IRRIGATION AND POWER
I
IRRIGATION
WATER RESOURCES THE integrated development of the water and land resources of the country is of fundamental importance to its economy and programmes for achieving this have a high priority. As the First Five Year Plan has pointed out the utilisation of the water resources has to be planned on a national basis.
2. The total river water resources in India were computed a few years ago at 1356 million acre feet. Investigations for an accurate assessment of water resources have begun and will continue during the second five year plan. The river flow that can be used for irrigation depends on topography, flow characteristics, climate, and soil conditions of the region, and differs from river to river. Of the available supplies, it is estimated that approximately 450 million acre feet could be put to beneficial use.
3. Only about 76 million acre feet had, however, been utilised upto 1951. This represented only 5.6 per cent. of the river flow in the country. Additional supplies will, however, be utilised by the projects taken up in the first plan, as a result of which the percentage of water used will rise to 10 in 1956. The position in regard to utilisation of water resources in the important river basins will approximately be as set out below:-
Additional Additional
Utilisation Utilisation
by pro- by pro-
Estimated Utilisation jects jects
River System average upto 1951 entered in entered in
flow the I Plan the II Plan
(on full (on full
develop- develop-
ment) ment)
1 2 3 4 5
(Figures in million acre feet)
1. Indus 168 8.0 11.00 1.2
2. Ganga 400 20.0 21.5 14.5
3. Brahmputra 300 nil nil nil
4. Godavari 84 12.0 1.0 1.5
5. Mahanadi 84 0.6 10.5 0.2
6. Krishna 50 9.0 15.6 2.6
7. Narmada 32 0.2 nil 10.1
8. Tapti 17 0.2 0.7 3.5
9. Cauvery 12 8.0 1.3 0.6
Large quantities of waters will still be available. A programme for planned development of these resources has, therefore, to be continued.
4. Substantial supplies are available from underground waters also. No inventory of these resources has been prepared so far, but as a result of the exploratory tubewells which have been taken up, reliable information in regard to sub-soil water resources for some of the regions in the country will become available. These waters would be utilised for irrigating areas which cannot be economically irrigated by canals or in areas which are susceptible to waterlogging where irrigation by tubewells is preferable to irrigation by canals.
EXISTING DEVELOPMENT 5. Irrigation has been practised in India from ancient times. Efficient and extensive irrigation works were constructed during the nineteenth century on the Ganga and Jamuna in Uttar Pradesh, on the Ravi and Sutlej in the Punjab, on the Godavari, Krishna and Cauvery in Madras and on the Sone in Bihar. During the past few decades, further irrigation works were constructed on the Sutlej in Punjab, on the Betwa and Sarda in Uttar Pradesh, on the Mahanadi in Madhya Pradesh and Orissa, on the Godavari in Bombay and Hyderabad, on the Krishna in Andhra and on the Cauvery in Mysore and Madras. Several large irrigation schemes were taken up under the first five year plan also, a number of them being multipurpose in character. In many cases, they involved construction of dams and reservoirs to store monsoon flows. Work is still in progress on some of the projects and most of it will be completed during the second plan. Statement I in the Annexure gives particulars of important irrigation works in the country.
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SECOND FIVE YEAR PLAN
6. The land utilisation statistics for the country as reported for 1954-55, are given below:-
Million Acres
(Approximate)
Gross area 811
Classified area 722
Forests 133
Not available for cultivation 122
Uncultivated land excluding fallows 95
Current fallows 28
Fallows other than current fallows 29
Net area sown 315
Culturable area 467
Cultivated area 343
Statement II in the Annexure shows important agricultural and irrigation statistics by States.
7. The area irrigated from all sources in 1950-51 was 51.5 million acres, out of which 17.9 million acres was irrigated by Government canals, 2.8 million acres by private canals, 8.8 million acres by tanks, 14.7 million acres by wells and 7.3 million acres by other sources. This constituted about 17.5 per cent of the total cultivated area of the country. Additional irrigation amounting to about 6.3 million acres will be available by 1956 from major and medium irrigation works taken up during the first plan. On full development, these works will irrigate about 22 million acres. The benefits for different States are given below:-
Irrigation Irrigation
State available on full
by 1956 development.
1 2 3
Thousand acres
Andhra 89 1960
Assam 152 234
Bihar 689 2576
Bombay 309 1505
Madhya Pradesh 10 244
Madras 240 396
Orissa 90 1875
Punjab 1520 3280
Uttar Pradesh 1674 1920
West Bengal 639 2144
Hyderabad 72 1517
Madhya Bharat 120 706
Mysore 39 384
Pepsu 204 1011
Rajasthan 182 1758
Saurashtra 116 270
Travancore-Cochin 38 138
Jammu & Kashmir 35 170
Ajmer 1 10
Himachal Pradesh 24 100
Kutch 24 48
Vindhya Pradesh .. 37
TOTAL 6267 22283
8. An addition of 10 million acres is expected to be made to the irrigated area from minor irrigation works taken up during the first plan. Some areas which were previously irrigated by minor works like wells and tanks will now be served by large irrigation works giving more secure irrigation. The net addition to irrigated area from the projects in the first plan may, therefore, be taken as 15 million acres. The percentage of irrigated area to cultivated area will increase from 16 per cent in 1951 to 20 per cent at the end of the First plan.
FUTURE DEVELOPMENT 9. Irrigation.-Adequate data are not available for determining the eventual target for irrigation or the total irrigation development possible under different kinds of sources in the country. It has, however, been roughly estimated that about 75 million acres may eventually be irrigated by multi-purpose, large and medium irrigation works. An equal area could be irrigated under other categories of irrigation sources thus making a total of about 150 million acres under irrigation from all sources. An all-India survey of the irrigation possibilities was made by the Irrigation Commission more than 50 years ago. There has been a great change in conditions since then. Firstly, there have been improvements in techniques of dam con- struction and in irrigation engineering generally. Schemes which were considered impossible in those days have now become practical pro- positions. Secondly, in recent years, there has been a great advance in the techniques of dry-farming, contour bunding, soil conservation etc. The estimates of possibilities of irrigation have to be revised from both these angles. We recommend that the Central and State Governments jointly should undertake a careful survey of future possibilities of large and medium irrigation projects and for minor irrigation schemes like tanks and wells. In each region, the question should also be studied at what point irrigation may cease to be economical and the adoption of dryfarming methods should be advocated. The investigations which we have proposed will provide a correct appreciation of the possibilities of development in the three directions indicated above, namely, how much irrigation can be developed under large and medium irrigation works; what are the possibilities of developing irrigation under minor irrigation works,
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IRRIGATION AND POWER
wells, etc; and thirdly, the scope for adopting dryfarming techniques, contour-bunding, arrangements for the preservation of soil moisture etc. Such investigations are necessary for drawing up future plans for the development of irrigation.
10. It is also essential that water requirements for crops under dry-farming conditions are kept in view in preparing projects for water utilisation by canal system. There is a danger that the total utilisation of catchment waters in lower areas by canal systems or storage reservoirs may deprive areas which cannot benefit from canal irrigation of the use of water through dry-farming techniques. Reservoirs should, therefore, not be so designed as to store the entire runoff from catchments without taking into consideration future water requirements of disadvantageously located areas in the upper reaches. Similarly,the requirements of areas lower down should be kept in mind in fixing sizes of storage reservoirs in the upper reaches of a river.
11. Navigation.-Apart from irrigation, power generation, water supply and disposal of sewage, an important use of river waters is for purposes of navigation. Being a cheap means of transport navigation can play an increasingly useful part in meeting the growing requirements of communications. The development of inland water transport has been hitherto confined to certain parts of Assam, West Bengal, Bihar and U.P., and much progress has not been made in this direction during the first plan. In view of the growing requirements of development the communication aspects of river waters have to be given greater attention and the possibilities of economic development of waterways for navigation have to be investigated more fully during the second five year plan. The problem has also to be given greater attention in connection with the planning of river valley projects.
12. Soil conservation.-The problems of soil conservation and steps to meet them were dealt with in the first plan. The necessity for careful attention to this problem is all the. greater in areas affected by river valley projects, where large storage reservoirs are constructed and the normal regimes of rivers and tributaries in the basin are considerably changed. Without suitable soil conservation measures in catchment areas, the detritus brought by flowing waters is deposited in reservoirs and the streams below and impairs their capacities. The flow conditions in the rivers below the reservoirs are also significantly altered by the construction of dams. This, in turn, affects the flow conditions in the tributaries with the result that the soil erosion problem in the valley below becomes more serious. Soil conservation measures should, therefore, receive particular attention in areas affected by river valley projects and find an important place in soil conservation programmes. Check dams required for the safety of the works connected with river valley projects should also receive attention simultaneously and should form an integral part of every large river-valley project.
PROGRAMME FOR THE SECOND PLAN 13. Physical Benefits.-The first five year plan was drawn up in the background of a long-term plan to double the area under irrigation from Government works over a period of 15 to 20 years. The total area irrigated in the country from all sources in 1951 was about 51 million acres. During the first plan, additional irrigation of 16.3 million acres would have been achieved: 6.3 million acres from large and medium projects and 10 million acres from minor works. During the second plan, it is proposed to bring under irrigation an additional area of 21 million acres: 12 million acres from large and medium projects and 9 million acres from minor irrigation works. Out of the 12 million acres to be irrigated by large and medium projects, 9 million acres will be irrigated by projects which are at present under execution and 3 million acres by new projects to be taken up during the second plan. The latter have an ultimate potential in irrigation benefits of about 15 million acres. During the second plan in the first three years, irrigation from these projects is expected to increase at the rate of 2 million acres per annum and in the last two years at the rate of 3 million acres per annum.
14. Financial Outlay.-During the first plan and in the immediately preceding years, there has been considerable activity in all parts of the country on irrigation projects. The total cost of irrigation and power projects initially included in the first five year plan was about Rs. 970 crores, of which irrigation accounted for about Rs. 620 crores. Additions were subsequently made such as the programme of medium irrigation schemes for permanent improvements in scarcity areas which involved an outlay of about Rs. 40 crores. The scope of some of the schemes was enlarged and, in certain cases, estimates had to be revised. Thus, the total cost of irrigation projects included in the first plan is about Rs. 720 crores of which about Rs. 80 crores had been spent before the commencement of the plan. The expenditure during the first plan is estimated to be Rs. 340 crores, the balance being carried over to the second and third plans. It is essential that projects in hand should be completed quickly so that expenditure already incurred may be put to productive use and benefits realised as soon as possible. During the second plan, these projects will require an outlay of about Rs. 209 crores.
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SECOND FIVE YEAR PLAN
15. The total cost of new irrigation projects included in the second plan is about Rs. 380 crores of which about Rs. 172 crores are expected to be spent during the second plan, the balance being required in the third and subsequent plans. The total provision during the second plan for major and medium irrigation works is Rs. 381 crores. An additional provision of Rs. 35 crores has been made for commencing projects for the utilisation of India's share of waters that will be released on the Indus system and certain other projects, decisions on which are yet to be taken.
16. The programme includes 195 new irrigation projects. Ten of these cost between Rs. 10 and 30 crores, seven between Rs. 5 and 10 crores and the rest less than Rs. 5 crores. Thus, in the second plan, there is a marked preference for medium irrigation projects. The total-number, costs, and benefits of the different sizes of new projects included in the second plan are set out below:-
Total es- Approxi-
timated mate irri-
Number cost. gation be-
Estimated cost of nefits on
Projects completion
(million
(Rs. crores) acres)
Between Rs. 10 and Rs. 30
crores 10 191 8.4
Between Rs. 5 and Rs. 10 crores 7 54 1.5
Between Rs. 1 and Rs. 5 crores 35 85 3.4
Less than Rs. 1 crore 143 46 1.5
TOTAL 195 376 14.8
The particulars of important irrigation projects in the second plan are shown in Statement III in the Annexure.
17. The inclusion of a project in the plan does not mean that it has been fully investigated from every point of view. In fact, for a number of projects detailed technical investigations and economic assessment will have to be completed before construction can begin. In the initial stages, work on such projects will have to be confined to surveys and investigations for completing the project reports or, in particular cases, to works of a preliminary nature like access roads etc. The technical, economic and financial aspects of some of these projects may require considerable modification as a result of detailed investigations and even their scope may need to be reviewed. As was emphasised in the first five year plan, it would be desirable that at defined stages in the course of its execution the economic and financial aspects of every project as a whole and of its different parts and phases, should be carefully reviewed.
18. In carrying out the irrigation programmes, it is desirable that States should give close attention to the question of phasing. Apart from considerations of finance, the phasing of projects will be determined by several other factors, such as the technical personnel available, the need for realising benefits from some of the projects at an earlier stage, the claims of projects under execution and the requirements or needs of different areas within a State. Thus, a number of major projects included in the plan will have to be taken up in the later stages rather than in the earlier stages of the plan. Along with certain schemes, where investigations are yet incomplete, the Vamsadhara project in Andhra; the Kansai in Bihar; the Ukai, the Narmada, the Mahi, the Khadakwasla, the Girna and the Banas in Bombay; the Tawa in Madhya Pradesh; and the Kangsabati project in West Bengal are in this category. On some of these, the scope and benefits are yet to be defined. The total cost of these projects exceeds Rs. 200 crores against which a provision of about Rs. 50 crores has been made in the second plan.