
Many municipalities around the U.S. and the world rely on elevated storage tanks to supply their daily water needs. Water towers have a rich history, and can be as fascinating as they are functional. Read about the various types of water storage tanks, and try your hand at some water tower trivia!
When driving through towns and smaller cities, especially in the South and Midwest, an iconic sight is their water towers. No two are alike – at least on the outside, since most of them are painted with municipality’s name and logo. Some are even whimsical, such as Peachoid in Gaffney, South Carolina, and its smaller cousin, Big Peach in Clanton, Alabama. Many universities, manufacturing plants, and other larger facilities have water towers too.
In the late 1800s and early 1900s, water towers in larger cities were often stately structures reflecting the architectural styles in vogue at the time: Neoclassical, Gothic Revival, Art Deco, Art Nouveau, etc. About 100 water towers and tanks – most of them decommissioned – are listed on the U.S. National Register of Historic Places, according to the Pittsburg Tank & Tower Group.
Water Towers: Functions and Forms
Water towers can be landmarks and points of pride. Of course, their larger purpose is functional.
What water towers do
It takes energy to convey water from a source to its destination. Aqueducts constructed during the Roman Empire relied on gravitational energy alone to transport large amounts of water from higher elevations to lower elevations. Today, a system of pumps and pipes use kinetic energy to move water around, such as from a wastewater treatment plant to a city’s homes, buildings, factories, and fire hydrants.
Pumps alone could satisfy a municipality’s water needs. But buying enough pumps for a city can be expensive, not to mention the cost of fuel to run them continuously. That’s why many municipalities have elevated storage tanks. When demand is low, such as overnight, pumps at ground level lift the water, filling the tanks and giving the water potential energy. This stored energy is released, becoming kinetic energy thanks to the pull of gravity, when demand is high, such as in the morning and evening or for fire suppression. This is why a community’s water tower is typically sized to hold a day’s worth of water.
Water Tower Trivia
You think you know about water towers? Test your knowledge with this quiz!
1) NYC has about how many rooftop water tanks?
a. 5,000 to 10,000
b. 10,000 to 15,000
c. 15,000 to 20,000
d. 20,000 to 25,0002) What type of storage tank is the Chicago Water Tower?
a. Underground storage tank
b. Fluted column
c. Gothic Revival
d. Standpipe3) Which type of elevated storage tank has a concrete shaft and a steel tank?
a. Cone-top
b. Pedesphere
c. Composite
d. Double cone4) The decommissioned water tower in Collinsville, Illinois, is famous for…
a. being the world’s largest catsup bottle
b. its Dixie Cup shape
c. replicating the Tower of Pisa
d. looking like a Swedish-style coffee potFind the answers at the end of this article.
There are several advantages to storing water in an elevated tank:
- Consistent, reliable water pressure
- Water supply unaffected by occasional power outages
- Cost savings due to running pumps overnight, when electricity is cheaper
- Less wear and tear on expensive pumps by not cycling on and off as demand fluctuates
As a bonus, since water towers are often the highest points for miles, telecoms are leasing these tall structures and installing cellular antennae, giving municipalities an additional source of steady income.
Types of water storage tanks
Elevated water storage tanks come in many shapes and sizes. The oldest and most basic design is the leg-style tank: a cone-topped cylinder or an ellipsoidal vessel resting on at least three supporting legs or columns. This is the style of water tanks – made of untreated wood for natural insulation and no contamination – found atop many buildings in New York City. Within the central shaft are the inlet pipe, outlet pipe, and overfill evacuation pipe. Thanks to struts, cross braces, and stay rods, this style of water tanks can be adapted to withstand high winds and seismic activities.
Some water towers are steel structures where a large vessel – spheroidal, double ellipsoidal, torospherical, cone-shaped base, etc. – sits atop a flared support pedestal with piping inside. Pedestal-style water towers are popular due to their small land footprint.
Similar to the pedestal-style, fluted column (fluted pillar) water towers also have a single support in the center. But the steel column – corrugated for strength – is nearly as wide as the tank, allowing plenty of space for machinery, storage, office space, and staircases inside.
Another popular style is the composite elevated tank (CET), so called because while the cylindrical storage vessel is steel, the central shaft is made of reinforced concrete. The column has a smaller diameter than that of the fluted column, but it’s still wide enough for storage, office spaces, and interior stairs. One advantage of the CET, besides its ability to support the largest water tanks, is that only the tank needs to be painted, resulting in much lower costs for structural maintenance. Besides these elevated versions, the water tank itself can be on the ground. Ground storage tanks are wider than they are tall, while standpipes are taller than they are wide. Some cities keep treated water in underground storage tanks, which offer the greatest capacity while taking up no land space.
Besides these elevated versions, the water tank itself can be on the ground. Ground storage tanks are wider than they are tall, while standpipes are taller than they are wide. Some cities keep treated water in underground storage tanks, which offer the greatest capacity while taking up no land space.
1) b, 2) d, 3) c, 4) a
The Dixie Cup Water Tower is in Lexington, Kentucky; the Leaning Tower of Niles is in Niles, Illinois;
and there are two (at least) water towers shaped like Swedish-style coffeepots: one in Stanton, Iowa,
and one in Lindstrom, Minnesota.
This series continues next week with the science of getting water to where it needs to go.