A water tower is an elevated structure that supports a water tank, as its name implies, built high enough to provide a pressurized supply. The main benefit of a water tower is to meet peak consumption without additional pumping energy, and can also serve as an emergency water supply for fire protection systems.
Water towers are built high to provide pressure, where each foot of height adds 0.43 psi. They must be high enough to achieve sufficient pressure for the buildings they serve and are usually located on elevated ground to increase pressure.
- In regions with multiple hills, water towers can be replaced by a simple tank on the highest hill in the region.
- In crowded urban locations like New York City, small water towers can be found above many buildings.
Water supply systems are very complex, but their main elements are water treatment plants, pumping systems and distribution pipes. After the water leaves the treatment plant, pumping systems establish the pressure necessary to reach homes and businesses. However, tall buildings normally use a water booster pump, as the supply pressure is not sufficient to reach the upper floors:
- When the water supply capacity exceeds consumption, the water tower fills.
- When consumption is higher, the water tank is gradually emptied.
Some common water sources are wells, rivers, and natural reservoirs such as lakes. Water treatment plants remove sediment through filtration and decantation, and water is also treated against bacteria with ozone, ultraviolet light and chlorine. After the water leaves the treatment plant, it is clean and germ-free.
Design a reliable drinking water supply for your building.
Benefits of a Water Tower
Water tower tanks are typically large, comparable to a backyard swimming pool in water holding capacity. A common design practice is to size the water tower according to a day's consumption, so that water can continue to descend with gravity if a pumping system fails.
One of the main advantages of water towers is that they allow sizing of pumps according to average demand instead of peak demand, reducing the installed cost of the pumping system.
- Without a water tower, a building owner must purchase a water pump powerful enough to meet peak demand.
- Pumping capacity is underutilized most of the time, increasing acquisition and maintenance costs without additional benefits.
Water towers can meet peak demand without extra pumping power. A clear example is the early morning, when people wake up and get ready for the day: taking a shower, cooking, brushing their teeth, etc. At night, when water consumption is minimal, the tower refills itself.
How Water Towers Improve Fire Safety
Water is vital to many fire protection systems and firefighting operations. A well-designed fire protection system can establish enough pressure to extinguish flames in any area of the building. However, a water tower provides an additional supply that does not rely on a pump or fire truck to establish pressure.
Because a water tower provides an additional measure of fire protection, it can help reduce fire insurance rates for building owners. In a worst-case scenario, where there is no way to pump water to a fire-affected area, the water tower provides a backup measure that does not rely on a pump.
Use of water towers in the USA
In New York City, millions of people use water towers located above tall buildings. These tanks provide available water supply even during blackouts. They also complement pumping systems, which would require very high capacity to serve tall buildings alone. Water towers offer a convenient solution in New York considering the large number of tall buildings.
The oldest operating water tower in the U.S. is the Louisville Water Tower in Kentucky, built in 1860. The second oldest is the iconic Chicago Water Tower, built in 1869. In small towns, water towers can serve an entire community rather than a single building. , and are often shaped and painted with a unique theme about their city.
