Did you know the world’s first dam is known to be the Jawa Dam, located in present-day Jordan? It was originally built in the 4th-century B.C.E, perhaps by the Mesopotamians, some of the first humans to build dams. Earlier, materials such as rocks or clays were used in dam construction. In modern times, mostly concrete is used instead. There are several reasons why dams are built, including three primary ones such as water storage, electricity generation, and flood control. Through them, the reservoirs are created which can then be used for industry, farming, and household applications. Now that you have a brief overview, let’s jump straight to the advantages and disadvantages of dams.
Advantages of dams
The water from the dam is extracted, adequately treated, and used by people in the vicinity for drinking purposes. Some other benefits of dams are as follows.
1. They help us store water
Dams help us to build water storage. These stored water can then be used for various purposes including domestic industry and irrigation. Everyday activities such as drinking, cooking, bathing, washing, and watering gardens are part of the domestic use facilitated through dams. The industry uses dams for generating electric power and improving river navigation. Lastly, they provide a water supply for irrigation that enhances food production. In other words, people can rely on dams to supply water even in drought.
2. Dams control floods
For centuries people have been building dams to prevent floods. The unpredictable floods need to be controlled otherwise it results in massive loss of lives and property. The dams capture the flood water into the reservoir. That way, the flow is controlled, allowing for proper storage and release of water in supervised conditions. It not only saves human settlements in the nearby areas but also the crops from unanticipated damage.
3. They provide a stable navigation system
The ships travel through water, but if the river is unnavigable, the journey will be affected. That’s when dams are built to provide a stable river navigation system. This way, the depth of water can be maintained yearly, allowing boats and ships to transport goods. In the absence of dams, the depth of the river may be uneven because of the changing weather, therefore making it unsuitable for transportation.
4. Dams generate electricity
One efficient way of generating electricity is by constructing dams. The kinetic energy of the downstream water turns the turbine, where its mechanical energy gets converted into electricity. That’s how dams are utilized to provide electricity to nearby houses and industries. It is eco-friendly and fulfills the power needs of both domestic and industrial purposes.
5. They offer recreational opportunities
Dams are not only used for yielding hydroelectric power and supporting irrigation systems, but also for recreational activities. This includes creating reservoirs for fishing. It is especially useful in summer when people can go swimming, camping, boating, and hiking. Not only this, the dam controllers release water for rafting, allowing rafters to hone their skills. Reservoirs may also have picnic areas near the water, offering recreational access to people.
Disadvantages of dams
Despite all the positives that dams have to offer, their downsides cannot be neglected. The following are some drawbacks dams have.
1. They displace the population
Even though dams are formed with the intention of improving the livelihood of people, the process itself displaces a huge population from the selected area. The formed reservoirs are huge and flood the area, making it unfavorable to live and work. This leads to the breaking up of existing communities as they relocate to a new location to set up their life. Plus, they may not have the land for agricultural activities, forcing them to develop new skills for their livelihood.
2. Dams are expensive
According to a study at Oxford University, it has been found that the construction of large dams is quite expensive and takes up several resources and years to complete. Considering the amount of money that goes in, the costs are too high to deliver a positive return. Thus, the long period it takes to build dams makes it ineffective for solving urgent energy crises. Additionally, along with construction, various aspects such as technical and engineering are involved that require absolute precision. Therefore, it is argued that these resources can be put to better use instead of constructing dams.
3. They disrupt the local ecosystem
The construction of dams alters the environment of the surrounding areas. The reservoirs not only disrupt human settlements but also have a negative impact on wildlife. Also, while some plants and animals may adapt to the changing environment, most of them won’t. Therefore, the local ecosystem will be destroyed in the new environment. Furthermore, the migratory fish are highly affected as they require the unobstructed flow of the river which is now controlled by dam construction.
4. Dams are at risk of flooding
Throughout history, we have seen many cases of dam failures. That’s why several factors are taken into account while constructing them. However, they are still at risk of flooding. Slight neglect in the construction process results in huge losses of lives. For instance, in 1963, the Vajont Dam outside of Italy failed only 4 years after its construction. The catastrophe resulted in the death of almost 2000 people. The failure was associated with the location of the dam in a geologically unstable area.
5. They lead to higher greenhouse gas emissions
The dams destroy the local ecosystem along with the vegetation. The decomposing plant matter in the reservoirs produces methane, the greenhouse gas. It is released into the environment and contributes to climate change. In recent times, several studies have highlighted the contribution of hydropower plants to global warming. It has been found that the reservoirs with more algae and nutrient-rich systems emit more methane. Additionally, the construction of dams results in deforestation. The trees store carbon dioxide, and when they are cut down, it is released back into the environment. To summarize, the construction of dams leads to higher greenhouse gas emissions.