Drinking Water Operations

The Water Division is responsible for providing safe drinking water and adequate supply for fire suppression to the community.

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Drinking Water Operations

The division is comprised of two specialized but interrelated groups, Distribution and Quality. The Distribution crew balances emergent repair work with scheduled maintenance programs for pressure-reducing valve stations, hydrants, and mainline valves. They are also responsible for system flushing, and utility locating. The Quality crew is responsible for meter reading and management, well and pump station operations, regulatory sampling, and cross-connection control.

The team operates and maintains-

  • 335 Miles of Water main
  • 12,800 Mainline valves
  • 4,200 Fire hydrants
  • 100 PRV stations
  • 5 Wells
  • 7 Reservoirs including 2 booster stations
  • 3 Pump Stations
  • 20,000 water services and meters
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Backflow Prevention


Backflow is the undesirable reversal of the flow of water or mixtures of water and other undesirable substances from any source (such as used water, industrial fluids, gasses, or any substance other than the intended potable water) into the distribution pipes of the potable water system. 

Cross Connection Control Program

A home owner or business owner is responsible if their water system contaminates the public water system. Your participation in the program is critical in assisting us to continue to deliver safe, reliable drinking water.

The City of Redmond, (Redmond-Municipal-Code-1310) in conjunction with the Washington State Department of Health (WAC 246-290-490) , requires customers within the Redmond water jurisdiction, that have the potential to back-flow water into the public system to install and maintain backflow assemblies. The most common concerns for residential customers are lawn irrigation and fire suppression systems.

A cross connection is an actual or potential pathway between our drinking water supply and a source of contamination or pollution. In our homes and businesses, water is often used to dilute, mix, cool and clean. Potable water may come in contact with dangerous chemicals and substances. Cross connected plumbing may put your drinking water in contact with contaminated water.  

The City of Redmond surveys commercial and residential properties to ensure cross connection compliance and safe drinking water quality. The need for cross connection control exists in all types of premises, whether industrial or residential.

Annual Testing

The City mails out reminder letters annually to all businesses and homeowners that need to have their assemblies tested. This is a simple testing procedure and mandatory for all water users that own a backflow assembly. The test is performed by any State Certified Backflow Assembly Tester, a list of local testers is included in the City’s reminder letter.

You can ensure your tester is certified by visiting Washington Certification Services BAT site where you can search by name or certification number.

If you have an irrigation system, fire system or any other potential cross connection and you don’t receive an annual letter from the City to test, please give us a call. We are pleased to help if you think you may need a backflow assembly or need information on how to get yours tested.

Protect Your Pipes From Winter Weather

When temperatures drop below freezing, water within fire sprinklers and some water pipes are susceptible to freezing. When the water thaws, the pipes can break. To prevent damage to pipes, sprinkler heads should be kept at 45° F (7° C), and we recommend heating interior spaces to a minimum of 50°  F (10° C).                           

Prepare Your Pipes

  • Know where your shut-offs are. In an emergency, you will need to know your main shut-off and any shut-off valves inside your house.
  • Warm unoccupied interior spaces to a minimum of 50° F (10° C). Fire sprinkler heads should be kept at 45° F (7° C) or more.
  • Protect water pipes from freezing in exposed or unheated areas (attics, basements, and garages) by wrapping them with tape and insulating materials from hardware stores. Follow the manufacturer's installation instructions.
  • Drain and remove all outdoor hoses.
  • Caulk around pipes where they enter the house and close all foundation vents to minimize cold wind from blowing into your home. Pipes exposed to drafts from open foundation vents are most at risk of freezing or splitting during cold weather. Close off these vents by sliding cut pieces of wood or foam blocks into the vent openings (open the vents again in the spring to prevent dry rot).
  • If you have a separate shut-off valve for outside faucets, now is the time to shut it off. Then go outside and turn on all faucets to drain the water from the pipes.
  • If you don't have a separate shut-off valve, wrap outside faucets or hose bibs (if you choose, foam-insulated covers are available for about $3 at hardware stores).
  • Shut off and drain in-ground sprinkler systems. Follow the manufacturer's instructions.


If Pipes Break or Freeze

If a water pipe breaks, close the main shut-off valve immediately to stop flooding. The shut-off valve can be indoors or outdoors, usually in a basement, crawlspace, or garage. If you cannot turn off the main shut-off valve, Redmond customers can call 425-556-2800 for assistance.