Home Articles Unidirectional Flushing Ensures a Safe, Reliable Drinking Water Supply Unidirectional Flushing Ensures a Safe, Reliable Drinking Water Supply Posted: Thursday, December 21, 2023 Mesa Water District (Mesa Water®) performs unidirectional flushing of the water main lines and fire hydrants as part of its regular preventative maintenance program. Unidirectional flushing involves cleaning pipes by forcing water through isolated sections at high velocities, in a single direction. This produces a scouring action that loosens and removes any sediment buildup and sand from pipes that deliver your water. The sediment that is present is normal, however removing it improves the appearance of the water. During a flushing operation in your neighborhood, you will see Mesa Water crews flushing water via fire hydrants and end of water main blow off pipes. Should you see water discharged in the street, please know that this a necessary part of maintaining a reliable, safe drinking water supply. Some of this discharged water will soak back into the groundwater basins for reuse. How will this affect my water service? Water flushing generally occurs between 9 a.m. and 3 p.m. and affected customers are notified in advance of this work with a door tag. Mesa Water’s Operations team asks that you refrain from using water during that time, especially hot water, including laundry use, due to the potential of sediment getting into your hot water heater and appliances. Residents are able to flush toilets during this time. Once the work is completed, you may notice some discoloration or sediment in your tap water, affecting only its appearance. The water is safe and will clear up in a few minutes when you run cold water through the faucet of your bathtub or other unscreened tap such as a garden hose. For more information on Mesa Water’s flushing program, contact the Water Quality Department at 949.574.1031. Thank you for the privilege of providing you with 100% local, reliable, clean, safe water. Mesa Water Notify Keeps You Informed Through our Mesa Water Notify system, we are able to send messages to our customers via email and text. The new year is a good time to contact our Customer Services Department at 949.631.1200 to be sure we have your most current email address and mobile number, so that we can reach you in real-time in the event of an emergency.