Hydrant Flushing

Why does the Town flush water out of open fire hydrants?

Although it may appear to waste water, "flushing" the hydrants is an important part of routine maintenance necessary to maintain the integrity of the water system and ensure high quality water is delivered to our residents. Flushing hydrants is a State of Texas requirement by the Texas Commission on Environmental Quality (TCEQ).

Water lines are flushed for these main reasons:

• To maintain water quality

  The disinfectant, chloramine, becomes less effective as water collects and becomes older. This process is exacerbated in warmer months as rising temperatures can accelerate the degradation of disinfection in the water. Flushing ensures that fresher water, with a higher concentration of disinfectant, flows through the water system. 

• To clean water mains

  Over time, small particles can build up inside the water distribution pipes and can have an impact of water quality. Water professionals use flushing to pull water at high velocity through pipes to a discharge point. The rapid flow of water scours the insides of the pipes.

• To conduct fire flow tests

  Fire hydrants are tested periodically to ensure and document proper functioning so they are ready for an emergency.

• During annual temporary change in disinfectant (also known as chlorine maintenance)

  Each spring for one month, our water provider, North Texas Municipal Water District (NTMWD), temporarily suspends the use of ammonia and uses free chlorine as the secondary disinfectant to maintain water quality year-round. We flush more frequently during this period to help move the chlorine-disinfected water through the system faster. This helps maintain the system, ensure high water quality and reduce the chlorine odor and taste.