India is ranked third in the world in terms of building large dams.
Of the over 5,200 large dams built so far, about 1,100 large dams have already reached 50 years of age and some are older than 120 years.
The number of such dams will increase to 4,400 by 2050 i.e., 80% of the nation’s large dams face the prospect of becoming obsolete as they will be 50 years to over 150 years old.
The situation with hundreds of thousands of medium and minor dams is even more dangerous as their shelf life is even lower than that of large dams.
Examples: Krishna Raja Sagar dam was built in 1931 and is now 90 years old. Similarly, Mettur dam was constructed in 1934 and is now 87 years old. Both these reservoirs are located in the water scarce Cauvery river basin.