Tank Irrigation in South India is centuries old technology
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TANK IRRIGATION- Challenges & Options
Submitted To
Prof. C. Shambu Prasad
Natural Resource Management
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Submitted By
Praful Ranjan; Roll No.- 28
Rohit Arya; Roll No.- 40
PGPRM-I (2006-08)
Xavier Institute of Management, Bhubaneshwar
EXECUTIVE SUMMARY
Water is most vital for sustenance of life and its scarcity has become a recurring phenomenon across the country. Though India is well endowed with sufficient average rainfall of 1215 mm per annum, but this rainfall is not erratic and concentrated in just four months of a year. This leads to floods during rainy season and water scarcity during summer months.
Agriculture guzzles about 80 % of total water requirement. So, there is a need for conservation of conservation primarily for irrigation purposes. Tank irrigation system is one of the important and oldest sources of irrigation in India. Southern parts of India, where average rainfall is around 700mm are noted for the intensity of tanks. There are about 127,000 tanks in the southern region consisting of Andhra Pradesh, Tamil Nadu and Karnataka states.
Technically, a tank can be described as a miniature version of a large dam. Water is impounded behind an earthen embankment to be released through sluices into canals to be further distributed to irrigated lands.
The 937AD to 1336 AD in South India is described as ‘Golden Age of Tanks’ that demonstrated that a high level of scientific thinking, technical parameters and user friendly management techniques had been embedded into these wonderful and sustainable water works. As a part of self-glorification, many kings used to erect Jal Stambha (liquid pillar of victory) rather than Jaya Stambha (Victory Pillar).
The major agency behind the decline of the tank irrigation had been the colonial government which had developed the river based irrigation systems. The private landowners under the ryotwari tenures resorted to wells. Other notable reasons are neglect of the colonial government in favour of river based canal system.
According to experts the development of minor irrigation should receive greater attention because of the several advantages they posses like small investments, simpler components as also being labour intensive, quick maturing and also farmer friendly.
INTRODUCTION
India is well endowed with sufficient average rainfall of 1215mm per annum. But this rainfall is not distributed throughout the year, as 80 % of rainfall occurs during four months of June to September due to south east monsoon. And of this 80% about 50% rainfalls occurs during 15 days. This leads to floods during rainy season and water scarcity during summer months.
Though the water is available in plenty but it is fast becoming scarce as well. The per capita availability of water in the year 1901 was 9400 cubic meters, in 1941 it was 7000 cubic meters and in 1981 it became only 3200 cubic meters. This has also affected the human consumption of water. The WHO recommends minimum requirement of water by the human body as 70 litres per person per day. But in India the present per capita availability of water is as low as 10 litres per person per day, which also signify the scarcity of water and need for water harvesting structures.
NEED FOR TANK IRRIGATION
First recorded scarcity of water was experienced during Sangam Period (300B.C.), and this led to construction of water harvesting structures. Since farming practices need huge amount of water and therefore water harvesting structure was developed for irrigation purposes. Tank irrigation system is one of the important and oldest sources of irrigation in India. Southern parts of India, where average rainfall is around 700mm are noted for the intensity of tanks. There are about 127,000 tanks in the southern region consisting of Andhra Pradesh, Tamil Nadu and Karnataka states.
Tank irrigation is also getting importance in other states like Maharastra, Gujarat, and Rajasthan. However, over years, the area under tank irrigation has been declining and policy makers and planners are exploring the possibilities to revive the Tank Irrigation.
Tank Irrigation is the typical example of the water harvesting techniques and are mostly managed by the local communities as common property resource. Budget constraints and poor community participation make the tank performance unsustainable. The immediate solution is to identify the appropriate investment strategies and make the local Panchayats responsible for the operation and maintenance of the tanks. For this it is resource mobilization and people’s participation is very essential.
WATER HARVESTING THROUGH TANK
Generally the tanks are the reservoirs of rainwater in low rainfall region. The efficiency of such tank depends on how the impounded water is managed for irrigational purposes. Water management involves integrated process of diversion, conveyance, regulation, measurement, distribution and application of rational amount of water at appropriate time.
Irrigation through tank system in South India is centuries old technology. In the tank rich state Karnataka, traditionally the water management was taken care of by two social institutions namely Panchyats and Nirgantis. These are classified on the basis of water management off the field and on the filed. Institution on the field was called Panchayant and that off the field are called Nirgantis.
The efficiency of water management in irrigation is finally evaluated in terms of water utilization for raising a crop even under adverse drought condition. Therefore, water management ultimately aims at producing the maximum by utilizing the available resources, which may be a scarce resource at a given time in the calendar of agricultural season. Existence of tank from time immemorial has helped farmers to develop various systems of water management based on the capacity of the tank, size of the command area, numbers of villagers benefited, social condition and above all, on the basis of rainfall pattern in that particular region.
TECHNOLOGY APPLIED
Technically, a tank can be described as a miniature version of a large dam. Water is impounded behind an earthen embankment to be released through sluices into canals to be further distributed to irrigated lands. Excess water from a reservoir is allowed to escape through waste weirs. Tank embankments are usually semi circular curved in shape. They could be a few hundred meters to a few kilometers long depending upon the shape and size of valleys they are bridging.
Tank irrigation system has three technological aspects namely- construction, distribution & lift technology. The water conserved through tank irrigation is used for two main purposes- first for crop management, irrigation and land improvement. Water conserved through tanks is also used for drinking domestic and religious purposes as well.
Due to introduction of the modern lift technology, the ground water crisis is deepening. The water yield of electric pump is much higher than that of the traditional lifts. The rate of water withdrawal exceeding the recharge rate, pushes the water table below the natural depth of water. The major consequences of the lowering ground water, about 30 to 40 % of the active wells are drying up in dry areas.
HISTORY OF TANK IRRIGATION
The 937AD to 1336 AD in South India is described as ‘Golden Age of Tanks’ that demonstrated that a high level of scientific thinking, technical parameters and user friendly management techniques had been embedded into these wonderful and sustainable water works.
As a part of self-glorification, many kings used to erect Jal Stambha (liquid pillar of victory) rather than Jaya Stambha (Victory Pillar).
DECLINE OF TANK IRRIGATION
The growth rate of well irrigation was 21.91% in 1961, had a steep rise to 63.06% in 1971, which came down to 49.19% in 1981. Significantly, the growth rate of tank irrigation was 26.23% before the end of Second Five Year Plan and reduced drastically to a phenomenal negative growth rate of -22.22% in 1981.
The construction of tanks reached a commendable height before the beginning of the British rule. British rulers did renovation and repair to some of these structures selectively. A number of these tanks have gone out of use due to weed and silts, signifying the neglect and suicidal act by the people.
The floods and natural calamities destroyed many bunds, famines and wars ‘displaced the village communities and broke the rural fabric, high and oppressive taxes were levied by the rulers to defray the expenditure for their warfare. Besides the British rulers regularly levied irrigation cess towards the repair works.
The declining of tank irrigation was found in the first half of the 19th century forced the then government of Madras for revival of such structures. In spite of it, a large number of tanks continued to ruin. Finally, the tank restoration scheme was adopted in 1883 to repair the tanks and hand them over to the villagers for maintenance.
The major agency behind the decline of the tank irrigation had been the colonial government which had developed the river based irrigation systems. The private landowners under the ryotwari tenures resorted to wells. Other notable reasons are neglect of the colonial government in favour of river based canal system.
ADVANTAGE OF TRADITIONAL TANK SYSTEMS
1. Appropriate irrigation devices in the cultivation of paddy
2. Flood control device
3. Insurance against low rainfall periods and also recharged groundwater
4. A device to protect the ecosystem
|Traditional Water Harvesting Structure At Different Places |
|Place |Structure |
|Rajasthan |Khadins |
|Madhya Pradesh |Havelis System |
|Himachal Pradesh |Guhl |
|Bihar |Ahar |
|Maharashtra |Phad |
MODERNIZATION OF TANK IRRIGATION
In the late 1970’ under a scheme funded by the European Economic Community (EEC), the PWD initiated a programme for Tank Modernization. The work of modernization was carried out by two departments of the government, the PWD and the Agricultural Engineering Department.
CHALLENGES FOR TANK IRRIGATION
✓ Tank irrigation becomes less significant if one traverses from south to north and from west to east in Karnatka.
✓ Tanks have been the most important source of irrigation in the wet region and the mixed region of south Karnataka where paddy is the main crop cultivated.
✓ Well irrigation replaces tanks in Deccan region of northern Karnataka where non-paddy crops dominate agriculture.
✓ Farmers resistance in sharing the common irrigation resources.
✓ “Jiski lathi usaki bhains” principle is applied in these cases.
✓ Sometime upstream farmers stop tank water to flow through the field channel passing through their land.
✓ Rich farmers or village head claim first right on water resources.
✓ Farmers also use other water sources for irrigation besides tank water.
✓ Farmers tap shallow ground water which slowly seeps through the previous geological formation through open shallow wells (Baori).
OPTIONS TO TANK IRRIGATION
According to experts the development of minor irrigation should receive greater attention because of the several advantages they posses like small investments, simpler components as also being labour intensive, quick maturing and mot of all farmer friendly.
Reservoirs and tanks in are losing their storage capacity due to heavy siltation. This in turn causes inadequate supply of water and also recurrent floods in some areas. Floods not only causes economic loss but also results in inundation of fertile top soil and erosion.
Siltation which results from soil erosion in the catchment areas is one of the major problems in tank irrigation systems. As a result there is loss of storage capacity and reduction in water spread area and water availability.
|Timeline For Emergence & Decline of Tank Irrigation |
|Origin of Water Harvesting to Irrigation Structures |
|Ramayan |Mentioned two lakes- Panchapsarotataka & Pamasaras |
|1500 B.C. |Earliest evidence of water reservoirs in the Deccan plateau |
|300 B.C. |Water scarcity was felt during Sangam Period |
|230 B.C. |Satavahanas kindom- existence of lakes & tanks |
|350 A.D. |Kadamba ruler Mayura Varma constructed a tank at Chandravelli near Chitradurga |
|430-450 A.D. |Kakusthavarama constructed in Talagunda tank in Shimoga district in front of Pranaveswar temple |
|485-519 A.D. |Kadamba king Ravi Varma excavated a big tank called Guddatataka in Uttara Kannada district |
|600-639 A.D. |Pallavas in the fifth century promoted some tanks and wells |
|670 A.D. |Chalukya ruler Vikramaditya granted rice land below a tank to subjects |
|670-700 A.D. |Paramesvaravarman I excavated Paramesvara tanks for irrigation purposes |
| |Paramesvaravarman II constructed famous Tenneri Tank near Kanchipuram |
|707 A.D. |Vidyaditya constructed tanks surrounding villages |
|Golden Age of Tanks (937-1336 A.D.) |
|973-1184 A.D. |Kalyana Chalukya took up vigorous tank bunding activities benefiting Dharwar, Bellary, Chitradurga & Shimoga district |
|1068-76 A.D. |Someswara I constructed several tanks in Dharwar, Bijapur & Bellary district |
|1080 A.D. |Vikramaditya constructed a number of tanks & repaired a breach tank of Tambasamudra |
|1108-52 A.D. |Hoysala kings Vishnuvardhana, Visa BallalaII promoted construction of tanks practically all over Karnataka |
|1204 A.D. |Two tanks were constructed in Belgaum |
|1242 A.D. |Hosakere of Dharwar & Beenihilla of Hubli were built |
|13th Century |Yadavs’ built many tanks |
|Post Golden Age of Tank Irrigation |
|1336-1565 A.D. |Biggest milestone of Vijaynagar Empire was Kaveri delta project and Suekere tank |
|1410 A.D. |Devaraya I built a dam on Harihara river benefiting five villages |
|14th Century |Several tanks, reservoirs and canals were constructed |
|15th Century |Renovation & maintenance of tank through co-operation & contribution of people |
|16-18th Century |Period of prosperity & great boom of activities in water works |
|1638-1799 A.D. |Hyder Ali & Tipu Sultan fought several wars and destroyed the time earned system of water harvesting |
|Pre-Independence Era |Decline of tanks was set in permanently during the British period |
|Post Independence Ear |The government emphasised initially on construction of dam, promoted tube well and more or less ignored traditional |
| |water harvesting structure as tank irrigation. |
References:
1. Title: Social Design
Author: Shah Esha
Publication: Wageningen University Water Resources Series
2. Title: Traditional Water Harvesting System
Author: Bhuban C. Barah
Publication: New Age International Publishers
3. Title: Water Resources Management
Author: Nishi Sinha
Publication: Har Anand Publication
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