IRRIGATION

North -East India is one of the wettest region of the world with an average annual rainfall of 2000 mm. The region also has a dense network of drainage channels with as many as 7 river -basins lying in it . The region as such is very rich in water resource. But this has never before been tapped for agricultural purposes, because the subsistence economy of the region with a limited population and abundant cultivated land did not realise the necessity of growing more crops than what was actually needed. But with a tremendous growth of population on the one hand and subsistence economy being replaced partially by modern industrial-commercial economy on the other , the need for growing more crops has arisen. As such the need of irrigation in the region is being increasingly felt.

A scientific probe into the present agricultural status of the region reveals that there is a great need of irrigation to develop agricultural production. The necessity is caused mainly by climatic factors but there are other factors too. In respect of the climatic factors, it is firstly seen that although the region has average annual rainfall of more than 2000 mm, about 80% of it comes between late June and late September. From about late September the rainfall becomes scanty and the months of November, December, January, February, and March remain practically dry except an occasional shower. Although a few thunder-shower occur in April and May, the water thus provided is partly absorbed by the thirsty soil lying under the long dry spell and partly lost in evapo-transpiration. In this long spell of drought the small rivers, rivulets, streams, ponds, ponds tanks and other shallow water bodies run dry, Even the underground water level sinks down by 10- 15 metres. Under such circumstances no large scale ravi crop can be carried out during the dry season from October to May without the help of irrigation.

Secondly, the vagaries of the South-west monsoon necessitates irrigation even during the amon crop can period. This is because, although the South west monsoon rains normally come during the month of June, sometimes it may not, affecting the sowing of paddy seeds and transplantation of seedlings. This early drought also affects jute plans in their healthy growth and by facilitating gregarious weeds to grow. Sometimes again, although the monsoon rain come, it may not be of sufficient quantity and affect agricultural operation. In some years again rainfall varies within the region, some areas of it receiving surplus and some other areas receiving deficient rainfall. Thus, it is realised that presence of irrigational facilities are necessary even in the growing period of the aman crops.

Thirdly as 72% of the area of the North -East India is hilly , the water from rainfall run down the hill slopes as sheetflood in these areas leaving little water for crops. In the hill slopes and hill tops the jhum cultivation may not need much water, but for paddy cultivation on the terraces, irrigational facilities are a must.

Fourthly ,in plains of the region there are sandy tracts, especially by the side of the present and old river courses. As water percolates down in the sandy tracts, no crops can be grown unless they are constantly supplied with water. Although such sandy tract are otherwise suitable for the growth of various vegetables and cash crops, in the absence of water supply production from them becomes very low. Irrigation. therefore, is necessary in such areas.

With the ever increasing population the region has become an increasingly food - deficient area. further except tea and jute, little other cash crops are grown in the region although, oil seeds pulses, potato and many other crops can be grown as cash crops provided water is available all the year round. In fact, deficiency in food crop production in the region was felt in the late nineteen thirties and early forties with the breaking out of World was II. and the then British government launching a grow more campaign in the early forties. Subsequently after independence , the Five Year Plans started laying stress on increasing agricultural production and the need of irrigation, along with other measures of innovation to that end was felt acutely. A Flood Control and Irrigation Department was created in 1954 in the then Assam which included major part of the North India except Arunachal Manipur and Tripura. Scarcity of foodstuffs began to be acutely felt in the nineteen sixties as a result of unnatural population explosion in the region on the one hand and extensive damage to agriculture by successive floods on the other. Realising the need of irrigation for increase in agricultural production, top priority began to be given on it and during the Fifth Five Year Plan period Irrigation Department was opened in all the states in the region which was entrusted with launching irrigation projects.

In spite of such efforts, out of the total agricultural land in the North East India , only 8.1 lakh hectares (22.50%) have been brought under irrigation. It is less than the national norm of 25.55% , Amongst the states of the region. Manipur has the highest percentage (46.4%) of its total agricultural area under irrigation followed by Nagaland (40. 5% ) Meghalaya (25.9%) Arunachal Pradesh (21.4%), Assam (21.2%) Mizoram (12.3% ) and Tripura (11.8%).

Following discussion gives a detailed account of irrigation in the individual states of the region :

Assam

The mainstay of the economy of Assam is agriculture. In order to improve the economic condition of the state, it is necessary to increase the agricultural output. This can be done if only water along with other inputs are supplied to the agricultural fields just in time . But let alone other inputs, even water, which is abundantly available in the numerous rivers of the region, has not been supplied to the fields at the time of dry season. This lack of irrigation facilities has been adversely affecting the agricultural of the region.

All the three methods of irrigation e.g canal irrigation, well irrigation, and tank irrigation may be adopted in Assam. As the Brahmaputra and most of its tributaries are perennial, canal irrigation is possible by damming the rivers in their upper courses. Again, as the underground water table is not far below the surface, especially in the plains of the state, both wells and tanks can be dug and used as source of irrigation For well irrigation shallow and deep tube wells can be sunk to obtain water. Electrically operated lift irrigation is feasibility in the state.

In spite of the opportunities stated above for development of irrigation facilities, these have not been done, partly because until very late the pressure of population was low and subsistence economy prevailed in the state. The peasants consequently hardly felt the need of irrigation . Secondly, neither the government nor the poor peasant could pull up enough capital to develop irrigation irrigational facilities rapidly.

It has been found that at the end of the sixth five year plan (1985-86), only 3.72 lakh hectares of agricultural land (out of the total of 36 Lakh ha of the state) were under irrigation. Having realized the growing population pressure and increasing deficit of food-crops, efforts have been made by the State Irrigation Department to bring more area under irrigation land in 1986-87 as much as 41,304 ha of additional agricultural land was provided with irrigation facilities. The Irrigation Department in the state was strengthened by opening new circles, and offices and setting up an advisory board.

During 1991-92 the Irrigation Department of the Government of Assam created an irrigation potential of 12,618 hectares (6816 ha under major and medium projects, 4,076 ha under Tribal Sub- Plan and 1726 ha under also Special Component Plan for Scheduled Casters). Besides the Department also generated potential through minor irrigation schemes covering 26,145 ha under the command Area Development Scheme.

In 1985-86 the state had 1963 irrigation schemes, out of which 2 were large and other were medium and small. A table of the large and medium irrigation schemes of the state are given below :

Irrigation Schemes Completed upto 1992

Medium Schemes

1. The Rupahi I.P.	Barpeta Dist.	9,320 ha
2. The Dekadong I.P.	Barpeta Dist.	28,155 ha
3. The Pahumara I.P.	Barpeta Dist.	12,950 ha
4. The Kaldiya I.P.	Barpeta Dist.	----------
5. The Sukal I.P.	Kamrup Dist.	13,000ha
6. The Jamuna I.P.	Nagaon	1,900 ha
7. The Lanka I.P.	Nagaon	-----------
8. The Bar Dikarai I.P.	Sonitpur	22,000 ha
9. The Harguti I.P.	Karbi Anglong	------------
10. The Dikhari I.P.	Karbi Anglong	------------
11. The Patradisa I.P.	North Cachar	9,000 ha
12. The Longa	Kokrajhar	----------
13. The Jajlaigaon I.P.	Dhubri	----------
14. The Mora Dhansiri I.P.	Golaghat	9000 ha
15. The Rukni I.P.	Cachar	----------

Besides the above, some large, medium and small irrigation projects are under construction. Of these the two large ones are Dhansiri Project, over the Jia Dhansiri River in Udalguri Subdivision (area to be irrigated ; 70, 445 ha ) and Champamati Project over the river of the same name in Kokrajhar District ( area to be irrigated 24, 994 ha). The Dhansiri Irrigation Project was started in 1976. Its headwork is located at Bhairabkunda at the foot of the Bhutan -Arunachal Himalaya where the rivers Bhairabi and Jampani meet. Its headwork construction has been completed and a few canals are left to be dug. The Champamati Irrigation Project was started in 1981 over Champamati River. It has been partly completed and is irrigating 5,000 ha of land. A barrage to be constricted over the river at Nangalbari of Dhubri District shall further extend the command area of the project.

The medium on going schemes include Kalanga ,Amtring, Hawaipur Projects (all in Karbi Anglong), Integrated Kolong Project (Nagaon), Baralia Project (Nalbari), Puthimari Project (Kamrup) and Kharmuja Project (Goalpara ).

Many small irrigation projects are coming up. Of these Kurua scheme in Darrang, Nalana in Nalbari, Sukonori in Barpeta, Thekesu -Bechumari Deosila flow Irrigation and Sijukoma Lift Irrigation at Balijana in Goalpara, Sondoba Lift Irrigation in Morigaon and Patiajong and Kuligaon projects of Karbi Anglong are the main. In Majuli the important lift and tubewell irrigation projects are located at Sensua Kumar Chapari, Khetopathar, Siran Deuri Gaon, Mijon Deuri Gaon, Kamalabari and Fulani. Several small irrigation projects are on their way of completion in the Barak Valley also. These include the ones located at Nuruleherra, Rupcherra, Daluganj, Nabincherra, Depocherra, Pechacherra, Gardhicherra, Sonabeel and Patharkandi Beel.

Manipur

The Manipur Plain is of great importance from the human point of view ,in that it is not only very densely populated, but also it has to produce most of the food-stuffs of the state, the other parts of it being hilly. Small scale irrigation projects of limited command areas were already there in the past. But the works on medium and large scale projects have been taken up very late. The medium irrigation projects of the state include (1) Imphal River Barrage (command area 1600 ha ) (2) Chakmai Dam (2000ha) , (3) Khampum Dam (1200ha), (4) Thoubal (1500 ha) (6) Disang (4000 ha) and (7) Jiri River Dam. The last named one was started in 1988-89 and when completed it will irrigate 5000 ha in Cachar district of Assam and 4000 ha in Manipur.

The only large scale irrigation project of the state is the Loktak Lift Irrigation Project. It was first commissioned in 1979. At present the project supplies water to 40, 000 ha of land.

Tripura

Tripura does not have any large irrigation project. It has, however, a few medium and many small projects. Of the medium projects, the Gomti river, the Khowai river and the Manu river Irrigation projects are the main. The state has, however, a large number of small irrigation projects by lift and tube-well. These were started in the fourth five year plan and so far more than 100 such projects have been completed and irrigation potentiality by now has been increased to about 20,000 ha.

Arunachal Pradesh

Although the lower parts of Arunachal Pradesh receive heavy rainfall, these need regular supply of water in the dry season, especially for �rabi� crops. Some Arunachalis, like the Apatanis irrigate their terraced agricultural fields by damming the hill streams and diverting their water through small gravity channels. In smaller holdings, power pump is used for irrigation. Up till now water is supplied to the agricultural fields of the river valley and foothill areas through nearly 400 small irrigation projects.

The state has started a few medium projects. Of these, the Lakhmi Irrigation projects at Roing in Debang Valley was commissioned in 1987 and has been irrigating about 5000 ha of agricultural land. The Tirap Irrigation Project when completed will supply water to both Arunachal and Assam. Six medium projects have also been under construction in Lohit, Dibang Valley and East Sing districts. Moreover, Sonaul, Kokila and in Lower Subansiri district 3 water pumps have been set up for irrigation. All these have substantially improved the irrigation potential of the state, bringing 26% of its 133430 ha of total agricultural land under it.

Meghalaya has no large irrigation project. It has only one medium and some small projects. Upto the late nineteen-eighties Meghalaya irrigated only 15,000 ha of agricultural land though small project. The state has taken up some flow and lift irrigation schemes in recent years and through them the potential has now increased to 2,5000 ha. The only medium project, of the state is Rongai River Project of West Garo Hills district, which has a command area of 4,775 ha.

Nagaland, like other hill states, dose not have any large irrigation project. Water to the terraced fields is supplied through indigenous but very ingenious gravity flow method. However, such irrigation is limited to a small area of Kohima district Small irrigation projects have therefore, been taken up in recent times to supply water to the rice fields of the river valleys. Water from the small rivers is diverted to the rice fields by constructing dams. Efforts have also been made to utilize ground water for irrigation. Schemes have been taken up to utilize the waters of the Dikhu, Milak and Dhansiri rivers. About 60,000 ha of land has so far been brought under irrigation in the state.

The difficult hill terrain of Mizoram has prevented the state for undertaking any ambitious irrigation scheme. The farmers of the state, however, use indigenous methods to irrigate their land by collecting stream water in tanks at vantage locations. Thus they used to irrigate about 2885 ha of agricultural land. During the period between 1974 and 1978 another 520 ha was brought under irrigation by 300 power- driven pumps. So far 15 small irrigation projects have been completed and 16 new schemes are under way in the state. The Charui River Irrigation Project, which is a medium one, has recently been completed . In 1990 the state had an area of 70,000 ha under irrigation.