One of the more useful and effective techniques used in the water industry is to open a hydrant to let water flow. Referred to as “flushing”, it is often seen as a waste of water especially when conservation is so important. However, flushing hydrants is one of the most important things Charlotte Water does to ensure that water used by businesses, industries, hospitals, residents, and firefighters are safe, clean and reliable.

Hydrant flushing is done for a variety of important reasons, including:

• Flushing clears older water from water pipes.  This is essential to maintain water quality.
• When main breaks are repaired, flushing can clear air and sediment from pipes and ensure water quality is high.
• Newly constructed water pipes must be disinfected and tested before they can be used; this requires flushing.
• Analyzing water system capacity to accommodate new customers often requires flushing hydrants to obtain critical measurements.
• Fire Department Operations also require routine flushing of hydrants to obtain data and assure proper operation.

“We sample and flush water from the system every single day. These activities are part of normal operations. Charlotte Water has a laboratory of national regard and field staff that take samples across the water system every day, all day. If we see our water quality parameters start to move in the wrong direction, we find and resolve the cause, states John Fishburne, Charlotte Water Senior Engineer”

Charlotte Water staff are working hard to make sure the water that comes into your home is fresh. Water has a shelf life, just like anything else. When pipes dead end or during low water use times (when it’s raining or in the winter)  the water sitting in the pipes waiting for you to use gets old.  We can fix this by flushing the old water out of the system. Something utilities do all over the world to ensure fresh water.

So, what staff are doing is flushing some water from some areas that help us move the water in the directions we want it to move. Charlotte Water staff (1) pick the best spots to move the amount of water we want to move in the time we want to move it. (2) then we monitor to see that water is moving the way we want it to.

Sometimes, it can take days to confirm that staff have completed the water redirection that they desired. Sometimes, the ideal spot to flush would flood the street too much or damage something.  So staff might use a lot of hydrants in a wider area to accomplish the same thing;

Staff are trying to influence water movement miles away through our large transmission water mains. Literally — miles. So, there is no cause for alarm because staff are flushing a hydrant in front of your home.  It’s just a good spot from an engineering perspective.

But that’s not all we’re doing to maintain fresh water for you, flushing is just the most visible. There are treatment technologies at work behind the scenes, something we plan to explain in a future post.

Water flowing from a hydrant represents a very small fraction of the millions of gallons pumped to customers daily.  Charlotte Water maintains over 4,300 miles of drinking water mains and more than 17,315 fire hydrants covering about 520 square miles.

What do you think? Did this article help explain why we are flushing water? Have any additional questions that weren’t answered? Please comment below.