Dams are some of the most impressive and well-noticed aspects of modern infrastructure. Throughout history, dams have played an important role in the growth and expansion of civilization. Many ancient city planners relied on dams to funnel water through their cities even if it was far away, while military leaders used dams to alter the terrain that they planned to fight on. However, their existence is contentious.
Pros of dams
Hydroelectric power:
One of the most beneficial aspects of dams is the potential to create hydroelectric power. Hydroelectric power is created when water passes through a dam via a turbine. Hydroelectricity is one of the most studied forms of alternative energy, as it is relatively reliable and stable, and most hydroelectric power plants have low maintenance and operational costs. According to FEMA, hydroelectric power currently amounts to 8 to 12 percent of current electricity needs, and overall creates about 100,000 megawatts of electricity.
Controlling waterways:
Flooding can be disastrous for many communities, especially if nearby water resources are hard to control. Dams are able to re-divert waterways to other areas to keep communities safe or open up more land to build on. Flood control dams specifically mitigate floodwaters by impounding water and then safely diverting the water towards other places.
Great source of irrigation:
The presence of a dam creates a reservoir that can be used as a great source of water, specifically for farm and industrial activities. Dams have been used for centuries for irrigation. The Aswan High Dam in Egypt gives local farmers protection against the harsh droughts and famines of the desert by controlling the water supply of the mighty Nile river. FEMA says about 10% of cropland in the United States is irrigated by dam water.
Environmental Protection:
Some dams help protect the environment by trapping hazardous materials in water and capturing sediment that could contain harmful or toxic substances. Some dams also have mine tailing impoundments, which help facilitate the processing of minerals in an environmentally friendly way. FEMA says dams also help facilitate the nation’s waterways, making river transportation seamless and easy, and reducing the risk of water-borne accidents or other problems, which could negatively affect the environment.
Cons of dams
Damaging to environment:
Rushing floodwaters replenish the nutrients in the soil in water, which is beneficial to all plant and animal life in rivers and other waterways. When water is diverted due to a dam, it can greatly disrupt the delicate natural ecosystem. Some flora and fauna are able to adapt to the changing conditions, but many will not, and could be destroyed in the new environment. After the Aswan High Dam in Egypt was built, scientists noticed a marked decline in fish production around the area, as the amount of nutrients and food was now less than before the dam. Fish ladders have been build at some dams to help fish migrate, but some are not able to use the ladder properly, especially if they are used to fast-moving water.
High Cost & Risk for Disaster:
The cost of building a dam often reaches astronomical levels. The engineering and technical aspects, along with the actual construction, is a time intensive and laborious process that has to be done with absolute precision. China’s Three Gorges Dam was built in an area with seismic activity, and small cracks have already been found in the infrastructure. A dam collapse or break would be an absolute catastrophe, especially from one the size of the Three Gorges Dam. After Hurricane Harvey hit Texas, dams in the Houston area were pushed to their limit by massive floodwaters.
It can be hard to imagine what civilization would be like without the presence of dams to control waterways and build reservoirs of water. Even though dams are a major part of modern infrastructure, their positives and negatives on society and the environment are still being studied.
In conclusion, I think that the advantages and disadvantages of transporting water and building dams are about the same or if anything the disadvantages would be catastrophic, but the advantages helps with a lot of the worlds current problems like pollution, global warming, and gas depleting.
