VACAVILLE, Calif. – The City of Vacaville Utilities Department will begin its annual Hydrant Flushing and Valve Exercising Program no earlier than February 9, 2026, with work expected to continue through March 2026.

This annual maintenance program is essential to maintaining water quality and ensuring the reliability of the City’s water distribution system. During flushing, fire hydrants are opened to move large volumes of water through water mains at high velocity while system valves are exercised. This process removes sediment and mineral buildup and ensures that hydrants and valves operate properly for fire protection and system reliability.

The City is broken down into Utility Work Zones for field staff to complete maintenance and repairs. The 2026 program will take place in the northwestern quadrant of the City, which is Utility Work Zones 10, 11, and 12 (map on second page of this release).  Geographically, this area is generally located north of Interstate 80 and east of Browns Valley Parkway.

Only select hydrants and valves will be utilized for hydrant flushing in each Zone. Physical signage will be posted in the specific neighborhoods in which hydrants are being flushed. Each Zone will be completed prior to moving onto the next Zone. The City will begin with Zone 10 and will continue in numerical order. Each Zone will take approximately two to four weeks to complete.

Regular updates will be made to the City’s Hydrant Flushing webpage, including the areas in which work is taking place. Information will also be shared on City social media and Nextdoor. When completing hydrant flushing, field crews will coordinate with other scheduled City services to lessen the physical impact in neighborhoods, e.g., the City will avoid Recology collection days.

What Residents and Businesses May Experience

During flushing activities, customers in affected areas may notice reduced water pressure and temporary water discoloration. Discoloration is caused by harmless particles being stirred up during flushing. The water continues to meet or exceed all state and federal drinking water standards and typically clears shortly after flushing is completed. Residents are advised to check water clarity before doing laundry, particularly when washing white clothing. Commercial customers, especially businesses that serve the public, should also be aware of potential temporary water quality changes during flushing in their area.

Environmental Protection Measures

As part of the physical hydrant flushing process and after water leaves the water system via the hydrant to the City vehicle, environmentally safe dichlorination tablets are added to remove chlorine from the flushed water before it enters the storm drain system. Due to the high velocity of water, these tablets may cause bubbling that gives the water a soapy appearance as it leaves the City vehicle. This is normal and does not pose an environmental concern.

While hydrant flushing may appear wasteful, it is a necessary practice to sustain high water quality and maintain a safe, reliable water system. The City of Vacaville thanks residents and businesses for their patience and apologizes for any inconvenience this program may cause.

For questions or concerns, please contact the City of Vacaville Utilities Department at (707) 469-6400.

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Contact: 
Joanna Leal
Public Relations Manager
707.449.5106
Joanna.Leal@CityofVacaville.gov