Recently Narmada Control Authority (NCA) has cleared the final raising of Sardar Sarovar Dam (SSD) in Gujarat. This has raised concerns that Raising the Sardar Sarovar dam to its full height will result in more large-scale submergence of habitations. Once the dam is at its full height, it will submerge one town and at least 176 villages, displace close to 20,000 families, flood productive agricultural land, and destroy hundreds of acres of biodiverse forest.
In this context we shall look at benefits and its cost including environmental and at society level. In particular we shall look at issues related to Sardar sarovar dam.
Pros and cons of a Multi-purpose river Project
Dams provide a range of economic, environmental, and social benefits, including recreation, flood control, water supply, hydroelectric power, waste management, river navigation, and wildlife habitat.
Dams are built worldwide to store water for irrigation, flood control, and to generate electricity. However, there are some negative environmental effects of building large hydroelectric dams. These affects are as follow:
Siltation of dam reservoir - All rivers contain sediments: a river, in effect, can be considered a body of flowing sediments as much as one of flowing water. When a river is stilled behind a dam, the sediments it contains sink to the bottom of the reservoir. As the sediments accumulate in the reservoir, so the dam gradually loses its ability to store water for the purposes for which it was built.
Sardar Sarovar dam Issue
The Sardar Sarovar Dam is a gravity dam on the Narmada river near Navagam, Gujarat in India. It is a part of the Narmada Valley Project. One of the 30 dams planned on river Narmada, Sardar Sarovar Dam (SSD) is the largest structure to be built. Following a number of controversial cases before the Supreme Court of India (1999, 2000, 2003), by 2014 the Narmada Control Authority had approved a series of changes in the final height. The recent decision to increase height has been taken in June, 2017. The project will irrigate more than 18,000 km2 (6,900 sq mi), most of it in drought prone areas of Kutch and Saurashtra. The total installed capacity of the power facilities is 1,450 MW.
The argument in favour of the Sardar Sarovar Project is that the benefits are so large that they substantially outweigh the costs of the immediate human and environmental disruption. The project has the potential to feed as many as 20 million people, provide domestic and industrial water for about 30 million, provide valuable peak electric power in an area with high unmet power demand. It will also provide flood protection to riverine reaches. However, the dam is one of India's most controversial, and its environmental impact and net costs and benefits are widely debated.
The benefits of a dam are easy to monetize as most of the benefits have a market to serve which help in correctly valuing the value of services it provide. For ex – Electricity produced by dam has per unit cost which is decided by dynamics of demand and supply of electricity. This helps in exactly determining benefits of a dam project in terms of electricity produced and revenue generated. However, in case of cost it is difficult to estimate as it is difficult to value true cost of environment degradation or cost of rehabilitation. So it is highly important to improve economic techniques of valuing costs of a dam so that true value is known and policymakers can correctly access net benefit before undertaking a project.