Why Were Rescue Efforts Delayed for Nine Days for Those Trapped Inside the Bhote Koshi-Trishuli Tunnels Following the Floods?
Image source, Reuters
More than nine days after the floods, officials report that only four individuals trapped inside various hydropower tunnels and powerhouses have been rescued alive.
The Nepali Army has retrieved three bodies from tunnels in different projects. On Thursday, two additional bodies were recovered from the Langtang Khola hydropower tunnel, according to the project’s promoter.
Tunnel technology experts, those present at rescue sites, and officials were interviewed to understand the challenges faced.
“If Permission Had Been Granted Initially…”
Image source, Nepali Army
On the ninth day after the flood, the Nepali Army recovered two bodies from Langtang hydropower project’s tunnel in Rasuwa.
Previously, rescue workers attempting to enter the flooded tunnel at the project site could only penetrate about 100 meters inside.
Project Managing Director Vijay Mohan Bhattarai said, “Had the Nepali Army allowed technical teams to enter from the very beginning, many trapped inside the tunnel could have been rescued alive.”
“We had requested from day one to deploy a technical team immediately. Hydropower structures are unlike other buildings. If permission had been granted, lives could have been saved,” Bhattarai added.
Bhattarai claimed that upon granting access, the project immediately facilitated pathways and routes for evacuation and rescue.
“Our technical team entered through the bifurcation pipe, reached the top via the penstock pipe where we created holes to access the areas where people were trapped. Then the army entered to retrieve the bodies,” Bhattarai explained.
According to him, two bodies were recovered about 150 meters inside the tunnel.
A 150-meter tunnel was constructed from the tunnel entrance to the mouth of the penstock pipe carrying water to the powerhouse, where 15 workers remain out of contact.
Why Could No Entry Be Made into the Tunnel and Powerhouse?
Officials say that among the 12 hydropower projects in Rasuwa and Nuwakot, people are trapped inside tunnels or powerhouses of five projects.
In the Rasuwa-Gadhi, Langtang Khola, Chilime, Upper Trishuli 1, and Trishuli 3A projects, it is estimated that over 150 people are trapped in their tunnels.
Tunnel engineer and Member of Parliament Shriram Nyaupane explained that floods brought large boulders and debris which clogged the tunnel entrances, making access difficult.
Nyaupane, coordinating rescue efforts for Upper Trishuli 3A, noted it took considerable time just to find the tunnel entrances.
Different methods are being applied to other tunnel locations.
“Tunnels whose entrances face the direction the Trishuli River flows are filled with boulders, large stones, and gravel. Inside, there is water at the top and silt at the bottom,” Nyaupane said.
“Only trained rescue teams can navigate these tunnels. Extracting tunnels blocked by boulders requires specialized machines and technology.”
Due to road destruction beyond Nuwakot district headquarters, the Nepali Army has been unable to deliver necessary equipment, the army reported.
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Nepali Army spokesperson Rajaram Basnet mentioned that many tunnel entrances lack helicopter landing sites.
“There is no available space near tunnel entrances to place helicopters or bring in heavy equipment, so obstacles cannot easily be removed,” Basnet explained.
He also reported that so far, four individuals have been rescued from inside tunnels, and 289 people have been saved from tunnel areas.
Tunnel engineer Chhatra Basnet added, “The tunnel entrances of high-altitude hydropower projects are sealed tightly, which means there aren’t even platforms to land helicopters. At Upper Trishuli 3A, stockpiling of supplies brought from above has begun.”
“Tunnel entrances face the river, through which floods, mud, stones, and debris entered, complicating rescue operations further,” he noted.
Image source, Nepali Army
An estimated 25 people remain trapped in the powerhouse of Upper Trishuli 3A. The main entry point lies 30 to 35 feet above the river’s surface, with another cable tunnel nine feet above it. Floodwaters have deposited large boulders and slabs, even covering the audit tunnel, said Nepal Electricity Authority’s Deputy Manager Suresh Raut.
Upper Trishuli 1 is the most affected location, with approximately 115 people trapped. Workers are trapped in a tunnel extending about four kilometers from the water intake to the earlier audit tunnel point. The tunnel is blocked with large boulders, gravel, and mud, along with various machinery and trucks stuck inside, according to project General Manager Giriraj Adhikari.
Where Did Rescue Efforts Fall Short?
Image source, Nepali Army
Families of those trapped inside tunnels criticized the government for the delayed arrival of international expert teams and technical equipment.
Small advanced equipment provided by the United States only arrived in Kathmandu on Wednesday. The lack of equipment hindered a South Korean technical rescue team from advancing their work.
Tunnel engineer Basnet acknowledged, “We are using our own resources, but there is a clear shortage of the right equipment, manpower, and methodology.”
“If the appropriate manpower and equipment had been deployed at the right time, outcomes would have been better. Involving a team of designers, engineers, and managers is essential. However, without equipment, identification and rescue remain challenging.”
MP and former road project chief Nyaupane noted that despite experience building over 400 kilometers of tunnels, damage from the earthquake and floods has delayed rescue efforts.
“With similar equipment, only 80 to 100 meters of tunnel can be excavated in a day. Excavation is quick, but it’s extremely difficult to bring the equipment into these locations. We also lacked advanced machinery,” he said.
Image source, NepaliArmy
Langtang Khola project Managing Director Giriraj Adhikari expressed concerns emphasizing the need for a review of Nepal’s rescue processes.
“No one should be blamed now. I believed the Nepali Army would be exceptional in this, but even they lack proper equipment,” he stated.
Prime Minister Balindra Shah ‘Balen’ had previously noted the difficulty of conducting rescue operations even with helicopter deployment over the hydropower project tunnels. However, questions arise regarding delays in involving the private sector and bringing in foreign equipment and experts, for which the government needs to provide explanations.
“It is now time to reflect on whether correct rescue methods were used. Tunnel excavation methods exist, but specific rescue methods for those trapped must be developed,” said Basnet.
Tunnel engineer Basnet emphasized that this incident offers important lessons for future planning.
