Sardar Sarovar Dam (SSD)

About Sardar Sarovar Dam (SSD):

• SSD is a concrete gravity dam built on the Narmada River at Kevadia in Gujarat’s Narmada district.
• The dam was named after Sardar Vallabhbhai Patel.
• Having a length of 1.2 km and a depth of 163 m, it is the third highest concrete dam in India, the first two being Bhakra (226 metres) in Himachal Pradesh and Lakhwar (192 meters) in Uttar Pradesh. 
• In terms of the volume of concrete involved in gravity dams, this dam will be ranked as the second largest in the world after the Grand Coule Dam in the USA.
• It is a part of the Narmada Valley Project, a large hydraulic engineering project involving the construction of a series of large irrigation and hydroelectric multi-purpose dams on the Narmada River. 
• The dam has two powerhouses – a canal head powerhouse and a river bed powerhouse with an installed capacity of 250 MW and 1,200 MW, respectively.
• Power benefits are shared among Madhya Pradesh, Maharashtra and Gujarat in the ratio of 57:27:16, respectively.
• Reservoir: The dam forms a vast reservoir known as the "Sardar Sarovar Reservoir" or "Narmada Lake," which spans across several districts in Gujarat.

Key Facts about Narmada River:

• It is the largest west-flowing river in the peninsula India.
• Origin: It rises from Narmada Kund, located at Amarkantak, in the Anuppur district of Madhya Pradesh, at an elevation of about 1057 m in the Maikala range.
• Course: The river flows through Madhya Pradesh, Maharashtra and Gujarat between Vindhya and Satpura hill ranges before falling into the Gulf of Cambay in the Arabian Sea about 10 km north of Bharuch, Gujarat.
• Length: The total length of the river from source to sea is 1312 kilometers (815 miles).
• The river has numerous waterfalls, notably the Dhuandhar Falls, southwest of Jabalpur. 
• Tributaries: The Narmada has several tributaries, with the most significant ones being the Tawa, Barna, Hiran, and Orsang rivers.

Q1) What is a gravity dam?

A gravity dam is a type of dam that relies on its own weight and mass to resist the horizontal pressure of water, thereby preventing the flow of water. These dams are constructed using concrete or masonry and are designed in such a way that their massive weight provides the stability needed to withstand the forces exerted by water.

Source: Heavy rain batters Gujarat, Narmada dam water discharge causes flooding; 9,600 shifted to safety