Major and Sustainability Essay

Matt Ackroyd

ENG 308J

Major and Sustainability Essay

Environmental Sustainability in the Eyes of Civil Engineers

Civil Engineering as a field is best described, in the most basic form, by the American Society of Civil Engineers organization as “the design and maintenance of public works such as roads, bridges, water and energy systems as well as public facilities like ports, railways, and airports.” To go into greater detail, today’s engineers deal with the careful and complicated planning, design, construction, and maintenance of most infrastructures of the world. These infrastructures include transportation systems, basic water systems such as waste water/ fresh water treatment, dams, flooding control, and irrigation systems, environmental systems including pollution control and things of that nature, and all kinds of structures. All of these private and public works have a direct effect on the environment and careful considerations are made in the planning and design in accordance to certain laws and codes. Every field of engineering deals with working with, and sometimes altering the environment is some way or another. And it has become a main concern for engineers to create more sustainable ways of going about their practices. They are constantly trying to come up with newer and more efficient techniques of working with the environment as opposed to against it. This can be a very challenging task considering the main goal of engineers is to build an environment that is better and efficient for human lives, without so much considering the environmental impacts. Though sustainability has always been something engineers try to consider, it has become more evident in the 21^st century that it needs to be emphasized more in the designing and maintaining of projects.

An example of one of the systems that engineers create and manage that has a large effect on our natural environment is our water systems. Almost all of our rivers and streams are affected by dams. There are 6,375 dams in the United States alone, which is about 13% of the world dam population ( www.dams.org/global/namerica.htm ). Building a dam on a river has many long and short term effects on the natural water systems and the surrounding environments. This practice of “damming” in the world has fragmented the river systems drastically, impacting various wildlife and vegetation ecosystems and the natural flow of the rivers. Every river has its own flood plain and natural flooding pattern that have its own benefits to the ecosystem, and building a dam greatly impacts and changes this. A flood plain is an area surrounding a river or body of water that is at a low elevation and usually very flat and is where the water can and will overflow onto during a flood. But this is also one of the goals of the engineer in building a dam, to control the river and its flow of water for reasons such as irrigation and flood control. And part of their job is to look at both sides; the positive benefits and the negative effects the dam would have on the area. If the benefits outweigh the effects, then the dam is built. And this is where they have to factor in sustainability.

Flooding is the most common hazard in the United States and can occur on a small scale, affecting only a town or two, or extremely large scale, affecting entire river basins and multiple states (http://www.fema.gov/hazard/flood/index.shtm). It causes major damage to life and property, plus the burden of very expensive water damage repairs. Many American cities and towns are built along and beside rivers to maximize their potential in trading and transporting goods. The floodplain land also provides flat, fertile soil for farming and such. And chances are that the city or town is located in the flood plain of the river. This presents the downside of living in a city next to a river, the flooding of that river into the city. So it is in our human nature to modify the system so that it works better for us. This is where the engineer steps in and considers ways to control the floods. If no other options are sustainable then flood control dams are built. They are often built along upstream tributaries of a larger river so that they will temporarily trap the excess water and runoff produced by a heavy rain. Then the water is slowly released through the dam instead of all of it rushing down to the one area. This greatly reduces the amount of water that would travel through the main river course, resulting in less flooding, which saves property, crops, and potentially human life. But that is only one of the many situations where engineers consider building a dam.

Almost all of the dams in the western United States are primarily used for irrigation purposes to provide the much needed water to the massive farming and the large populations in these flat, but dry regions of the country. Without a dam, the only accessible water source is ground water and there is only so much that can be accessed. Once that’s gone, it’s gone forever. So the solution seems obvious to an engineer. Build a dam to hold back the accessible water that can be used for whatever the need happens to be. Other benefits also come into play when building a dam that help the sustainability argument, the main one being that they are used in producing hydroelectric power.

Figure 1: American Dam Uses.

Source: National Inventory of Dams, 2005.

Hydroelectric power is considered clean power, meaning it has no negative impact on the environment, and it is renewable. It is produced by the energy of the falling water, which is converted to electricity. The U.S. is one of largest generators of hydroelectric power, in which dams provide 8-12% of the nation’s power needs (http://www.fema.gov/hazard/damfailure/benefits.shtm ). It is estimated by the U.S. Department of the Interior Bureau of Reclamation, that their 58 hydroelectric power plants, i.e. dams, produce an average of about 42 billion kilowatt-hours per year (http://www.usbr.gov/power/edu/pamphlet.pdf ). This is enough electricity to provide about 14 million citizens with residential power. Hydroelectric power plants are also generally inexpensive to maintain and do not need any other natural resources to make the electricity. More importantly, they have the extremely useful ability to produce electricity whenever it is needed, like during a power outage. The future holds a lot of potential for the use and production of hydroelectric power, but issues, such as the environmental impacts, are holding it back. And every method and reason for damming has an impact on a river’s environment and its ecosystem, both upstream and downstream.

This is why engineers also have to factor in the many effects the dam would have on the river. There would be a major impact on the river’s surrounding environment, including the land and the people living along the river, along with the wildlife in and around it. Sometimes many people have to be displaced from an area in order to have a reservoir that consumes an entire valley. Worldwide, 40 to 80 million people have been displaced due to dam building (http://www.civilengineergroup.com/negative-impacts-hydroelectric-dams.html ). Many animals’ habitats and ways of life are altered as well. In the Loire Valley in France, for example, salmon were very abundant and about 100,000 migrated up the river before a dam was built, and in 1997 only 389 were counted traveling upriver (Marks, 2007). Also, in Maine, when the Edwards Dam was taken down in 1999 on the Kennebec River, biologists observed the return of many species of animals that originally resided there, such as the striped bass, Atlantic salmon, and the bald eagle (Marks, 2007). But it is important to point out that taking down a dam does not simply return the ecosystem back to normal. It is a very complicated process that involves many other factors that engineers would have to consider before knocking one down, such as all the sediment built up behind that dam that would be released into the river. The figure is a picture of a large hydroelectric dam showing the general large scale impact it has on the area.

Figure 2: Large hydroelectric dam

So in this particular engineering example, damming, it is the engineer’s job to weigh the benefits of building a dam against the negative effects it has on the environment of the area. They have to come up with sustainable arguments that support the project. Such arguments include if the dam is going to help the area’s environment more than hurt it and if it is worth the cost and effort put forth to complete the complicated project. And as mentioned earlier, if the benefits outweigh the negative effects, then the dam is built.

In all areas of engineering, engineers are called in to assess a situation, make a plan with a design considering all the possible factors of the project, and usually building something, in this case, a dam, to make the situation better for us humans. It is part of their job to do this as sustainably as possible, with careful considerations to things like environment impacts a certain project would have. And it has become one of their main goals to do this more effectively; to have less of an impact on the environment while making the environment better for the people.