Rescuers in Nepal have made a breakthrough in their search for workers potentially trapped within hydropower tunnels following a devastating glacial collapse last month. The disaster occurred on August 26, when a large glacial lake outburst flood sent massive waves of water, rock, and debris through the Bhotekoshi and Trishuli river valleys. The resulting inundation killed over 1,300 people and left more than 4,000 missing across Nepal and neighboring China.
The focus of the current rescue efforts has been the Trishuli 3A hydropower project, one of several facilities severely impacted by the flooding. Hundreds of workers were reported missing after the incident, many believed to be inside the tunnels that had been flooded or buried. Nepal’s mountainous terrain and reliance on hydroelectric energy have led to extensive underground tunnel systems, which posed significant challenges to rescue teams.
Australian geologist and engineer Andre Midk was brought in by Nepali authorities to assist with locating the buried hydropower infrastructure and planning rescue operations. Initial efforts involved piecing together satellite images, engineering schematics, and old maps to identify “Goldilocks zones,” or small underground spaces where survivors might have taken shelter. This approach guided rescuers to prioritize the project’s cable tunnel, which connects the underground powerhouse to the electric grid.
The rescue operations were painstaking and dangerous, requiring teams to excavate mud, blast through large rock formations, and build drainage channels to remove pooled water from inside the tunnels. Because of changes to the river flow after the flood, rescuers had to create a new canal to prevent the tunnels from refilling, ensuring the safety of both trapped workers and those conducting the rescue.
After more than a week of difficult work, rescuers succeeded in establishing a narrow access point within the cable tunnel. On September 4, they heard responses from survivors, including acknowledgment in the Nepali language. Two workers, both employed by the Nepal Electricity Authority, were located alive and immediately flown to Kathmandu for medical care.
Sources familiar with the rescue effort indicated that over 40 individuals may remain inside the tunnel, and occasional voices suggest there could be additional survivors. The rescue team remains cautiously hopeful as they continue to listen and search.
Mr. Midk, who has advised on previous major underground rescues in the Himalayas, described the moment of contact as emotional and underscored the ongoing challenges for survivors isolated in darkness for over a week. The newly rescued individuals face the difficult prospect of learning about the wider scale of the disaster and the loss of colleagues and friends.
Immediately upon arrival in Kathmandu, Mr. Midk plans to apply lessons from this operation to other at-risk hydropower sites in Nepal. He praised the dedication and courage of the rescuers, describing their efforts as nothing short of extraordinary under the circumstances.