Benefits Of Large Dams

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
• IRRIGATION
• FLOOD CONTROL
• HYDRO POWER GENERATION
• INLAND NAVIGATION
• RECREATION

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.

Recreation:

• The reservoir made possible by constructing a dam presents a beautiful view of a lake. In the areas where natural surface water is scarce or non-existent, the reservoirs are a great source of recreation.
• Alongwith other objectives, recreational benefits such as boating, swimming, fishing etc linked with lakes are also given due consideration at the planning stage to achieve all the benefits of an ideal multipurpose project.

While dams provide a yeoman service to the mankind, the following impacts of the construction of dams are required to be handled carefully:-

• Resettlement and Rehabilitation
• Environment and Forests
• Sedimentary issues
• Socio economic issues
• Safety aspects

The above problems related to the construction of dams may be resolved successfully in case the approach of management is objective, dynamic, progressive and responsive to the needs of the hour.