Rainfall: With an average annual rainfall of 1,170 mm, India is one of the wettest countries in the world. At one extreme are areas like Cherrapunji, in the northeast, which is drenched each year with 11,000 mm of rainfall, and at the other extreme are places like Jaisalmer, in the west, which receives barely 200 mm of annual rainfall. Though the average rainfall is adequate, nearly three-quarters of the rain pours down in less than 120 days, from June to September.
Groundwater: India’s groundwater resources are almost ten times its annual rainfall. According to the Central Groundwater Board of the Government of India, the country has an annual exploitable groundwater potential of 26.5 million hectare-meters. Nearly 85% of currently exploited groundwater is used only for irrigation. Groundwater accounts for as much as 70-80% of the value of farm produce attributable to irrigation. Besides, groundwater is now the source of four-fifths of the domestic water supply in rural areas, and around half that of urban and industrial areas. However, according to the International Irrigation Management Institute (IIMI), the water table almost everywhere in India is falling at between one to three meters every year. Furthermore, the IIMI estimates that India is using its underground water resources atleast twice as fast they are being replenished. Already, excessive ground water mining has caused land subsidence in several regions of Central Uttar Pradesh.
Surface water: There are 14 major, 44 medium and 55 minor river basins in the country. The major river basins constitute about 83-84% of the total drainage area. This, along with the medium river basins, accounts for 91% of the country’s total drainage. India has the largest irrigation infrastructure in the world, but the irrigation efficiencies are low, at around 35%.
Utilization of Water in India
Community water supply is the most important requirement and it is about 5% of the total water use. About 7 km3 of surface water and 18 km3 of groundwater are being used for community water supply in urban and rural areas. Along with the increase in population, another important change from the point of view of water supply is higher rate of urbanization. According to the projections, the higher is the economic growth, the higher would be urbanization. It is expected that nearly 61% of the population will be living in urban areas by the year 2050 in high-growth scenario as against 48% in low growth scenario. Different organizations and individuals have given different norms for water supply in cities and rural areas. The figure adopted by the NCIWRD9 was 220 litre per capita per day (lpcd) for class I cities. For the cities other than class I, the norms are 165 for the year 2025 and 220 lpcd for the year 2050. For rural areas, 70 lpcd and 150 lpcd have been recommended for the years 2025 and 2050. Based on these norms and projection of population, it is estimated that by 2050, water requirements per year for domestic use will be 90 km3 for low demand scenario and 111 km3 for high demand scenario. It is expected that about 70% of urban water requirement and 30% of rural water requirement will be met by surface water sources and the remaining from groundwater.
The irrigated area in the country was only 22.6 million hectare (Mha) in 1950–51. Since the food production was much below the requirement of the country, due attention was paid for expansion of irrigation. The ultimate irrigation potential of India has been estimated as 140 Mha. Out of this, 76 Mha would come from surface water and 64 Mha from groundwater sources. The quantum of water used for irrigation by the last century was of the order of 300 km3 of surface water and 128 km3 of groundwater, total 428 km3 . The estimates indicate that by the year 2025, the water requirement for irrigation would be 561 km3 for low-demand scenario and 611 km3 for high-demand scenario. These requirements are likely to further increase to 628 km3 for low-demand scenario and 807 km3 for high-demand scenario by 2050.
The hydropower potential of India has been estimated at 84,044 MW at 60% load factor. At the time of independence, the installed capacity of hydropower projects was 508 MW. By the end of 1998, the installed hydropower capacity was about 22,000 MW. The status of hydropower development in major basins is highly uneven. According to an estimate, India has plans to develop 60,000 MW additional hydropower by the twelfth five-year plan. It includes 14,393 MW during the tenth five-year plan (2002–2007); 20,000 MW during eleventh (2007–2012) and 26,000 MW during the twelfth (2012–2017) five-year plans. A potential of the order of 10,000 MW is available for development of small hydropower projects in the Himalayan and sub-Himalayan regions of the country. Therefore, it is not only desirable but also a pressing need of time to draw a master plan for development of small, medium and large hydro-schemes for power generation.
Water requirement Rough estimates indicate that the present water use in the industrial sector is of the order of 15 km3 . The water use by thermal and nuclear power plants with installed capacities of 40,000 MW and 1500 MW (1990 figures) respectively, is estimated to be about 19 km3 . In view of shortage of water, the industries are expected to switch over to water efficient technologies. If the present rate of water use continues the water requirement for industries in 2050 would be 103 km3 ; this is likely to be nearly 81 km3 if watersaving technologies are adopted on a large scale.
Scarcity of Water
The highly variable nature of the climate makes groundwater the most popular alternative for irrigation and domestic water use across India and accounts for over 400 km3 of the annual utilizable resource in the country. This dependence on groundwater resources is particularly critical where dry season surface water levels are low or where wet season flows are too disruptive to be easily tapped. In addition to being accessible, groundwater quality is generally excellent in most areas and presents a relatively safe source of drinking water for Indians in rural and urban centers.
Agriculture remains central to the Indian economy and it therefore receives a greater share of the annual water allocation. According to the World Resources Institute (2000), 92% of India’s utilizable water is devoted to this sector, mostly in the form of irrigation. Groundwater alone accounts for 39% of the water used in agriculture and surface water use often comes at the expense of other sectors such as the industrial and domestic supply.7 Demand from the domestic sector has remained low and accounts for only 5% of the annual freshwater withdrawals in India8 .
The demand from domestic sector over the next twenty years will increase from 25 billion m3 to 52 billion m3. However, this increase in the demand from the domestic sector will not be as much as that from other sectors over the next several years.7 Currently, only 85% of the urban and 79% of the rural population has access to safe drinking water and fewer still have access to adequate sanitation facilities. Recognizing that the growing demand for water in agriculture and industries sets a pattern of water scarcity even in areas where there is sufficient water for domestic purpose, the national water policy has rightly prioritized drinking water over other uses.
However, in giving subsidies to the industrial and agriculture sectors where the water consumption is highest and allowing these sectors to use more water at negligible prices, the government has effectively contradicted its own water policy. This has resulted in mining of ground water leading to a rapidly falling water table. For example, the bottling companies of Pepsi and Coca-cola in different parts of India pay very little towards water mining and have practiced unsustainable water mining in these areas to the detriment of villagers and small farmers in the area.
Most urban areas are serviced by a municipal water distribution system. Usually, the municipal water supply originates from local reservoirs or canals, but in some cases water may be imported through inter-basin transfer. Although the major cities in India enjoy access to central water supply systems, these schemes often do not adequately cover the entire urban population and are notoriously inefficient and unreliable. In rural areas, access to water is even more precarious. Over 80% of the rural domestic water comes from groundwater sources since it is more reliable in terms of water quantity and quality. Still, in areas where water is scarce, rural women must travel long distances to wells or streams to fetch water for their daily needs.
In the past several decades, industrial production has increased in India owing to an increasingly open economy and greater emphasis on industrial development and international trade. Water consumption for this sector has consequently risen and will continue growing at a rate of 4.2% per year. According to the World Bank, demand of water for industrial, energy production and other uses will rise from 67 billion m3 to 228 billion m3 by 2025.
The United Nations has warned that by 2025 two-thirds of the world will face severe water shortages if the current pattern of water consumption continues. Water-privatization has been sought as one of the solutions to address the looming crisis.
In view of the existing status of water resources and increasing demands of water for meeting the requirements of the rapidly growing population of the country as well as the problems that are likely to arise in future, a holistic, wellplanned long-term strategy is needed for sustainable water resources management in India.
Ground Water Management
Groundwater management to protect the aquifers from overexploitation, an effective groundwater management policy oriented towards promotion of efficiency, equity and sustainability is required. Agricultural holdings in India are highly fragmented and the rural population density is large. The exploitation of groundwater resources should be regulated so as not to exceed the recharging possibilities, as well as to ensure social equity. The detrimental environmental consequences of over-exploitation of groundwater need to be effectively prevented by the Central and State Governments. Overexploitation of groundwater should be avoided, especially near the coasts to prevent ingress of seawater into freshwater aquifers .
Clearly, a joint management approach combining government administration with active people participation is a promising solution . In critically overexploited areas, bore-well drilling should be regulated till the water table attains the desired elevation. Artificial recharge measures need to be urgently implemented in these areas. Amongst the various recharge techniques, percolation tanks are least expensive in terms of initial construction costs. Many such tanks already exist but a vast majority of these structures have silted up. In such cases, cleaning of the bed of the tank will make them reusable. Promotion of participatory action in rehabilitating tanks for recharging would go a long way in augmenting groundwater supply. Due to declining water table, the cost of extraction of groundwater has been increasing over time and wells often go dry. This poses serious financial burden on farmers. Hence, special programmes need to be designed to support these farmers. Finally, the role of government will have to switch from that of a controller of groundwater development to that of a facilitator of equitable and sustainable development. Shah18 mentions that three large-scale responses to groundwater depletion in India have emerged in recent years in an uncoordinated manner, and each presents an element of what might be its coherent strategy of resources governance .
For an equitable and sustainable management of shared water resources, flexible, holistic approach of Integrated Water Resources Management (IWRM) is required, which can cater to hydrological variations in time and space and changes in socio-economic needs along with societal values. Watershed is the unit of management in IWRM, where surface water and groundwater are inextricably linked and related to land use and management.
Watershed management aims to establish a workable and efficient framework for the integrated use, regulation and development of land and water resources in a watershed for socio-economic growth. Local communities play a central role in the planning, implementation and funding of activities within participatory watershed development programmes. In these initiatives, people use their traditional knowledge, available resources, imagination and creativity to develop watershed and implement community-centered programme.
Currently, many programmes, campaigns and projects are underway in different parts of India to spread mass awareness and mobilize the general population in managing water resources. Some of these are being implemented by the Central/State Governments, while others have been taken up by various Non-Governmental Organizations (NGOs). For example, Hariyali (meaning ‘greenery’) is a watershed management project, launched by the Central Government, which aims at enabling the rural population to conserve water for drinking, irrigation, fisheries and afforestation as well as generate employment opportunities.
The project is being executed by the Gram Panchayats (village governing bodies) with people’s participation; the technical support is provided by the block (sub-district) administration. Another good example of water conservation efforts is the ‘Neeru-Meeru’ (Water and You) programme launched in May 2000 by the Government of Andhra Pradesh. During the last three years, an additional storage space of more than 18,000 lakh m 3 has been created by constructing various water-harvesting structures such as percolation tanks, dugout ponds, check dams, etc. through peoples’ participation.
Rainwater harvesting is the process to capture and store rainfall for its efficient utilization and conservation to control its runoff, evaporation and seepage. Some of the benefits of rainwater harvesting are:
· It increases water availability
· It checks the declining water table
· It is environmentally friendly
· It improves the quality of groundwater through dilution, mainly of fluoride, nitrate, and salinity, and
· It prevents soil erosion and flooding, especially in the urban areas.
Even in ancient days, people were familiar with the methods of conservation of rainwater and had practised them with success. Different methods of rainwater harvesting were developed to suit the geographical and meteorological conditions of the region in various parts of the country.
Traditional rainwater harvesting, which is still prevalent in rural areas, is done by using surface storage bodies like lakes, ponds, irrigation tanks, temple tanks, etc. For example, Kul (diversion channels) irrigation system which carries water from glaciers to villages is practised in the Spiti area of Himachal Pradesh. In the arid regions of Rajasthan, rainwater harvesting structures locally known as Kund (a covered underground tank), are constructed near the house or a village to tackle drinking water problem. In Meghalaya, Bamboo Rainwater Harvesting for tapping of stream and spring water through bamboo pipes to irrigate plantations is widely prevalent. The system is so perfected that about 18–20 litres of water entering the bamboo pipe system per minute is transported over several hundred meters.