How Do Water Towers Work?
MINNEAPOLIS (WCCO) -- As cities ask homeowners to conserve water, it's bringing up questions about how we get our water in the first place.
Tom from St. Cloud and Nancy from Edina asked this Good Question: How do water towers work?
"Water towers have two primary purposes, one is for pressure," said Jon Eaton, superintendent of utilities for the City of Eagan. "The second thing we do is primarily for storage and fire protection."
Pumps lift the water to create the pressure people feel in their homes. Due to the elevation, gravity pushes the water down. The extra storage also allows for a buffer for when water demand is high.
"The second thing we do is primarily for storage and for fire protection," Eaton said. "So it allows us a buffer during day when demands get really high."
Why can't we just store it on the ground? Eaton says the issue is space and there aren't many cost-effective places to store one million gallons of water. It would also be expensive to pump the water once again to create the required pressure.
"Part of this is saving the public a significant amount of money by just storing it up high and letting nature do the work," he said.
Cities across the metro get their drinking water from a variety of places, including wells and surface water. No matter where it comes from, the water towers work the same.
Water comes into the tower underground from a single big pipe outside. It moves through that pipe straight up to the bottom of the bowl. Depending on demand, the water in this tower often turns over five times a day.
So why doesn't it freeze in the winter?
"We purposefully cycle the water in the towers up and down," Eaton said.
Eaton says the drought doesn't affect how much water is in the tower.
"What the drought really affects is our source water, so we're constantly watching what the water levels are, the aquifer levels," he said.
And why doesn't the Eagan Water Tower have the city's name on it? Eaton says while the tower supplies water to Eagan, it also supplies it to parts of neighboring Inver Grove Heights — where the tower is actually located.