Water Resources And Irrigation- 2 | SSC CGL Tier 2 - Study Material, Online Tests, Previous Year PDF Download

National Water Grid
 India has large resources of water but unevenly distributed. While he rivers like Ganga, Brahmaputra, Mahanadi and west flowing rivers in western coastal India have large surplus flows in the monsoons, the other rivers of the country have highly variable and relatively meagre water-flows. In order to even out this variation in water-flows of the rivers and to utilise the water efficiently, the Central Water and Power Commission under the guidance of Dr. K. L. Rao conceived the idea of a National Water Grid under which various rivers will be interlinked with following objectives :
 (i) Surplus waters of the various rivers should be utilised beneficially by its transfer to water deficit zones, from north to south and from west to east by means of canal river links.
 (ii) Even in water deficit areas, some rivers are in floods every year, and water flows waste to the sea. These rivers must, therefore, be interlinked to make use of such surplus waters for evening out the variations in the water supply for agriculture.
 (iii) Surplus waters be used on priority basis in chronically drought affected areas.
 

To achieve these objectives, the following links are to be made :
 (i) Ganga-Cauvery link passing en route through the basins of the Sone, Narmada, Tapti, Godavari, Krishna and Pennar;
 (ii) Brahmputra-Ganga link;
 (iii) Link canal from the Narmada to Western Rajasthan;
 (iv) Canal from the Chambal to pump water 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 Ghat, towards the east.
 The waters of the Grid will be used for irrigation in drought affected areas.
 

National Water Management Project
 National Water Management Project (NWMP) was designed to supplement the resources of the states to promote the process of improved water management through upgradation of the main systems of the selected irrigation schemes. The basic objective of the project was to improve irrigation coverage and agricultural productivity and thereby increase incomes of farmers in the command through a  more reliable, predictable and equitable irrigation service. The first phase of the programme lasted from June 1987 to March 1995.
 The Project being a pilot programme, has been modestly successful. Irrigation management has improved significantly in the schemes completed under NWMP.

Command Area Development Programme
 A Centrally-sponsored Command Area Development Programme was launched in 1974-75 with the main objective of improving utilisation of irrigation potential and optimising agricultural production and productivity from the irrigated areas by negotiating all functions related with irrigated agriculture.
 Beginning with 60 major and medium irrigation projects in 1974, the Programme includes 217 irrigation projects at the end of 1997-98 with Culturable Command Area (CCA) of 21.78 million has spread over 23 states and two union territories.

Minor Irrigation
 All ground water and surface schemes having CCA upto 2,000 ha individually are classified as minor irrigation schemes. The development of ground water is mostly done through individual and cooperative efforts of the farmers with the help of generally funded from public sector outlay
 

Yamuna Water Accord
 The co-basin states of Haryana, Uttar Pradesh, Rajasthan, Himachal Pradesh and National Capital Territory of Delhi reached an agreement in May 1994 for sharing of Yamuna water upto Okhla. Haryana has been allocated 5.730 billion cubic metres (bcm), Uttar Pradesh 4,032 bcm, Rajasthan 1.119 bcm, Himachal Pradesh 0.378 bcm and NCT of Delhi 0.724 bcm of Yamuna water annually.
 The upper Yamuna River Board was constituted by the Government of India on 11 March 1995 to regulate allocation of available flow of Yamuna upto Okhla among the beneficiary states.
 Draft agreements among the basin states were also finalised on the following projects :
 (i) Construction of Hathnikund Barrage Project in Haryana;
 (ii) Construction of Renuka Dam Project in Himachal Pradesh, and
 (iii) Construction of Kisau Dam Project in Uttar Pradesh.

Central Water Commission
 Set up in 1945, the Central Water Commission (CWC) is the apex national organisation in the field of development of water resources. It shoulders the general responsibility of initiating, coordinating and furthering in consultaton with the state governments concerned, schemes for the control, conservation and utilisation of water resources for purposes of flood management, irrigation,. navigation and water power generation throughout the country.
 The Commission, if so required, also undertakes the construction and execution of any such schemes. Over the years the Commission has developed considerable technological know-how in planning and investigation and expertise in plan formulation, appraisal, design of major hydraulic structure and water resources development projects and is sharing this knowledge with other developing countries of the world.
 CWC operates a national network of 877 hydrological observation stations maintained by its field offices on various inter-state and international river basins. At present Hydrology Project assisted by World Bank is being implemented in Peninular river basins in India with participation by seven state governments agency and CWC, CGWB, NIH, CWPRS and IMD, IDA credit is SDR 90.1 million (US $ 142.0 million equivalent).
 One of the important activity of CWC is Flood Forecasting Services through the network of 157 Flood Forecasting Stations spread over eight major river systems which includes 62 river basins covering most of the inter-state rivers of the country including inflow forecast for 25 reservoirs.

Central Soil and Materials Research Station
 The Central Soil and Materials Research Station (CSMRS), New Delhi deals with field exploration, laboratory investigations and basic and applied research in the field of geomechanics and construction materials relevant to river valley projects. The Research Station primarily functions as adviser and consultant to various departments of Government of India, state governments and Government of India undertaking/enterprises. Activities of the Research Station cover the disciplines of soil mechanics, foundation engineering, concrete technology, construction materials technology, instrumentation geophysical investigations and chemical analysis and geosynthesis.

Central Water and Power Research Station
 Central Water and Power Research Station (CWPRS) provides comprehensive R & D support to a variety of projects in the areas of water and energy resources development and water borne transport. The UNDP aid delivered through projects in selected disciplines such as ship hydrodynamics, photo-elasticity, hydro-machinery, coastal engineering, hydraulic instrumentation, earth sciences, hydraulic structures and information technology, over the last four decades, has brought the Research Station on par with the leading hydraulic laboratories of the world. The infrastructure developed with these inputs over the successive Five Year Plans has paved the way for further assistance by the UNDP in the areas of ‘Mathematical Modelling of Fluvial and Ocean Hydromechanics’ and ‘Automated Operation of Irrigation Canal Systems’.
 The CWPRs was recognised as the Regional Laboratory for the ESCAP in 1971. Nearly 80 per cent of the research efforts is currently devoted to the study of government financed projects executed through various Central and state agencies. In this context, a typical analysis carried out earlier revealed that the Research Station is connected with the projects constitution over 30 per cent of the planned investments in the country.

Central Ground Water Board
 Central Ground Water Board is the national apex organisation, vested with the responsibilities of carrying out nation-wide surveys and assessment of ground water resources and guiding the states appropriately in scientific and technical matters relating to ground water. Besides advising the state governments on planning, financing and administration of ground water development schemes, the Board also assists the Ministry of Water Resources on formulation of the policy for the ground water sub-section and provides technical assistance to Ministry of Rural Areas and Employment for scientific source finding work for sustainable water supply to rural habitations under the Rajiv

Gandhi National Drinking Water Mission.
 Rajiv Gandhi National Training and Research Instituted for Ground Water, being set up at Raipur, Madhya Pradesh will, besides conducting induction level, mid career and management level courses, lay special emphasis on strengthening the infrastructure for training on information systems, sectoral and project planning and formulation, imparting knowledge on the latest scientific and technological advances as well as personnel development towards professional excellence. The institute will also take up research studies on various aspects in the field of ground water.
 The Board in coordination with the states have re-estimated the Ground Water Resources and Irrigation Potential for all the states of the country. Accordingly, the total replenishable ground water resources in the country has been estimated at 43.19 million hectare meters (mham) per year. Of this 7.09 is for drinking, industrial and other uses leaving 36.10 mham for irrigation. The utili sable irrigation potential for development has been estimated as 64.05 mha.

Minor irrigation works are being preferred over major irrigation works
 During the Plans, greater emphasis was laid on major and medium irrigation projects. It is now being in creasingly realised that this obsession with major irrigation works has raised the irrigation costs per hectare of prohibitive

• There are certain inherent problems associated with major irrigation works. Firstly, it has been observed that as much land goes out of production owing to waterlogging and salination every year as is brought under production through setting up of new projects. Secondly, the gestation period associated with major projects is long. Thirdly the large associated bureaucracy is generally corrupt and inefficient. As result the cost over-runs are much greater. Fourthly, large area of agricultural land is lost in developing distribution system Finally, there is heavy loss of irrigation water due to seepage and evaporation. These losses occur as the distributaries are unlined and thus waterlogging is a serious problem.
  
   On the country, minor irrigation projects have a shorter gestation period. They are mostly in the private selector consisting of wells, tubewells, pump sets etc. There is, therefore, no wastage of land in distributaries. Problem of waterlogging are not associated with minor irrigation works. Farmers tend to economise the use of water since the system is directly under their control. The key to better management therefore lies not in big dams constructed at exorbitant financial and economical costs but in promotion of minor irrigation which ensures maximum use of ground water and better control over irrigation sources.

Adverse environment effects of big dams
 The planners have relied excessively on large irrigation dams as a means of raising agricultural production. These gigantic dams costing crores of rupees have caused positive harm to the people and the environment. Whenever drainage works are neglected while building roads, rail and canal embankments, rain and flood water is held up and land gets waterlogged.

•  Waterlogging is becoming a serious problem and a positive menace in Punjab, Haryana, U.P., West Bengal, Gujarat, M.P. and Maharashtra. Another associated problem is of salinity. Such salt-affected regions lie in fertile Indo-Gangetic plains of Punjab, Haryana and U.P. The problem is quite serious in the deep and medium black cotton soils which are covered under new irrigation projects. Construction of large dams has displaced millions and created the attendant problems of rehabilitation. Large dams have also resulted in submerging of millions of hectares of vital forests in the catchment areas, increased soil erosion and land-slides and consequently greater danger of floods earthquakes and dam bursts.

Major wasteland areas
 Large wasteland areas are found in the states of Rajasthan, Gujarat, Madhya Pradesh, Orissa Himachal Pradesh, Uttar Pradesh and Bihar and in the north-eastern areas. Wastelands are those areas which are rendered uncultivable because of heavy water-logging or several soil erosion.

•  Wastelands can be made cultivable by appropriate land management practices. The major steps include proper drainage of water logged areas, afforestation schemes to check soil erosion and irrigation to being arid waste under cultivation. The steps taken for wasteland rehabilitation will have significant impact on the availability of food, fodder and fuel. Food crops can be grown on recovered wastelands to augment the supply. Areas where this cannot be done can be turned into grasslands or forests improving the quality of the environment and at the same time increasing the supplies of fodder and fuel. Fuel plantations is a concept that is gaining ground.

Water shortage in India
 The main reasons for water shortage are deforestation, increasing population and pollution. Deforestation reduces the supply of water, population increase the demand and pollution makes eventhe available water unusable.

• Irrigation potential in India has increasedgreatly after independence. It is now about 638 lakhs hectares. However, even now 70% of the country’s cropped area is entirely dependent on rainfall.
• An effective water management strategy has to meet the demands for irrigation, municipal and industrial purposes. Surface and ground water resources have to be efficiently utilised for these purposes.
• Following steps have been suggested for achieving optimal use of irrigation potential.
   (1) Canal lining to prevent seepage loss.
   (2) Field channels and drainage system for Command Area Projects.
   (3) Use of scientific irrigation systems like sprinkler and drip irrigation.
   (4) Regulated use of water between water intensive crops like paddy and sugarcane and other crops.
   (5) Re-cycling of water.

Areas of tank irrigation 
 Areas of tank irrigation mostly occur in Peninsular India including Maharashtra and Gujarat. This is because the rivers of the Deccan are not perennial. During the monsoon period, many streams become torrential and dry up with the exit of the monsoon. The undulatory terrain and its rocky nature makes canal construction very expensive. As the soil is rocky, water does not get absorbed by it and storage of large quantities of water without less is feasible. Water is collected and distributed from these reservoirs through channels to arable lands in the winter season. Another factor is that the population is scattered which is favourable for tank irrigation.

•  The disadvantages of tank irrigation are:

(a) quick silting of tanks which require de-silting at regular intervals;
 (b) high rate of evaporation from the open surfaces of tanks;
 (c) loss of valuable fertile lands which are occupied by tanks.


 Installation of deep pumping systems
 Tube wells or deep pumping system have a greater advantages in that besides performing much faster than older methods, they can also lift water from greater depths. Deep well pumping of sub-soil water has been successfully done in the upper reaches of the Indo-Gangetic valley and in some coastal deltaic regions.
 

•  The conditions for installation of deep pumping systems are:
   1. The water table should be stable and have adequate flow of sub-soil water.
   2. The depth of the water from the surface should not normally be more than 50.
   3. The demand for water extends over a wide area and endures for not less than 3000 hours in the year to make power offtake economic.
   4. Reasonably cheap electric power is available.
   5. The nature of the soil is alluvial so that water bearing strata occurs at various levels.
   6. The soil is productive enough to optimise the higher costs involved in the use of power and construction of wells, etc.
   
• Areas of tube wells irrigation in India are:
   — Lower & middle Ganga plain
   — Eastern Rajasthan
   — Punjab & Haryana
   — Northern & Southern side of Ghagra
   — Eastern Delhi plain

Large area of Canal Irrigation 
 Geographically, Northern Indian irrigation system posses some natural advantages.
 (1) The rivers fed by the Himalayan snows are perennial.
 (2) The slope of the plains is gradual enabling the canals taken out in the upper course of these rivers to fully irrigate the lands in the lower valleys.
 (3) The northern plain have no rocky soils and the canals can be constructed without difficulty.
 (4) The sub-soil day is deep and enables the water that sinks through the porous alluvium to be trapped by wells.

• So canal irrigation largely occur in Northern India.

 Water-shed management
 A water shed has been defined as a geo-hydrological unit on a piece of land that drains at a common point. It is the boundary line that separates different river systems. As water availability is limited and its demand high, it is necessary to ensure that water sheds do not deteriorate and available water is put to the optional productive use. This is the aim of water shed management. There are a number of central schemes of integrated watershed management.

• Centrally sponsored schemes in the catchment of river valley projects such as DVC and soil and water conservation programmes which are implemented in critically degraded watersheds help water conservation.
• The Ganga basin development scheme is another centrally sponsored programme for enhancing the ability of the catchment to absorb larger quanti ties of rain-water.
• The scheme for development of the ravine areas of Madhya Pradesh, Uttar Pradesh, Rajasthan and Gujarat have helped in reclamation of large areas for cultivation.
• The All India Soil and Land Use Survey monitors the progress of the centrally sponsored integrated watershed management schemes. It is helped by Space Application Centre/ISRO and is engaged in mapping of selected drought-prone districts and salt encrusted lands, privatization of water sheds in catchments by remote sensing techniques, etc.

Sources of irrigation in India
 The main sources of irrigation in India are canals, tanks, wells and other ground water sources like tubewells, bore-wells, etc. Since rainfall in India is uneven in time and space, irrigation is a necessity for cultivation purposes and has been practised for centuries.

• Since independence, irrigation has been one of the principle areas of our developmental efforts and large sums of money have been set apart for irrigation in the various Five Year Plans from 1950. It is customary to divide irrigation sources into major, medium and minor projects and express irrigation potential in hectares. Major projects are those that have more than 10,000 hectares of cultivable command area, medium projects have 2000-10,000 hectares and minor project less than 2000 hectares.
• The total irrigation potential in 1951 was 226 lakh hectares (out of which 97 lakh hectares were from major projects and 129 lakh hectares from medium and minor projects). By the end of the eigth plan is was about 89.44 mha (provisional).
• The major objective of irrigation policy in India is to attain a gross irrigation potential of 1130 lakh hectares based on conventional methods of diversion and storage by the end of this century. 580 lakh hectares out of this would be from major and medium sources. Minor irrigation programmes depend on development of ground water resources through individual and cooperative efforts. Accordingly these programmes do not require outlay of expenditure by Government to the extent that major irrigation sources need. The Command Area Developments Programmes (CAD) are financed by states with the Central Government providing a matching assistance. The CAD Programmes are expected to maximise agricultural production.