In this article we will discuss about:- 1. Introduction to Irrigation 2. Need for Irrigation 3. Role 4. Sources 5. Major and Medium Irrigation Works 6. Financing of Irrigation Projects 7. Modernising Irrigation 8. Causes of Inadequate Utilization of Irrigation Potential 9. Measures for Effectively Increasing Irrigation Potentials 10. Benefits of Irrigation 11. Demerits 12. Future Prospects.
Contents:
- Introduction to Irrigation
- Need for Irrigation
- Vital Role of Irrigation
- Sources of Irrigation
- Major and Medium Irrigation Works
- Financing of Irrigation Projects
- Modernising Irrigation
- Causes of Inadequate Utilization of Irrigation Potential
- Measures for Effectively Increasing Irrigation Potentials
- Benefits of Irrigation
- Demerits of Irrigation
- Future Prospects of Irrigation
1. Introduction to Irrigation:
Agriculture has held a dominant position in the country’s economy. But this major occupation is rendered hazardous by scanty rainfall in large areas and by erratic monsoon elsewhere. Partial failure or even delayed arrival of the monsoon can cause extensive damage to crops. Conscious efforts are, therefore, being made continuously to supplement rainfall and to mitigate the grave consequences of a dry spell by supplying water artificially to parched lands. Irrigation implies maintaining the storage of water in the soil required for plant growth at times and places of deficient water supply.
Different systems of irrigation are complimentary and supplementary rather than competitive, as has been rightly observed by the Famine Enquiry Commission. “The problem of water supply will not be solved by mere extended application of one particular method of irrigation but by the use of all methods.” Irrigation comprises of three different aspects, viz., engineering, agricultural and economic and social.
Under engineering aspects are included the designing and construction of structures required for storage, diversion, conveyance, delivery and distribution through channels and distributaries, determination of water yields of rivers and water supplies for irrigated lands. The agricultural aspect refers to the use of irrigation water and various agricultural practices and cropping patterns, methods of application and the quantity of water for single irrigation. The socio-economic aspect refers to the satisfaction of social needs and desires which is essential for any community enterprise.
2. Need for Irrigation:
The necessary for irrigation arises due to the following reasons:
(i) Nearly 70 per cent of the country’s gross cropped area depends exclusively on rainfall which is unevenly distributed both in respect of time and space. The rainfall is, thus, most unreliable and is marked by wide variations in different parts and also variation from year to year in its quantity, incidence and duration. India is served by south west and the north-east monsoons. Most of the rainfall (i.e., about 73.7 per cent occurs during June-September); while winter rains amount only to 2.6 per cent; post-monsoon rains are about 13.3 per cent and pre-monsoon rains about 10.4 per cent.
The rainfall over the country is unequal, irregular and quite often liable to complete failure. With such a wide difference in rainfall between one part and another (such as 1,270 cms. at Cherapunji and only 25 cms. in Western Rajasthan) famines have occurred several times in the past. The areas generally affected by variations in the rainfall are those which receive a rainfall of 127 cms. and less per annum.
Whenever rain falls, i.e., when it is less than 80 per cent of the average, or when it does not occur at the proper crop season, production falls. If deficiency of rainfall is 40 per cent or more, famines result and crops do not even grow. To banish famines, the only remedy is artificial supply of water to the lands through irrigation. Sone Canal command area and the Krishna and Godawari Deltas, which are today the granaries of rice, used to be famine-ridden only a few years back. Irrigation is the antidote to famine
(ii) Irrigation is deemed necessary for the maximum production of most farm crops, especially in the arid and semi-arid regions. Even in the areas of high rainfall, irrigation of second and third crop or for multiple-cropping when rainfall fails. According to the I C.A.R. the production of irrigated crops is on an average 50 to 100 per cent higher than that of the unirrigated crops in the same locality.
According to a Note on the Rate of Growth During the Fourth Plan, the average yields of irrigated fields have shown a wide difference over the unirrigated fields, such as in case of rice it has been of the order of 52.2 per cent; wheat 53.1 per cent; barley 57.2 per cent; bajra 48.9 per cent; maize 53.0 per cent; and total production 92.6 per cent during 1964-65.
(iii) In India, the growing population demands higher quantities of foodgrains for its consumption, but in the absence of which imports ranging from 150 to 200 crores of rupees per annum have to be made. To cut short imports, self-sufficiency in food-grains is very necessary. This can be achieved, besides putting various inputs in the fields, through increasing irrigation facilities. In fact, among the measures that may be adopted for increasing area under cultivation and the yield of crops, the first place must be given to the works for the supply and conservation of water.
(iv) At present, 20 per cent of the cropped area of the country is under cash crops, which produces 30 per cent of the country’s production commanding 33.3 per cent of the total value of agricultural products. Only about 12 per cent area under cash crops is irrigated at present. As is known, cash crops ensure employment through industries, and about 60 per cent of the annual foreign exchange earnings come from these products (pepper, spices, tobacco, cashewnuts, cotton, jute and oilseeds etc.).
Therefore, their productivity can be stepped up through provision of increased irrigation facilities. With regard to cereals, where the mean percentage variation in production from year to year is large, improvement in irrigation facilities leads to higher yields.
Water requirements of crop depend primarily on climatic and soil factors. Crop season in India is predominantly kharif followed by rabi. The area under cultivation during hot weather is very small being less than 5 per cent. During kharif, the monsoon meets a substantial part of water requirements of crops.
Within limits some extra moisture stress does not seriously affect yield. Deep rooted crop can tolerate longer dry spells than the shallow rooted ones. Similarly, hot weather crops use up water at a faster rate than rabi and kharif crops because of the higher rate of evapotranspiration in summer.
(v) Different crops require different quantities of water supply throughout their growing period. For example, grain crops require their maximum supply during the time ear-heads are formed; while sugarcane, cotton, chillies require more water. Most annual crops do not require water when they are maturing.
The total requirement of crops varies from 10.6 acre-inches for mustard to 95.0 acre-inches for sugarcane. The water needs of other crops are- linseed 12.7 acre-inches; barley 14.1; oats 14.4; wheat 14.8; maize 17.8; jowar 25.7; groundnut 25.1; potato 26.7; ragi 29.8; chillies 38.8; tobacco 39.2; rice 41.7 and cotton 42.2 acre-inches.
The ICAR Handbook gives the water requirements of some major crops as below:
In addition to the above crops, the water requirements of deciduous fruit trees is about 30 inches; and of citrus and evergreen trees, about 40 inches a year. Touch crops such as beans, lettuce and water melons require about 16 inches of water, common feeder grasses about 24 inches and perennial legumes such as lucerne, berseem and clover about 36 inches of water per year. When the required quantity is not available through natural water supply, irrigation has to be resorted to.
(vi) The need for irrigation also arises from the fact that inspite of considerable advantages of the soil, sunshine and climate, crop production in India is not so efficient as in other parts of the world, specially, because of the lack of moisture in the soils. Sandy soils require frequent water than the alluvial or black soils. In dry season, enough residual moisture is not available in the soil to support multiple cropping.
It cannot be over-emphasized than to state that “a sadder commentary on our economic situation cannot be found than the close, direct correspondence between harvests and mortality and the security of harvests depends primarily upon the adequate supply of water”.
(vii) Many of the Indian rivers are not perennial and carry insignificant flows in the rabi season. Besides, there is a wide disparity in water flow from year to year too. In the case of Snowfed Rivers in the north, the flows are normally perennial, but the variation between the winter and the monsoon flows may be as much as 1 to 100 in the main rivers traversing the plains and as much as 1 to 300 or more in small hill streams.
The characteristic of central and southern rivers is that about 80 to 90 per cent of the annual run-off takes place during 4 months of monsoon rains, the rivers are largely dry during the remaining 8 months of the year. It is obvious, therefore, that to make use of a sizeable portion, of the average annual run-off large storage capacities are needed. Through conservation of surface water, parched lands may be watered round the year so that multiple crops can be grown the year round.
Fortunately, efforts have borne fruit in this respect. For example, Bhakra Dam on Sutlej conserves 45 per cent of the river flow and irrigates about 14.56 lakh hectares; Nagarjunsagar on Krishna holds water to serve 8.90 lakh hectares; Chambal Dam serves 5.56 lakh hectares.
Some of the other projects which serve and supply water through mere diversion structures on the perennial rivers are the Gundak which will supply water to 14.56 lakh hectares; Kosi supplying 7.28 lakh hectares; besides 3.23 lakh hectares on the Western Kosi Canal when it is completed. The Sona Barrage serves 2.83 lakh hectares. These storages have helped and will further help in moderating floods, preventing large-scale destruction of property, crops and life.
(viii) India has vast ground-water reserves specially in the Gangetic plain, Narmada basin and deltaic areas, that is, in about 40 per cent of our country’s sown area. According to Dr. G.C. Chatterjee (G.S.I) that average annual rainfall in India is 3 x 1012 m3, about 801 + 109 m3 of water seeps down annually in the soil. Of the quantity seeping into the soil, only 370 x 109 m3 of water percolates down to replenish the ground water body. The total storage of groundwater down to 305 metres has been estimated at 37,000 x 109 m3. We are still using only 22 x 109 m3 of the ground water. Therefore, large scope exists for the development of these underground water resources.
(ix) India’s total geographical area of 328 m. hectares lies in tropical and sub-tropical zones. The total culturable area is 256 m. hectares, and the net sown area in 1974-75 was 138 m. hectares and the gross cropped area (including area cropped more than once) was 164 m. hectares. At the beginning of the Fourth Plan only 23 per cent of the cropped area was getting irrigation i.e., 77 per cent of cropped area exclusively depended on rainfall. Development of irrigation has, thus a very important role to play in the growth of Indian agriculture, especially in unirrigated and dry areas.
(x) The total land area in the country under food crops is 118 m. hectares. There are 52.60 m. hectares in the Indo-Gangetic Plain (i.e., six states of Punjab, Haryana, Rajasthan, U.P., Bihar, and West Bengal). In Central India (i.e., Gujarat, M.P. Maharashtra, and Orissa), the sown area for foodgrains is 38.4 m. hectares; while in Peninsular India (Kerala, Karnataka, Andhra Pradesh, and Tamil Nadu), the food crops are grown on 22.6 m. hectares.
The productivity differs considerably from zone to zone and from State to State. While in Punjab and Tamil Nadu, a hectare yields as much as 800 to 1000 kg. in M.P., or in Karnataka the average yield of food crops is 500 kg. per hectare. This disparity in food production is entirely due to differences in availability of water for the land either through rain or artificial supplies.
(xi) Lastly, in good rainfall areas (like Assam, West Bengal, Orissa, Andhra Pradesh, Tamil Nadu and Kerala) irrigation is required mostly as a supplemental need to protect their single crop agriculture against occasional drought. In Karnataka, Gujarat, Maharashtra and Bihar too the predominant crops receiving irrigation benefits are that of paddy and to a lesser degree that of sugarcane, percentage of other irrigated crops being comparatively small. It is only in Punjab, Haryana, Rajasthan, M.P., Gujarat, and North-Western U.P. where irrigation is used extensively for other seasonal crops as well.
Development of adequate and dependable irrigation facility is, therefore, very essential to banish famines as a result of drought conditions. Irrigation alone supplies dependable and timely supplies of water. In the absence of irrigation the farmer cannot risk his investment in other inputs which contribute to increased productivity. Thus, irrigation has necessarily a crucial role to play in the country’s agricultural production strategy.
It may, however, be noted that irrigation can yield best results only if it is accompanied by other factors such as suitable change in the cropping pattern, improving and maintaining the fertility of soils, use of improved varieties of crops, application of chemical fertilisers and green manuring, adoption of plant protection measures and improved cultural practices and many other allied matters. These will yield results only when sufficient water supply is available.
3. Vital Role of Irrigation:
Irrigation has proved beneficial to the country. In fact it forms the datum line for sustained successful agriculture. It alleviates suffering, preserves life, averts famines and advances the material prosperity of the country. In fact, as pointed out by Sir Charles Trevelyan, “Irrigation is everything in India. Water is more valuable than land, because when water is applied to land it increases its productiveness at least six-fold and renders great extents of land productive, which otherwise would produce nothing or next to nothing.”
Dr. Knowles writes, “The irrigation works have made security of life, they have increased the yields and the value of the land and the revenue derived from it. They have lessened the cost of famine relief and have helped to civilize the whole region. In addition, they yield handsome profits to the government.”
Dr. Gadgil’s survey of the economic effects of the Godawari and Pravada Canals in Decca has shown that the total direct and indirect effects of the irrigation projects were very favourable. Due to irrigation, farmers could make additional investments in cattle, farm implements and on more valuable crops like sugarcane and the total employment of the farmers and labourers was greater.
4. Sources of Irrigation:
It may be noted that the systems of irrigation developed in different parts of the country is governed by local, meteorological, geological and other physical conditions. Therefore, there cannot be any uniformity in the system of irrigation in different tracts. Alluvial tracts in the Gangetic and coastal plains is especially suited for canals and wells- in crystalline areas of the Deccan Plateau irrigation from tanks is most extensive and in the northern parts and black cotton tracts of Deccan, submarine regions of the eastern and western sides of the Western Ghats and the Punjab, a considerable proportion of land is irrigated by wells.
Of the area irrigated more than half depends for its irrigation supplies on minor works. Rest of the area is irrigated from river canals, their distributaries and channels, all of which are included under medium and major irrigation works.
The following table shows different sources of irrigation available in India:
The table shows that area irrigated by Government canal and tubewells has increased considerably.
Gross and net irrigated area has increased during the plan period. From the table below it can be inferred that the area irrigated is served by canals, tanks, tubewells and other sources. At the beginning of the planning canal system was the most important source of irrigation.
During the plan period the relative importance of various sources of irrigation has changed. In 1950-51 about 34.3 per cent of the net area sown was irrigated by canals. Area irrigated by tubewells and other wells was only 28.7 per cent of the net cropped area. The area irrigated by tubewells has increased substantially. Area irrigated by tubewells was only 0.6 per cent of the total irrigated area which increased to about 33.1 per cent in 1992-93. Area irrigated through tanks has declined sharply.
Area irrigated by tanks and ponds was around 18.5 per cent of the total irrigated area. It is declined to only 6.5 per cent in 1992-93. It shows that tanks are not being maintained properly. Other wells are also being neglected and their share is also declining. Now canal and tubewells occupy the most important place in the irrigation system.
Taking the situation of irrigated area under different crops, the table given above would reveal that percentage of irrigated area under different crops is increasing. But area under some specific crops is more irrigated. Sugarcane is highly irrigated crop. It is followed by wheat, barley and rice. Others in irrigated important crops are oilseeds, pulses, cotton, fruits and vegetables. The table given above shows that about 89 per cent are under sugarcane and 85 per cent. area under the wheat crop is irrigated.
5
. Major and Medium Irrigation Works:
During 1950-51 and 1973-74, 97 major and 513 medium irrigation schemes were taken up. Of these 22 major and 358 medium schemes were completed and the rest spilled over to the Fifth Plan. During Fifth Plan, 64 out of 75 major and all the 155 medium schemes will be completed. Besides, work will be initiated on 109 major and 313 medium irrigation schemes. The total investment on major and medium irrigation projects between 1951-52 to 1976-77 was Rs. 4,595 crores, and that for the Fifth Plan being Rs. 3,135 crores. The outlay for 1977-78 is Rs. 989 crores.
The importance of major and medium irrigation works lies in conservation of the surplus and flood waters. Mere concentration on minor irrigation schemes would lead to a great waste of total usable water that is yet untapped. Only major and medium projects can be utilised as a safeguard against floods and these alone can be developed as Multi-purpose Projects which may serve not only the purpose of irrigation but also that of hydro-power generation, supply of domestic water, navigation, fish culture and recreation facilities.
But major and medium irrigation projects, at the same time, suffer from certain drawbacks. A large number of pre-requisites are needed for their successful implementation.
Firstly, they need a vast amount of capital expenditure for purchase of land, construction of dam, surface storage and provision of distribution channels and require money for resettlement of the ousters from the areas that may be submerged under the dams.
Secondly, the loss in distribution system is when distributaries are not lined. It amounts to about 40 per cent of the total water left in the channels.
Thirdly, a large area might suffer from the problems of water-logging, needing vast amount of money for reclamation purposes.
Fourthly, the catchment area of the dams needs protection from soil erosion, otherwise, the dam may be silted very soon and go out of use.
Fifthly, such schemes involve more time in investigation, planning and construction and the gestation period is even large.
Finally, they are less reliable for timely supply of water.
As a result of all these factors the major and medium irrigation projects can be undertaken by the Government itself.
Minor Irrigation Works:
Minor irrigation programmes relate to the development of groundwater resources on scientific lines.
Such programmes include:
(i) Surface water schemes such as small stream diversions;
(ii) Rain storages in small catchments, generally located on small streams or tributaries of rivers;
(iii) Renovation of existing tanks and diversion works;
(iv) Groundwater tapping through construction of open wells, boring of wells for augmenting supplies, deepening of wells in rocky areas by pneumatic blasting, sinking of tubewells of various capacities; lifting of water from the wells through large-scale installation of water pump-sets in place of the old country methods of water lifting such as counter poise lift and rope and bucket lift;
(v) Construction and repair of small drainage channels, embankments for flood protection and head water tanks, percolation tanks ahars, bundhies, for conserving moisture and replenishing groundwater.
Minor irrigation includes all irrigation schemes having up to 2000 hectares of culturable command area. This is on the basis of classification of 1978 done by the Government of India. Under the new definition all groundwater structures are classified as minor irrigation. Ground water development is under private sector to the extent of 90 per cent.
Minor irrigation schemes like dug wells, shallow tubewells, borewells, filter points, small surface water lift up to 10 H.P. are generally within the reach of individual farmers. The farmer, thus, becomes the proud owner of his own irrigation system and gets assured supply of water at his command.
Minor irrigation schemes have great advantage in that they yield results promptly:
(i) They can be conceived and completed quickly and handled to a large extent by the cultivators themselves.
(ii) The construction period is hardly 15 days to one month. They need small outlay of capital and mostly use local talents and resources.
(iii) The utilisation of the irrigation potential is almost immediate.
(iv) Since these works are owned by the cultivators themselves, they bring major satisfaction of the psychological and the physical needs of the cultivators.
(v) Since the cultivators know fully the capacities of these works, water supply from these can be more reliable, so that they may adopt a cropping pattern to suit their needs.
(vi) As the utilisation of water in these cases is usually confined to the area very near to the sources, loss of water and its distribution is very much reduced.
(vii) These are essentially people-centred programmes which provides scope for individual as well as co-operative efforts.
(viii) The cost per hectare of minor irrigation is lower than in major irrigation. Tubewells as a major component of minor irrigation are far more reliable than storage schemes.
(ix) Groundwater has the great advantage in that it is doubtful and can be freely stored and freely move underground so that the loss by evaporation and seepage both during storage as well as during conveyance.
(x) Minor irrigation system does not require a large army of men to maintain and operate it.
It is of interest to note that though in certain areas, major and medium irrigation schemes may be more feasible, there are others where minor irrigation schemes would be more beneficial such as in the contiguous patches of cultivable land available in undulating areas and rocky terrain, and are generally small. There are yet other areas where major, medium and minor schemes have to play a complementary role to perform.
Thus, in areas allocated to High Yielding varieties of seeds minor irrigation schemes have been accepted as complementary to major schemes. It is for this reason that emphasis has been, under the Fourth Plan, to develop minor irrigation schemes.
However, minor irrigation schemes do suffer from certain defects:
(i) Except diversion schemes, all minor irrigation schemes have a certain span of life. Tanks gradually lose their irrigation capacity as a result of silting.
(ii) The discharge of tube-wells generally reduce as a result of gradual deterioration of strains.
(iii) Mechanical appliances have to be replaced after 10 to 20 years.
(iv) It is difficult to have any precise assessment of the area lost by depreciation.
(v) The surface storage schemes, if they are located in high areas tend to be unreliable if rains fail.
Progress of Minor Irrigation Schemes:
There were about 5 million open wells and only 3,000 to 4,000 tubewells in the country at the beginning of the First Plan, since then phenomenal progress has taken place.
The number of wells increased from 3.64 million in 1956 to 5.11 million in 1966 and further to 6.10 million in 1971. Easy credit from institutional sources, expansion of rural electrification and profitability of farming as a result of the introduction of high yielding varieties, encouragement of multiple cropping and incentive oriented price policy were the main contributory factors.
There has been substantial increases in minor irrigation schemes. As per 1986-87 minor irrigation census, 95 lakh wells, 0.64 lakh deep tubewells and 4.75 lakh shallow tubewells have been dug. Similarly 4.22 lakh surface works have been completed and the number of pump-sets energised rose from 0.2 million in 1950-51 to 11.2 million by 1989-90.
The number of energised pump-sets further increased to about 11.5 million by the end of Eighth Five Year Plan. At the beginning of the First Five Year Plan only 0.47 per cent of the pump-sets were energised. It is increased sharply during the planning period and percentage of energised pump-sets increased to 79.12 in 1996-97.
The area irrigated by the minor schemes prior to planning was 12.9 million hectares. The cumulative achievement of potential under this programme by the end of Eighth Plan was 56.6 million hectares which includes an addition to potential of 9.1 million hectares created during the Seventh Plan.
The ultimate potential for development of minor irrigation has been assessed at 55 million hectares comprising 15 million hectares from surface water and 40 million hectare from groundwater. The area irrigated by minor irrigation in 1996-97 was about 52.3 million hectares against the potential created 56.6 million hectares. The first census (1986-87) of minor irrigation schemes showed that there were 5,07,212 minor irrigation tanks in the country except Rajasthan. Fresh census is needed to be made to update the data along with improvement both quality and scope-wise.
Various tanks have gone out of use due to various reasons. It clearly indicates that the upkeep of the tanks has not been done properly. From the planning point of view, the estimation is of importance that if just 3 per cent of the total land area is used for making such tanks/ponds, it can usefully store about 10 per cent of our total rainfall.
The table above shows the progress of creation of irrigation potential in minor irrigation.
6
. Financing of Irrigation Projects:
In ancient India, construction of irrigation work was benevolently undertaken by the kings and philanthropists. In the early years of the British Rule expenditure on these was met from Government revenues and the initial responsibility for their construction was that of the military engineers. Subsequently the P.W.D, and later on the Provincial Governments got powers over irrigation works and development.
In the middle of the 19th century attempts were made to promote irrigation development through private companies with a Government guarantee of 5 per cent return upon capital invested, but this did not prove successful. By 1866, the raising of specific loans for the purpose was considered justified if the works could reasonably be expected to be remunerative. The acceptance of this principle gave a definite stimulus to the development of irrigation and for the first time funds were assured in reasonable amounts and on a regular basis.
In 1879, the Committee (set up by the British Parliament to prescribe tests of productivity and to safeguard the loan capital for the execution of irrigation projects) laid down that “simple interest, on capital cost of works at the beginning of a year plus working expenses for the year should be less than the direct and indirect receipts for the year.” It was, therefore, decided that the results of irrigation works should be tested by their financial returns.
Schemes were sanctioned and loans raised for their execution after the Government felt satisfied that they would be able to recover through water rates, as additional dues, revenues sufficient to meet annual working expenses on maintenance and operation and to pay interest on the loans raised. Several of these schemes brought revenues to the Government which exceeded the annual working expenses and interest charges and, thus, yield substantial net profit.
Irrigation schemes works were classified by the Government as productive and unproductive:
i. Productive Works:
A productive work was one the net revenue derived from which within ten years after the date of its completion was more than a definite percentage on the total capital outlay. This definite percentage was fixed by the Central Government from time to time. It was 4 per cent for works sanctioned before 1 April, 1919 to 5 per cent.
For works sanctioned between 1 April, 1919 and August 1, 1921 – 5%
For works sanctioned between August 1, 1921 till March 31, 1937 – 3.75%
From April 1, 1949 to March, 1954 and from March, 1960 – 5%
Unproductive works were those which yield a net revenue less than the percentage fixed for productivity.
After 1992, all “productive” works were financed by Provincial Governments either from the general revenues or more often from loans raised on Government security. “Unproductive” and “minor” works were financed always from general revenues of Provinces concerned or by grants from Central Government from general revenues. “Minor” works were small works for which detailed capital and revenue accounts were not maintained, and they may be productive or unproductive.
After the great famine of 1877-78, “protective” works came to be recognised. These works were designed primarily for the protection of precarious cultivation, the direct result becoming a secondary consideration. After 1901, many new protective works were taken up for the construction. Nevertheless due to paucity of funds the emphasis remained on the remunerative’ or productivity’ of irrigation projects rather than the security, they could afford to insecure and precarious areas.
This system continued to be followed till about 1950, when it was felt that even though the projects did not fully satisfy the productivity test, but were otherwise useful, should also be developed. So that now the financial criterion according to which the utility of irrigation projects used to be determined has yielded place to the concept of benefit-cost ratio.
The value of a scheme is judged by the overall benefits it confers on the community as compared to its annual costs. The primary benefit accruing from an irrigation project is the net addition value of the increased production after irrigation. This is the difference between the values of the farm produce after meeting cultivation expenses after and before irrigation.
The amount arrived at in this manner is compared with the annual costs consisting of the interest assumed at the rate of 10 per cent on capital outlay, depreciation and administrative expenses. It has been felt that a project should be considered worthwhile if the benefit- cost ratio is not less than 1.5 : 1, though special consideration is given to exceptional cases such as those of scarcity and backward areas.
The financial assistance from the Centre to the State is normally in the form of loans for a specified carrying interest at 5.75 per cent per annum, from the date of commencement of such loans. These loans and interest thereon, are payable in equal instalments—generally, 5 to 10 years after the commencement of the project, interest charges, however, being payable annually.
For major irrigation works, the total financial assistance sanctioned by the Central Government consists partly of loans and partly of grants. A subsidy ranging from 25 to 50 per cent is granted to private and cooperative ventures by the Central and State Governments. Subsidies for tubewells and lift irrigation and grants for the purpose of diesel engines are also given by the Centre.
Irrigation Revenue:
Revenues realised from irrigation projects are classified as ‘direct’ and ‘indirect’. Direct revenue to the Government from irrigation works consists of the charge for the supply of water. This varies with type of crops cultivated and is levied on the basis of area irrigated.
Indirect revenue consists of a share of enhanced land revenue less increased cost of civil administration; interest on sale proceeds of Government waste lands developed from the project; rent or lease money for temporary cultivation of Government, waste lands irrigated from a project before they are sold; and receipts from canal plantations, pisciculture and provision of recreational facilities.
While irrigation projects are financed from public funds, benefits accrue to individuals by way of improved productivity from land and appreciation in its value. It is, therefore, considered equitable that the Government should take part in this unearned gain. This charge is termed as betterment levy, and represents the share of the Government in the increase in value of land accruing as a result of the provision of irrigation facilities.
This is to be assessed on the basis of appreciation of land values or the increased productivity from land on account of provision of irrigation. It is levied only once when irrigation is first introduced and is usually recovered in a number of equal annual instalments. The amount so recovered is considered as a reduction in the capital cost for working out financial return.
7. Modernising Irrigation:
The National Commission on Agriculture has assessed the irrigation potential from all sources, at about 93 million hectares which is only about half of the total gross cropped area of 192 million hectare with full harnessing of the water resource only about one-fourth of the cropped area would be irrigated.
Hence, maximum benefits need to be derived from the irrigational schemes. The Irrigation Commission has also felt the need for improving the irrigation system in order to increase their efficiency and usefulness. It has pointed out that in the run-off of the river schemes, which derive their supply of water solely from diversion works on rivers, shortages are experienced during the low stage of river flows which occur in summer in the peninsular rivers and in winter in the plain area rivers.
The earlier irrigation systems of North India were designed with low intensities and cultivators gives a share of water proportionate to their holding in the commanded areas. They have naturally been applying water thinly to irrigate as much area as possible. Thus, mode of irrigation is not conductive to high yields particularly from high yielding varieties.
On many irrigation systems, the channel capacities are inadequate for meeting peak demands during crucial periods like transplanting of rice, and irrigation of rabi crops. The tall reaches of canals suffer most from these inadequates. Therefore, it is necessary that the existing efficiency of the irrigation schemes should be greatly improved.
The National Commission on Agriculture has suggested the following measures for the modernisation of irrigation measures:
(a) Augmenting Channel Capacity:
The Commission has emphasised upon augmenting irrigation supplies through conjunctive use of surface and ground water. It can take the form of supplementing canal supplies with water from state owned tube-wells or use of water from private tube-wells and filter points in the anicut for irrigating the same or additional area during periods of low canal supplies or canal closures. State tube-wells can be sunk to irrigate high patches of land in the canal command area. Also in irrigation systems which run for one crop season only, ground water could be used for a second or third crop.
In many states, there are restrictions on sinking tubewells or wells within a prescribed distance of irrigation channels on the ground that this may lead to larger losses of water due to percolation in unlined channels. Hence, the State Governments should review these restrictions particularly if the soils are of clay type with minimal percolation losses in the canals or if the canals are lined. Ground water pumping is also absolutely essential in order to combat waterlogging by lowering the water table.
The adoption of proper cropping pattern is also of utmost importance which would suit the irrigation schedule. Storage schemes offer greater flexibility in regulating supplies as releases can be made to suit the requirements.
(b) Reducing Transit Losses:
Available irrigation supplies can be increased by reducing transit losses. This can be done by lining canals. It was estimated in 1960 that the unlined canals in India carried a discharge of about 11,300 cusecs and that lining could save enough water to irrigate an additional 6 million hectares. Canal seepage losses can be removed by pumping ground water. But experiments have shown that the lining of channels has been more efficient and cheaper method as against pumping e.g., in the Krishna and Godavari Deltas, the capital cost worked out to about Rs. 620 per hectare as against Rs. 500 for lining channels.
However, the lining of field channels which serve an area of less than 6 hectares or which run for less than 400 hours in a year, would not be economical. According to the Commission better water management can also be achieved through use of concrete pipes for distribution of water to the fields as is being done in states like Gujarat, Haryana and Tamil Nadu. Lining water courses has also a good employment potential spread over a large rural area.
A hectare of irrigated land normally requires about 75 metres of water-course. In half of the irrigated area of 20 million hectares at present served by major and medium irrigation projects is to have lined water courses, about 750 thousand kms. would have to be lined. This would cost about 600 to 700 crores and provide employment of more than a million man years.
(c) Planning Drainage Schemes:
Drainage should be provided alongside the development of irrigation systems so that water percolating from irrigation channels and irrigated fields could raise the ground water table and lessen the waterlogging problem. The drainage system should extend to field drains, which may be needed not only for crops requiring light irrigation but for rice fields. The nullahs lower dam have also to be kept clear of all obstructions so that the drainage systems can function efficiently.
The responsibility for construction and maintenance of field drains should correspond to that for water courses and field channels i.e., the responsibility of the project authority should end at 40 hectare blocks below which the construction and maintenance of channels and drains should devolve on cultivators. The farmers should be provided with proper guidance in the matter of alignment and design by the extension staff.
The order of water distribution (i.e., warabandis or osrabandis) should be firmly laid down by the state departments of agriculture as has been done in Punjab, Haryana and U.P., the system of water supply should be simple and should involve a minimum of procedural steps. Canal officers should be entrusted with sufficient powers so that offenders wasting water can be prosecuted.
The National Commission on Agriculture after making study of some important irrigation schemes such as the lower Bhawani Project (Tamil Nadu), the Badua Project (Bihar) Shetrunji Project (Gujarat), Ghod Project (Maharashtra) and the Harsi Project (M.P) has reached the decision that considerable scope lies for improvement in the following directions-
(a) Augmentation of supplies from other sources, surface or underground;
(b) Improvement of engineering structures like remodelling of headworks, enlargement of channel capacities, lining, provision of more regulatory structures, extension of drainage system and improvement of outlets in respect of their structure and capacity.
(c) Ayacut developments or improvement comprising land levelling shaping; realignment of water courses and field channels and their lining, where necessary; field drains; ayacuts roads and storage facilities; consolidation of holdings.
(d) Making change in the cropping pattern.
(e) Operating of channels to better conform irrigation supplies to water requirement of crops.
The importance of timely supply of irrigation water cannot be over-emphasised. If the sowing of wheat is delayed beyond three weeks of its proper sowing time, a drop in the yield of 3 quintals per hectare is likely to occur for each week’s delay. Likewise, if transplantation of rice is delayed by a month a heavy drop in the yield of even upto 50 per cent may take place.
(d) Command Area Development Programme:
This programme seeks to accelerate the process of utilisation of irrigation potential and improves the efficiency of utilisation through a multi-disciplinary approach.
The ultimate objectives are:
(i) Securing of maximum yields per unit of water or per unit of land as the case may be, depending on the availability of water, soil and climatological factor in a basin;
(ii) Enabling the farmer not only to secure maximum production, but also to get the maximum economic benefit by proper and timely disposal of his produce through adequate facilities like communications, markets and processing industries.
8
. Causes of Inadequate Utilization of Irrigation Potential:
The gross non-utilization and under-utilization of water has been due to a number of causes such as:
(a) Delay in the construction of link canals and field channels, which has prevented the peasants to take water to their fields as soon as it became available.
(b) There is no certainty about the utilization of the irrigation potential by the farmers. Whenever there is a good rainfall, cultivators hardly use any irrigation water. But in years of scanty rainfall, all the cultivators rush to utilize irrigation water causing further scarcity. This leads to uneven distribution of water in field adversely affecting the productivity of crops.
This system has three main disadvantages:
(i) Loss to the state revenues in the years of non-utilization of irrigation water;
(ii) Adverse effects on agricultural productivity; and
(iii) Financial loss to peasantry as they have to pay 3 to 4 times more, than the normal irrigation rates in years of scanty rains.
(c) Unwillingness of the farmers to share financial burden of irrigation facilities such as water cess and improvement taxes.
(d) A lag in agricultural efforts either because of the inadequacy of investigational data or hurried planning of the project or through persistent political or socio-economic influences.
(e) Higher rent of the irrigated land—often 50 to 60 per cent of the gross produce or even more—virtually takes away the incentive effect from the producer in deriving the benefit of higher productivity.
(f) In surface irrigation, using distribution system consisting of main canals, branch canals, field channels, etc. It has been estimated that 40 to 45 per cent of the water entering the distributing system is being lost into earth by percolation before reaching the field; and half of the water given to the fields is lost before it gets to the roots of the plant. An assessment on the Ganga Canal indicates that losses occur upto 15 per cent in the main canal 7 per cent in the distributaries and 22 per cent in village water courses,
(g) In some areas the farmers are used only to rain-fed crops with the result that newly created irrigation potential is not being fully utilised.
(h) Medium and minor irrigation projects have not been able to show the desired results due to the inadequacy of steel and cement and many of the tubewells have been reported to be working below capacity or not working properly, due to want of electricity or fuel-oil for working the pumps.
(i) Lack of advance planning in the distribution of improved seeds, fertilizers and other inputs.
(j) Lack of coordination between States’ Irrigation, Agriculture Planning and Development Department, due to which the farmers, who are willing to utilise irrigation water, do not receive takavi loans for the purchase of pumps, oil engines, rahats, lifts and other accessories and financing for preparing land for irrigation well in time.
(k) Lack of coordination between major and minor irrigation works; inadequate attention to drainage needs, inadequate attention to irrigation research on water requirements of crop on different soils, and the silting down of canals due to floods are other reasons.
9
. Measures for Effectively Increasing Irrigation Potentials:
1. It is necessary to see that our water supplies are put to utmost efficient use. Water management is regarded as a “must” in agricultural technology. Water management has to be accompanied by suitable systems of soil surveys, crop patterns and crop rotation, use of high yielding seeds, application of adequate and appropriate quantities of chemical fertilizers and pesticides and adoption of improved and scientific agricultural practices. Besides, land preparation, levelling and grading of land and designing proper layout for irrigated farming are extremely important for optimum use of available water supply.
2. At least during the first 2 or 3 years the irrigation rates should be attractive, even subsidised, if necessary, so that the farmer gets used to the benefits of irrigation. Also water charges should be fixed at a uniform rate for each crop irrespective of the fact whether water is supplied through major irrigation canals, tube-wells or minor irrigation projects.
3. Effective demonstration must be given to convince the cultivators of the proper use of water for different areas and crops. He should also be made conversant with simple methods of determining moisture content, root zone and the actual depth of water percolation on the fields at the time of irrigation.
4. Forming of Osrabundi (schedule of turns) and responsibility for enforcing it should progressively be transferred to beneficiaries either through co-operatives of beneficiaries, panchayats or panchayat.
5. In order to ensure that as far as possible, the irrigation water reaches the cultivator’s fields about the same time it becomes available at the head works, there should be synchronization in the programmes for the construction of headworks, canals, distributaries, water courses and field channels.
6. In order to eliminate delay in the excavation of water courses and channels, their alignment should be marked out by the project authorities on village maps and these maps should be supplied to the district and block authorities for getting the field channels excavated by the beneficiaries in time.
7. What is required urgently is organisational integration of all types of irrigation works under one technical control for single control will lead to better utilisation of irrigation than what has been possible so far. Streamlining of irrigational management is urgently called for.
8. Administratively, irrigation works can be classified more rationally under two categories- local and trunk. Where long distance transmission of water is involved, the works should be included under the trunk category, whereas where water is made available from local resources, they should be reckoned as local. A unitary control on both types of works could lead to proper dovetailing of irrigation facilities provided under different types of irrigation works.
9. More systematic attention must be paid to the stepping up of the efficiency of minor irrigation works by the installation and energisation of pump-sets. Besides, not only the number of minor irrigation works should be increased but the existing ones need should also be kept in a proper state of maintenance and those needing repair like silted tanks, and irrigation channels, wells with lower water tables, brought into a state of efficiency.
10. Transit losses can be reduced by improving the conveyance methods. Application losses can be reduced by educating the farmer properly on the proper methods of lay-out of land, proper control of distribution of water. Evaporation losses can be reduced by adopting proper devices.
10
. Benefits of Irrigation:
As a result of the studies undertaken in 1958 and 1961 in eleven projects from each of the regions, it was observed that “canal irrigation has helped in promoting the greater utilisation of land; enlarging the average size of the farm; generating demand for additional farm labour; shifted in new and better varieties of crops; increasing additional productive investment in farm business; favourable input-output ratio; widening the scope for increase in land revenue and other local receipts. In addition to direct benefits, there are also secondary and tertiary benefits, e.g., canal irrigation has led to general expansion of secondary and tertiary activities in the area affected by it resulting in greater work opportunities; more employment to both family and hired labour; higher value of output per industrial unit, and higher turnover of business establishments in the project areas.”
The purpose of irrigation is to help increase agricultural production from the lands served.
The services provided by irrigation may be viewed from two angles, viz.:
(a) Protective aspect to make up the moisture deficiency in soils during the cropping season so as to ensure proper and sustained growth of the crops grown.
(b) Additional land use aspect to enable a second or third crop being raised on the lands provided with irrigation which could otherwise not be cultivated efficiently more particularly during the post or pre- monsoon period. While the protective aspect helps to stabilise agriculture production against droughts, the second facility i.e., overcoming low productivity due co dryness or excessive water supply.
“Irrigation development in India in the past had mostly taken place as a measure of drought relief. Famines fathered the idea of artificial irrigation. Irrigation work was built; designed and operated mostly on a defensive pattern. With the population swelling rapidly, irrigation has now to have a new purpose—increased agricultural production.” The yields in irrigated areas are said to be 60 to 100 per cent higher than in other areas. Irrigation by helping the plant to take up the manure in a suitable form leads to increase in fertility to increase in corn yields.
11
. Demerits of Irrigation:
Irrigation water when misused spoils the soil beyond repair. Mr. Pugh traces back the history and remarks that soil civilisation in the Middle-East disappeared because of misuse of irrigation water.
Agricultural Reorganisation Committee U.P. (1949) pointed out that at some places yield of crops decreased due to irrigation water. This is due to:
(a) Greater demand of soil nutrients to produce higher yields;
(b) The leaching effects of irrigation; and
(c) Collection of injurious salts in upper layers of the soil.
The important fact is that whenever water is available to the cultivator for irrigation, he invariably resorts to over-irrigation under the mistaken belief that higher the application, higher the yield and also the feeling that he must make the fullest use of the water for which he has paid.
Experimental studies undertaken by Shri A P. Bhattacharya (in Sarda and Canal area) have given convincing proof that over irrigation is harmful from the point of view of lowering of yields because the unused water not consumed by the plant brings down plant nutrients, while percolating to the ground water table, which keeps on being augmented ultimately leading to water logging which in its turn brings malaria along with complete loss of fertility. A rough estimate shows that the yearly loss to the country is of the order of Rs. 40 crores, apart from the long term effects of water-logging and malaria.
Other demerits of excessive irrigation are:
(i) It causes water logging, etc.:
Canal irrigation, however, suffers from a very serious defect against which it is very necessary to guard effectively. An abundant supply of water from the canals for irrigation does not only lead to a great waste of water but also what is more serious is that it causes waterlogging and self-effervescence. Water-logging may be defined, says Professor Brij Narain “as the rise in the level of the subsoil water which renders land unfit for cultivation.”
What happens actually is that the salts of the soil come upto the surface with the rise of the subsoil water level. The canals act in two ways in ensuring this phenomenon. Firstly, they intersect drainage lines and cause rain and flood water to be held up. Secondly, they cause their own water fall vertically until it reaches the spring level.
“If the subsoil outflow is not enough to balance the inflow, the spring level rises being drawn up by capillary attraction and all the salts of the earth come to surface and make the land unfit for crops.” This causes the soil to deteriorate by bringing out alkali or reh to the surface of the soil.
The remedies usually suggested for this phenomenon are:
(a) Pumping out of water by tube-wells and other methods of drainage,
(b) Proofing of canal beds by concrete,
(c) Opening out of closed and obstructed drainage,
(d) Replacing canal irrigation by well irrigation,
(e) Prevention of over-irrigation, by forcing the cultivator to economic water,
(f) Attempts should be made to change the time of supplying canal water and that the beds and sides of canal should be rendered impervious inter alia treating them with sodium carbonate.
(ii) They have created unhealthy conditions:
Canal irrigated areas have shown susceptibilities to encourage malaria with its very harmful and pernicious effect on the health of the peasant and the village folk. In order to safeguard against this, the Royal Commission recommended that “careful drainage surveys should be made in future in all irrigation projects and drainage maps should be prepared”.
Sir John Russel also emphasised the urgent need for proper soil surveys and agricultural analysis. “It may be laid down as an absolute rule that no irrigation scheme should ever be carried out until a proper soil survey of the region has been made. Barley one-half of the water delivered at the head of the canal reaches the field.”
12
. Future Prospects of Irrigation:
The water potential is an enormous volume. In spite of a vast irrigational development, greater possibilities still exist for further expansion. Greatest opportunities for developing irrigation lie along large rivers in the arid regions which are fortunate in enjoying a warmer climate, good facilities for drainage and rich soils. These three conditions make them very suitable for diversified farming and high priced agriculture provided irrigation facilities are developed here.
As rivers often dry up during summer season, a constant flow of water can be maintained only if storage reservoirs are made across the rivers from which canals may be dug. Though irrigation of these areas will be a costly affair, yet the construction of reservoirs would prove economically useful where possibilities of superior agriculture will be much developed.
Besides, in areas where flow irrigation is not possible either due to unfavourable topography or due to insufficient water supply, but where ample underground water exists, reliance should be put on its maximum exploitation by making tubewells as in Western Rajasthan, Gujarat, parts of Andhra Pradesh and South-West Punjab where water table is not below 50 ft.
Irrigated agriculture is not merely application of water to the fields on a random basis, but the questions when to take water, how much water to be applied, methods of water application, also have a great bearing on the efficiency of irrigation. Irrigation has to be operated on considerations like soil, moisture and plant growth relationship, determination of optimum moisture, duration of different crops, interval between successive irrigation in soils of high, medium and low moisture capacities, and inter-relationship between the above factors.
The quantity of water to be supplied is also governed by factors like rate of consumption and evaporation at different stages of crop growth and soil moisture deficits, to fix amount of water to be applied.
In the application of irrigation, uniformly of depth adds considerably to efficiency. Proper drainage, check on soil erosion and easy workability of agricultural operation are also important factors needing attention. Besides, an irrigator has to take into account many other factors like slope of land, texture and intake rate of soil discharge to be handled, length of run and depth of strips and in case of border strips, length of furrows and distance between furrows and size of plots in relation to discharge of water. In fact irrigation is not only a science, but also an art in itself.
While agricultural land forms the body, water is a vital fluid that sustains our agrarian economy. Timely supply of this vital fluid is getting precious day by day. The rule of thumb practices had to yield place to precise and rational criteria to ensure that we develop a planned economy with regard to the utilization of water for irrigational purposes. Water from the Ganga, Ken and Sone rivers could be explored to store it in reservoirs in South Bihar and South-Eastern UP.
Natural depressions such as the Phalgu River could be utilised for storing this water in South Bihar; while the waters of Ganga and Sone can be pumped 250 to 300 metres for storing it in the drought prone areas of Varanasi, Banda and Mirzapur, as a result of which about 4 lakh hectares could be brought under irrigation.
Our ultimate objective should be to reduce the extent of rain-fed and unutilized lands by regular supplies of water. Scarcity areas in the Ganga basin itself (such as Mirzapur, Rewa Plateau, Palamau and Gaya belt) must be developed to become granaries as the Krishna and Godavari Deltas have been converted into rice bowls.
Next in importance are the irrigation projects for Gujarat and M.P, and in particular the exploitation of the Narmada Water Conservation Projects like Krishna, Tehri and Rajghat dams must be built quickly. Storages on Sarda, Ghagra and Rapti are necessary to save eastern U.P, from floods and also for conserving water.
A National Water Grid has been conceived to interlink the various rivers to achieve the following objectives:
1. Surplus waters of the various rivers should be utilised beneficially by transfer to water deficit zones.
2. Even in water deficit areas, the river or the other is in flood every year, which flows waste to the sea. The rivers must, be interlinked to make use of such surplus waters when available. This will even out the variations from year to year in the water supply for agriculture.
3. Surplus waters must be used on priority basis in chronically drought affected areas. With the climatic conditions in India, and the large population dependent on agriculture, additional food production and additional employment opportunities to the largest segment of population can accrue only if water for irrigation is made available in arid and semi-arid areas of India which cover two-thirds of the country.
4. There is no communication by water between the northern and the southern part of the country in the absence of a river flowing from north to south. A national Water Grid will provide such a water link.
5. Navigation provides the cheapest mode of transport for bulk materials. Extensive exploitation of coal for power generation and other uses requires its transport by the cheapest way and it is best done by a National Water Grid.
6. The interior parts of Central India are at present isolated and inaccessible. These areas which are rich in coal, minerals and other natural resources have to be opened up for economic development. This can best be done by a National Water Grid.
7. Drinking water is scarce in most parts of Central Plateau of India. A National Water Grid can provide an excellent source of water in these areas.
Some of the components of the Grid which can at present be visualised are:
(i) Ganga-Cauvery link, connecting the Ganga in the North with Cauvery in the South and passing enroute through the basins of Sone, Narmada, Tapti, Godavari, Krishna and Pennar.
(ii) Brahmaputra-Ganga link.
(iii) Link canal from the Narmada to Western Rajasthan.
(iv) Canal from Chambal to pump areas to Central Rajasthan.
(v) A canal link from the Mahanadi to serve coastal areas in Orissa and Andhra Pradesh and establish link with other canal systems.
(vi) Links from west flowing rivers of Western Ghats towards the east.
The waters of the Grid are proposed to be used for irrigation in the drought affected districts, which have about a third of the country’s crop area and a third of the country’s population. These areas will have very little irrigation and that too with a large proportion of supply from insecure sources like small tanks and shallow wells, even after all possible local sources are exploited. Such drought affected districts lie in South Uttar Pradesh, Bihar, Gujarat, Rajasthan, Madhya Pradesh, Karnataka, Maharashtra, Andhra Pradesh and Tamil Nadu and also a few small patches in Odisha, West Bengal and Haryana.
The scheme envisages the taking off a canal from the Ganga near Patna at an elevation of 46 metres and lifting 1,700 cu. metre/sec. of water to Sone barrage for pumping. After allowing 283 cu. metre/sec for use in South U.P. and South Bihar, 1,415 cu. m/sec. will be lifted along the Sone river in stages. The water so lifted, after cutting across the ridge between the Sone and the Narmada basins, will be conveyed to the proposed Bargi reservoir on the Narmada river. A part of the transferred water will be released into the Narmada river for use in drought affected area in the Narmada and the adjoining basins.
The remaining water will be diverted into the Wainganga river and led into the proposed Inchampalli reservoir on the Godavari river. Some utilization enroute is also proposed. The transferred water together with surplus water of the Godawari and Narmada will be pumped into an elevation of 305 metres from where a gravity canal will lead the waters into the Srisailam reservoir, which is under construction on the Krishna river.
The water from this reservoir would be fed into Kunderu river, tributary of the Pennar river. From Pennar near Cuddapah, a gravity canal will carry water to the upper Anicut on the Cauvery river. The total length of link would be about 2,643 km. out of which 1,064 km. would be along the canal and 1,533 km. along the river water route.
In view of the size of the scheme and the complex magnitude and the cost of the studies required therefore, it was considered advisable to consult international experts before embarking on the investigations. The U.N. Mission which examined the proposals has in its report endorsed the concept of a National Water Grid.
It has stated that- “India’s National economy in its development and growth will be confronted with the problem of increasing scarcity of water within the next thirty years. From basic complications of future water demands and water yields it becomes evident that yields by the year 2000 or so the National Water Grid will be a vital necessity. No time should be lost to start the very complex and difficult investigations today so that plans will be matured and prepared in due time and the facilities will become operative when the need comes.”
Future Irrigation Policy:
In view of the complete inadequacy of water resources to meet the agricultural and other requirements. It becomes necessary that the available resources are conserved and utilised most judiciously and economically. The National Commission on Agriculture has, therefore, very rightly observed that “there has to be proper planning for water use with river basins/sub-basins as natural units of such a plan, to provide a comprehensive outline of development possibilities of land and water resources of basins; establish priorities in respect of water uses for various purposes and indicate inter priorities of projects.”
Accordingly, the irrigation policies in general should envisage.
(i) Maximum production per unit area through multi-cropping in areas with ample water resources.
(ii) Maximum production per unit of water in regions of medium and low rainfall, in which a large part of the country lies.
(iii) Provision of maximum protection in drought areas;
(iv) Maximum utilisation of irrigation supplies from storage during the eight months of the year excluding summer months when evaporation losses are highest; and
(v) Conjunctive use of surface water and underground water.