How many fire hydrants does the city of La Porte City have and maintain? The answer may surprise you. There are more than 100 hydrants located inside the city limits.

Each year, usually in April or May, La Porte City Utilities “flushes the mains.” While the sight of water gushing out of a hydrant can be impressive (see photo), some may question if the practice is a waste of an important natural resource.

In addition to helping remove rust and sediment that can accumulate in water over time, there are a couple of other important reasons why this practice is important to helping keep city residents safe and healthy.

The first relates to the concentrations of chlorine in the water supply. As part of the process of preparing water for consumption at the La Porte City Water Treatment Plant, chlorine is an important disinfectant used to ensure bacteria are not thriving in the city’s network of water pipes. Chlorine in water, though, degrades over time. That makes it possible for chlorine concentrations in water that is sitting in pipes for an extended period of time to drop below acceptable levels. The annual flushing of hydrants helps prevent water from stagnating in pipes.

Another way water can become contaminated comes from the pipes themselves. Over time, particularly when dealing with very old pipes, sediment, rust and chemicals can leech into the water supply due to broken pipes or from the inner lining of them as they age.

Finally, the flushing of fire hydrants provides an opportunity to measure the flow of water. This is especially important to firefighters, who need to know the water pressure that is available, should they be called to the scene to battle a blaze.

Following the annual flushing of La Porte City’s fire hydrants, the City identified the available water flow for each of its hydrants and identified them by color. According to the National Fire Protection Agency (NFPA), it is recommended that fire departments and water districts follow a set standard of color-coding. Known as NFPA 291, fire hydrants using public water supply systems should have their tops painted a certain color to indicate the available amount of water, measured in gallons per minute (GPM). Those hydrants below 500 GPM should be red, 500-999 GPM should be orange and 1,000-1,499 GPM should be green.

With La Porte City’s fire hydrants now color-coded, the fire department can more quickly assess the situation when called to the scene. And in the case of fires, every second saved could make a tremendous difference hen it comes to the potential loss of life and property damage.

Water: The Natural Fire Extinguisher

A fire needs heat, fuel, oxygen and the chemical reaction between the three to sustain it. To put the fire out, simply remove one of the four from the equation. The application of water is the most common method used.

Water puts out a fire in two ways:
First, it cools the fuel down to below its fire point, the temperature required to keep it burning.
Second, as the water applied to the fire is heated and converted to steam, the steam replaces available oxygen in the area, effectively smothering the fire. The amount of steam created by the water depends upon the atmospheric pressure, temperature of the environment, as well as the temperature of the water being applied.