Sacramento County Water Agency

Hydrant Flushing

Why We Do It​...

You have probably seen it many times and thought to yourself, “what a waste of good clean water!” Flushing hydrants can be frustrating to residents. While it may seem like a waste of good clean water, flushing of hydrants is essential to keeping your water safe and maintain the integrity of a pipe network. Flushing hydrants can be done to not only test the fire flow capacity in the event of a fire, but also to remove sediment and rust from the water, or to maintain proper chlorine concentrations in your area.

Sacramento County Water Agency flushing crews work from 7 a.m. to 4 p.m., Monday through Saturday to provide our customers with the absolute best water quality possible.

What is the Water Main (Hydrant) Flushing Program?

To improve water quality and minimize discoloration, Sacramento County water mains are comprehensively flushed by a technique known as unidirectional flushing. The procedure is performed during the year and involves the systematic opening and closing of hydrants, one section of main at a time, to force the water through the pipes at high velocity, removing accumulated mineral sediment until the water is clear. The operation can take from a few minutes to over an hour, although most last about 30 minutes.

Unidirectional flushing differs from conventional flushing in that it involves the closing of adjacent valves and the use of a single hydrant per flush so as to isolate individual sections of main. Conventional flushing also removes accumulated sediment from pipes, but it involves the flushing of multiple hydrants at a time and does not include turning off the valve of individual sections of main, thereby diminishing the “scouring” efficiency. Conventional flushing is used in areas of the county where fewer minerals build up in the mains.

The main objective of water main flushing is to clean the pipes & improve water quality. Flushing removes & aids in the following:

  • Accumulation of sand, silt, iron & manganese in the distribution system
  • Degraded water
  • Biofilm formation
  • Circulates chlorinated water into areas that have become depleted of free available chlorine
  • Decreased taste and odor problems, customer water quality complaints
  • Decreased Total Trihalomethanes & Haloacetic acids disinfection by products
  • Safe Drinking Water Act primary and secondary regulatory compliance

How Will Flushing Affect Water Service?

When flushing crews are working close to your residence or business, you may experience periods of very low pressure or even a complete stoppage of service. We attempt to always maintain a constant water pressure and to not lose water service, but outages do occur.

We ask for your patience and understanding during this critical main cleaning process. If you have any concern or questions please don’t hesitate to call 3-1-1.