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|Year: 2011||Revision date: Feb 2015||Revision type: Minor: Correction Table 3 in PDF|
|Regional report:||Water Report 37, 2012|
India is located in southern Asia and has a total area of almost 3.3 million km2 (Table 1), making it the largest peninsula in the world and the seventh largest country. It is bordered in the northwest by Pakistan, in the north by China, Nepal and Bhutan, and in the northeast by Myanmar and Bangladesh. In the south, some 7 600 km of coastline is on the Arabian Sea, Indian Ocean and Bay of Bengal. The peninsula can be divided into three main regions: peninsular India, located south of the Vindhya and Satpura mountain ranges; the plains of the Indus (northwest) and Ganges (north and northeast) rivers; and the mountainous terrain of the Himalayas. In addition, the Lakshadweep Islands in the Arabian Sea and the Andaman Islands and Nicobar Islands in the Bay of Bengal are part of the territory of India. For administrative purposes, India is divided into 28 states and seven union territories.
The total cultivable area is approximately 183 million ha, or over 55 percent of the total area of the country. In 2009, the total cultivated area was about 170 million, of which 158 million ha were annual crops and 12 million ha were permanent crops. Between the early 1960s and the late 1980s the cultivated area increased by 5 percent, since then there has been hardly any increase in the cultivated area. Crop yields, however, have increased significantly (food grain yields have more than tripled since 1950) as well as the cropping intensity, which increased from 111 percent in 1950 to 118 in 1970, 130 in 1990 and 135 in 2006.
India has a typical monsoon climate. In this region, surface winds undergo a complete reversal from January to July, and cause two types of monsoon. In winter, dry and cold air from land in the northern latitudes flows southwest (northeast monsoon), while in summer, warm and humid air originates over the ocean and flows in the opposite direction (southwest monsoon), accounting for some 70-95 percent of the annual rainfall. For most parts of India the rainfall occurs under the influence of the southwest monsoon between June and September. However, in the southern coastal areas near the east coast (Tamil Nadu and adjoining areas) much of the rainfall is influenced by the northeast monsoon during October and November.
The average annual rainfall over the country is around 1 170 mm, but varies significantly from place-to-place. In the northwest desert of Rajasthan, the average annual rainfall is lower than 150 mm/year. In the broad belt extending from Madhya Maharashtra to Tamil Nadu, through parts of Andhra Pradesh and Karnataka, the average annual rainfall is generally lower than 500 mm/year. At the other extreme, in a short period of a few months, more than 10 000 mm of rain falls on the Khasi hills in the northeast. On the west coast, in Assam, Meghalaya, Arunachal Pradesh (states located in the northeast) and in sub-Himalayan West Bengal the average annual rainfall is about 2 500 mm.
Except in the northwest of India, the inter-annual variability of rainfall is relatively low. The main areas affected by severe droughts are Rajasthan and Gujarat.
The year can be divided into four seasons, the:
Temperature variations are also marked. During the post-monsoon and winter seasons, from November to February, the temperature decreases from south to north owing to the effect of continental winds over most of the country. From March to May, the temperature can increase to 40 °C in the northwest. With the advent of the southwest monsoon in June, there is a rapid fall in the maximum daily temperature, which then remains stable until November. The temperatures are suitable for year-round crop production throughout India, except at higher elevations in the Himalayas.
In 2009, India was the second most populous country in the world, with an estimated total population of 1 208 million. In 2009, 849 million inhabitants (or 70 percent) were living in rural areas. The country’s average population density then was an estimated 367 inhabitants/km2, varying from fewer than 15 inhabitants/km2 in the states of Arunachal Pradesh and Himachal Pradesh to more than 9 300 inhabitants/km2 in Delhi State. During the period 1999-2009 the average annual population growth rate was an estimated 1.5 percent.
In 2008, 88 percent of the population had access to improved water sources (96 and 84 percent in urban and rural areas respectively), but only 31 percent had access to improved sanitation (54 and 21 percent in urban and rural areas respectively).
In 2009, the national gross domestic product (GDP) was US$1 310 171 million. Agriculture accounted for 17 percent of GDP, while in 1999 it represented 25 percent. In 2009, the total economically active population was 486 million, or 40 percent of the total population. The economically active population in agriculture, then, was about 267 million, of which 32 percent were women. In 2004, about 238 million people comprising 21 percent of the total population were assessed to be below the poverty line.
The major cereals grown in India are rice, wheat, maize, bajra (spiked millet), barley, jowar (great millet), and ragi. The average yield of food grains (cereals and pulses) increased from 522 kg/ha in 1950 to 1 727 kg/ha in 2003-2004, meaning there was an average annual growth rate of 4.35 percent. Total food grain production in 2006-2007 was almost 212 million tonnes. The average operational farm size reduced from 1.57 ha in 1992 to 1.17 ha in 2002.
India has an annual average precipitation of 1 170 mm and about 80 percent of the total area of the country experiences annual rainfall of 750 mm or more (Table 2). Owing to the large spatial and temporal variability in the rainfall, water resources distribution is highly skewed in space and time.
The two main sources of water in India are rainfall and glacial snowmelt in the Himalayas. Although snow and glaciers are poor producers of freshwater, they are good distributors as they yield at the time of need, in the hot season. Indeed, about 80 percent of the river flow occurs during the four to five months of the southwest monsoon season. Several important river systems originate in upstream countries and then flow to other countries: the Indus river originates in China and flows to Pakistan; the Ganges-Brahmaputra river system originates partly in China, Nepal and Bhutan, and flows to Bangladesh; some minor rivers drain into Myanmar and Bangladesh. However, no official records are available regarding the annual flows into or our of the country.
The rivers of India can be classified into four groups:
For planning purposes, the country is divided into 20 river units, 14 of which are major river basins, while the remaining 99 river basins have been grouped into six river units, as presented in Table 3. The spatial imbalance of water resources distribution can be appreciated by the fact that the Ganges-Brahmaputra-Meghna basin, which covers 34 percent of the country’s area, contributes about 59 percent of the water resources. The west flowing rivers towards the Indus cover 10 percent of the area and contribute 4 percent of the water resources. The remaining 56 percent of the area contributes 37 percent to the runoff.
The potential surface water resources is assessed as the natural runoff of the rivers. Looking at the Indus Water Treaty (1960) between India and Pakistan, however, these are an estimated 1 869.37 km3, of which only 690.31 km3 are considered usable or exploitable because of constraints related to topography, uneven distribution of the resource over space and time, geological factors and contemporary technological knowledge (Table 3).
Annual renewable groundwater resources are an estimated 432 km3, of which around 90 percent or 390 km3 are considered overlap between surface water and groundwater. Annual internal renewable surface water resources (IRSWR) have been estimated as 1 446.42 km3, of which 1 404.42 km3 surface water, 432 km3 groundwater and 390 km3 overlap. The IRSWR have been estimated by deducting the inflow from the total renewable surface water resources.
Under the Indus Water Treaty (1960) between India and Pakistan, it was estimated that 73.31 km3/year is available for India (Table 3). The following rules apply:
Besides this outflow to Pakistan from the Indus basin, 1 121.62 km3 flows annually to Bangladesh (525.02 km3 from the Ganges, 537.24 km3 from the Brahmaputra, 48.36 km3 from the Meghna and 11 km3 from other rivers into southeast Bangladesh), and 20 km3 flows to Myanmar.
In 1996, produced wastewater was an estimated 25.4 km3. In 2004, wastewater production in urban centres (rural areas with larger population have not been accounted) was an estimated 10.585 km3 and the treated wastewater was about 2.555 km3.
No reliable statistics are available on the number or the status of desalination plants, or on their capacities or technologies adopted. Estimates indicate, however, that there are more than 1 000 membrane-based desalination plants of various capacities ranging from 20 m3/day to 10 000 m3/day. There are few thermal-based desalination plants. In 1996, some 550 000 m3 of seawater were desalinated in the Lakshadweep Islands, mainly using electro dialysis and reverse osmosis (RO). Solar stills are also installed on the peninsula, as in Gujarat in the northwest. A 6 300 m3/day desalination plant is being set up at Kalpakkam, Chennai with a capacity of 4 500 m3 from multi stage flash (MSF) method, using low pressure steam from the Madras Atomic Power Station and 1 800 m3/day from RO method. While the Plant using the RO method is under operation, the MSF-based plant is to be commissioned soon.
The total constructed water storage capacity, up to 2005, was 224 km3. Another 76.26 km3 are estimated to be possible from dams under construction and 107.54 from dams under consideration. Seven dams have a reservoir capacity that exceeds 8 km3. They are the Nagarjuna Sagar dam on the Krishna river (11.56 km3), the Rihand dam on the Rihand river (10.6 km3), the Bhakra dam on the Sutlej river (9.62 km3), the Srisailam dam on the Krishna river (8.72 km3), the Hirakud dam on the Mahanadi river (8.1 km3), the Pong (Beas) dam on the Beas river (8.57 km3) and the Ukai dam on the Tapti river (8.5 km3).
India controls the flow of the River Ganges using a dam completed in 1974 at Farraka, 18 km from the border with Bangladesh. The Farakka barrage is a low diversion structure and not classified as a large dam.
India is endowed with rich hydropower potential, ranking fifth in the world. The gross hydropower potential was an estimated 148 700 MW as installed capacity, or 84 000 MW at 60 percent power load factor, of which the Brahamaputra, Ganges and Indus basins contribute about 80 percent. Further, small, mini and micro hydropower schemes (with a capacity of less than 3 MW) have been assessed as having almost 6 782 MW of installed capacity.
The earlier-mentioned dam at Farraka, 18 km from the border with Bangladesh, was a source of tension between the two countries, when Bangladesh asserted that the dam held back too much water during the dry season and released too much water during monsoon rains. A treaty was signed in December 1996, under which Bangladesh is ensured a fair share of the flow reaching the dam during the dry season.
The Indus Water Treaty (1960) between India and Pakistan, described earlier, helped to resolve the issues between these two countries; although during the last few years Pakistan has objected to India’s development of hydropower projects on the western rivers, Chenab and Jhelum.
Similar arrangements exist between Nepal and India for the exploitation of the Kosi river (1954, 1966) and the Gandak river (1959).
It is estimated that in 2010 total water withdrawal was 761 km3 of which 91 percent, or 688 km3, are for irrigation. About 56 km3 are for municipal and 17 km3 for industrial use(Table 4 and Figure 1).
In 2010, primary surface water withdrawal accounted for 396 km3, primary groundwater withdrawal accounted for 251 km3, and reused agricultural drainage water accounted for 113 km3. In 1996, some 550 000 m3 of seawater were desalinated (Figure 2).
In 1990, total water withdrawal was an estimated 500 km3, of which 92 percent was for irrigation. Primary surface water withdrawal was 362 km3, while the amount coming from primary groundwater was an estimated 190 km3.
The history of irrigation development in India can be traced back to prehistoric times. Ancient Indian scriptures referred to construction of wells, canals, tanks and dams and their efficient operation and maintenance. Irrigation to produce food grains is known to have been in existence for over 5 000 years (Framji, 1987). There is evidence of irrigation being practised since the establishment of settled agriculture during the Indus Valley Civilization (in 2500 Before the Common Era [BCE]). These irrigation technologies were in the form of small and minor works. Traces of irrigation structures dating back 3 700 years have been found in the state of Maharashtra. During the Mauryan era (2 600-2 200 years ago), it is reported that farmers had to pay taxes for irrigation water from neighbouring rivers.
The Grand Anicut (Canal) across the Cauvery river in Tamil Nadu was begun 1 800 years ago and its basic design is still used today. In 1800, some 800 000 ha were irrigated in India. Major irrigation canals were built following the major famines at the end of the nineteenth century and, in 1900, the Indian peninsula (including Bangladesh and Pakistan) had some 13 million ha under irrigation. In 1947, India had about 22 million ha under irrigation. High priority has been given to irrigation with nearly 10 percent of all planned outlays since 1950 being invested in irrigated agriculture. This has resulted in the development of, on average, 0.6-0.7 million ha new irrigated schemes every year.
The emphasis on irrigation development was initially on run-of-the-river schemes. Subsequently, the need was felt for storage projects for either single or multiple purposes. Irrigation schemes are grouped under three categories: major (>10 000 ha), medium (2 000-10 000 ha) and minor (<2 000 ha) schemes. Minor irrigation projects generally have both surface water and groundwater as sources, while major and medium projects exploit surface water resources. In 1993 around 65 percent were minor schemes. In new major irrigation works, social and environmental costs (resettlement of displaced people, loss of biodiversity in submerged areas, etc.) are more systematically considered than in the past.
While in 1993 the ultimate irrigation potential of India was an estimated 113.5 million ha, new estimates give a figure of 139.5 million ha, of which 58.1 million ha for major and medium irrigation schemes and 81.4 million ha for minor irrigation projects. Of the 81.4 million ha of minor irrigation potential, groundwater based potential is estimated to be 64.1 million ha and the surface water based potential is 17.3 million ha.
Total area equipped for irrigation was around 66.3 million ha in 2008 (Table 5). Irrigation is mainly concentrated in the north of the country along the Indus and Ganges rivers: Punjab, Rajasthan, Uttar Pradesh and Madhya Pradesh. A classification of irrigation by origin of water is in common use in India. It differentiates irrigation from canals (29 percent in 2001), most of which are government canals, tanks (4 percent), groundwater wells (63 percent), the majority being privately owned and managed, and other or undefined sources (4 percent) (Figure 3). In 1993 the area equipped for irrigation was about 50.1 million ha of which irrigation by canals accounted for 34 percent (97 percent are government canals), tanks 6.5 percent, groundwater 53 percent (generally privately owned and managed) and other or undefined sources (6.5 percent). This shows that the use of groundwater for irrigation has increased considerably.
Of the 19.75 million minor irrigation schemes, groundwater schemes account for 18.5 million and the rest are based on surface water resources. The surface flow schemes typically comprise tanks and storage developed by construction of check dams. Groundwater schemes are composed of dug wells, dug cum bore wells, borings, and both shallow and deep tubewells. There is considerable variation in the development of minor irrigation from state-to-state. The full potential of minor irrigation has been tapped in Uttar Pradesh, Punjab, Haryana, Rajasthan. In some of the Union Territories it is as low as 18 percent in Manipur and 20 percent in Madhya Pradesh. Minor irrigation schemes are generally in the private sector and very few (6 percent) are owned by public institutions.
Over the past few decades, the main driving force behind the expansion of groundwater irrigation and improvement in agricultural productivity, was support to investment to provide electrical infrastructure and credit. Private groundwater irrigation, with shallow wells that serve 3-5 ha each, is considered to be the most cost-effective solution. Of the 18.50 million groundwater wells 16.43 million wells are in use (7.85 million dug wells, 8.10 million shallow tubewells and the rest deep tubewells). Development of groundwater resources varies from state-to-state. Groundwater is still available for exploitation in the eastern parts of the country, and in Madhya Pradesh, Chhattisgarh, specific pockets of Andhra Pradesh, Karnataka, Maharastra and Jammu and Kashmir. In Punjab, Haryana, Rajasthan, Gujrat and Tamil Nadu, exploitation exceeds the recharge to groundwater.
In many states, especially in the north (Uttar Pradesh, Punjab and Haryana), the conjunctive use of surface water and groundwater has been practiced using canal systems and tubewells or dug wells to increase the yield and general efficiency of the water system. Water from the tubewells, which are installed alongside existing canals, is added into the canals for use in the canal command areas. This practice helps prevent waterlogging, but requires that farmers adopt good management techniques.
The irrigation component of the Bharat Nirman Programme of the Government of India, a business plan for rural infrastructure, started in 2005, envisages the development of an additional irrigation area of 10 million ha through various irrigation schemes. Currently, 166 major, 222 medium and 89 environmental resources management (ERM) projects are reported to be ongoing in various states. The Government of India provides support to State Governments through the Accelerated Irrigation Benefits Program (AIBP) and other schemes.
In recent years, the development of sprinkler and localized irrigation has been considerable, mainly the result of the pressing demand for water from other sectors, a fact that has encouraged governments and farmers to find water-saving techniques for agriculture. Sprinkler irrigation was not widely used in India before the 1980s; however between 1985 and 1996 more than 200 000 sprinkler sets were sold. In 2004 the area under sprinkler irrigation was an estimated 1.4 million ha, while in 1996 it was about 0.7 million ha.
Localized irrigation is also expanding rapidly in India. This can be partly explained by the subsidies offered by the Government to adopt drip systems. From about 1 000 ha in 1985, the area under drip irrigation increased to 70 860 ha in 1991, mainly in Maharashtra, Andhra Pradesh and Karnataka. In 2004 the area under localized irrigation was about 578 207 ha (Figure 4). Drip-irrigated crops are mainly used in orchards, mainly grapes, bananas, pomegranates and mangoes. Localized irrigation is also used for sugarcane and coconut. In 2004 surface irrigation covered approximately 61.9 million ha. The approximate capital cost of sprinkler systems (excluding pump cost) ranges from US$345-450/ha. The approximate cost of localized irrigation is US$1 780-6 240/ha.
Water-harvesting systems, comprising tanks and other water conservation works, are devised to capture, store and distribute water for irrigation, besides meeting the municipal needs of the population. According to the third minor irrigation census carried out in 2001 the number of tanks, storage and other water conservation works is 0.457 million.
Irrigation development has enabled diversification of cropping patterns with crops grown all year round. The expansion of irrigation has not only directly enabled yield increases, it has also facilitated high input, high-yielding agriculture involving the use of chemical fertilizers and high-yielding varieties of wheat rice and maize. The food grain production has increased from about 50 million tonnes in 1951 to 213 million tonnes in 2004. Although irrigated crop yields have increased considerably, they are still low compared to those of other countries. This is mainly because of poor water management in many surface irrigation schemes.
In 2004, the harvested irrigated crop area covered around 76.8 million ha, of which 31 percent wheat, 29 percent rice, 2 percent maize, 7 percent oil palm, 6 percent vegetables and fruits and 5 percent sugarcane (Table 5 and Figure 5). In 1993, the total harvested area was an estimated 66.1 million ha.
In 1991, drainage works had been undertaken on about 5.8 million ha, which was 12 percent of the irrigated area. Investment in drainage has been widely neglected and, where such investment has been made, poor maintenance has caused many drainage systems to become silted up. On the eastern Ganges plain, investment in surface drainage would probably have a larger productive impact, and at a lower cost, than investment in surface irrigation. In 2010, only some irrigation systems, predominantly of south and western India, have well laid out drainage systems.
Under the Indian Constitution, the states are responsible for water. Thus the federal states are primarily responsible for the planning, implementation, funding and management of water resources development. The responsibility in each state is borne by the Irrigation and Water Supply Department. The Inter-State Water Disputes Act of 1956 provides a framework for the resolution of possible conflicts.
At central level, which is responsible for water management in the union territories and in charge of developing guidelines and policy for all the states, three main institutions are involved in water resources management:
Further, the Indian National Committee of Irrigation and Drainage (INCID) coordinates with the International Commission on Irrigation and Drainage (ICID) and promotes research in the relevant areas. The Central Pollution Control Board (CPCB) is in charge of water quality monitoring, and the preparation and implementation of action plans to solve pollution problems.
In 1996, the Central Groundwater Authority was established to regulate and control groundwater development to preserve and protect the resource.
Water resources planning and management should be seen in a context of food grain availability. From the mid-1960s onwards, food grain production increased in the 1950s and 1960s as a result of increases in the cultivated area, expansion in irrigated area and the use of high-yielding varieties (HYVs). Irrigation also helped reduce inter-annual fluctuations in agricultural output and India’s vulnerability to drought. One of the goals of Indian policy is to find ways to maintain the level of food grain availability per inhabitant in a context of population increase. Total water demand is expected to equal water availability by 2025, but industrial and municipal water demand are expected to rise drastically at the expense of the agricultural sector, which will have to produce more with less water.
The centrally sponsored Command Area Development (CAD) Programme was launched in 1974-1975. The main objectives of the programme are to improve use of the area equipped for irrigation and optimize agricultural production and productivity from irrigated agriculture. The Programme involves the implementation of on-farm development works such as construction of field channels and field drains, reclamation of waterlogged areas, renovation and rehabilitation of minor irrigation tanks, correction of irrigation water distribution system deficiencies.
The programme also involves ‘software’ activities such as adaptive trials, demonstrations, training of farmers, evaluation studies, etc. One component of the programme is Warabandi, which is a rotation system for the distribution of irrigation water to ensure equitable and timely supply of water to all farm holdings in the command. An amount of Rs 35 280 million has been released to the states as central assistance under the programme from inception until the end of March 2008. Since the programme’s inception, and up to the end of March 2007, 18.07 million ha had been covered. The CAD Programme was restructured in April 2004, the and renamed as the ‘Command Area Development and Water Management (CADWM)’ Programme.
The main systems of irrigation water management (distribution) schemes practised are:
A broad distinction can be made between supply-based systems (such as warabandi) that distribute water according to predetermined procedures and require farmers to respond accordingly for cropping patterns and areas, and demand-based systems (such as shejpali) that attempt to meet crop–water needs. In supply-based systems, the role of the irrigation department tends to be simpler than under demand-based systems, which require that the department responds to the changing needs of farmers with more complex and flexible infrastructure and more intensive management. The average overall water-use efficiency in canal irrigation systems is an estimated 38-40 percent.
The National Water Policy 2002 emphasises a participatory approach for water resources management. It has been recognized that participation of beneficiaries will help optimize the upkeep of the irrigation system and promote the efficient use of irrigation water. The participation of farmers in irrigation management is formulated based on the creation of water user associations (WUAs), which aim to: i) promote and secure distribution of water among users; ii) ensure adequate maintenance of the irrigation systems; iii) improve efficiency and economic use of water; iv) optimize agricultural production; v) protect the environment; and vi) ensure ecological balance by involving the farmers and inculcating a sense of ownership of the irrigation systems in accordance with the water budget and operational plan. The WUAs are formed and work guided by the executive instructions and guidelines laid down by each state government. There is no central legislation or legal instrument in this regard. However, Andhra Pradesh is the only state that has passed legislation exclusively covering farmer participation in the management of irrigation systems. A total of 55 500 WUAs were constituted in India covering 10.23 million ha.
The National Groundwater Recharge Master Plan (NGRMP) provides a nationwide assessment of the groundwater recharge potential and outlines the guiding principles for an artificial groundwater recharge programme. The plan estimates that by using dedicated recharge structures in rural areas and rooftop water harvesting structures in urban areas a total of 36 km3 can be added to groundwater recharge annually. The master plan follows two criteria for identifying recharge: availability of surplus water and availability of storage space in aquifers. Investments in the programme would, therefore, be driven by the potential available for groundwater recharge, and not by the need for recharge. Thus, the three states of Andhra Pradesh, Rajasthan, and Tamil Nadu, which together account for over half of India’s threatened groundwater blocks, receive only 21 percent of funds, whereas the states of the Ganges-Brahmaputra basin, which face no groundwater over development problems, receive 43 percent of the funds. If implemented successfully, this recharge programme will be able to add a significant quantity of water to India’s groundwater storage, but it will not provide much help in the areas that are most in need of help.
Currently, there is no uniform set of principles to fix the water rates. The water charges vary from state-to-state, project-to-project and crop-to-crop. The rates vary widely for the same crop in the same state depending on irrigation season, type of system, etc.
Water rates, being abysmally low, do not generate sufficient funds for the proper maintenance of irrigation systems, leading to poor quality of service. The state governments need to evolve a policy for periodical rationalization and revision of water rates, so that the revenue generated by the irrigation sector is able to meet the cost of O&M. However, in view of unreliable and poor quality of services, farmers are reluctant to pay increased water charges. They may not be averse to paying increased water charges if the quality of services is first improved.
It is imperative that the tariff structure is reviewed, and revised with simultaneous improvement in the quality of services provided, to restore efficiencies. Rationalization of water rates will also act as a deterrent to excessive and wasteful use of water. Shifting towards fixing the water rates based volume is desirable. This will encourage farmers to avoid over-irrigation and wasteful use of water, thereby increasing water-use efficiencies. A uniform formula of water pricing for the entire country would have no practical value. A recommendation may be considered of setting up an independent State Regulatory Authority to rationalize water rates in each state.
India adopted a National Water Policy in 1987, which was revised in 2002, for the planning and development of water resources to be governed at the national level. It emphasizes the need for river basin based planning of water use. Water allocation priority has been given to drinking water, followed by irrigation, hydropower, navigation and industrial or other uses. As water resources development is a state responsibility, all the states are required to develop their state water policy within the framework of the national water policy and, accordingly, set up a master plan for water resources development.
Water quality is a major issue in India. Although in their upper reaches most rivers are of good quality, the importance of water use for cities, agriculture and industries, and the lack of wastewater treatment plants in the middle and lower reaches of most rivers cause a major degradation of surface water quality. Groundwater is also affected by municipal, industrial and agricultural pollutants. The over exploitation of groundwater can also lead to seawater intrusion. For example, there is an inland advance of the saline-freshwater interface in the Chingelput district of Tamil Nadu, where a well field along the Korttalaiyar River supplies water to the city of Madras.
In 1992, the Central Pollution Control Board completed water quality studies in all major river basins. The pollution control action plan of the Ganges River basin was formulated in 1984 and has been enforced by the Ganges Project Directorate, under the Central Ganges Authority, to oversee pollution control and the consequent cleaning of the Ganges River. The water quality in the middle stretch of the Ganges River, which had deteriorated to class C and D (the worst class is E, the best A), was restored to class B in 1990 after the implementation of the action plan. Similar programmes for other rivers have been developed, as well as a national river action plan to clean the heavily polluted stretches of the major rivers.
According to the National Commission on Floods, the area subject to flooding is an estimated 40 million ha (about 12 percent of the area of the country). About 80 percent of this area, or 32 million ha, could be provided with reasonable protection. Bihar is the worst flood hit state. Hardly a year passes without severe flood damages. With the onset of the monsoon, rivers come down from the Himalayan hills in Nepal with enormous force, leading the following rivers the Ghagra, Kamla, Kosi, Bagmati, Gandak, Ganges, Falgu, Karmnasa, Mahanadi to rise above the danger level. This results in severe floods in North Bihar.The Kosi River, popularly known as “the sorrow of Bihar”, has not yet matured enough to settle on a course, and has changed its course 15-16 times, the last time as recently as August 2008. About 2.8 million people were said to have been marooned by these floods in Bihar.
The total area subject to waterlogging was an estimated 8.5 million ha in 1985, including both rainfed and irrigated areas. This is thought to be a substantial underestimate as precise data are lacking. It is estimated that about 24 percent irrigated command areas of major and medium irrigation projects is subject to waterlogging. Measures to counter waterlogging and salinity are being taken by constructing field channels and drains, and by encouraging the combined use of surface water and groundwater. Furthermore, it is estimated that out of the total irrigated area about 3.3 million ha are affected by salinity.
Water-borne diseases have continued to increase over the years in spite of government efforts to combat them. States such as Punjab, Haryana, Andhra Pradesh and Uttar Pradesh are endemic for malaria as a result of the high water table, waterlogging and seepage in the canal catchment area. There are also numerous cases of filariasis. In 1998 the population affected by water-related diseases was 44 million inhabitants.
Climate change may alter the distribution and quality of India’s water resources. Some of the impacts include occurrence of more intense rains, changed spatial and temporal distribution of rainfall, higher runoff generation, low groundwater recharge, melting of glaciers, changes in evaporative demands and water use patterns in agricultural, domestic and industrial sectors, etc. These impacts lead to severe influences on the agricultural production and food security, ecology, biodiversity, river flows, floods, and droughts, water security, human and animal health and sea level rise.
Water resource availability is replete with severe uncertainties. Frequent severe droughts and floods are not uncommon. There is a need to produce as much as 325-350 million tonnes of food grains by 2025 to meet the food, feed, fodder and fibre requirements of India. To meet this estimate of food grain requirement it is assumed that the overall irrigation efficiencies will be 50 percent for surface water systems and 72 percent for groundwater systems, compared to the present level of 35-40 percent, and that the national average food grain production yields are expected to increase to 3.5 tonnes/ha for irrigated areas and 1.25 tonnes/ha for rainfed areas, compared to the present levels of 2 tonnes/ha in irrigated areas and 1 tonne/ha in rainfed areas. In the wake of the development of large-scale irrigation facilities, there were several serious problems related to the degradation of soil, water, and environment, which threatened the sustainability of agricultural production. These include:
The important issues that need to be addressed immediately, to overcome these constraints, and to achieve sustainable development and use of water resources to ensure the targeted food grain production of 325-350 million tonnes by 2025 the include:
To intensify research and development (R&D) efforts to seek ways to improve water-use efficiency, both location specific field studies and analytical studies should be implemented to develop systematic decision support systems for planning and implementing real time operations in the irrigation systems. These measures would allow growing multiple crops under limited water supply, using modern tools such as medium range weather forecasts, and modern irrigation methods.
Efficient water management in agriculture could fulfil the future food needs of India because of several comparative advantages. The most common strengths and opportunities for increasing food grain production, through improved water management include:
Uncommon opportunities, which are high technology innovations that are likely to be developed in the future are:
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