Irrigation system in India – In India, agriculture is mainly dependent on rainfall. The rainfall is generally unpredictable in its incidence and variable in amount. The distribution of water in India is, therefore, very uneven. The rainfall in the country is concentrated usually during four months in the year when there is excess water that flows down unutilized, while in other seasons, there is an acute shortage of water. India has large water resources, great river systems, and vast thirsty tracts of land and is thus designed, so to say by nature for the development of irrigation.
Irrigation system in India
Irrigation is a technique of supplying water to dry land as a supplementation of rainwater. It is mainly aimed at farming. There are various types of Irrigation system practices in different parts of India. Irrigation in India is carried on through wells, tanks, canals, perennial canals, and multipurpose river valley projects. The irrigation engineer should be acquainted with the type of soil moisture, quality of irrigation water, and frequency of irrigation for the proper implementation of the irrigation system.
Being an agriculture-dependent country, irrigation is the backbone of India. India is a vast country with a diverse biodiversity i.e. topography, climate, and vegetation. The total cultivable area in the country is about 185 million hectares. At present, about 172 million hectares are under cultivation. 70% of India’s vast population depends upon agriculture directly for their living, and therefore, agriculture has always been and promises to remain the main industry of India in the predictable future also. In India, agriculture is mainly dependent on rainfall.
The rainfall is generally unpredictable in its incidence and variable in amount. The distribution of water in India. is, therefore, very uneven. The rainfall in the country is concentrated usually during four months in a year when there is excess water that flows down unutilized, while in other seasons, there is an acute shortage of water. India has large water resources, great river systems, and vast thirsty tracts of land and is thus designed, so to say by nature for the development of the Irrigation system.
India’s Irrigation system is mostly groundwater well-based. At 39 million hectares (67% of its total irrigation), India has the world’s largest groundwater well-equipped irrigation system (China with 19 MHA is second, USA with 17 MHA is third). However, even when the full potential of available resources is developed, irrigation facilities can be extended to 115 million ha, of which 80 million ha are from surface water and 35 million ha from groundwater.
The gross cropped area is expected to increase to about 200 million ha during the next two decades due to the introduction of multiple cropping and land reclamation. Among the agricultural inputs which include seeds, fertilizers, plant protection, machinery, and credit, irrigation assumes an important place. Irrigation means watering the fields by any means other than rain or is the artificial application of water to the land or soil. It is the replacement or supplementation of rainwater with another source of water. It is used in dry areas and during periods of inadequate rainfall.
Need for Irrigation system
- India is a big country and stands next to China when we talk about population and so irrigation facilities are needed to grow more food to feed our teaming millions.
- The distribution of rainfall is uneven and uncertain which either causes famines or drought. By means of irrigation, we can check both problems.
- Different water requirements of different crops can only be met through irrigation facilities.
- India, being a tropical country, the temperature is high and evaporation more rapid, so, artificial irrigation is necessary for an ample supply of water and also to prevent water scarcity in the long dry winter season.
Sources of Irrigation system in India
According to Agricultural Census 2010-11, India’s total area under irrigation is 64.7 million hectares. Of this, a maximum of 45% is shared by tube wells followed by Canals and wells.
Since 1950-51, the government had given considerable importance to the development of command areas 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 percent of the total irrigated area.
Types of Irrigation System
Depending upon the availability of surface or groundwater, topography, soil, and rivers, various types of irrigation practiced in India are as follows:
1. Tank Water Irrigation System
It is prevalent in the uneven and relatively rocky plateau of Peninsular India. Tanks are commonly used in Deccan Plateau, Andhra Pradesh, Karnataka, Tamil Nadu, Eastern Madhya Pradesh, Chhattisgarh, Orissa, and Maharashtra. About 8% of the total irrigated area is irrigated by tanks. There are about 5 lakh big and 50 lakh small tanks irrigating over 25.24 lakh hectares of agricultural land. Most of the tanks are small in size and built by individuals or groups of farmers by raising bunds across seasonal streams.
- Most of the tanks are natural and do not involve heavy costs for their construction. Even an individual farmer can have his own tank.
- Tanks are generally constructed on rocky beds and have a longer life span.
- In many tanks, fishing is also carried on. This supplements both the food resources and income of the farmer.
But there are some drawbacks of this Irrigation system: Tanks cover a large area of cultivable land. Evaporation of water is rapid due to the large expanse of shallow water tanks, which do not ensure a perennial supply of water. Moreover, lifting water from tanks and carrying it to the fields is a strenuous and costly exercise that discourages the use of tanks as a source of irrigation.
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2. Well Water Irrigation System
It is more widespread in plains, coasts, and some regions of peninsular India. It is less costly and more flexible as water can be drawn whenever needed ‘evaporation loss’ is minimized and no fear of “over-irrigation”.
- There were about 5 million wells in 1950-51 and their number has now increased to about 12 million. Well, irrigation accounts for more than 60% of the net irrigated area in the country against 29.2% of the canal and only 4.6% of tank irrigation. It accounted for 59.78 lakh hectares in 1950 51 which rose to about 332.77 lakh hectares in 2000-01 thereby registering a more than a fivefold increase in good irrigation.
- Uttar Pradesh has the largest area under good irrigation which accounts for about 28% of the well-irrigated area of India. This is followed by Rajasthan (10%), Punjab (8.65%), Madhya Pradesh (8%), Gujarat (7.3%), Bihar, Andhra Pradesh, and Tamil Nadu, etc.
- In Gujarat, about 82% of the net irrigated area is under good irrigation. The other states where well irrigation plays a significant role are Punjab (80%), Uttar Pradesh (74%), Rajasthan (71%), Maharashtra (65%), Madhya Pradesh (64%), and West Bengal (60%)
- Uttar Pradesh, Rajasthan, Punjab, Madhya Pradesh, Gujarat, Bihar, and Andhra Pradesh account for three-fourths of the total well-irrigated area of India.
Wells are of two types:
- Open wells: Open wells are shallow and irrigate a small area because water availability is limited and the level of water goes down during the arid season.
- Tube wells: Tube wells are deep, more suitable and have the capacity to draw a large volume of water. Such a type of well always has water irrespective of time. A deep tube well worked by electricity can irrigate a much larger area. (about 400 hectares) then a surface well (1/2 hectares). It has increased in recent years. Tube wells are also used for irrigation purposes. Tube wells can be installed and used near agricultural land where groundwater is readily available.
These are mostly used in U.P., Haryana, Punjab, Bihar, and Gujarat. In Rajasthan and Maharashtra, artesian wells are now supplying water to agricultural lands. In artesian wells, the water level remains at a high level because of the natural flow of water due to high pressure.
3. Inundation/Canal Irrigation system
Canal irrigation is playing a vital role in Indian agriculture because it is the main source of irrigation in India. It covers near about 42% of total irrigated land. The net area under canal irrigation is about 15.8 million hectares. In many places during the rainy season, there is a flood in the rivers. The flood water is carried to the field through canals. These canals are found in W.B., Bihar, Orissa, etc.
They supply water only when there is a flood in the rivers, and therefore, are of no use during the dry season when water is required most.
Punjab and Haryana have become the first granaries of the country due to these canals which include Western Yamuna Canal, Sirhind Canal, Upper Bari Doab canal & Bliakra Canal. The important canals of Uttar Pradesh are the upper and lower Ganga Canal, Agra, and Sharda Canal and Rajasthan has become the third granary due to the Rajasthan canal project. In Tamil Nadu, the most important is the Buckingham canal and the Periyar canal.
4. Perennial Canals Irrigation System
The perennial canals get the supply of water either from the river directly or through the reservoirs of the river projects. In order to supply water throughout the year, reservoirs are constructed for storing water across the water bodies, referred to as “Dams”. From these reservoirs, water can be supplied to the fields whenever there is a demand for it. So this Irrigation system of irrigation ensures a supply of water in all seasons. This Irrigation system is greatly adopted in Tamil Nadu, Andhra Pradesh, Karnataka, etc. Even in Northern India, this type of perennial canal is found mostly in Punjab, U.P., and Tamil Nadu for storing water. From these reservoirs, water is carried to the fields through canals.
In Punjab, the upper Bari Doab canal connecting the Ravi and the Beas and Sirhind (from the Sutlej) canal is famous. In U.P., the Upper Ganga and the Lower Ganga canals, Agra and Sarda canals, etc. are important. In Tamil Nadu, the most important is the Buckingham canal and the Periyar canal. In many places, rain-water harvesting systems are installed and water is stored in large artificial reservoirs to be used for agricultural purposes.
5. Multipurpose River Valley Projects
In recent years, multi-purpose river valley projects are helping in irrigation and the growth of agriculture.
| S.N. | Name of the project | River | Beneficiary states |
|---|---|---|---|
| 1 | Bhakra Nangal Project | Satluj | Punjab, HP, Haryana & Rajasthan |
| 2 | Damodar Valley project | Damodar | Bihar & West Bengal |
| 3 | Hirakund Dam | Mahanadi | Orissa |
| 4 | Thungbhdra Project | Thungbhdra | AP & Karnataka |
| 5 | Nagarjuna Sagar Project | Krishna | AP |
| 6 | Kosi Project | Kosi | Bihar |
| 7 | Farakka Project | Ganga Bhagirathi | West Bengal |
| 8 | Gandak project | Gandak | Bihar, UP & Nepal |
| 9 | Beas Project | Beas | Rajasthan & Punjab |
| 10 | Rajasthan Canal | Satluj | Rajasthan, Punjab & Haryana |
| 11 | Chambal Project | Chambal | Madhya Pradesh & Rajasthan |
| 12 | Ukai Project | Tapti | Gujarat |
| 13 | Tawa Project | Narmada | Madhya Pradesh |
| 14 | Sri Ram Sagar Project | Godavari | Andhra Pradesh |
| 15 | Malaprabha Project | Malprabha | Karnataka |
| 16 | Mahi Project | Mahi | Gujarat |
| 17 | Mahanandi | Mahanandi | Orissa |
| 18 | Indukki Project | Periyar | Kerala |
| 19 | Koyna Project | Koyna | Maharastra |
| 20 | Upper Krishna Project | Krishna | Karnataka |
| 21 | Ram ganga project | Ram ganga | Uttar Pradesh |
| 22 | Tehri dam | Bhilan ganga & Bhagirath | Uttar Pradesh |
| 23 | Narmada Sagar | Narmada | MP, Rajasthan, Gujarat & Maharastra |
| 24 | Massanjore (Canada) Dam | Mayurakashi | West Bengal |