are now being used to refine rescue strategies at sites where workers remain unaccounted for.

Officials confirmed on Monday that the next phase at Trishuli 3A will involve sending fully equipped rescuers into the tunnel carrying oxygen supplies, medical kits, two-way communication gear, and cameras, in an attempt to make direct contact with any survivors still inside. The operation will proceed only when conditions permit safe entry, and every minute of delay is measured against the dwindling air supply in those sealed chambers.

For a nation that has staked much of its economic future on turning Himalayan rivers into electricity, the floods have exposed a painful vulnerability: the very infrastructure built to power the country can become a tomb when the mountain’s fury exceeds the engineering margins. Nepal’s neighbors, watching from across the border, face the same question about their own Himalayan projects. The answer, for now, is buried under mud.