Sources of Irrigation in India
According to State of Indian Agriculture 2015-16, India has a net sown area of around 140 million hectares (2012-13) of which around 66.10 million (around 47%) is under irrigation.
India’s water budget
India accounts for around 4% of world’s renewable water resources. The average annual precipitation in India is around 4000 BCM (Billion Cubic Meter). Of this, around half (1869 BCM) water runs off from rivers to oceans. What is left from that only 690 BCM is utilizable surface water. This along with 430 BCM groundwater makes India’s total annual utilizable water resources to be close to 1120 BCM.
The major challenge in water budget is to make use of as much as possible part of the runoff from the rivers. A large number of dams, barrages, hydropower structures, canal networks are efforts towards this challenge only. Currently, the major and medium irrigation projects of India have a storage capacity of around 225 BCM. This is less but has provided assured irrigation in substantial command areas, extended the supply of drinking water to remote areas and ensure water supply to hydro and thermal power plants and to meet other requirements. Added to this is the minor irrigation potential of about 100 BCM, created through check dams, small structures, ponds, etc. Finally, groundwater potential of about 243 BCM was available.
Different Sources of Irrigation
Various Sources of Irrigation in 2012-13 are as follows:
Trends in Sources of Irrigation
Since 1950-51, the government had given considerable importance to the development of command area under canals. In 1950-51, the Canal irrigated area was 8.3 million hectares and it currently stands at 17 million hectares. Despite that, the relative importance of Canals has come down from 40% in 1951 to 26% in 2010-11. On the other hand, the well and tube well accounted for 29% total irrigated area and now they share 64% of the total irrigated area.
This implies that “despite of heavy public expenditure on canals, our governments have not been able to reduce the groundwater depletion” done by the remarkable progress of the tube wells in last many decades. The key reason is widening gap between irrigation potential created and actually utilized.
States under Well Irrigation
Well Irrigation is common in alluvial plains of the country except the deserts of Rajasthan. Plains of UP, Bihar, Gujarat, Karnataka & Tamil Nadu are the states which are more prominently under the well irrigation.
States under Canal irrigation
Canals are second most important source of irrigation in India after wells and tube wells. The Canals are irrigating those lands which have large plains, fertile soils and perennial rivers. The plains of North India are mostly canal irrigated. Other parts are coastal low lands and some parts of Peninsular India. The states are: Andhra Pradesh, Assam, Haryana, Jammu & Kashmir, West Bengal, Punjab Rajasthan, Bihar, Karnataka, Tamilnadu and UP.
Major States under Tank irrigation
The Tank irrigation is more in the rocky plateau area of the county, where the rainfall is uneven and highly seasonal. The Eastern Madhya Pradesh, Chhattisgarh, Orissa, Interiors of Tamil Nadu and some parts of Andhra Pradesh have more land under tank irrigation.