Dams have been a large point of controversy in the past few decades. The main two sides that seem to have developed involve those that mainly support human development and those that are advocates for the environment. It is a fact that dams have some positive effects and throughout history have made some arid climates in the USA and across the globe possible to sustain human life (Altinbilek). It was once the popular view that dams were a modern marvel with only positive benefits, with the human race chiefly in mind. This can be witnessed under Roosevelt’s New Deal and the creation of the Public Works Administration that built a number of dams across the nation in an attempt to pull the USA out of the Great Depression. In Deep Water Jacques Leslie describes the Hoover Dam, completed in 1935, as “America’s Great Pyramid” that “transformed the West” (Leslie 3).  The jobs produced by building the dams helped pull the United States out of the Depression, but most importantly solidified the “American belief in technology, the extraordinary assumption that it above all will redeem our sins” (Leslie 4). Essentially, dams became a way for America to harness nature for its own benefit, and this movement began to spread against the globe. Despite this, as history progressed the passage of time yielded the negative effects that dams have. Within the past couple decades, the popular opinion towards dams has become increasingly opposing. Scientific and cultural studies of the areas surrounding dams began to show the negative environmental impacts that dams have and even on the people in the surrounding area. As a result, this has caused many to consider if the positive effects of dams actually outweigh the negatives. Dams have both positive and negative effects on the areas surrounding them. Despite their positive effects, dams have been shown to be predominately negative based on their effects on river life, weather, and the people in the area.

C.J.A. Binnie of The British Dam Society discusses how dams have had a positive impact throughout history; however, there is a flaw in his thinking. He discusses how dams have improved health and life using the reservoirs it creates as clean water (Binnie). They have also been a protection from drowning and flooding, using the dams for power, using water for irrigation, and the reservoir can also have recreation and environmental benefits (Binnie). Though dams in developed countries have come under fire for their environmental impacts, they were once a necessity for development and still provide flood protection, water for irrigation, and power for surrounding areas (Binnie). Binnie claims they simply cannot be taken away (Binnie). Additionally, many underdeveloped countries are still having dams built in some arid climates in order to have a constant supply of clean water. Binnie claims that they may have some negative environmental impacts, but in many instances they seem to be a necessity. Despite this, dams are only a temporary fix. Dams have become overall irrelevant as their negative effects on river life, the weather, and displaced peoples make the negatives outweigh the positives. Though dams may be able to help certain underdeveloped countries they would begin having a negative impact on the surrounding area. Essentially, the positive effects are not worth the negative effects. The dams would eventually destroy the ecological affects and displace the already suffering people in the area. An extreme effect that dams have been seen to cause are dangerous weather. 

A study done by Hyeongsik Kang examines how dams can affect the physical elements of the area around, the vegetation elements in the area, and the habitat elements in an area. An assessment model was made for these factors and applied to the Yeongju Dam in the Nakdong River basin in Korea (Kang). It was estimated that the overall ecological value of the region decreased by 10% after the building of the dam (Kang). The purpose of this was to develop better ways of planning restoration in dam reservoirs (Kang). One of Kang’s sources focuses on using an ecological network model in order to find quantity based information about the effects of building a dam from an unattached perspective (Shaoqing). It makes sense for the original source to use this as a citation. The original source most likely used it in order to get a better sense of making an appropriate model for assessing the impact of dams. As the source’s source is focused on evaluating dams from a holistic perspective then the original source could have used it in order to help eliminate bias in their model and to focus on the correct factors. This is important as it shows that actual intense studies have been done to assess the impacts that dams have on the environment. 

A study was conducted comparing the presence of dams to the biological measures of river health in the Loire River Basin. River health was evaluated metrics of density of ecological guilds, taxonomic richness and life history traits, hydromorphology, and catchment characteristics (Looy). It was found that overall river health upstream was drastically better than that downstream from the dam, and there was a larger presence of biological organisms (Looy). One major negative effect of dams is that they hinder the flow of nutrient sediment downstream. Usually as a river flows it deposits nutrient rich sediment upon the river banks. The deposited nutrients have allowed life to thrive and farming upon the banks of rivers even in arid climates. An example of this is the banks and delta of the Nile River in Egypt, which supported life in the middle of a desert. When a dam is thrown into the equation the sediment intended to flow downstream cannot pass the dam and remains in the reservoir. In fact, if Hoover dam can withstand 1,100 years then its reservoir, Lake Mead, will be “filled with sediment” which will result in “turning the dam into an expensive waterfall” (Leslie 4). Due to the better health of the river system upstream from the dam the evidence seems to support the theory that dams have a negative impact.

River life is the most negatively impacted by dams. Similar to how dams block nutrient rich sediment from flowing downstream, dams become an almost unsurmountable blockade for fish that migrate. This can be seen through a study done on Puerto Rican dams. In Puerto Rico 335 dams were observed that block the migration of fish to 74.5% of upstream regions (Cooney). They also observed the occupancy of migratory fish in 118 river reaches (Cooney). A type of fish known as Gobies have actually obtained the ability to climb (Cooney). It was found that it takes a 12 meter barrier to restrict gobies and a 32 meter barrier to destroy the population in the region (Cooney). Fish incapable of “climbing” are restricted by a 2 meter tall barrier and completely wiped out by a 4 meter barrier (Cooney). Even the smallest of dams can destroy entire fish populations. The findings show how dams can wipe out migratory fish populations and that development strategies should be changed. Aquatic life are not the only organisms horribly affected by dams. In fact, the human species that builds dams for their gain suffer negative effects. 

Anne Minard explains how dams have allowed cities to be established in areas once impossible; however, she mainly concentrates on how dams have displaced 472 million poor people that live downstream (Minard). In fact, the article states this is a conservative number. To find this number the population density around the 7,000 largest dams in the world were observed (Minard). They recorded how many people relied on agriculture and fishing, as disrupting the river flow has been shown to destroy these industries. Additionally, the article talks about how the Glen Canyon Dam destroyed the environment around it, including the once sediment-rich water, how they have killed off native populations, and how the new environment has allowed invasive plants to take over (Minard). It is stated how if there are needs for power already existing then dams should be modified to more efficiently provide power (Minard). The purpose of dams are to improve the lives of the human. Despite this intention, dams have actually harmed those that lived in the area before their building. Established communities and in foreign countries indigenous countries often have lived in the same area for generations. Among these people there may be those that suffer financially. Thus, when a government demands their land for the construction of a dam, possibly without compensation, or the dam completely changes the aspects of the region the already suffereing people can be further empoverished. An example of this is the Cocopa Indians along the Colorado River. Leslie says that if all the Colorado River dams were destroyed then the river could “again enrich the downstream wetlands, the river could again become “an unparalleled repository of marine life,” and the Cocopa Indians could have an opportunity of “avoiding cultural extinction” as they used the once life abundant and nutrient rich river for fishing and farming (Leslie 5). Due to the discovers of negative dam effects “dam opponents in recent years have won the more telling victories” (Leslie 5). Accordingly, the largest financier of dams, the World Bank, has made policies in order to protect people where dams could be built and tightened regulations to protect the environment (Leslie 5). Sadly, Leslie states that it has often “ignored its own policies” (Leslie 5). Too often this has been the case with controlling the growth of dams. Various organizations claim to be protecting the environment and people in the area; however, the organizations simply disregard their own rules in order to make a profit.

Additionally, a newer trend that is being researched in science is that dams can actually create their own weather (Minard). This is due to the large reservoirs of water that they create (Minard). The bodies of water cause more water to evaporate, which creates larger rainfall (Minard). More recent studies suggest that the dams are also causing more frequent storms, which scientists fear could cause the dams to break (Minard). This could be catastrophic for the people and river life in the area. Additionally, the risk is especially great in the US as dams grow older with dense populations. This also contributes to the idea that dams are only a temporary fix for arid climates or energy; eventually a dam will break and could do more damage than the effort was worth. 

Also, a YouTube video by Discovery News recognizes the immense benefits of hydroelectric dams in some countries; however, it argues that the river impact and displacement of people is not worth the cost in addition to only 3% of dams in the U.S. being used for power (“Why We Should Stop Building Dams”). There are always more clean alternatives to dams for power such as new advances in wind power and harvesting the ocean’s waves for energy (“Why We Should Stop Building Dams”). It is important to explore alternative energy sources other than hydroelectric dams due to their negative impacts.

Overall, dams’ negatives outweigh the positives due mainly to their effects on river life and even on the people and weather in the area. Dams negatively impact the environment by restricting nutrient rich sediment flow and creating an almost insurmountable barrier for migrating fish. Additionally, dams even further harm struggling populations and indigenous cultures that may have relied on a dam-free river for survival. Finally, dams have negative causes that are still being researched such as effects on the weather could cause a dam to fail. Dams are in fact only a temporary solution for solving a water and energy crisis. Those that build the dams do not even have all humans in mind; usually only those that they can make money from. As a result of these atrocities new solutions to water control and the energy crisis should be researched. Things such as solar panels and wind power and still being improved. Further, completely new techniques are being discovered. Truly, dams are a modern marvel past their prime.
