a part of the land adjoining the Tehri dam area is sinking gradually and a 50-metre-long crack has appeared near the coffer dam site, says a report. It has posed serious concerns whether construction of the 2,400- mw dam is fraught with danger. However, H C Sharma, general manager of the Tehri Hydro Development Corporation ( thdc ), describes the report as "baseless'.

The report has triggered a debate on whether the phenomenon is only of a local nature or related to seismic activity in the Garhwal region. Geologists associated with the dam are said to be studying the crack.

D P Dhaundiyal, former director general of the Geological Survey of India, says that the crack might have appeared due to some constructional lacunae and not because of any seismic activity. The Garhwal region has experienced several tremours in the past.

According to experts, frequent tectonic activity along the outer Himalayan belt, made of fragile rocks along with frequent rainfall have often triggered fluvial action and slope failure.