When India started planned economic development in 1951, the irrigation potential from major and medium irrigation was about 10 million hectares, to taking 23 million hectares. By 1999-2000, the total irrigation potential created had increased to 94 million hectares.
India is one of the few countries with abundant land and water resources. The average precipitation over the country is about 400 million hectare metre. Annual water resources in the various river basins of the country is estimated at 187 million hectare metre.
Need for Interlinking rivers
The distribution of water resources of India over the land is uneven. This is because of the seasonal and regional distribution of rainfall. Most of the rain occurs during the monsoon months, the precipitation during the remaining part of the year being insignificant, large areas in Western, Central and South India have a very low rainfall while in the northern and eastern regions, heavy monsoon raths cause extensive floods and large volumes of water flows into the sea.
The uncertainty of rainfall marked by continuity for a long time, dry spells and fluctuation in seasonal and annual amount is a serious problem for the country water grids have been conceived for remedying this imbalance to a certain extent by transferring water from surplus regions to deficit regions by interlinking the various river basins so that trans basin transfer of water becomes possible.
India now ranks among the more important dam building nations in the world. Dams were regarded as "the temples of modern India" by Jawaharlal Nehru. Till now "irrigation and hydropower have been the major objectives of water resources development in India.
Aimed at linkage of rivers : The National perspective plan prepared in 1980 comprises Himalayan river development plan Peninsular river development plan including diverting a part of the water of the west flowing rivers in Kerala and Karnataka to the east for irrigating the drought prone areas of Karnataka, Tamil Nadu and Andhra Pradesh.
The Garland Canal Scheme : 1. Himalayan Canal 2. The Central and Southern Garland Canal
The National Water Grid : The National water grid was formulated by K.L. Rao and sponsored to some extent by the central water and power commission during the 1970. The scheme includes several water links from one river basin to another. 1. The Brahmaputra - Gangal link 2. The Narmada river - link 3. The Chambal river, Rajasthan - Gujarat link 4. The Ganga - Cauvery link, passing enroute through the basins of the Narmada, the Tapti, the Godavari, the Krishna and the Pannar. 5. Canal from Narmada to Western Rajasthan. 6. Canal from chambal to central Rajasthan. 7. Canal from the Mahanadi to serve coastal area of Orissa and Andhra Pradesh.