Economic value of Water: Water provides goods (e.g. drinking-water, irrigation water) and services (e.g. hydroelectricity generation, recreation and amenity) that are utilized by agriculture, industry and households. Provision of many of these goods and services is interrelated, determined by the quantity and quality of available water. Management and allocation of water entails consideration of its unique characteristics as a resource. These are discussed in brief below. Water used for irrigation can be pumped from reserves of groundwater, or abstracted from rivers or bodies of stored surface water. It is applied to crops by flooding, via channels, as a spray or drips from nozzles. Crops also obtain water from precipitation. Water infiltrates into the soil, evaporates, or runs off as surface water. Of the water that infiltrates the soil, some is taken up by plants (and later lost through transpiration) and some percolates more deeply, recharging groundwater. This water can be polluted with agrochemicals (fertilizers, herbicides and pesticides), with salts leached from the soil and with effluent from animal waste. However, pollution can be attenuated as the water moves through the ground by processes that include sorption, ion exchange, filtration, precipitation and biodegradation. Aquifers can also be sources of pollution. Pollutants can be released into groundwater from pockets of contaminants or natural materials (e.g. sources of fluoride) within the aquifer. When river levels are low and groundwater levels are high, groundwater can recharge the levels of surface water, which creates a two-way linkage between resources of surface and groundwater. It is not easy to control or prevent water use. Many uses of water involve the withdrawal of water from the hydrological system (known as 'extractive' or 'off-stream' use). Typically, only a small proportion of the water withdrawn is consumed. Water consumption is exclusive in its use. Consumed water is retained in plants, animals, or industrial products, so it is not available for other uses. However, most of the water withdrawn is not consumed and it returns to the water system for reuse at a later time and a different location. Water in return flows can reenter the surface water system further downstream, can percolate into aquifers, or evaporate, returning to the hydrological system in gaseous form. Therefore, water withdrawals are not exclusive within a broad perspective on water use, but only within a narrow location- and time-specific context. Water can also be used in-stream without removal from the hydrological system (e.g. in hydroelectric power generation or boating). Such uses generally entail little or no consumption of water but do affect the location and time at which water is available for consumption by other uses (Young, 1996). Water is a 'bulky' resource. This means that its economic value per unit weight or volume tends to be relatively low. Therefore, its conveyance entails a high cost per unit of volume and is often not economically viable over long distances unless a high marginal value can be obtained. The costs of abstraction, storage and any conveyance tend to be high relative to the low economic value that is placed on the use of an additional unit of water. This can create values for water that are location specific (Young, 1996). A further characteristic of water is that the quantity of supply cannot be readily specified; it is determined by various processes: the flow of water; evaporation from the surface; and percolation into the ground. In the case of surface water, supply is determined largely by the climate. Consequently, the quantity supplied is variable and can be unreliable. This can preclude certain uses of water (e.g. the development of water-dependent industries) and affect the value of water in some uses (e.g. irrigation). The quality of water (i.e. the nature and concentrations of pollutants) can exclude certain uses (e.g. drinking-water for household use), but have no impact on others (e.g. hydroelectric power generation). Characteristics of demand for water for irrigation relate to quantity, location, timing and quality. Irrigation generally requires large volumes of water, which can be low in quality. This is in contrast to household use of water, for example, which requires low quantities of water of high quality. The large volumes of water required for irrigation usually have to be transported over some distance to the field. For surface water, canals and pipes can enable conveyance; in the case of groundwater, extraction is provided via tubewells. In terms of timing, demand for irrigation water can extend through the growing season and, where adequate supplies are available, extend into the dry season for multiple cropping. Peak demand for irrigation water does not usually coincide with peak flows of surface water.

This creates the need for storage capacity, which naturally occurring waterbodies (lakes, wetlands and aquifers) or specially constructed dams may provide. Although the quality of water required for irrigation is low, high levels of salinity preclude its use for irrigation, and contaminated supplies can reduce the quality of produce (e.g. contamination of horticultural produce with pathogens in polluted water supplies). Agriculture is implicated in issues that concern water quality. Leaching of effluent from animal wastes, especially from intensive livestock production, can pose a serious water pollution risk. Both return flows of irrigation water and precipitation runoff from arable land can pollute surface water with nutrients, herbicides, pesticides, salts leached from the soil, and sediment. Irrigation is a vital component of agricultural production in many developing countries. In 1997-99, irrigated land provided two-fifths of crop production in developing countries, and accounted for about one-fifth of the cultivated area. The divergence in these statistics reflects the high crop yields and multiple cropping that are achieved through irrigation (FAO, 2002a). Developing countries are particularly dependent on irrigation: in 1997-99, 59 percent of cereal production in developing countries was irrigated (Bruinsma, 2003). Food production in developing countries is increasing in response to the demands of an expanding population and rising prosperity. Some of this demand will be met by increased productivity of rainfed agriculture, some by increased imports, but irrigated agriculture will be a major contributor.

Agriculture is the largest user of water in all regions of the world except Europe and North America (FAO, 2002b). In 2000, agriculture accounted for 70 percent of water withdrawals and 93 percent of water consumption worldwide, where consumption refers to withdrawals net of returns flows and evaporation (Figure 1). This is in contrast to industry, which accounted for 20 percent of withdrawals and 4 percent of consumption worldwide in 2000, and household use, which accounted for 10 percent of withdrawals and 3 percent of consumption (FAO 2004 (AQUASTAT-database) FAO, 2002b). The water requirements of agriculture are large relative to water requirements for other human needs. The human body needs about 3 litres of water per day;

For domestic uses people use approximately 30 - 300 litres of water per person per day;

To grow their daily food needs people require 3000 litres of water per person per day. (FAO 2003)

FIGURE 1 Water withdrawals and consumption

Demand for water in India: The forecast of a below normal monsoon for the second consecutive year has brought the focus on the perilous state of water resources in the country, but India’s water crisis has been in the making for a long time. The rapid growth of population and its growing needs has meant that per capita availability of fresh water has declined sharply from 3,000 cubic metres to 1,123 cubic metres over the past 50 years. The global average is 6,000 cubic metres. As water demand is expected to rise further, the future does not appear rosy. The pace of growth in demand halves between 2025 and 2050, but remains high enough to outstrip supply. Unit is billion cubic metre

The forecast of a below normal monsoon for the second consecutive year has brought the focus on the perilous state of water resources in the country, but India’s water crisis has been in the making for a long time. The rapid growth of population and its growing needs has meant that per capita availability of fresh water has declined sharply from 3,000 cubic metres to 1,123 cubic metres over the past 50 years. The global average is 6,000 cubic metres. As water demand is expected to rise further, the future does not appear rosy. Future projection The demand supply mismatch is more severe in certain areas. In urban areas, where the demand of 135 litres per capita daily (lpcd) is more than three times the rural demand of 40 lpcd, the scarcity assumes menacing proportions. Already, Delhi and Chennai are fed with supply lines stretching hundreds of kilometres. According to projections by the UN, India’s urban population is expected to rise to 50% of the total population by 2050. This would mean 840 million people in the most water-starved parts of the country compared with 320 million today. The issue of inequity in water availability has already proved to be fertile ground for several inter-state and intra-state disputes, and unless mitigating steps are taken now, these conflicts would only escalate. By 2050, energy generation is set to assume a much larger proportion of water usage. This should further nudge India towards renewable resources since thermal power plants are highly water-intensive and currently account for maximum water usage among all industrial applications. In order to match rapidly increasing demand, India needs to make judicious use of its two sources of fresh water — surface water and groundwater. Surface water — with rivers as its main source — is being relentlessly utilised through dams. These dams have robbed some rivers of their usual water flow, while diverting the course of others. As much as 55% of India’s total water supply comes from groundwater resources, which is also a cause of concern. Unbridled exploitation by farmers has led groundwater levels to plummet dangerously across large swathes of the countryside. Groundwater is critical to India’s water security. Irrigation, of which over 60% comes from groundwater, takes up over 80% of total water usage in India. Besides, nearly 30% of urban water supply and 70% of rural water supply comes from groundwater. Global Water Scarcity: Water scarcity is the lack of sufficient available water resources to meet water needs within a region. It affects every continent and around 2.8 billion people around the world at least one month out of every year. More than 1.2 billion people lack access to clean drinking water.[1] Water scarcity involves water shortage, water stress or deficits, and water crisis. The relatively new concept of water stress is difficulty in obtaining sources of fresh water for use during a period of time; it may result in further depletion and deterioration of available water resources.[2] Water shortages may be caused by climate change, such as altered weather-patterns (including droughts or floods), increased pollution, and increased human demand and overuse of water.[3] The term water crisis labels a situation where the available potable, unpolluted water within a region is less than that region's demand.[4] Two converging phenomena drive water scarcity: growing freshwater use and depletion of usable freshwater resources.[5] Water scarcity can result from two mechanisms:

physical (absolute) water scarcity economic water scarcity

Physical water scarcity results from inadequate natural water resources to supply a region's demand, and economic water scarcity results from poor management of the sufficient available water resources. According to the United Nations Development Programme, the latter is found more often to be the cause of countries or regions experiencing water scarcity, as most countries or regions have enough water to meet household, industrial, agricultural, and environmental needs, but lack the means to provide it in an accessible manner.[6] Many countries and governments aim to reduce water scarcity. The UN recognizes the importance of reducing the number of people without sustainable access to clean water and sanitation. The Millennium Development Goals within the United Nations Millennium

Declaration aimed by 2015 to "halve the proportion of people who are unable to reach or to afford safe drinking water.

Water stress: The United Nations (UN) estimates that, of 1.4 billion cubic kilometers (1 quadrillion acre-feet) of water on Earth, just 200,000 cubic kilometers (162.1 billion acre-feet) represent fresh water available for human consumption.[9] More than one in every six people in the world is water stressed, meaning that they do not have access to potable water.[6] Those that are water stressed make up 1.1 billion people in the world and are living in developing countries. According to the Falkenmark Water Stress Indicator,[10] a country or region is said to experience "water stress" when annual water supplies drop below 1,700 cubic metres per person per year. At levels between 1,700 and 1,000 cubic meters per person per year, periodic or limited water shortages can be expected. When a country is below 1,000 cubic meters per person per year, the country then faces water scarcity . In 2006, about 700 million people in 43 countries were living below the 1,700 cubic metres per person threshold.[6] Water stress is ever intensifying in regions such as China, India, and Sub-Saharan Africa, which contains the largest number of water stressed countries of any region with almost one fourth of the population living in a water stressed country.[6] The world's most water stressed region is the Middle East with averages of 1,200 cubic metres of water per person.[6] In China, more than 538 million people are living in a water-stressed region. Much of the water stressed population currently live in river basins where the usage of water resources greatly exceed the renewal of the water source. Water Scarcity in India: Water resources in India are increasingly becoming scarce. Since rainfall occurs only for three months in a few spells, storage by dams is imperative to utilize waters. On account of topographic limitations, ultimate storage capacity is only 16% of average annual flows and utilizable water is only 38% of the available total. The Indian economy is predominantly agricultural. Irrigation and power have brought self‐reliance in food production and economic prosperity but with an increasing population, demands for water are rising fast. By 2025, all utilizable waters will be consumed. This article presents the existing and future scenarios, answers criticisms and brings out the inevitable necessity of major dams.

Water scarcity involves water stress, water shortage or deficits, and water crisis. This may be due to both natural and human factors. But, many reports suggest that the scarcity is more due to the human factor than anything – such as industrialization, irrigation, domestic use, etc. The acute water shortage prevailing in the forest areas of Tamil Nadu's districts of Madurai and Dindigul has led to the deaths of Indian gaurs found in the forest of the region, as they come in search of water are killed falling into the wells.With support from government and UNICEF, villagers in Palve Budruk, located in the drought-prone Parner Block in Ahmednagar district of Maharashtra, developed a catchment plan covering

1,400 hectors – over 80% of the land available. The system has three check dams, 20 canal bunds, two small percolation tanks linked to the main tank and 19 village ponds. Water stored in the percolation tank, is strictly meant for domestic use only. Piped water is supplied for an hour a day in the morning, during which time families fill up water for drinking and cooking.

The Central Ground Water Authority (CGWA) has notified 82 areas (Districts, Blocks, Mandals, Talukas, Municipalities) for regulation of ground water development.[4] In these areas, installation of new ground water abstraction structures is not permitted without prior specific approval of the Authority / Authorized officer. Moreover, proposals for setting up/expansion of ground water based industries including bottled water manufacturing units are forwarded by State Pollution Control Boards and Bureau of Indian Standards to CGWA for seeking No Objection Certificate (NOC) for ground water withdrawal. NOC is not accorded to such industries including bottled water manufacturing units proposed to be located in areas notified by the Authority. In non-notified areas, NOC is issued with mandatory pre-conditions of adoption of rain water harvesting system, monitoring of ground water abstraction as well as monitoring of ground water level and quality etc. by the industry. For enforcement of the regulatory directions issued under Section 5 of Environment (Protection) Act, 1986, concerned Deputy Commissioners/District Collectors have been authorized to take necessary action in case of violations of directives of CGWA in the notified areas.

Rainwater harvesting – Rain water is accumulated and used for ground water recharge. This increases the ground water availability.[5]

Farm pond – Farm ponds are constructed near the farming field. The rain water which runs off the ground are collected by these ponds. These ponds helps agriculture in dry lands.[6][7]

Sources: Google.