Sikkim Earthquake impact studies at the dam sites of NHPC



Earthquake not caused by Hydro Power Projects: Sikkim CM



India’s power ministry has asked seismic experts from the Indian Institute of Technology-Roorkee (IIT-R) to conduct earthquake impact studies at the dam sites of state-owned NHPC Ltd and North Eastern Electric Power Corp. Ltd (Neepco).



The Sikkim earthquake has raised questions on the future of India’s hydropower development. The 18 September 6.8 magnitude earthquake on the Sikkim-Nepal border has wreaked havoc in the Himalayan country and the Indian state, and scientists say the likelihood of a much greater earthquake in north India remains. At least 118 people have been killed in Sikkim, West Bengal and Bihar in the quake.

Teesta Urja Ltd, which is building the 1,200MW Teesta-III project in Sikkim, suffered losses of personnel, with 17 people killed, one missing and 10 hurt.

The decision to take IIT-R’s help was taken at a review meeting last Thursday that was chaired by minister of state (power ministry) K.C. Venugopal.

“It was decided to avail the services of seismic experts from IIT-R to analyse earthquake data and conduct the earthquake impact study at the dam sites of NHPC in the region, and more specifically those in Sikkim,” the ministry said in a statement. “Neepco was also asked to compile the seismic data collected from its power stations in north-eastern states for further analysis at IIT-R.”

The total hydropower generation potential of India’s north-eastern states and Bhutan is about 58,000MW. Of this, Arunachal Pradesh alone accounts for 50,328MW. Sikkim, as well as most of north India, falls in seismic zones 4 and 5, regions classified as highly vulnerable to high-intensity quakes.

Any delays in construction of hydropower projects in the region, particularly those on rivers originating in China, would affect India’s strategy of establishing its prior-use claim, according to international law.

India is concerned that hydropower projects planned in Arunachal Pradesh may be affected by China’s plan to divert water from rivers that flow into the Brahmaputra to the arid zones of Xinjiang and Gansu.

“India’s hydro potential is locked in the North-East,” said former power secretary Anil Razdan. “You can’t plan for this kind of thing. It is a grey area. Earthquake prediction is very difficult.”

Hydropower projects come with their own set of problems. Their construction requires specialized technology and design. They also have to deal with geological surprises such as earthquakes, floods and landslides. With the share of hydropower generated in the country falling from 40% to 25% in the past 20 years, the government is worried as this makes up only 38,206MW of the 181,558MW power generating capacity.

“We and Neepco are the major hydropower developers active in the North-East. We’ll study data from our monitoring centres to know the impact of the quake for future references,” said D.P. Bhargava, director, technical, NHPC. “We’ll first study it internally and then send it to IIT-R.”

NHPC has a power generation capacity of 5,295MW that includes two operating projects in Sikkim. It is constructing a 2,000MW project in Arunachal Pradesh and also has plans to set up projects having a total capacity of 6,696MW in north-eastern states such as Sikkim, Manipur and Arunachal Pradesh.

Bhargava defended the design of his projects. “There has been no damage to our projects,” he said. “We design our projects for earthquakes and such an incident should not stop us for planning for projects in the region.”

Several hydro projects have been delayed and India has met less than half the target of 14,393MW set for hydropower generation in the 10th Five-year Plan period (2002-07).

The country plans to add another 16,501.17MW of hydropower capacity by 2012. While the country has a hydropower potential of 300,000MW, around 145,000MW of this can be exploited.