04/22/2026
WHY DOES THE CITY/COUNTY FLUSH WATER LINES AND FIRE HYDRANTS?
Residents who notice Water Department crews working at fire hydrants and see water running into the street may think that the Department is ignoring its own philosophy of conserving our water resources. The process of periodically "flushing" water lines with fire hydrants, however, is an important preventive maintenance activity. Although it may appear to waste water, this process is part of a routine maintenance program necessary to maintain the integrity of the water system and allowing us to continue to deliver the highest quality water possible to our customers.
The flushing route is carefully planned, and valves are opened and closed to control the direction of the water flow. Flushing the water system on a routine basis removes sediment from lines and keeps the entire distribution system “refreshed”. As a result of the line flushing process, residents in the immediate vicinity of the work may experience temporary discoloration of their water. This discoloration consists primarily of harmless silt and air and does not affect the safety of the water. If you experience discoloration in your water after crews have been flushing in your neighborhood, clear the pipes in your own home by running all water faucets for a minute or two.
This same philosophy of water line preventive maintenance is one that you should use in your own home to ensure the quality of water inside your home. Your home's water heater should be drained and flushed on a regular basis, according to manufacturers’ recommendations, to keep it working effectively and efficiently.
Also, if you go out of town and there is no water use in your home for a week or more, when you return, it's always a good idea to run all your faucets for a minute or so before using the water. This ensures that you don't use any stagnant water that may have developed in your home's pipes while you were away. Water your house plants with this potentially stagnant water so it’s not wasted.
FREQUENTLY ASKED QUESTIONS
• Why does the water system need to be routinely flushed?
• What should I do when I see crews flushing hydrants in my area?
• What should I do after the flushing?
• Why does my water look funny after hydrant flushing?
• Won’t flushing hydrants also cause problems by “stirring-up” sediment up in the water?
• What can water users do about temporary disturbances that may accompany flushing activities?
• Is it OK to drink sediment-laden or discolored water during temporary disturbance events? • Is systematic flushing of distribution systems something “new” or is this a common water utility practice?
• What are the benefits of a flushing program?
• What about flushing for non-routine water quality problems such as a known contamination event?
• How is the flushing program related to hydrant testing by the fire departments?
• How can I find out when hydrant flushing crews will be in my area to perform these annual line flushing activities?
Q: Why does the water system need to be routinely flushed?
A: The treated water distribution system is a complex network of pipes and storage reservoirs where sediment or deposits may naturally accumulate over time. If not removed, these materials may cause water quality deterioration, taste and odor problems or discoloration of the water. Water may also stagnate in less-used parts of the distribution system. This can result in degraded water quality. The normal flow of water through the system will reduce some, but not all of these accumulation and stagnation problems over time, thus supplemental measures are periodically needed to clear out the system. Systematic flushing of fire hydrants in a unidirectional fashion is an effective way to accomplishing this needed cleaning.
Q: What should I do when I see crews flushing hydrants in my area?
A: If you see a crew flushing hydrants on your street or in your neighborhood, avoid running tap water, your washing machine or the dishwasher until the flushing is complete. If you see hydrant flushing crews working in the area, please drive carefully and treat them like any other construction crew. DRIVE SAFELY.
Q: What should I do after the flushing?
A: If the tap water is used during flushing, it could come out full of sediment and discoloration. If you encounter discolored water, shut the water off and wait several minutes. After waiting, check the clarity by running cold water for a few minutes allowing new water to work its way into your pipes. If not, wait a few more minutes and check again. In some cases, you may experience slight discoloration for a few hours. This discoloration only affects the appearance of the water; it does not affect the taste or water quality. Avoid washing laundry during scheduled flushing times. Wait until the water is clear from the tap, and then wash a load of dark clothes first. If pressure or volume seems low, check your faucet screens for trapped debris.
Q: Why does my water look funny after hydrant flushing?
A: When a hydrant is opened, there will always be temporary incidences of discolored water containing fine sediment particles. There is no health hazard associated with discolored water. Allow a few hours for discoloration to dissipate. To verify the water has settled allow your cold water tap to run for a few minutes.
Q: Won’t flushing hydrants also cause problems by “stirring up” sediment in the water?
A: While the long-term benefits of systematic flushing are well-documented, individual flushing activities may cause temporary disturbances in the water system. These could include water with sediments or discoloration, or temporary disruption of service.
Q: What can water users do about temporary disturbances that may accompany flushing activities?
A: Running several cold water taps at full force for a short period will usually flush out sediment laden or discolored water. A general recommendation is to flush for up to 10 minutes - if the water is not clear, wait for half an hour before flushing for up to 10-minutes again. Running water in a garden hose is often an effective way to flush, as the water can also be used for landscape watering. Clothing should not be laundered during such events as clothing may be stained. It is also best not to use hot water until the water has cleared to avoid drawing sediment into the water heater.
Q: Is it OK to drink sediment-laden or discolored water during temporary disturbance events?
A: It is recommended that water users wait until the water has cleared before using it for potable purposes.
Q: Is systematic flushing of distribution systems something “new” or is this a common water utility practice?
A: The procedure is considered a best management practice for distribution system water quality protection and maintenance and is commonly used by rural & municipalities nation-wide.
Q: What are the benefits of a flushing program?
A: The development and implementation of the Water Districts flushing program can improve both, water quality and hydraulics. It can improve water quality by restoring disinfectant residual, reducing bacterial re-growth, dislodging bio-films, removing sediments and deposits, controlling corrosion, restoring flows and pressures, eliminating taste and odor problems, and reducing disinfectant demand throughout the distribution system. These efforts should prolong the life expectancy of the distribution system.
Q: What about flushing for non-routine water quality problems such as a known contamination event?
A: Having a flushing program also provides capability for rapid and effective removal of potentially harmful water if a contamination event were to be detected in the drinking water system. This could represent a key component for emergency response to potential accidental or willful contamination of the potable water system.
Q: How can I find out when hydrant flushing crews will be in my area to perform these line flushing activities?
A: The Water Department publishes a schedule of these activities on the website. Please remember that this schedule is only a planning tool and may be off by a day or two due to problems that may be encountered in the field from time to time.
