Hydroelectric Dams have disadvantages which are quite different from those of other forms of renewable energy like solar, wind, geothermal or nuclear energy. Hydro Power in small sizes which is constructed keeping nature in mind has almost no drawbacks, however the big Hydro Power Dams have some sizable problems. Some of these are tail risks with enormous risks such as earthquakes which can cause massive destruction. Though there has been no concrete evidence that massive hdyro dams result in seismic activity, studies have indicated that the correlation exists between massive hydro projects and earthquakes .Note most of these cons can be corrected but are not done so in the interests of massive investments and development of the economy. Note the disadvantages of hydroelectricity has been overcome by the massive benefits of hydel power resulting in the massive capacity building of hydro power globally particularly in China.

Disadvantages of Hydroelectricity

1) Environmental, Dislocation and Tribal Rights – Large Dam construction especially in populated areas leads to massive Tribal Displacement, Loss of Livelihood and Religious Infringement as potentially sacred Land is occupied by the Government.

2) Wildlife and Fishes get Affected – The Fishes are the most affected species from Dam Construction as the normal flow of the river is completely changed form its river character to a lake one. Submergence of land also leads to ecological destruction of the habitat of land based wildlife.

3) Earthquake Vulnerability – Large Dam Construction has been linked to increased propensity of Earthquakes. Massive Earthquakes in China and Uttarakhand in India were linked to the building of Massive Dams in these countries.

4) Siltation When water flows it has the ability to transport particles heavier than itself downstream. This has a negative effect on dams and subsequently their power stations, particularly those on rivers or within catchment areas with high siltation.

5) Tail Risk,Dam Failure – Because large conventional dammed-hydro facilities hold back large volumes of water, a failure due to poor construction, terrorism, or other cause can be catastrophic to downriver settlements and infrastructure. Dam failures have been some of the largest man-made disasters in history. The Banqiao Dam failure in Southern China directly resulted in the deaths of 26,000 people, and another 145,000 from epidemics.

6) Cannot be Built Anywhere – This disadvantage of Hdyro Energy is present with other forms of Energy as well. Some forms of Energy are just better suited to some places. For example you can’t build a nuclear plant on top of an earthquake prone region, you can not build a wind farm near the Dead Sea etc. Hydro Energy can only be built in particular places though enough of those places exist globally.

7) Long Gestation Time – The time to construct a large hydro power project can take between 5-10 years which leads to time and cost overruns.

Summary

Hydroelectricity because of large Dam construction can have massive risks if not designed and maintained well. It also leads to ecological damage and affect human rights which any large industrial project entails. Large Dam construction is being opposed heavily in many of the developing countries where human rights is not given enough weight. However hydroelectricity is very useful, non polluting source of energy if designed and constructed appropriately.

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