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Frequently asked questions about the Flood Warning System and app

The purpose of the King County Flood Warning System is to warn you about rising floodwaters on major rivers so you can prepare before serious flooding occurs. In most places, the warning system provides at least 2 hours lead time before floodwaters reach damaging levels.

Use the links below to sign up for e-mail or phone flood alerts to get advance notice of flooding in your area and download the phone app to access river data anytime.

A list of frequently asked questions about the Flood Warning System is provided on this page. For general information about the system, visit the Flood Warning System page

About the Flood Warning System

When does flooding and high water typically happen in King County?

Flooding and high water are most common from October through April during periods of heavy rainfall or rapid snowmelt. Historically, King County rivers have flooded in every month but August.

What other information is available from the Flood Warning Center?

King County works closely with the National Weather Service to obtain forecast information used to make flood predictions. Close coordination occurs with King County’s Office of Emergency Management, Roads, and other agencies to obtain up-to-date information about problems sites, road closures, evacuations and other emergency services. Coordination also occurs with the U.S. Army Corps of Engineers and Seattle Public Utilities regarding dam operations. Personnel at the Center are available to answer questions and help interpret gage readings during a flood event. Current river and flood information is always available through the phone menu system.

Call the Flood Warning Center at: 206-296-8200 or 800-945-9263.

About the Sign-Up Form

How many alert lists can I sign up for?

You can sign up for as many of the rivers and flood phases as you like. 

Note that the three public phase alerts for each river are issued separately. If you want to get alerts for each phase on a river, check all three boxes for that river. Learn more about the phases of flood alerts on our Flood Warning System page.

How will I know I'm signed up?

If you signed up on the webpage (https://green.kingcounty.gov/floodalertsystem), you can log in using your e-mail address and password to confirm your subscriptions. If you don't remember your password, there is a password reminder feature which will e-mail your password to you.

If you no longer have access to the e-mail address you used to sign up, don't have e-mail, or need further assistance, you can call 206-477-4899.

Why do I keep getting a "server busy" message?

You may be redirected to this page for a number of reasons – in order to serve as many people as possible, our subscription form limits the number of accounts you can sign up for at once. If you need to sign up multiple people for alerts (for example, family or co-workers), you can add more the next day or call 206-477-4899. You may also see this page due to a large number of people signing up at once. Please try again later.

Is my contact information kept private?

Please see the King County’s privacy policy. Your contact information is provided to our message-delivery vendor, Konexus for the sole purpose of delivering flood alerts by e-mail, text message, and/or phone. The county does not sell or rent information to others and takes steps to safeguard your information. However, as a public entity, your information may be subject to public disclosure as directed by local, state, or federal laws.

About the alert messages

Where do the messages come from?

King County has contracted with the vendor Konexus for message delivery. E-mail and text messages will come from the address msg@mail1.alertsense.com – you may need to add this address to your "allowed sender" list or adjust spam-blockers to receive the alerts. Phone messages will come from the phone number 206-296-8200.

Will I get phase alerts when the river levels go down?

No, the Phase 2, 3, and 4 alerts are only issued as the rivers rise past the phase thresholds. They are not re-sent as the rivers recede back past the thresholds again. However, if a river falls and the phase is lowered, and then later the river rises above the next threshold again, a second alert may be issued.

Will I receive any other alerts besides the ones I signed up for?

You will also be added to a "River emergency" list for each river you signed up for. The "River emergency" alerts will be used for any flood-related emergency. If you receive a "River emergency" alert, please check your local news media, King County flood services, or call 206-296-8200 or 800-945-9263.

What does "River emergency" mean?

The "River emergency" alerts will be sent for emergency conditions that do not fall within a Phase 2, Phase 3, or Phase 4 declaration. Possible examples of a “River emergency” alert could include events such as levees being damaged or overtopped, a chemical spill into a river, etc. Because of the wide range of possible emergencies, the alerts themselves are not specific. If you receive a "River emergency" alert, you will need to consult other sources (e.g., news media or the Web) for more information.

An example of a "River emergency" alert:

"This message is to inform you of emergency conditions associated with the Tolt River. For more information, see King County flood services or call 800-945-9263."

How do I sign up for the "River emergency" alerts?

You are automatically signed up for emergency alerts for any rivers you sign up for. For example, if you sign up for Cedar River Phase 2, 3, or 4 you will also be added to the Cedar River Emergency alert list.

Do you issue alerts for other rivers or streams?

The Flood Alert System only issues alerts for six major rivers in King County: Cedar River, Green River, Issaquah Creek, South Fork Skykomish River, Tolt River, White River, and the Snoqualmie Basin. River gage data is available online for other river systems (e.g. Skykomish River and Raging River) at King County flood services.

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