Introduction
IUPUI students raft their way down the Ocoee
River in eastern Tennessee. The Ocoee has numerous dams installed by
the Tennessee Valley Authority, which have severely reduced the natural behavior
of the river. However, these same dams regulate the water to ensure water
is always available every weekend for rafting trips. Every September
IUPUI Earth Sciences sponsors a rafting trip for students enrolled in any geology course. (Photo: IUPUI Earth Sciences.)It’s been raining the past few days. You are driving to the grocery store on a quick errand when you encounter a stream flooding over the roadway. You’ve never noticed the stream there before, but you notice everyone in front of you is driving their car through the flooded road without a problem. So you give it a try, but halfway through, the rear of your car starts to float, your car turns 90 degrees, and water starts shooting over your car. What happened?
When you think of water, you probably immediately think of a river or lake. In this section, we’ll learn the geology behind how rivers and lakes work and take a look at the ugly side of river systems: flooding.
Why should you care about rivers? Human society (you, me, and the residents of Indianapolis, Indiana, the US, and the world) have increased flood risk and decreased water quality in many rivers and streams in the U.S. Flooding in the U.S. has caused our country billions of dollars. In the 1980s, flooding caused an average of 3.9 billion dollars in damage. In the following decade and up to 2005, this number has doubled. Is flood risk getting worse? After reading this section, you’ll understand how rivers work, and how flooding is a more dangerous hazard than tornadoes and hurricanes. You’ll also learn that because nobody “owns” the rivers, local and state governments have no incentive to prevent residential, commercial, or industrial development from impacting them.
Once you understand how rivers work, you’ll know why they should be protected, and how we can reduce the risk of people dying in floods. We will discuss how humans and rivers have combined to degrade the quality of the river and increase the hazards to humans. We’ll discuss why you should never drive across a flooded road and why you should be very cautious to buy or rent a house/apartment near a river, even a small stream.
Have you ever been involved in a flood? What was your experience? Let us know in the class Chat Room. This isn’t a graded assignment but may help you (and your classmates) to make connections to the material.