Figure 1: Net Area under irrigation by sources (2009-10)

Canal used to be the main source of irrigation in 1950-51, irrigating almost 50 per cent of the total irrigated area of India. In 1960s, there was a tremendous increase in the tube-well irrigated area promoted by the government. Consequently, the percentage of canal irrigated area declined to less than 40 per cent and in 2009-10, it is only 26 per cent.

Canals are an effective in low and leveled relief, productive plain areas where perennial source of surface drainage is available. These conditions are ideally found in the Northern plains of India, Kashmir and Manipur valleys and the Eastern Coastal plains (figure 2). High density of canals is found in Uttar Pradesh with Ganga canal system, Punjab, Haryana and Western Rajasthan with Indira Gandhi Canal. In Peninsular region, Damodar, Mahanadi, Godavari, Krishna, Narmada rivers etc. rivers have important canal system. Uttar Pradesh has the first rank in canal irrigation followed by Andhra Pradesh.