KATHMANDU: Nepal has entered the ‘tunnel era’ with construction of tunnels on three major roads making significant progress.
Five tunnels having a combined length of 10.5 kilometers are currently under construction, while three tunnels covering 3.5 kilometers are entering construction soon.
The ongoing projects include the Nagdhunga-Naubise tunnel (2,688 meters), Siddhababa tunnel (1,126 meters), and three separate two-lane tunnels on the Kathmandu-Tarai/Madhesh Fast Track road – Lendanda (1,633 meters), Dhedre (1,728 meters) and Mahadevtar (3,355 meters). All tunnels, except the one at Mahadevtar, have achieved breakthroughs.
Likewise, three more tunnels on the fast track are in the design phase: Chandrama Bhir (2,250 meters), Devichaur (1,000 meters) and Sisautar (390 meters).
The government has announced plans to build over a dozen tunnels across the country. Preliminary works like feasibility studies, detailed project report (DPR) preparation, and environmental impact assessments (EIA) are underway for some of these projects.
Among the five tunnels under construction, Nagdhunga and Siddhababa are targeted for vehicle operation within a year. The tunnels on the fast track, however, will come into operation after the entire road project is completed.
Nagdhunga tunnel to be operational by October
The Nagdhunga-Naubise tunnel is slated to open by October 2025. The project, which is estimated to cost Rs 22 billion, has achieved 87% physical progress and 76.68% financial progress.
Senior Divisional Engineer Sanjay Panthi said the tunnel will be operational by October if there are no significant obstructions. “Works like concreting, electrical wiring, ventilator installation and finishing inside the tunnel is currently underway,” Panthi said. “If there are no further disruptions, we will complete the remaining work and open the tunnel by October.”
However, the construction company has proposed revising the timeline, according to Panthi.
The 2,688-meter main tunnel achieved breakthrough on April 25, 2024, while the 2,557-meter emergency tunnel breakthrough was achieved on August 23, 2023. Three underpasses, four box culverts, one overpass and three bridges under the project have already been constructed, while a flyover in Balambu has achieved 95% physical progress with only railing and finishing works remaining.
Of the 9,956.11 meters of approach, ramp and other roads, 6,562.05 meters have already been built.
The tunnel is being constructed by Japanese contractor Hazma Ando JV.
Siddhababa Tunnel will be ready within a year
The Siddhababa tunnel, a project of national pride, is expected to come into operation within a year – ahead of its scheduled timeline.
According to Chief Senior Divisional Engineer of the Siddhababa Tunnel Project, Krishna Raj Adhikari, work is making significant progress and could be completed ahead of schedule. “Lining, concreting and culvert construction work are currently underway. Likewise, slope stabilization, helipad construction and culvert work are in full swing outside the tunnel,” Adhikari said. “Equipment procurement is also underway. We aim to complete all work and open the tunnel within 11–12 months.”
The project has achieved 45.58% physical and 43.8% financial progress, according to Adhikari.
The 1,126-meter main tunnel achieved a breakthrough on January 24, 2025. Construction of three bypass tunnels have also been completed. Of the 2,300 square meters of slope protection required on the southern side, works have been completed on 1,495 square meters, while 495 meters of the 1,100-meter northern slope protection is complete.
Built under the Engineering, Procurement, and Construction (EPC) model by China State Construction Engineering, the tunnel lies on the Butwal-Tansen section of the Siddhartha Highway, from Siddhababa Temple to Dobhan in Palpa, a high-risk landslide area. Once operational, it will provide relief from landslide risks for residents of Palpa, Baglung, Gulmi and other districts.
Which vehicles can use the tunnels?
The government has drafted an operational guideline for tunnels, which is awaiting approval, according to the Ministry of Physical Infrastructure and Transport.
According to Panthi, two-wheelers, three-wheelers and trucks carrying petroleum productions will be prohibited on Nagdhunga-Naubise tunnel.
However, no specific vehicle restrictions have been finalized for Siddhababa Tunnel. Given the tunnel’s purpose of avoiding landslide risks, it is likely that most vehicles will be permitted.
The draft guideline proposes a toll fee for tunnel use, ranging from Rs 50 to Rs 500 depending on the vehicle type. However, these rates may change upon approval of the guideline.
