Today’s Wonder of the Day was inspired by jackie. jackie Wonders, “Why are water towers high in the air?” Thanks for WONDERing with us, jackie!

If you live in a big city, you may see these dotting the rooftops of many buildings. If you live in a smaller town, you may see them looming over neighborhoods or along back roads in the countryside. What are we talking about? Water towers, of course!

Have you ever WONDERed why water towers exist? Are they really full of water? Why does anyone need a tower of water? Does it have a spigot so you can drink from it like a water fountain?

Water towers are indeed full of water. And, no, you can’t drink from them like a water fountain. Every water system needs water towers to help provide water.

You’ve probably noticed that other utilities may go out from time to time. In a storm, you may lose electric power. Your phone service might also experience interruptions. But what about your water? Most water systems are very reliable, and water towers play an important role in providing that reliability.

When you turn on your water faucet at home, the water comes out because the water is under pressure. Your local water system pushes the water to your home. It is usually supplied at a pressure of somewhere between 50 and 100 PSI (pounds per square inch).

Water towers are tall and are often placed on high ground. That way, they can provide enough pressure to deliver water to homes. Each foot of a water tower’s height provides a little less than half a pound per square inch of pressure.

Experts can use mathematical formulas to determine how tall a water tower needs to be. In areas with lots of hills, they can be placed on higher ground, which means they don’t have to be as tall. In flat areas, taller structures may be necessary.

An average backyard in-ground swimming pool holds over 20,000 gallons of water. Most water towers can hold 50 times that amount—that’s one million gallons! The exact size of the tank can vary greatly. Most are built to hold approximately one day’s water supply.

Water towers can be unique symbols of local pride. Sometimes they are painted with a town’s name or a local school’s . They can also take on interesting shapes. One in South Carolina looks like a giant peach! 

As for the smaller water towers you see on the roofs of buildings in large cities, those are often required by local laws. They ensure that buildings above a certain height will have their own sources of water in an emergency. If you ever visit New York City, you can see hundreds of buildings with their own holding tanks.

Water is very important to daily life. That’s why reliable water service is important. Thankfully, water towers help keep the water running. What other important structures help people every day?

Standards: CCRA.L.3, CCRA.L.6, CCRA.R.1, CCRA.R.2, CCRA.R.4, CCRA.R.10, CCRA.SL.1, CCRA.SL.2, CCRA.W.3, CCRA.L.1, CCRA.L.2

Wonder What's Next?

Tomorrow’s Wonder of the Day explores why all good things must come to an end.