Risk Factors to be Considered During Dam Construction

written by: Haresh Khemani • edited by: Lamar Stonecypher • updated: 9/30/2008

The dam or water reservoir is crucial part of the hydroelectric power plants. Water stored in the dam is used for generation of electricity in the hydroelectric power plant. This article discusses the risk factors to be considered during dam construction

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    Why consider Risk Factors?

    The dam is most important and sensitive part of the hydroelectric power plants. It is here where huge quantity of water is stored and which is used for the generation of electricity. Improper chosen site for the dam and its improper construction will have devastating effects in the surrounding areas.

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    Risk Factors to be considered

    Before construction of the dam on the river, following risk factors should be considered:

    1) Risk when there is maximum quantity of water in river: Designing the dams based on the maximum water in the river during peak seasons is not sufficient. Many times due to heavy rainfall there is over excessive water in the river. During the designing of dams forces exerted by water during spate in river should be considered. One horrific instance that occurred due to floods in the river can be traced back to the year 1889 in US. Due to heavy floods a dam Johnston gave away taking toll of about 2000 people.

    2) Effect of the earthquake: This is a very important risk factor that should be considered while designing the dam. For this it is important to consider the stability of the land surrounding proposed reservoir of water. The site of the dam, and also its adjoining areas should not be prone to any earthquakes. Even a minor earthquake can destroy the whole basin of the dam.

    3) Ecological impact: When the huge structures are built in the middle of the river, there is bound to be disturbance in ecology of water. This disturbance is much more in the downstream of the river. The stagnant water in the reservoir has less oxygen content which affects the lives of fishes and other water animals. When this water is released suddenly in the downstream there is great increase in the oxygen content of water, fishes can’t sustain their lives in such atmospheres.

    The surrounding plant and animal life also depends greatly on the river. If there is change in flow of water in the river, these plants and animals are also bound to be affected.

    4) Human displacement: When a huge dam is constructed for the large hydroelectric power plants a number of families are bound to get displaced from the place where they have been living since hundreds of years and where they have been cultivating for their daily livelihood. While designing the dam, the engineers should see that there is minimum displacement of people. On the other hand, the governments and companies should ensure that the displaced people get suitable land for residing as well as for cultivation.

    During construction of Three Gorges Dam in China, the world’s largest dam, almost 1.2 to 1.9 millions of people were displaced. In India during construction of Narmada Sarovar dam, large scale protests were held and are still being held due to improper resettlement of the displaced people.

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    During the construction of the dam if above risk factors are considered and steps are taken to deal with them as per the satisfaction of all, the hydroelectric power plant project will be successful. If they are not considered the wide scale protests and devastations in future are bound to occur.

Dam in Hydroelectric Power Plants

Dam or water reservoir are the most important part of the hydroelectric power plants. Water stored in the dam carries potential energy. This series of articles covers important topics related to dams like types of dams, factors affecting selection of location for dams, risk factors with dams etc.
  1. Types of Dams in Hydroelectric Power Plants
  2. Factors Affecting the Location of Hydroelectric Power Plant Dams
  3. Risk Factors to be Considered During Dam Construction