Sikkim earthquake may have been accelerated by dams across Teesta'-damages 2 project sites

Professor Jeta Sankrityayan, former member State Planning Board, West Bengal and also a member of the landslide expert committee 1998, has opined that the presence of multiple dams on the river Teesta and its tributaries could either induce or accelerate earthquakes.
“In early 1970 a
major earthquake in Maharashtra had been triggered by the Koyna dam located on the Sahyadri Hills. Though the role of the dams on the River Teesta in the recent quake is yet to be studied, the earthquake could have been induced or accelerated by the dams (dam induced seismicity )” feels Sankrityayan.

The committee on landslides, which had also studied the tectonic plate movement, had handed over recommendations to the government of West Bengal in 2000. The committee had recommended that no constructions should be allowed on the rivers.

The Central government’s “master vision” identifies the North-Eastern region as “India’s future powerhouse” by building about 168 dams in the region. To do this, the Teesta river in Sikkim is being extensively dammed.

Around 35 hydel power projects have been identified in this region with the Teesta Low Dam (TLD) project being the most prominent. The TLD project, harnesses the Teesta river, which originates in Sikkim and flows through North Bengal, creates a 332 MW capacity split into four stages.

The first two stages for a total of 100 MW are in Sikkim, while stage III of 100 MW and stage four of 132 MW are in West Bengal.

“It is very unfortunate that the Government does not pay heed to recommendations of its own committee for which the public have to suffer. Something more devastating can happen any day. It is time the public woke up and pressurized the Government to act more reasonably. Electricity in lieu of lives is not a very human option” added Sankrityayan.

The Himalayas are a young chain of mountains formed by the Indian tectonic plate colliding with the Eurasian plate.

While the river Teesta flows in a north-south direction, the Himalayan fault lines lie in the east west direction.

“A major fault line is located at Kalijhora (considered the best location to study Himalayan fault lines) and Teesta Low Dam Stage 4 is located at Kalijhora” stated Sankrityayan. Bad weather disrupts rescue work

Explaining dam induced seismicity, Sankrityayan stated that owing to the dams checking the flow of the river, the water becomes heavy and starts going down, usually seeping into crevasse.

“Water being a new element in the faults and crevasses in the mountain, the mountain starts adjusting which causes the seismic movements” stated Sankrityayan. The very flow of Teesta is an indicator of the fault line.

While in Sikkim the Teesta flows is curves (zig zag) after Teesta Bazar in West Bengal it flows in a straight line which suggests that it could be flowing along fault line in West Bengal.

“Very few earthquake movements are in a North-South direction but the 6.8 magnitude quake which hit Sikkim and this region was in a North-South movement. The epicenter was at the base of Mount Kanchenjunga. The mountain moved.”

“It took a mere two seconds for the earthquake to reach North Bengal University near Siliguri in the plains from Gangtok which is very unusual” stated the Professor. The shake intensity recorded was 7 Mercalli in Mangan, 38 km from the epicenter and 7 Mercalli in Siliguri 144 km away from Mangan. Gangtok too recorded a shake intensity of 7 Mercalli “ stated Sankrityayan.  Sikkim toll now 73

“A full scale inspection and study should be conducted by geologists and earth scientists into the recent quake and on the dam induced seismicity. It should be an independent probe not influenced by the Government. We should not be accelerating or bringing in such natural events otherwise we will definitely have to pay a dear price” suggested the Professor.
HT

                       Quake damages 2 Teesta project sites

Sunday's earthquake, which left a trail of destruction in Sikkim, has caused massive damage to some structures at two of the five project sites of the 1,200-megawatt hydro-power project in the upper reaches of the Teesta river. It claimed the lives of 16 workers and officials and caused injuries to several workers.

But Teesta Urja Limited, the company that is building the Rs.10,000-crore project, said no damage was done to any of the tunnels or the dam. Senior Deputy General Manager Mukul Jain told The Hindu that landslips triggered by the 6.8-magnitude earthquake caused massive damage to office buildings, workers' colonies, tents and approach roads at the two sites. However, the headrace tunnel bringing water from the dam site to the powerhouse, the dam and the tunnels were intact.

Mr. Jain said a number of workers who were inside the tunnel were safe, and those who died or were injured were working outside the tunnels.

The project was nearing completion, and most of the construction work was in the final stages, he said.

However, extensive damage at the two sites, coupled with the loss of lives, has triggered panic among workers, who fled the project sites. About 200 workers have taken shelter in a relief camp at the Singik project site, 7 km from here

On Wednesday, there was a mass exodus of workers employed by the company as well as contractual labourers engaged by sub-contractors. Hundreds trekked hilly tracks and walked over the debris of blocked roads for more than three hours from different project sites before arriving at Mangan and boarding buses that would take them to their homes in West Bengal, Bihar, Assam and several other States.

Mr. Jain said the right bank access road along the project site was damaged in some locations, and the project tunnel was being used for transporting men and material. All casualties, injured and missing employees were accounted for.

Children orphaned

Anand Biswakarma, 25, was shocked to receive the bodies of his elder brother Bishnu Lama and sister-in-law Sita, which started decaying in the Mangan district hospital on Tuesday.

On Wednesday, he was waiting for the helicopter of Teest Urja Limited, of which Bishnu was an employee, to airlift the coffins.

Anand had other worries than taking back the coffins of his brother and sister-in-law. Back home at Joygaon in West Bengal's Jalpaiguri district, he would have to face the Lama couple's six-year-old daughter Kripti and three-year- old son Prajal, now left orphaned by the earthquake. The Lama couple were crushed to death under the rubble of the landslips triggered by the earthquake when Bishnu was at the wheels of a mini-bus. His wife was seated behind; several workers of the company were also on the bus, returning to their bases after taking part in the Biswakarma puja at one of the project sites of the company. 

thehindu