System flushing is maintenance performed periodically to ensure optimal water quality.
Click here to view the map of current flushing area.
Flushing water mains to maintain water quality is central to the Water Bureau’s system maintenance work. Uni-directional flushing increases the water system’s reliability, operability and emergency preparedness. Flushing methodically works through a whole pressure zone to bring up local chlorine residuals, and test the system gates and hydrants, and clean out accumulated sediments and biofilm. The sediments and biofilm is harmless and exists in all water systems, yet is only discharged under extremely high pressure.
Maintenance of the water system often causes second glances, when water gushes out of a hydrant at a rate of about 800 gallons per minute sending water rushing down neighborhood streets. The public often does not understand that flushing is essential to system maintenance.
Advice to Residents: If a flushing crew is on your street, please do not run water in your home while they work unless it’s necessary. If you experience some discoloration in your water, turn on each cold water faucet and allow it to run for several minutes. This should clear up any discoloration – it’s only temporary. No one will be out of water during flushing. If you experience ongoing water quality problems that does not clear up, please call (503) 823-7525.
If flushing is actively occurring in your neighborhood, please read this important flyer with tips and information about flushing.
The water quality benefits to the system are clear to see when the murky flushed water gushes out. There is peace of mind knowing that when a gate is needed in an emergency shutdown or if a hydrant is needed to put out a fire they can be depended upon to work properly.