Kathmandu, July 21

The rate of tunnel excavation of the Melamchi Water Supply Project has decreased from an average of 29 metres to just one metre per day for the last three days because the excavation put stress on the soil, leading to instability.

The Melamchi Water Supply Development Board said that a portion of loose soil has been appearing since July 15, making it necessary to decrease the average excavation speed by 96 per cent.

Excavating loose soil is risky, because it is important to keep the area stable.

“We noticed the loose soil while keeping the soft rock section stable on July 15,” Executive Director at Melamchi Water Supply Development Board Ghanashyam Bhattarai told The Himalayan Times, “So we had to bring the excavation speed down considerably. Before that, our excavation speed was 29 metres per day.”

Bhattarai said that it appears the problem will continue for more than one week. “It appears that the next nine metres of the tunnel will be covered with loose soil, so we can only excavate one metre daily until the portion is finished, which will take another nine days,” Bhattarai added.

About 500 to 600 construction workers are currently involved in the excavation and clearance under the Italian firm CMC Cooperativa Muratori e Cementisti di Ravenna.

Deputy Executive Director of the Board Jyoti Kumar Shrestha said the average excavation rate of the tunnel had decreased by 25 metres daily since June because of soft rocks in the tunnel.

Shrestha said despite these setbacks, the target of supplying water by September 2017 could be achieved.

The project aims to excavate the tunnel at an average speed of one kilometre per month, but various hurdles have reduced the speed to around 800 metres a month.

Of the planned 27.5 km long tunnel, 9.5 km remains to be excavated. The MWSP has allocated a year forcompletion of this section, which will be by July next year.

The Melamchi project was envisioned in the late 1990s, but the first agreement to construct the project was only signed in 2003 with funds from various donors and developmental partners. The project took off only in 2010, seven years after the agreement was signed.

Construction works were halted until the government gave the contract to CMC Cooperativa Muratori e Cementisti di Ravenna in July, 2013.

The Melamchi Water Supply Development Board had awarded the contract to CMC with a target of completing the project by February 19, 2016. But last year’s earthquakes closed down construction work completely for around 10 months.

The government had earlier given the contract to China Railway 15 Bureau Group, but the contract was terminated on September 2012 due to its unsatisfactory work.