Hydrant Flushing

Hydrant FlushingUPDATED  April 4, 2018

The City of Napa Water Division is currently conducting our annual Hydrant Flushing Program. This year's program is expected to continue through April 2018. View the Press Release (PDF) for full details.

City staff will isolate the flushing areas by closing pre-selected system valves. This state of the art program directs the water to flow in one direction ("unidirectional") and increase the velocity of the water in the pipes, thus more effectively removing particles and minerals from the pipe compared to just operating hydrants without closing valves. Although customers will continue to have water service during this program, flushing operations may activate low-pressure alarms on automatic fire sprinkler systems due to temporary reductions in water pressure in the vicinity of flushing operations.

This year's program will take place throughout the City, including Napa Valley Commons (corporate park), Soscol Gateway, portions of Alta Heights and Browns Valley, Silverado Resort, and northwest Napa. View map of the Full City Flushing Area (PDF). At times there may be crews working in 2 or 3 areas simultaneously.

Current Flushing Area

Current Flushing Area 1

Next Flushing Area

Next Flushing Area 1

Hydrant flushing is a periodic maintenance activity to clean and flush the City water mains. Fire hydrants are opened to move a large volume of water at a higher than normal velocity through the mains. This procedure mobilizes particles and minerals that have settled over time and flushes them out of the system. This activity assists the City in maintaining the highest quality of water in the public water system.

The flushing program may cause periods of discolored water and reduced water pressure in localized areas where flushing is being conducted. The discoloration is due to mobilization of particles and minerals by the high velocity water before they are discharged through the fire hydrants. The water will remain safe to use and generally clears within a few hours after flushing has been completed. Residents should monitor their water prior to starting laundry, especially when washing white clothes.

Commercial customers, especially businesses that serve the public, should be aware of the water quality while flushing is taking place in their area. Due to the nature of the program, it is difficult to determine the exact day an area will be flushed; however, on average, each flushing set takes 1 to 3 days to complete, depending on the quantity of water mains to be flushed and the number of valves that are operated.

The City thanks Napa residents and businesses for their patience and apologizes for any inconvenience our program may cause. Please contact the City of Napa Water Division at (707) 257-9521 with any questions or concerns, or consult our Frequently Asked Questions (FAQs) below.