The Tehri Dam is the highest dam in India and one of the highest in the world. Location : On the Bhagirathi River. 200 miles north east of Delhi. Height : 855 feet (261 m) 5th tallest dam in the world. Capacity : power generation capacity of 2400 MW provision of irrigation to an area of 270,000 hectares. The Tehri Dam withholds a reservoir for irrigation, municipal water supply and the generation of 1,000 megawatts of hydroelectricity. Tehri Development Project approved in 1972 Construction started 1978 Cofferdam completed 1996  Closure of last two tunnels December 2002  Projected completion August 2003 Benefits to Nation / Region 2400MW of environment friendly Peaking power. Irrigation of 2.7 lakh hactors Of new area. 162 million gallons per day of water supply to Delhi. All round development of the region through better infrastructure and easy avalaibility of electricity. Development of pisciculture.

1. Tehri dam

2. INTRODUCTION
• The Tehri Dam is the highest dam in India and one of the highest in the
world.
• Location : On the Bhagirathi River. 200 miles north east of Delhi.
• Height : 855 feet (261 m) 5th tallest dam in the world.
• Capacity : power generation capacity of 2400 MW provision of irrigation
to an area of 270,000 hectares.

3. • The Tehri Dam withholds a reservoir for irrigation, municipal water
supply and the generation of 1,000 megawatts of hydroelectricity.
• Tehri Development Project approved in 1972
• Construction started 1978
• Cofferdam completed 1996
• Closure of last two tunnels December 2002
• Projected completion August 2003

4. Benefits to Nation / Region
• 2400MW of environment friendly Peaking power.
• Irrigation of 2.7 lakh hactors Of new area.
• 162 million gallons per day of water supply to Delhi.
• All round development of the region through better infrastructure and
easy avalaibility of electricity.
• Development of pisciculture.

5. Concerned issues
Negative Impacts
Change in the
• Water chemistry, especially with respect to dissolved oxygen and
• Turbidity of water.
Seismic Risks
• Worlds most earthquake prone regions.
• Designed for 7.2 ; expected: 8.5 or more.

6. Floods
• If the dam fails or a major landslide causes a huge wave to overtop the
reservoir, a 260 m high flood wave would crash down into the densely
populated valleys below the dam.
Protests
• 1978 – Tehri Bandh Virodhi Sangharsh Samiti (TBVSS).
• 74-day hunger strike in 1996 by Sunderlal Bahuguna.
• Many Anti-dam rallies and protest.

7. Environmental issues
• Protests was against displacement of town inhabitants and consequence of
week ecosystem.
• The Tehri dam is located in the Central Himalayan Seismic Gap. This region
was the site of a 6.8 magnitude earthquake in October 1991, with an
epicenter 53 km from the location of the dam.
• Dam is designed to withstand an earthquake of 8.4 magnitude but some
seismologists say that earthquakes with a magnitude of 8.5 or more could
occur.
• If it breaks down, numerous towns downstream would submerge whose
population is near one million.

8. Measures for Ecological Impacts
• Compensatory Afforestation : afforestation in an area of 4586.07 ha.
• Catchment area treatment : To reduce soil erosion and 52.204 ha. treated.
• Command area development : To mitigate water logging and sanity and the
network of field and drains were developed.
• Flora and Fauna : Botanical garden (14.28ha.) to preserve important flora
and Mahseer fish hatchery and fish farm.

9. Measures for Ecological Impacts
• Water quality maintenance : No adverse effect on the water quality and 5
monitoring stations at upstream and downstream.
• Green belt : Along the rim of the reservoir
• Along the rim of the reservoir and resultant siltation to protect and
regenerate the vegetation to increase the natural beauty