Argumentative Essay Draft

Individual Analysis of Dams

Dam construction and use has been a controversial issue for decades due to the environmental effects of dams. Some individuals see the negative environmental effects of dams and call for the complete removal of dams. Others will see the positive environmental effects of dams and call the negatives unimportant, so dam use and construction should remain or even increase. However, the truth lies in-between these viewpoints. Dams are beneficial assets to human life, but should only be built and maintained if they are also designed to not be environmental liabilities through the equal distribution of water and sediments, the proper preparations for reservoirs, care for surrounding life, and the installation of hydroelectric capabilities.

The argument that all dams need to be removed is incorrect. The positive environmental effects of dams need to be maintained. Dams minimize the chances of floods occurring by controlling the flow of water. The control of water flow also allows for the continued availability of water during times of drought (Yuksel 103). Without the use of dams, the lives of animals, vegetation, and humans would be in danger from flooding and drought. Some dams provide for hydroelectric power. Hydroelectric dams produce electricity with few emissions and use water a renewable energy source (Yuksel 103). As far as renewable energy is concerning, hydroelectric dams produce nearly half of the renewable energy generated in the United States (Atkins). If dams were to be removed, the efforts for less pollution and use of renewable energy sources would be gravely damaged. Simply removing dams is not the answer.

So, all dams should be maintained and countless more should be built right? That is also incorrect. Dams bring with them numerous negative environmental effects that need to be fixed. To start with, there needs to be an equal distribution of water and sediments both above and below dams. When dams control the flow of water, water sometimes ends up being unable to reach the mouth of the river. The area around the mouth becomes starved of water and dries up. Any vegetation, animals, and humans dependent on that water will either have to migrate or die. This area will change to appear more like a desert as the former ecosystem is lost. Sediments are also unequal distributed by dams. As the sediments move down river, dams block the majority of them from moving below the dam. As a result, the reservoir or lake created by the blocking of water above the dam ends up with a large amount of sediments. These sediments become trapped on the bottom of the reservoir and actually decrease the amount of water the reservoir can hold (McCartney 125). This decrease in carrying capacity will allow less water for use by humans for consumption and irrigation purposes. As another result, “Downstream of a dam, reduction in sediment load in rivers can result in increased erosion of riverbanks and beds, loss of floodplains (through erosion and decreased over-bank accretion) and degradation of coastal deltas.” (McCartney 125) So, erosion occurs below dams causing the loss of land surrounding the rivers. This erosion can also lead to landslides as has been predicted with the Three Gorges Dam (Yardley 1). These landslides will then endanger additional vegetation and animal life.

There are solutions to allow for a more equal distribution of water and sediments. The water flow of a dam can be accelerated at times to almost create artificial floods (McCartney 130-131). These times of increased water flow will also allow additional sediments from the reservoir to move downstream. It can also allow water to reach the mouth of the river. Sediments can also be transported and placed along the riverbed past dams in order to control some of the erosion (McCartney 130-131). It is always important to make sure that the flow of water through a dam is enough to allow for the continuation of live down river.

The reservoirs created additional problems of their own. When dams are created, they block a large amount of water that turns into the reservoir. As the reservoir fills, it floods land that was previous home to a diverse group of animals and vegetation. Land is in itself a limited resource when compared to the growing, large population of humans and the vastness of oceans. Reservoirs have flooded approximately 248.548 square miles of land globally (McCully). The use of dams needs to be monitored as they are taking away large portions of land. Reservoirs take away vegetation-rich land and kill or displace a diverse group of animals. It can be hypothesized that a large percent of animals have gone extinct due to the loss of homes and lives by dams and reservoirs (McCully). Humans also end up displaced when reservoirs are created on land that used to hold their homes. The rapid filling of a reservoir can also lead to “a major earthquake induced by pressure from the rising water” (Yardley 3).

There are solutions to minimize some of the effects of reservoirs. One of the solutions is to transport animals and vegetation before the filling of a reservoir begins (McCartney 130-131). This group of vegetation and animals could be moved to a similar ecosystem to the one about to be flooded and thus greatly increase their chances of survival. A proper analysis of the effects of creating a reservoir within a particular ecosystem needs to also be completed. The land needs to be reviewed for its diversity of life, amount of life, and overall rarity of land and life. If the land is found to hold a percentage of any of these, the reservoir should not be created as the environmental effects would be too great. The need for a dam can be offset by the proper management of water for consumption and irrigation within the nearby community (WWF).

Dams also create additional issues for animals. Dams greatly disrupt the migration of fish. Fish end up either being unable to make it through the reservoir to move downstream or past the lower walls of the dam to move upstream. Some fish can thrive in the lake-like reservoir while others are too accustom to a river system and therefore cannot survive (McCartney 128). Overall, the majority of these fish cannot survive in a reservoir (McCully).

As stated by Matthew McCartney, “Downstream of dams, marked changes in fish populations occur as a consequence of blockage of migration routes, disconnection of the river and floodplain, and changes in flow regime, physiochemical conditions (e.g. temperature, turbidity and dissolved oxygen), primary production and channel morphology. These changes may benefit some species but they generally have an adverse effect on the majority of native species.” (8)

As a result, the fish populations all around the dams are negatively impacted by the environmental effects of dams.

Land-based animals also suffer from the loss of migration paths. As land-based animals are unable to move past a dam, they grow more dependent on the immediate environment. They must eat more of the surrounding fish, damaging the fish population even further. Any edible vegetation will also be greatly decreased. The lack of mates will cause inbreeding to occur among the land-based animals (McCully). The resulting mutations from inbreeding can be disastrous to the future populations of the particular animals. The predator animals can also greatly wipe out the more prey-like animals due to the constricted environment.

Solutions to the hindering of migration patterns can be used to end these horrendous problems. A ladder system can be placed on dams in order to transport fish above and below dams safely (McCartney 130-131). Routes around dams can also be created to allow land-based animals to easily move past dams (McCartney 130-131). Similar routes can also be created to aid fish in movement past dams (McCartney 130-131). These solutions are important to use with dams in order to allow the continued health and safety of animals.

Although an overall positive environmental effect of dams, hydroelectric power generation also has an issue. The issue is a lack of usage. Only about three percent of the dams in the United States are equipment with hydroelectric capabilities (Atkins). Hydroelectric power generation is a large positive of dams. If a dam is not generating hydroelectric power and the need for water in nearby communities is not great, then I do not see a reason for keeping the dam unless it is modified to generate electricity. So, the solution is to increase the use of hydroelectric capabilities on dams. It has been found that some 64 dams in the United States can be modified to become hydroelectric dams (Myron 14).

My main argument is that all of these problems need to be assessed on a case by case basis with dams. If the problems are found to be too large or the benefits are found to be too little, then the dam should be either torn down or never built. For example, four dams in Washington have been proposed to be removed because of the negative effects they are having on Salmon (Lovett 574). In this situation the negative environmental effects on fish have been found to be too severe even though the dams also produce hydroelectricity. Cases concerning the loss of land have been very heated in the past. There was an attempt to flood part of the Grand Canyon, but the public stopped it from taking place (Anderson). In India, dam construction was halted because of “an uninhabited, biologically-rich tropical rain forest, one of the last remnants of its kind in the country” would have been lost (Krishna 217). The side for the maintenance of land is not also as strong in every case though. The Hetch Hetchy Dam was constructed in order to provide humans with water even though there was an outcry for the maintenance of the beautiful land (Wood). The negatives environmental effects of dams cannot just be ignored because of the presence of some positive environmental effects like the availability of water. However, the positive environment effects and the impact on surrounding humans also cannot be ignored when arguing for the complete removal of dams. With any dam though, every step possible must be used to minimize the described negative environmental effects and insure the positive environmental effects. Both sides must be used together to determine the need and environmental effect of dams.

The building and maintenance of dams needs to be determined on an individual basis by taking into account the positive environmental effects and taking the necessary steps for the equal distribution of water and sediments, the proper preparations for reservoirs, the care of surrounding life, and the installation of hydroelectric capabilities. If these things are not taken into consideration the dam should not be built or maintained. However, if they are taken into consideration, the dam can continue to function.

References

Anderson, Faye. “Environmental Movement, Role of Water in The.” Water Encyclopedia. Water Encyclopedia, Mon 1 Mar 2010. http://www.waterencyclopedia.com/Da-En/Environmental-Movement-Role-of-Water-in-the.html.

Atkins, William Arthur. “Hydroelectric Power.” Water Encyclopedia. Water Encyclopedia, Mon 1 Mar 2010. http://www.waterencyclopedia.com/Ge-Hy/Hydroelectric-Power.html.

Krishna, Sumi. Environmental Politics: People’s Lives and Development Choices. California: Sage Publications, 1996, Print.

Lovett, Richard. “As Salmon Stage Disappearing Act, Dams May Too.” Science, New Series, Vol. 284, No. 5414 (Apr. 23, 1999), pp. 574-575. American Association for the Advancement of Science. http://www.jstor.org/stable/2897908.

McCartney, Matthew. "Living with dams: managing the environmental impacts." Water Policy 11.s1 (2009), 121-139.

McCully, Patrick. "Rivers No More: The Environmental Effects of Large Dams." International Rivers. International Rivers, Web. 1 Feb 2010. http://www.internationalrivers.org/en/node/1636

Myron, Levin. "INNOVATE: CLEAN POWER THAT'S EASY ON THE ENVIRONMENT." Sierra 95.1 (2010), 14-14.

Yardley, Jim. “Chinese Dam Projects Criticized for Their Human Costs." New York Times November 19, 2007: 1-5. Web. 1 Feb 2010. http://www.nytimes.com/2007/11/19/world/asia/19dam.html.

Yuksel, I. "Dams and Hydropower for Sustainable Development." Energy Sources Part B Economics Planning and Policy 4.1 (2009), 100-110.

Wood, Harold. “Hetch Hetchy, Time to Redeem a Historical Mistake.” Sierra Club. Sierra Club, Mon. 1 Mar 2010. http://www.sierraclub.org/ca/hetchhetchy/.

WWF, . "Dams Initiative." WWF for a living planet. Web. 22 Feb 2010. http://www.panda.org/what_we_do/footprint/water/dams_initiative/dams/agriculture/.