Hydrant Flushing

Hydrant Flushing in Your Area

Periodically, you will see Public Works personnel releasing water from hydrants. Hydrant flushing is necessary to test the hydrants to make sure adequate flow and pressure is available. Flushing is also done to remove sediment from the pipes in order to maintain water clarity and quality in the distribution pipes.

 You will often see our City Public Works crews replacing water pipes as part of a comprehensive strategy to keep our infrastructure strong. This is especially important for a City of our age, where some of our pipes can be up-to 80 years old.

When we install new water pipes and hydrants in your neighborhood, they must be completely cleaned after installation. This is not just a good idea, it is also the law. This is done with a solution of chlorine and water, which disinfects the pipes and removes foreign contaminants such as rust or sediment. In order to completely remove the solution, the pipes must then be flushed-out with high-pressure water.

It is required that this flushing be done, as it neutralizes the chlorine solution. It also removes any remaining sediments in the pipes before they are connected to your homes. Unfortunately, this means that large volumes of non-drinkable water will occasionally need to be discharged into the nearby storm drain system. This gives the appearance of wasting large quantities of water. The good news is that this is not the case.

No Water is Being Wasted

The discharged water is being collected by the storm drain system, which then flows to the Santa Ana riverbed. Once in the riverbed, it is absorbed into the groundwater aquifer basin for future use. This is made possible by the Santa Ana River's sandy bottom, which acts as a natural filter as it absorbs the water. This natural system that has been cleaning the water and recharging the aquifer for thousands of years.

The groundwater basin lies far underground, and provides a vast store of safe drinking water which we rely on to supply about 75% of our City's water needs.

We have been asked if the City could capture the water instead of sending it to the storm drains. Unfortunately, a recent test of that idea proved impractical. The large volume of water that must be moved under high pressure was too great to capture. Lowering the pressure or the volume did not do the cleaning job necessary to meet the required water quality standards.