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The first solutions for getting across a river were stepping-stones and logs. The first dwellings were caves.
But caves exist only in certain areas. And vast regions of Earth are not near rivers or lakes. That’s where civil engineering comes in. Civil engineers are people who design and build housing, dams, bridges, roads, airports, tunnels, and more. They work on all the building projects we think of as infrastructure.
Channel Tunnel Construction
▲ The big expanse of water you see — that’s the English Channel. It’s 21 miles across at the shortest distance and separates England and France. What you don’t see is the tunnel that runs underneath it and joins the two countries. Called the Channel Tunnel, or Chunnel, it’s the longest undersea passageway in the world. Like the Brooklyn Bridge, it solved a problem of uniting people separated by water.
How is it possible for more than 600,000 people in Washington, D.C., to travel to work, to school, to shopping on a single day? What about the 5 million people who do the same in New York City? The answer is not cars or bikes. In these and other cities, civil engineering provides a different answer — subways, or underground railroads. Washington, D.C., has 118 miles of subway tracks. New York City has around 665 miles. That’s about the same as the distance from there to Indianapolis, Indiana. ▶
▲ Think about your home. Have you ever wondered why the doors and windows are located where they are? Why they are the size they are? How well the building keeps cold air out during winter and hot air out in summer? How the building makes use of natural light? Your answer may be no, but these questions and so many others are the ones civil engineers ask as they design any new building. As the climate changes, answers to questions like these have greater and greater importance since they affect how efficiently a building uses energy.
◀ The Colorado River flows through seven states — Arizona, California, Colorado, Nevada, New Mexico, Utah, and Wyoming. Before 1936, the river would overflow periodically and flood nearby farmland. The engineering solution was the Hoover Dam, a barrier built to hold back the Colorado River and control the flow of its waters. The dam has many benefits. The water it holds back is used to generate hydroelectric power, irrigate farmland, and provide a dependable supply of water for about 30 million people. At the same time, the water behind the dam forms Lake Mead, one of the biggest artificial lakes in the world and a place people go to have fun.
