- Even after the enactment of the Dam Safety Act in 2021, the threat to the life, property, and livelihood of millions of people from dam-related perils remains endless.
Status of Indian dams and issues associated
- India has more than 5,740 large dams and countless other barrages.
- India is now placed third in the world, next to China and the US, in terms of the number of functional dams.
- Nearly 20 percent of the dams in India have outlived their rated life span of 50 years.
- Most of these old dams were constructed with locally available material and in accordance with the water flows and risk factors prevailing at that point of time.
- Further development of the water-use infrastructure in the later years and global warming-induced uncertainties of the volume of water flows poses a major risk on the old dams.
- Risk factors like flash floods, landslides, and increased sedimentation are much more pronounced now than in the past.
- The latest report of the Parliamentary Standing Committee on Water points out that though 234 large dams are 100-300 years old, none has been decommissioned.
- Retiring a dam has rarely been deemed an option in India even if the structure turns highly hazardous.
- For instance, nearly 130-year-old Mullaperiyar dam is not being replaced with a new one despite having been declared unsafe by the Kerala government.
- The country has witnessed more than 40 major dam failures in recent decades. Some of them include the calamity in Chamoli, Uttarakhand in 2021 and the most disastrous being Machchu Dam failure in Gujarat in 1979.
- Precise estimation of the potential life span of dams following the US system of risk appraisal through a web-based integrated risk management model called Dam Safety Analysis Tool using variables from dam bursts in the past is needed for decommissioning them. It generates a fairly reliable prognosis of downstream risks of dam failures.
- Decommissioning vulnerable dams, which is a common practice to avert dam-related disasters in developed countries, notably in Europe and the US, should also be followed by India.
- An indigenous system for this purpose, using the expertise available in scientific institutions like the Indian Institutes of Technology for monitoring dam safety would be of great help in preventing dam-related mishaps.