List of Major Dams in India, Names, Significance, Impacts

Dams have been pivotal in India's development, providing crucial irrigation for agriculture, clean hydroelectric power, and flood control. According tothe 7th Schedule of the Indian Constitution, water management falls under state jurisdiction. With 5,334 dams, including 447 significant ones, India's water infrastructure is extensive.

However, a recent study by the United Nations University- Institute on Water, Environment and Health (UNU-INWEH),raises concerns about sediment accumulation, predicting a 26% loss in storage capacity for around 3,700 Indian dams by 2050. 

Major Dams in India

Dams are massive structures used for reservoirs, water supply, and flood control. They are gravity-based, earth-fill dams, and arch dams, which are curved structures that transfer water force horizontally. They are critical components of a country's water management infrastructure. 

- The table below shows some of India's major dams, their connected rivers, and the states where they are located:

Significance of Dams

Dams are critical to India's water management and development efforts. They offer significant benefits, including:

• Renewable Energy Source: Many dams have turbines installed to generate electricity from the regulated water flow. These hydroelectric dams are a vital source of renewable energy for the country. 
  • For instance, In 2023, a hydropower capacity of about 46,865 MW (megawatt) accounted for roughly 11% of power generation capacity in India. 
• Irrigation: Large dams have played a crucial role in improving irrigation facilities, increasing the area under cultivation, and boosting agricultural productivity, contributing to India's self-sufficiency in food grain production.
• Flood control and water supply: During heavy rainfall, dams can prevent floods by controlling the release of water. Contrarily, they maintain a reliable water supply during dry conditions.
• Efficient land use: While large dams submerge land, they do so relatively sparingly compared to alternative small dams. They utilise land more efficiently and are capable of irrigating larger areas, providing multiple benefits including irrigation and power generation.

Impact of Dams

Despite the manifold benefits dams provide, they also present challenges. The following points elucidate the adverse impact of dams:

• Ecological impact: Dam construction causes habitat destruction, biodiversity loss, animal migration routes disruption, and wetlands devastation, impacting local populations and livelihoods, increasing flood risks, and affecting agriculture.
• Human impact: Displacement and urban migration lead to overcrowded cities and poor living conditions, and a disproportionate impact on vulnerable communities; for example projects like Sardar Sarovar Dam and Koel-Karo Dam. 
• Financial impact: It can exceed initial estimates, leading to fiscal burdens for governments and borrowing from international institutions. It also raises questions about the government's ability to fulfil other development and welfare commitments.

Dams in India UPSC PYQs

Question 1: Write a short note on Nagarjuna Sagar Projects. (UPSC Mains 2002)

Question 2: What do you know about the Hirakud Project? (UPSC Mains 2002)

Question 3: Suppose the Government of India is thinking of constructing a dam in a mountain valley bound by forests and inhabited by ethnic communities. What rational policy should resort to in dealing with unforeseen contingencies? (UPSC Mains 2018)

Dams in India FAQs

Q1. What are the largest dams in India?

Ans. The largest dams in India include- Sardar Sarovar Dam; Hirakud Dam; Nagarjuna Sagar Dam; Tehri Dam; Bhakra Nagal Dam.

Q2. Which is the oldest dam in India?

Ans. Kallanai, on the Kaveri River in Tamil Nadu, dates back to the 2nd century CE. Built by the Chola dynasty, is one of the oldest functioning water-regulation systems globally.

Q3. Which is the highest dam in India?

Ans. Situated in Uttarakhand, the Tehri Dam holds the distinction of being the tallest dam in India, towering at a height of 260.5 meters.

Q4. Which is the longest dam in India?

Ans. The Hirakud Dam, located on the Mahanadi River is the longest in India, spanning a total length of 25.79 kilometers. Additionally, it ranks among the longest dams globally.

Q5. What is the rank of India in building large dams? 

Ans. India is ranked third in the world in terms of building large dams.