Indian Prime Minister Narendra Modi inaugurated the country's biggest dam on Sunday, ignoring warnings from environment groups that hundreds of thousands of people will lose their livelihoods.

The controversial Sardar Sarovar Dam on the Narmada river in Gujarat that will provide power and water to three big states was dedicated to the people of India by Narendra Modi.

The project has been beset by controversies since the laying of the foundation stone by Prime Minister Jawaharlal Nehru in 1961. The construction of the project began in 1987.

The dam is the second biggest dam in the world after the Grand Coulee Dam in the United States.

Ahead of the inauguration Modi said in a tweet, “This project will benefit lakhs of farmers and help fulfil people’s aspirations.” (1 lakh = 100,000)

The dam is expected to provide water to 9,000 villages and the power generated from the dam would be shared among three states - Madhya Pradesh, Maharashtra and Gujarat.

The Narmada Bachao Andolan (NBA), led by social activist Medha Patkar, has been protesting against the project, raising several environmental concerns.

Construction on the dam had been suspended in 1996 following a stay by the Supreme Court which allowed work to resume, four years later, but with conditions.

Patkar and her supporters started the protest against the inauguration of the dam on Saturday and the opening of its gates which would raise the level of water and risk displacing several villages.

“Today is a very sad day for India, and for one of our biggest peoples’ movements and struggle - the Narmada Bacchao Andolan,” Ravi Chellam, executive director at Greenpeace India said in a statement.

“The Sardar Sarovar Project... signals ruin not development for tens of thousands of unsuspecting, hapless and poor farmers,” Chellam added.