INTER-LINKING OF RIVERS: A PROBABLE SOLUTION TO WATER PROBLEM

Suggestions for a National Water Grid envisaging interlinking of rivers with a view to transferring surplus water available in some regions to water deficit areas have been made from time to time. The Govemment of India prepared a national perspective plan for water resources development in 1980 envisaging interlinkages be­tween various peninsular rivers and Himalayan rivers for transfer of water from water-surplus basins for optimum utilisation of water resources. The Government of India established the National Water Development Agency (NWDA) in 1982 to firm up these proposals.

In December 2004, the Centre set up a committee of experts to advise the government on environ­mental and socio-economic aspects of the interlinking programme.

The total amount of water that can be usefully transferred is esti­mated to be about 220 bcm. However, there are apprehensions that the assessed surplus is somewhat illu­sory for many basins and future generations would actually need all the water. Sceptics have reservations about the economic viability of such large projects. Environmental concerns would need to be addressed through the environmental appraisal process of each project. For these reasons the pace of progress in the Tenth Plan period has been quite modest.

Per capita availability of water varies from 18.417 m3 in the Brahmaputra river to 380 m3 in some east-flowing rivers in Tamil Nadu showing that many basins in the country are already critically starved of water. Out of the annual precipitation and snowfall of 4000 bern, 747 bcm runs waste to the sea, mainly from the Ganga and Brahmaputra rivers systems, which have 60 per cent of the water potential. Only 19 per cent of the water potential is available in Maha[1adi, Godavari, Krishna and Cauvery.
In the circumstances, inter-linking of rivers as­sumes importance as a part of the 747 bcm running waste to sea (about 160-220 bcm) is proposed to be transferred through a series of 30 inter-linking proposals from- surplus basins to deficit basins. Long-distance, trans-basin transfer of water is not a new concept.

Many examples of existing projects can be given in this regard-Western Yamuna canal, Periyar project, Kumool Cuddapah canal, Indira Gandhi canal, and Sardar Sarovar canal. International examples can be given of California water transfer project from north to central and southern parts of the US, China, the erstwhile USSR, Sri Lanka, and Mexico. Pioneering work was earlier done on a National Water Grid by K.L. Rao and Capt. Dastur. These were refined by the MoWR and 30 links identified-16 as peninsular component and 14 as Himalayan component. Pre-feasibility studies of 16 links (14 in peninsular component) have also been completed.

Since interlinking rivers on such a large scale is bit costly, evaluation of the economics of the proposals is necessary. Environmental impacts have to be care­fully assessed.