The Sardar Sarovar Dam on the Narmada was dedicated to the nation by Prime Minister Narendra Modi on:

Prime Minister Narendra Modi dedicated the Sardar Sarovar Dam to the nation on 17 September 2017, his birthday, at Kevadia in the Narmada district of Gujarat.

About the dam:

• It is a concrete gravity dam on the Narmada river, near Kevadia (now Ekta Nagar), Gujarat.
• Its full height is about 163 metres, making it one of the largest concrete gravity dams in the world by volume of concrete.
• Jawaharlal Nehru laid its foundation stone on 5 April 1961.
• The height was increased in stages over decades, and the gates were finally closed in June 2017, raising it to full height.

Benefits:

• It is a multipurpose project, providing irrigation, drinking water and hydroelectricity.
• The Narmada Main Canal, one of the largest canals in the world, carries water across Gujarat and into Rajasthan.
• It provides drinking water to thousands of villages and many towns in Gujarat, including drought-prone Saurashtra and Kutch.
• Its power (about 1,450 MW) is shared among Madhya Pradesh (57 percent), Maharashtra (27 percent) and Gujarat (16 percent).

Narmada Water Disputes Tribunal:

Set up in 1969, it gave its award in 1979, deciding the sharing of water among the four states.

Controversy:

The Narmada Bachao Andolan, led by Medha Patkar and supported by Baba Amte and others, opposed the dam for decades because of the displacement of tens of thousands of people, mostly tribal communities, and environmental damage.

In 2000, the Supreme Court allowed construction to continue, subject to rehabilitation of the displaced.

Statue of Unity:

• The 182-metre Statue of Unity of Sardar Vallabhbhai Patel, the world's tallest statue, stands about 3.2 km downstream, on Sadhu Bet island.
• It was inaugurated on 31 October 2018, Patel's birth anniversary.

Why not the other options?

• ✗31 October 2018 is the date the Statue of Unity was inaugurated.
• ✗15 August 2015 and 26 January 2018 are not associated with the dam's dedication.