A week after catastrophic glacier-triggered floods devastated northern Nepal, rescuers battle thick silt and debris in underground powerhouses while families cling to fading hope for trapped hydropower workers.

A week after a massive flash flood triggered by a glacier collapse near the Nepal-China border unleashed a torrent of ice, rock, mud and debris down the Bhotekoshi and Trishuli river valleys, rescue teams continue to struggle against nearly impossible conditions to reach hundreds of hydropower workers feared trapped in underground tunnels and powerhouses. The August 26 disaster has claimed hundreds of lives – with official death tolls climbing past 900 and thousands more still missing across the border region – while special attention focuses on the roughly 900 to 947 workers linked to multiple hydropower projects who remain unaccounted for.

Of those, many are believed to be sealed inside vast networks of tunnels and underground facilities filled with thick, sticky mud and silt rather than simple rockfalls. Around 279 workers have been rescued or managed to emerge under their own power from the mud-riddled sites, but contact has yet to be established with those still inside at key projects including Upper Trishuli-1, Upper Trishuli-3A, Upper Trishuli-3B, Rasuwagadhi, Chilime and Langtang Khola.

PM Shah: Immediate Tunnel Rescues Not Feasible

Prime Minister Balendra (Balen) Shah addressed the House of Representatives on Wednesday, September 2, stating bluntly that immediate rescue operations inside the flooded hydropower tunnels are not possible. Thick mud inundation – a rare and complex challenge for which Nepal lacks specialised immediate-extraction technology – means teams must wait until conditions dry and stabilize before safe entry can occur. Rugged terrain further prevents the rapid deployment of multiple excavators at tunnel mouths. Expert teams from Nepal, India and China remain actively engaged on site, Shah said, urging the public and media to support security forces rather than criticise delays amid the hazardous conditions.

The disaster’s unique nature has complicated standard approaches. Experts note that typical landslide-clearing methods do not apply when entire tunnel systems are packed with slurry-like sediment deposited by the floodwaters. At sites such as Trishuli 3A, teams have drilled openings, pumped air, lowered cameras and even used controlled blasting, yet responses from inside have been absent in several cases.

Families Demand Answers as Hope Fades

Families of the missing have grown increasingly vocal and frustrated. Narayani Joshi, whose husband is among about 40 people believed trapped in the underground powerhouse of the 60-megawatt Upper Trishuli-3A project, described a week of agonising uncertainty. “We have been told the powerhouse is intact, so we are clinging to the hope that they are still alive,” she said. “How can the government be so slow? Why aren’t better equipment and pumps being used?”

Similar anguish is felt at other sites. More than 550 people are reported missing from the 216-megawatt Upper Trishuli-1 project alone, despite 254 rescues from the surrounding area. At Upper Trishuli-3B, 191 remain unaccounted for; Rasuwagadhi has 93 missing; Langtang Khola 41; and Chilime eight. Relatives have confronted project operators, including gatherings at PowerChina offices in Lalitpur that required police mediation. Many insist technical specialists from the developers should have been mobilised from the first day.

Home Minister Sudan Gurung has insisted the State has not lost hope, noting the possibility that some survivors may still be drawing on residual water or air pockets inside the structures. “Our security teams are still working at the site. We are also looking at whether we can drill down from above,” he said. Joint operations now include Nepali Army and police personnel alongside Indian, Chinese and South Korean specialists, plus sniffer dogs in some locations.

Ground Reality: Mud, Bodies and Inadequate Gear

First-hand accounts from the affected districts paint a grim picture of the broader rescue environment. Journalist Rajneesh Bhandari, reporting from Rasuwa and Nuwakot, described markets reduced to mud, slurry and debris, with houses swept away or buried. Bodies lay exposed in places such as Betrawati while a foul odor spread; locals complained of slow recovery of the dead. Police officers told him they were forced to enter collapsed houses without ropes or proper safety equipment, risking further collapses.

Access remains a critical bottleneck. Roads and bridges were destroyed across large stretches, forcing reliance on helicopters and long foot approaches. Overnight rain has repeatedly refilled excavation pits. At some tunnel entrances, rescuers have advanced only limited distances – sometimes just dozens or a few hundred metres – before being halted by chest-deep mud or complete blockages. In one early foray, teams called out after descending but received no reply.

Survivors who escaped the initial surge have recounted walls of water chasing them through darkness, gripping roof rungs as concrete and debris swept past. Those who made it out describe colleagues left behind in the tunnels. The Independent Power Producers’ Association of Nepal has stressed that while some underground rooms might theoretically sustain life for days or longer if air supply holds, the window is narrowing.

Multi-Nation Effort Meets Engineering Limits

Nepal initially indicated its own forces could handle general search-and-rescue but quickly sought specialised tunnel expertise from neighbours India and China. Teams have used heavy machinery, hydraulic cutters, thermal cameras on drones, air compressors and controlled explosions. At Trishuli 3A, a joint force of around 90 personnel has worked around the clock. Progress has been incremental: locating buried entrances, clearing sediment, attempting to reach powerhouse levels. At Rasuwagadhi, partial tunnel clearance has occurred but the path to the underground powerhouse remains blocked.

Climate change has been repeatedly cited by officials, including the prime minister, as amplifying risks in the Himalayan region. The glacier collapse that initiated the flood underscores growing vulnerabilities for communities and the hydropower infrastructure on which Nepal depends for the vast majority of its electricity. Reconstruction costs for damaged projects and infrastructure could run into billions of dollars.

Coordination Challenges and Lingering Risks

Local leaders and former officials have pointed to coordination gaps between central government, provincial authorities and project operators in the early days. Technical teams from developers arrived later than many families wanted. Ongoing concerns include the risk of secondary flooding from temporary barrier lakes formed by debris, unstable slopes and the sheer volume of sediment – estimated in the millions of tonnes – that must be managed.

As operations enter a second week, the focus remains dual: recovering those who may still be alive inside the sealed underground spaces while systematically retrieving bodies and supporting devastated communities. Security personnel continue labouring in hazardous conditions with limited specialised tools for mud-filled tunnels. Families wait, oscillating between fragile hope and deepening grief, as every passing hour without contact weighs heavier.

The scale of the challenge – vast tunnel networks, unprecedented siltation, destroyed access routes and the absence of rapid mud-extraction technology – has made this one of the most complex rescue efforts in Nepal’s recent history. Authorities maintain that every feasible step is being taken under the circumstances.