Lesson Plan - Get It!
- Have you ever seen one of these tall structures?
They look like giant lollipops coming out of the ground! Maybe you've seen one of them on your way to school or even just driving around town. Most people see these structures every day but never really think about what they are or how they serve their community.
Now is the time to answer your questions. Take a closer look at the structure.
- What do you think is inside it?
- Why does it have to be a tower?
- How does it work?
Discover the wonders of engineering design in these powerful tools that help you get yourself ready for school every day!
- Did you guess these tall structures hold water?
Well then, you were right!
Water towers, like these, are scattered all over the country, and each holds about 30,000 gallons of water high above the ground!
- Do these towers simply hold water, or do they do more?
- Why are they built on tall towers and not just on the ground or even underground?
Let's get started to find out!
What Are Water Towers?
A water tower is a structure that supports an elevated water tank containing a community's water supply. You normally see one or two towers in flat terrain areas containing small towns. They are incredibly simple but useful devices that come in many shapes and sizes.
It is true that building a water storage tank underground would be cheaper; however, there is a reason why it's a storage tower.
The houses where water is needed are on the surface of the ground. Getting the water from underneath to the surface requires more energy, just like when you sip water using a straw.
- But, what if the water could just use gravity and flow down from a height?
That makes it easier because gravity is a natural phenomenon on earth. This means that water flowing from above will come naturally and will require less energy.
It's All About the Pressure!
Sometimes, pressure is a good thing! In water towers, pressure works wonders.
All water distribution systems rely on pressure to supply a continuous flow of water. The higher the pressure is, the faster the water will flow. Pressure is the energy force that pushes the water through the pipes, delivering it to homes and businesses.
Look again at the energy diagram above. The image on the left shows how you need more of a push to get the water from below up to the surface for distribution. The image on the right shows how gravity pushes the water down for you.
The water is delivered to your home with a certain amount of pressure. Municipal water supply usually runs at 50 pounds per square inch (psi) to 100 pounds per square inch (psi). The unit pound per square inch (psi) is literally a pound of force on a square inch of area.
This amount of pressure must be maintained by the municipal water supply for the appropriate amount of water to come out of your faucet when you turn it on. Therefore, municipal water towers must be high enough to support this level of pressure. They are often built on mountains or hills whenever possible.
Water Towers Save the Day
Everyone in your household uses water every day.
- What time of the day do you think you use the most water?
If you thought the morning, you are correct. In the morning, everyone needs water to brush their teeth, wash their faces, and shower to prepare for work or school.
- When do you think people use the least amount of water?
If you thought at night, you are right!
If the average municipal water consumption is 500 gallons per minute, it can easily shoot up to 2,000 gallons per minute in the morning! The municipal water supply center needs a way to accommodate these varying demands for water each day.
With water towers, the solution is very simple! Water can be saved inside the elevated water tank and delivered when it is needed. When water demand is low, the extra water can be saved. Then, when the demand rises, there is extra water just waiting to meet it. Storing water allows a city or town to only worry about the average water consumption rather than buying enough expensive pumps to meet the highest levels of demand. A water tower is a much cheaper alternative.
Water towers save the day, indeed!
To summarize all you've just learned, watch How Do Water Towers Work? from Concerning Reality:
- Aren't water towers fascinating?
If you would like to dig a little deeper, you can watch How Water Towers Work from Practical Engineering:
When you are ready to test what you've learned about water towers, head over to the Got It? section to demonstrate your understanding of the mechanisms involved in water towers!