Is Hydropower Really Environmentally Friendly - Essay Example

Hydropower’s negative impacts on the environment are almost equal to its positive impacts, thus making its impacts on the environment a heated topic for debate. The positive and negative impacts of Three Gorges Dam on the environment will also be explored in this paper (Draper 7, 11; Honningsvag et al. 183; Moog 1; Gunkel 1). There is a possibility that fossil fuels are gradually decreasing and because the global warming is increasing due to their use, water is apparently a much cleaner source of energy.

Moreover, unlike fossil fuels, water cannot be depleted. This is because when water evaporates from oceans and lakes, it is pulled back down to earth by gravity and back into these water bodies. There are many measures that make hydropower an environmentally friendly source of energy. These include changes that are made either to the hydropower plant or the area surrounding it. Trees can be planted on the land along the banks of the water nearest to the hydropower plant, in order to prevent erosion of the soil there.

Fluctuations in the level of the water can be minimized by making sure they take place within the regulation height normally used instead of taking place between the whole maximum and minimum regulation height. This measure avoids many fishes from remaining stranded in the reservoir when the rest of them migrate to rivers or deeper water (Draper 7, 11; Honningsvag et al. 183, 204, 206). However, according to a quantitative study of several Austrian rivers, artificial fluctuations in water can have an adverse effect on the fish fauna and benthic invertebrates living in those waters.

In the investigation, the breakdown of benthic invertebrates and fish fauna was calculated throughout the length of the rivers. The results showed that between 75 and 95 percent of benthic invertebrates’ biomass was found in the first few kilometers of river length. On the other hand, a decrease of between 40 and 60 percent of benthic invertebrates’ biomass, compared with areas undisturbed by fluctuations, was found within the following 20 to 40 kilometers. When the biomass of fish fauna was detected in the same length of river, the results were similar to the ones mentioned previously.

This proves that hydropower plants can reduce the biomass of fish fauna and benthic invertebrates in the rivers that precede them (Moog 1). Another negative effect of hydropower plants, according to some new investigations, is that they do contribute to the emissions of carbon dioxide and methane, which are greenhouse gases. When reservoirs, which are part of hydropower plants, are in a eutrophic state, and trophic levels are high, anaerobic conditions are bound to occur with the emission of methane.

The pathways for the production of methane include diffuse emission through the water-air interface, foaming, and degassing in the hydropower plant’s turbines and downstream in the reservoir spillway and the initial river length. High emission rates of both carbon dioxide and methane are found particularly in shallow and tropical reservoirs. By calculating the energy density, hydropower capacity and ratio of the reservoir surface, it has been found that some reservoirs have a global warming potential that is more than that of coal use for production of energy.

This investigation questions the labeling of water as a