The rising concern of India’s ageing dams

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Syllabus: GS 3 – Infrastructure: Energy, Ports, Roads, Airports, Railways etc.

Synopsis: The ageing dams in India are threatening water security for the future. As the reservoir water is being replaced by soil, technically known as silt or sediment.

Introduction:

• In the race of building large dams, India ranks in the third position in the world.
• India has built over 5,200 large dams. Among which 1,100 large dams have crossed the age of 50 years. Some have even completed over 120 years.
• The number of such dams is going to reach 4,400 by 2050.

What are the issues in water reserviours of India?

After a certain time period, the Silt or sediment start to replace the water in the reservoir due to Siltation. Therefore, the water storage capacity of the dam decreases with time.

Siltation reduces the capacity of Some of India’s Largest dams. Due to Siltation, the functioning of the Bhakra dam has been reduced from 47 years to 88 years.

The medium and minor dams are even in the worst position. They are in such a dangerous position that they can collapse in the near future. This situation is because of their lower shelf life as compared to large dams.

The High siltation rate shows that reservoirs of India are designed with a poor understanding of sedimentation science.

What are the consequences of the siltation of dams for farmers?

1. Firstly, it affects crop yield- when soil replaces the water in reservoirs, water availability reduces. It results in less water for the cropped areas. It increases dependency of farmers on rains or groundwater which is already over-exploited. Reduced crop yield results in low Agri credit, crop insurance, and investment.
2. Secondly, chances of flooding increases- Due to Low capacity, reservoirs cannot store extra water from rainfall. It will lead to an increase in flooding rates.

For Example, The flooding in Bharuch in 2020, Kerala in 2018 and Chennai in 2015

Way Forward

At present 80% of the India’s large dams are in a situation of becoming obsolete. India need to come together to address the situation urgently. As eventually in 21^st century, Nation will not be able to find sufficient water. It will not be able to feed the rising population by 2050, grow abundant crops, create sustainable cities, or ensure growth.