Conservation of Water, through dam construction (With special reference to India)

Dr. Vandana Tiwari,

HOD, Department of Economics

Mata Gujri Women’s College.

Marhatal, Civic Center

JABALPUR

Conservation of Water, through dam construction ( with special refrence to India)

With only 1% of water available for human consumption, doesn't it make sense that we should treat our water supply with more respect? Water is the source of life on this planet. If you look at the earth's surface and see that 70 per cent of it is water, it may be hard to grasp that many parts of the world are suffering from a lack of this seemingly abundant resource. Of all the water present on earth 97.5% of it is not fit to drink.

Only 2.5% of water is consumable, with one third frozen in the form of glaciers and polar ice. The water left for human use is roughly 1% of the total water present. In order to fulfill the demands of consumption, the water from rainfall is collected in huge dams and is purified to make it drinkable. These filtering and detoxifying methods require sufficient funding. Because of the technological and financial resources needed to make water fit to drink, many economically challenged countries simply go without. In addition, there has been a great change in the world weather and the rainfall patterns due to global warming. This phenomenon adds to the water scarcity issue in various parts of the world.

Water conservation should not be considered an option any longer. Current circumstances require our full attention if we hope to thrive as a civilization.

The studies conducted in 2005 revealed that there has been a decrease of 7% in water consumption in households as compared with the results obtained in 2001. The main reason of this reduction in water usage is increased awareness of global warming and involvement in the going green campaigns. Another reason is a boost in green technology and the production of energy efficient appliances.

Water is essential for sustenance of all forms of life on earth. It is not evenly distributed all over the world and even its availability at the same locations is not uniform over the year. While the parts of the world, which are scarce in water, are prone to drought, other parts of the world, which are abundant in water, face a challenging job of optimally managing the available water resources. No doubt the rivers are a great gift of nature and have been playing a significant role in evolution of various civilizations, nonetheless on many occasions, rivers, at the time of floods, have been playing havoc with the life and property of the people. Management of river waters has been, therefore, one of the most prime issues under consideration. Optimal management of river water resources demands that specific plans should be evolved for various river basins which are found to be technically feasible and economically viable after carrying out extensive surveys. Since the advent of civilization, man has been constructing dams and reservoirs for storing surplus river waters available during wet periods and for utilization of the same during lean periods. The dams and reservoirs world over have been playing dual role of harnessing the river waters for accelerating socio-economic growth and mitigating the miseries of a large population of the world suffering from the vagaries of floods and droughts. Dams and reservoirs contribute significantly in fulfilling the following basic human needs: -

Water for drinking and industrial use:

Due to large variations in hydrological cycle, dams and reservoirs are required to be constructed to store water during periods of surplus water availability and conserve the same for utilization during lean periods when the water availability is scarce.

Properly designed and well-constructed dams play a great role in optimally meeting the drinking water requirements of the people.

Water stored in reservoirs is also used vastly for meeting industrial needs. Regulated flow of water from reservoirs help in diluting harmful dissolved substances in river waters during lean periods by supplementing low inflows and thus in maintaining and preserving quality of water within safe limits.

Irrigation:

Dams and reservoirs are constructed to store surplus waters during wet periods, which can be used for irrigating arid lands. One of the major benefits of dams and reservoirs is that water flows can be regulated as per agricultural requirements of the various regions over the year.

Dams and reservoirs render unforgettable services to the mankind for meeting irrigation requirements on a gigantic scale.

It is estimated that 80% of additional food production by the year 2025 would be available from the irrigation made possible by dams and reservoirs.

Dams and reservoirs are most needed for meeting irrigation requirements of developing countries, large parts of which are arid zones.There is a need for construction of more reservoir based projects despite widespread measures developed to conserve water through other improvements in irrigation technology.

Flood Control:

Floods in the rivers have been many a time playing havoc with the life and property of the people. Dams and reservoirs can be effectively used to control floods by regulating river water flows downstream the dam.

The dams are designed, constructed and operated as per a specific plan for routing floods through the basin without any damage to life and property of the people.

The water conserved by means of dams and reservoirs at the time of floods can be utilized for meeting irrigation and drinking water requirements and hydro power generation.

Hydro power generation:

Energy plays a key role for socio-economic development of a country. Hydro power provides a cheap, clean and renewable source of energy.

Hydro power is the most advanced and economically viable resource of renewable energy. Reservoir based hydroelectric projects provide much needed peaking power to the grid. Unlike thermal power stations, hydro power stations have fewer technical constraints and the hydro machines are capable of quick start and taking instantaneous load variations.

While large hydro potentials can be exploited through mega hydroelectric projects for meeting power needs on regional or national basis, small hydro potentials can be exploited through mini/micro hydel projects for meeting local power needs of small areas. Besides hydro power generation, multi purpose hydroelectric projects have the benefit of meeting irrigation and drinking water requirements and controlling floods etc.

Inland navigation:

Enhanced inland navigation is a result of comprehensive basin planning and development, utilizing dams, locks and reservoirs that are regulated to play a vital role in realizing large economic benefits of national importance.

Conclusion:

One-third of the developing world will face severe water shortages in the twenty-first century even though large amounts of water will continue to annually flood out to sea from water-scarce regions. The problem is that the sporadic, spatial and temporal distribution of precipitation rarely coincides with demand. Whether the demand is for natural processes or human needs, the only way water supply can match demand is through storage.

There are four major ways of storing water—

in the soil profile,

in underground aquifers,

in small reservoirs, and

in large reservoirs behind large dams.

Water Scarcity and the Role of Storage in Development

By 2025, one-third of the population of the developing world will face severe water shortages. Yet, even in many water scarce regions; large amounts of water annually flood out to the sea. Some of this floodwater is committed flow to flush salt and other harmful products out of the system and to maintain the ecological aspects of estuaries and coastal areas. However, in many cases, the floodwater is not fully utilized; and, of course, the floods themselves can do a great deal of harm. This problem is epitomized in India, where annual precipitation is concentrated in the 4 months of the monsoon, and then in only a few hours of these months. Because of the sporadic spatial and temporal distribution of precipitation, the only way water supply can be controlled to match demand is through storage.

On the land, surface water is stored in watercourses, lakes, and other water bodies and in frozen form as snow and ice. Man can create and enhance water storage by such activities as water conservation tillage, constructing dams and dikes to impound water, and artificially recharging groundwater. Regardless of the method or type of storage, the purpose is to capture water when and where its marginal value is low—or, as in the case of floods, even negative—and reallocate it to times and places where its marginal value is high. Here, “marginal value” includes all of the economic, social, and environmental values of water.

India is sometimes referred to as the "Land of Rivers". The multitude of tributaries and the close binding of Indian civilization and culture to the local rivers is the reason for this characterization. The Indian River Systems can be divided into four categories – the Himalayan, the rivers traversing the Deccan Plateau, the Coastal and those in the inland drainage basin. The Himalayan Rivers are perennial as they are fed by melting glaciers every summer. During the monsoon, these rivers assume alarming proportions. Swollen with rainwater, they often inundate villages and towns in their path. India has an annual precipitation of 1140 mm/year, which translates into 400 million hectare meters (mham) of water availability in the country. Out of 400 mham, 70mham is lost to the atmosphere through evaporation, 215 mham recharges the Ground Water, while 115 mham flows as a surface run-off. However the actual surface runoff is 180 mham. As some water comes from Nepal, Tibet etc. These streams which come from catchments areas of other countries feeds the country’s water resources to an extent of 20 mham, while 45 mham is obtained by Ground Water regeneration. Out of 180 mham, 70.2 mham is the utilizable flow. A list of important rivers of India are Beas, Bhagirathi, Brahmaputra, Cauvery (Kaveri) , Chambal, Ganga (Ganges) Godavari, Gomati, Indus, Jhelum, Krishna, Kali, Mandovi,  Narmada,  Periyar,  Ravi,  Sharavati, Sutlej, Tapti, Tungabhadra, Yamuna .

Conclusion

Theses record illustrates that India can be the largest manufacturer of dam, If Government emphasis on it at priority basis. A dam is a barrier that impounds water or underground streams. India having maximum rivers and good rainfall lack dam construction, list of largest dams in world is enclosed, in which no Indian dam exists. The datas show that Dams generally serve the primary purpose of retaining water, while other structures such as floodgates or levees (also known as dikes) are used to manage or prevent water flow into specific land regions. Hydropower and pumped-storage hydroelectricity are often used in conjunction with dams to generate electricity. A dam can also be used to collect water or for storage of water which can be evenly distributed between locations. After independence we have made lots of progress in Dam and Water Reservoirs, Now India is one of the world’s most prolific dam-builders. Around 4300 large dams already constructed and many more in the pipeline, Almost half of which are more than twenty years old.

  The dam benefits human society in several ways such as: agriculture, water, damage prevention and power generation, it also benefits nature and wildlife (especially fish and rare species), impact on the geology of an area - whether the change to water flow and levels will increase. Reservoirs held behind dams affect many ecological aspects of a river. Rivers topography and dynamics depend on a wide range of flows whilst rivers below dams often experience long periods of very stable flow conditions or saw tooth flow patterns caused by releases followed by no releases. The impact of dam on human society is also significant; they get water source, electricity and opportunities of employment in the region of dam establishment.

Refrences:

Agarwal, Anil; and Sunita Narain (Eds.). 1997. Dying wisdom: Rise, fall and potential of India’s traditional water

Babbitt, Bruce. 1998. Dams are not forever. Remarks of the Secretary of the United States Department of Interior to

the Ecological Society of America, August 4, 1998, Baltimore, MD, USA. Speech available at

http://www.doi.gov/secretary/ecologic.htm.

Chambers, Robert. 1988. Managing Canal Irrigation. Oxford, England and New Delhi, India: Oxford & IBH Publishing

Company Pvt. Ltd.

Gleick, Peter (editor). 1993. Water in crisis: A guide to the world’s fresh water resources. Oxford, England: Oxford University Press.

Gleick, Peter. 1998. The world’s water 1998-1999: The biennial report on freshwater resources. Washington, D.C.,USA: Island Press.

http://genepi.louis-jean.com/cigb/chartean.html. International Commission on Large Dams.

Journal of Applied Irrigation Science, Volume 33, No. 2, October 1998, Frankfurt, Germany.

Agrawal and Narain 1997

http:www.benefits-of-recycling.com