Irrigation development in India up to the 19th century was mainly through the development of tanks. Later, with advances in construction technology, diversion schemes on large riversl such as the Ganges, Krishna, Godavari and Mahanadi were taken up. Construction of large storage dams followed thereafter. The Indian rivers could be classified either on the basis of hydrological characteristics, or on the basis of availability of water per capita or per hectare, or on the basis of the size of the drainage area. Some of the river basins are so large, and cover such widely different regional characteristics, that it is convenient to break them into sub‐basins for the purposes of planning and development. It is also necessary to work beyond the basins. Proposals for inter‐basin transfer of water from well‐placed areas to deficit areas for ensuring the optimum use of the country's water resources are being investigated by the National Water Development Agency set up by the Government of India in July 1982. As about 80% of rivers' annual flow passes through them in a matter of four monsoon months only the construction of large storages on the risers is necessary to hold back the available waters for use throughout the year. For a properly integrated management of the basin's waters and their quality, the setting up of comprehensive river basin organizations has been recommended.