None of the half million people in a corner of Uttarakhand said to be at risk of being affected by the Tehri dam get to enjoy the fruits of their sacrifice.

Of the 10 hydroelectric dams on Bhagirathi, which gives birth to the Ganges, the Tehri dam is the largest and faces the strongest criticism. Besides the grave environmental threats, the tallest dam in India standing around 80 storeys (855 feet) high also poses serious security risk to surrounding towns and villages.

The 1000MW Tehri dam covers irrigation on 8,700 square km -- roughly the size of Bhola, Barisal, Barguna, and Jhalokati districts put together. A fraction of the pristine waters that the dam diverts also provide for just over 1 billion litres of drinking water every day, which is sufficient for half of Dhaka city or 5 million urban homes, according to Indian standards.

But most of the benefits of this dam are enjoyed by people far away in Delhi and elsewhere in Uttaranchal and Uttar Pradesh. For people living in the vicinity, it is quite the opposite.

Having served in the Indian military for some time, 70-year-old PC Ramola is now into farming his ancestral lands beside the dam’s reservoir. He remembers a time when the seasons changed with the months just like they were supposed to. But ever since the dam got built, they began to change says the retired military man.

“Now the winters are longer and the rainfall has become irregular.” Instead, what they get are long periods of foggy weather. The septuagenarian explains that the reservoir generates fog and mist up in the air. That in turn falls as dew on his crops. “Sometimes that leads to pests and blight.”

He says such phenomenon has never happened in the last five centuries that the Ramolas have been living in this idyllic village. Ramola’s 27-year old grandson Mastu could not appreciate the benefits of the dam either. “Tehri is a disaster for us. It hurts our livelihood.”

He said because of the pest attack and failing agricultural production, many of the locals were considering migration.

“They had spoken about livelihoods and generating employment for people around the dam. But now people have to leave this place to go make a living.”

Although proponents claim that the structure is strong enough to withstand quakes notching up 8.4 on the Richter scale, seismologists say the Central Himalayan Seismic Gap, where the dam is located, could very well generate shockwaves of 8.5 or higher.

The area witnessed an earthquake with a magnitude of 6.8 in 1991 from an epicentre 53km away.

Opponents say that such a huge dam in a delicate ecosystem like the Himalayan foothills could have serious impact on the environment.

Despite several reassessments of the project pressured by the anti dam movement, the dam went into operation in 2007. However, at one point in the 1980s the government was forced to abandon the project faced with sharp criticism by a government appointed review committee.

The project was referred to an environment ministry committee again in 1987 to assess safety, and environmental and social impacts. But the Indian government overruled this committee’s unanimous decision against the Tehri dam and restarted the project.

Protesters point out that the Tehri reservoir of 4 cubic km would submerge the Tehri town and 40 surrounding villages, affecting upwards of half a million people. Official estimates vary from 67,500 to just under 100,000.

“An idyllic town was displaced to set up a small 1000MW project. In 2005, it was extended to 1500MW. But in the last 10 years, it never produced more than 250MW.”

The government plans on running 10 hydro power projects along the 200km stretch of the hilly Bhagirathi river between the Gangotri glacier and Devaprayag.

The swift Bhagirathi twists and turns along its mountainous route to meet the Alaknanda at Devaprayag where it gives birth to the mighty Ganges contributing the bulk of the water of the holy river.