Public Works routinely performs water main flushing to maintain high quality within our system. This routine maintenance moves water systematically through sections of the drinking water distribution system, creating a scouring action to clean the line. The increased flow rate scours the water pipe’s inner walls and helps to remove build-up of naturally occurring debris and sediment. The water is discharged through select fire hydrants onto local roads or other surface areas. System flushing is a universal maintenance technique conducted by public water systems around the world to improve water quality.
The process is critical to the overall maintenance of a distribution system and is one of the most important practices carried out by public drinking water systems to maintain high water quality, improve the carrying capacity of pipes, and ensure proper operation of distribution system components, such as hydrants and valves.
Depending on the length of the line from its supply, hydrants may run for more than one day to expel older water and allow fresh water to move into the system. Water quality is monitored during the flushing process to limit the amount of water that needs to be discharged.
Water delivered to customers near a flushing event could temporarily be discolored, but this should not last long. In the event customers draw discolored water into the home, flush a cold tap for up to 15 minutes.
In most cases, it is not feasible to capture and reuse the water being flushed from hydrants due to the high velocities and volume of water being released. If you are flushing water to clear out your own pipes from your home faucet or outdoor spigot, you can capture that water and reuse it for watering plants or other uses.
Flushing may be done at any time depending on the situation, particularly if there has been a water main break that requires emergency flushing during off hours. However, planned flushing for distribution system maintenance is more commonly done during daylight when it is safer for our employees to work in the streets.