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The first solutions for getting across a river were stepping stones and timber logs. The first homes were caves.
But caves exist only in certain areas. And big 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, bridges, roads, dams, airports, tunnels, and more. They work on all the building projects we think of as infrastructure.
Channel Tunnel Construction
▲ The body of water you see is the English Channel. It’s 21 miles across at the shortest distance, and it separates England and France. What you don’t see is the tunnel that runs underneath it and joins the two countries. It is called the Channel Tunnel, or Chunnel for short. The Chunnel is the longest undersea passageway in the world. Like the Brooklyn Bridge, it solved a problem of connecting 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 provided 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 where they are? Why they are the size they are? How well the building keeps out cold air during winter and hot air in summer? How it uses natural light? Your answer may be no, but civil engineers ask these questions and many others when designing buildings. As the climate changes, such questions are becoming even more important, since they affect how efficiently a building uses energy.
◀ The Colorado River and its tributaries flow through seven states: Arizona, California, Colorado, Nevada, New Mexico, Utah, and Wyoming. Before 1936, the river would sometimes overflow and flood nearby farmland. The engineering solution was the Hoover Dam. This barrier was 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 create hydroelectric power. It also irrigates farmland and provides water for about 30 million people. Also, the water behind the dam forms Lake Mead, one of the biggest artificial lakes in the world. It’s also a place people go to have fun.
