DON'T LET OLD DAMS BE DAMNED

BEFORE WRITING this column, a little bit of Google search about dams in India and around the world, produced interesting snippets. India’s oldest (and the world’s fourth oldest) dam ‘Kalanai’ aka ‘Grand Anicut’, on the Kaveri in Tamil Nadu, with a storage capacity of just over 15 metres cube (3,650 cubic metres) built by the Cholas in 150 CE is still in use! Our largest dam now – Indira Sagar on the Narmada in Madhya Pradesh (MP) has a capacity of 12.22 billion cubic metres.

- Krishan Kalra

And world’s largest, the Kariba in Zambia, finished in 1960, claims 185 billion cubic metres. Three Gorges Dam in China, measured for power generation capacity, boasts of an awe inspiring 22,500 MW – way ahead of any other single location utility in the world.

Heritage Dams

The parliamentary report (source National Register of Large dams – 2019) had listed 234 functional dams, all over 100 years old and ‘possibly unsafe’. Oldest of these – Thonnur Tank in Karnataka – was commissioned in the year 1000. The next 14 (five in Maharashtra, four in Rajasthan, three in Uttar Pradesh and one each in Andhra and Odisha) were all commissioned between the years 1500 to 1860. Looking at all 234 – covering MP, Maharashtra, Gujarat, Rajasthan, Telangana, Uttar Pradesh (more than 50 in each state) Karnataka, Chhattisgarh, Andhra, Odisha, Bihar, Kerala and Tamil Nadu.

Decommissioning Dilemma