The tragedy in Kerala has highlighted the dangers of excess water accumulation in dams. More than 20 dams released water that cascaded down the hills, leaving behind a trail of destruction. The opening of the gates of the Idukki dam, for instance, caused the Periyar river to swell rapidly and discharge seven lakh litres of water per second. Yet, the argument for dams — that they provide drinking water and water for agriculture — is today scientifically discredited. For independent geologists and hydrologists, dams represent a nightmare, an ephemeral triumph of engineering over common sense and the natural sciences. Increasingly, it is evident that dam proponents are ignoring crucial decision-making data now available on patterns of rainfall, geology and climate change. Dams store millions of tonnes of fresh water in large reservoirs, submerging prime forests, villages, farms and livelihoods. The 4,700 large dams built since 1947 have cumulatively displaced 4.4 million people. This makes dams the single largest cause for displacement post-Partition. Solving the drinking water crisis does not require giant storage structures; these dams take decades to come up and only a fraction of their output is for the household sector. Over 85% of them are used in agriculture for producing cash crops such as sugarcane. Dams have displaced the poorest of India’s people in favour of richer farmers and urban residents, often with little or no compensation.
Source : https://www.thehindu.com/todays-paper/tp-opinion/until-dams-do-us-part/article24787911.ece