Figure 18 – Major river Basins of India

On the basis of mode of origin, the drainage of India may be divided into (i) Himalayan Drainage; and (ii) Peninsular drainage. However, many of the Peninsular rivers like the Chambal, Betwa, Ken, Son are tributaries of Ganga river system which originate in Himalayas (figure 17).

On the basis of the size of the watershed, the drainage basins of India are grouped into three categories: (i) Major river basins with more than 20,000 sq. km of catchment area (figure 18). It includes 14 drainage basins such as the Ganga, the Indus, the Godavari, the Krishna, the Brahmaputra, the Mahanadi, the Narmada, the kaveri, the Tapi, the Pennar, the Brahmani, the Mahi, the Sabarmati, the Barak, the Suvarnarekha; (ii) Medium river basins with catchment area between 2,000-20,000 sq. km incorporating 44 river basins such as the Kalindi, the Periyar, the Meghna, etc.; and (iii) Minor river basins with catchment area of less than 2,000 sq. km include fairly good number of rivers flowing in the area of low rainfall.