Work on Kullu NHPC tunnel halts after slush ingress

Abhinav Vashisht

Kullu, April 16

The work on the NHPC’s Parbati-II hydel project at Shilagarh in Kullu district was stopped yesterday after the sudden ingress of slush into its under-construction tunnel. The videos of workers panicking after seeing the slush and water flowing into the tunnel went viral on social media. 

According to information, several workers were working in the tunnel when it was suddenly  flooded with water and slush due to a leakage  last evening. There was chaos and the workers ran here and there to save their lives.  However, no casualty has been reported in the incident so far while the company has suffered a loss of crores of rupees. This is the second incident of leakage in the tunnel in a week. The tunnel became swampy due to the slush flowing in.

Gammon India is executing the work on the 32-km Head Race Tunnel  between Shilagarh and Siund. Excavation in 9.050 km is being done through the tunnel boring machine (TBM) from Adit-II at Shilagarh. The tunnel is being constructed for the past 24 years but its construction work could not be completed due to several incidents of leakage in it. 

The ingress of a huge amount of slush into the tunnel damaged the boring machine in November 2006 when about 4 km had been excavated. At that time, the Himachal Joint Venture, a subsidiary of Satyam company, was executing the project. It had hired Robbins company of the USA to operate the TBM.

The then Union Power Minister, Sushil Kumar Shinde, had inspected the construction of the tunnel in May 2010 and advised the NHPC to speed up the work. Even after repeatedly restoring the TBN, boring could not be restored and only around 70 metres more were excavated till 2014 and that too at a huge cost. The NHPC authorities had stated that the pace of construction of the Parbati Stage-II project was hindered due to poor geological conditions at the tunnel site. According to sources, the construction work of around 800 metres is yet to be accomplished to meet both mouths of the tunnel. 

Experts say that the delay in the project has already caused a loss of more than Rs 10,000 crore to the country. There have been many accidents during the construction of the tunnel and many workers have died. In May last year, four workers were killed in an accident in a diversion tunnel.