<P> Irrigation in India includes a network of major and minor canals from Indian rivers, groundwater well based systems, tanks, and other rainwater harvesting projects for agricultural activities . Of these groundwater system is the largest . In 2013 - 14, only about 47.7% of total agricultural land in India was reliably irrigated . The largest canal in India is Indira Gandhi Canal, which is about 650 km long . About 2 / 3rd cultivated land in India is dependent on monsoons . Irrigation in India helps improve food security, reduce dependence on monsoons, improve agricultural productivity and create rural job opportunities . Dams used for irrigation projects help produce electricity and transport facilities, as well as provide drinking water supplies to a growing population, control floods and prevent droughts . </P> <P> The earliest mentions of irrigation are found in Rigveda chapters 1.55, 1.85, 1.105, 7.9, 8.69 and 10.101 . The Veda mentions only well - style irrigation, where kupa and avata wells once dug are stated to be always full of water, from which varatra (rope strap) and cakra (wheel) pull kosa (pails) of water . This water was, state the Vedas, led into surmi susira (broad channels) and from there into khanitrima (diverting channels) into fields . </P>

Which is the main source of irrigation in india