Water Towers

Following a U.S. highway for a reasonable distance will just about always take one past those mammoth structures we call water towers. They are essential to every modern municipal water system and therefore incredibly common which causes them to be frequently taken for granted and overlooked. These structures have an incredibly long history which can be traced back as far as the Romans, Greeks and even King Solomon. However, before we explore the history, let's take a look at how exactly these towers work.

Because the most emblematic style of water towers is the man-made elevated reservoir we will begin by examining the functional aspects of that particular style.

This diagram shows water being pumped up (typically to a height of 120 feet) where it is collected in a large holding tank high above the nearby structures. The reason for this is that water which then drains from the bottom becomes pressurized by the weight of the water above it, enabling it to travel back up and in to homes and out of faucets, shower heads, etc. This style is best suited for areas where there is little variation in elevation and the landscape is generally flat. It should also be noted that the larger of the two pipes which connect to the water tower is the output, or pressurized water.

Another style which may be familiar to some is simply a giant tank on a hill:

Essentially the same concept without the tower stilts.

Why water towers?
Water towers essentially fulfill two needs in a water system: to provide a community or building with a reserve supply of water in case of emergency and, as previously discussed, to pressurize. Having a large reserve of water is useful in case of emergency (such as power outages and fires) and for handling "peak" times of water usage - i.e. morning and evening... or half time during the Super Bowl!


These are not the only forces which affect the way water towers look. In order to further explore the reasons that water towers look the way they do, let us consider those that have been tucked away high above the streets in New York City:

Notice how all of these towers are made from wood. The alternative is steel, but wood is less conductive of heat which enables the water reservoir to stay cooler in the summer and less likely to freeze in the winter. Additionally, steel tanks are much harder to maintain due to rusting. Some people swear by the wooden tanks because, they claim, the water tastes better too. This solution is relatively low-tech and thus has a long history as a pervasive style.

Although water towers are popular in NYC, they are remarkably absent from other American cities. Electric pumps are used in their stead, but are incompatible with New York's older infrastructure.

 Another structure relating to water pressure that is also referred to as a water tower is a water standpipe. standpipes were used to equalize pressure and stabilize water flow in the system. They became outdated once rotary pumps (something like this) began to be widely used in municipal water systems in the very early 20th century. These structures were often well decorated landmarks such as the famous Chicago water tower:

Only 7 of the roughly 500 water tower stand pipes which used to exist in the United States still stand today; three of them are located in St. Louis. This is really rather unfortunate since they were usually beautiful structures: