Around 3,700 dams in India will lose 26 per cent of their total storage by 2050 due to accumulation of sediments which can undermine water security, irrigation and power generation in future, warns a new study by the United Nations.
The Central Water Commission, had in 2015, reported that among 141 large reservoirs which are over 50-years-old, one quarter had lost at least 30 per cent of their initial storage capacity.
Trapped sediment has already robbed roughly 50,000 large dams worldwide of an estimated 13 to 19 per cent of their combined original storage capacity.
The study by the United Nations University Institute on Water, Environment and Health (UNU-INWEH), also known as the UN's think tank on water, shows that 6,316 billion cubic metre of initial global storage in 47,403 large dams in 150 countries will decline to 4,665 billion cubic metre, causing 26 per cent storage loss by 2050. The loss of 1,650 billion cubic metre storage capacity is roughly equal to the annual water use of India, China, Indonesia, France and Canada combined.