KATHMANDU: Preparation has begun to devise a new technology to excavate tunnel to bring Yangri and Larke rivulets water to Kathmandu under the second phase of the much-awaited Melamchi Drinking Water Project.

The diversion tunnel was excavated by Drilling, Blasting and Mucking (DBM) technology to divert raw water from Melamchi rivulet to Sundarijal outlet in the first phase. As this method was more time-consuming with change in contractors, the Ministry of Water Supply and Melamchi Drinking Water Development Committee have mooted the new technology.

A cost estimation was also made to expedite the excavation work through DBM method to divert water from Yangri and Larke to the valley. The excavation of around 11km tunnel through this method has been estimated to cost Rs 10 billion.

Since excavation seems to cause delays while working through the DBM method, the Melamchi Drinking Water Project has made revision in a way to apply a new technology.

Yangri is nine kilometers away from Ambathan of Helambu Rural Municipality — the origin of the Melamchi rivulet, while Larke is two kilometer away from Yangri. Both Yangri and Larke rivulets are located in Panchpokhari Thangpal Rural Municipality of Sindhupalchok district.

Melamchi Project’s Deputy Executive Director Kamal Raj Shrestha was quoted in Rastriya Samachar Samiti as saying that preparation was in the final stage to work in the tunnel using Tunnel Boring Machine (TBM) method for excavating tunnel.

The TBM technology was also applied in the construction of Bheri-Babai project. The project had successfully piloted the technology in Nepal.

Compiled by Suresh Chaudhary