FAQ
What is happening on April 23rd?
On April 23, 2026, school districts in Puyallup, Sumner, Orting, Bonney Lake, Buckley, Carbonado and Wilkeson are practicing the evacuation procedures and shelter-in-place procedures (for those out of the immediate path of a lahar) that would really happen if the valley experiences the impact of a lahar from Mount Rainier.
What is a lahar?
Lahars are rapidly moving flows of water, mud, rock, and woody debris that originate on volcanoes. They can flow almost as fluidly as water yet be as dense as wet concrete. They commonly accompany volcanic eruptions but can also develop from landslides that occur on steep volcano slopes in the absence of any eruptive activity. Lahars triggered without an eruption are known locally as “no-notice lahar.” In such cases, lahars may occur without warning, accentuating the importance of anticipating their downstream behavior and hazards.
Large lahars can bury nearly everything in their paths, leaving behind deposits of rocky sediment. Lahars can flow many miles downstream from the volcano. Lahars can occur by rapid melting of snow and ice during eruptions, by liquefaction of large landslides (also known as debris avalanches), by breakout floods from crater lakes, and by erosion of fresh volcanic ash deposits during heavy rains.
Lahars can range significantly in magnitude. The Osceola Lahar produced by Mt. Rainier over 5,000 years ago resulted in a flow 460 feet deep, which covered an area of 130 square miles. Lahars can also range in speed. Smaller lahars may only reach up to a few meters per second. However, larger lahars can reach speeds of over 20 miles per hour. In steep areas, lahars can exceed speeds of 120 miles per hour.
Why are we doing an exercise?
A future eruption or large lahar could risk thousands of lives and infrastructure in Pierce County. The best way to mitigate volcano hazards is to ensure local communities know the threats and take steps to minimize risk.
Mount Rainier has erupted many times over the course of thousands of years. The largest ash-producing eruption occurred about 2,200 years ago, and the most recent eruption occurred about 1,000 years ago. About 500 years ago, the collapse of weakened rocks caused a large lahar at Mount Rainier called the Electron Mudflow. That lahar traveled through the Puyallup River valley.
When is this happening?
The full-scale exercise will occur on Thursday, April 23, 2026, from 9:00 am to 12:00 pm. During that time, all participating school districts will evacuate their students along their lahar evacuation routes. Schools that are outside of the lahar zone will practice their shelter-in-place procedures.
Who is involved?
The following agencies have organized and are participating in this exercise:
- Puyallup School District
- Orting School District
- Sumner-Bonney Lake School District
- White River School District
- Carbonado Historical School District
- City of Puyallup
- City of Orting
- City of Sumner
- City of Bonney Lake
- City of Buckley
- Town of Carbonado
- Town of Wilkeson
- Town of South Praire
- Central Pierce Fire and Rescue
- East Pierce Fire and Rescue
- Cascade Christian Schools
- All Saints Catholic School
- Northwest Christian School
What are the impacts of this exercise on downtown Puyallup?
You may notice a large number of pedestrians, specifically school children, walking on the sidewalks through downtown. If you are driving downtown, please drive slowly and watch for people crossing the street.
Please plan your day accordingly if you live downtown near the school evacuation routes. Increased pedestrian traffic will mean longer commute times in and out of downtown.
What are the impacts of this exercise on South Hill?
All students will walk their evacuation routes to a specified evacuation exercise location. In the event of an actual lahar, all schools in the lahar hazard zone have a designated school out of the lahar hazard zone. Schools in South Hill, which are out of the lahar zone, will be practicing shelter-in-place procedures. There will still be a large number of students walking from downtown up the hill to their pre-determined evacuation locations. Please drive slowly and watch for pedestrians crossing the street.
What are the impacts of this exercise to Sumner?
As all Sumner schools participate, Sumner Police and Public Works will guide a rolling shutdown of roads. Drivers in and through downtown Sumner will experience delays and should plan accordingly, especially on Valley Avenue, Main Street, and 160th Street. Staff will reopen roads as soon as students clear the area as quickly as possible, but student safety remains the priority.
Can I participate in the exercise?
This exercise is for students and faculty only. To ensure security and student safety, only students and teachers are allowed to walk the evacuation route together.
However, this exercise provides a great reminder for all ages to update and check their lahar preparation tips. For a list of preparation tips, please go to our page here.
What are some things I can do to be prepared?
Planning in advance helps you respond to any kind of unexpected emergency including lahar, earthquake, wildfire or flood.
Make a Plan – Identify the evacuation route nearest you to the places you commonly visit in the valley, including home, work, or school. Make a plan for how you are going to evacuate. Write down a list of family members and their contact information, and create an action plan that answers some questions, including “What escape routes are in my home?” “If separated, what is our meeting place?” “If I cannot return home, where do I go?”
Know what’s happening – Cities in Pierce County have localized alert systems in addition to the county-wide County system. Choose to receive updates about this exercise and/or real emergencies by text, phone, email, or the app. Sign up today:
To sign up for alerts in your community, please contact your local government agency.
Have an Emergency Kit – Make sure it includes such things as an N95 mask, first aid, water, food, flashlight, blanket, cell phone charger, change of warm clothes, and other items.
Communicate – Have a list of your immediate friends and family members’ phone numbers available. Make sure to establish regular contact with them before, during, and after an emergency.
For more lahar tips, visit our website. To see the recently updated regional lahar evacuation routes, visit the newly launched East Pierce Interlocal Coalition for Emergency Management website at www.epiceoc.com.
I am a parent/guardian of a student who is participating. Can I walk the route?
Participation on April 23rd is limited to the participating schools and pre-screened volunteers. This is a great opportunity for parents and guardians to talk more with students who are participating about your home’s plans in the event of a lahar or other disaster.
What about students who are not able to walk their routes?
The exercise planning team and all participating schools plan for students and staff with access and functional needs to ensure they can participate in the exercise. We encourage everyone who lives, works, or recreates in the lahar impact area to have a plan and be ready. Pedestrian and vehicular routes, as well as evacuation locations, are available on the www.epiceoc.com website.
I live/work in the area and must drive during the exercise. What should I do?
In short, avoid the impacted areas as much as possible that morning. There will be thousands of students and faculty out that morning. In Puyallup and Orting, that means lots of pedestrian traffic using the sidewalk and crosswalks. In Sumner, that means the rolling closure of key roads, including Main Street, Valley Avenue, and 160th Street. There will also be additional police present to make sure the kids can get to their destination safely.
If you live in one of the impacted areas – please adjust your driving plans accordingly to avoid frustration. You may also want to time any major deliveries/repair work to avoid delivery vans, etc., trying to access an area that is temporarily closed or heavily congested.
If you own a business in the impacted areas, especially one that schedules appointments with clients, please warn clients to allow extra time or reschedule for that afternoon to avoid frustrating customers.
If a lahar does happen, how will I be notified?
You will be notified in a few ways. First, the lahar sirens will sound. These are the sirens tested throughout the Valley on the chime setting on the first Monday of every month at noon. In a real emergency, they would alert you on the full “wail” setting. To listen to how those sound, click here (https://www.piercecountywa.gov/5888/Outdoor-Warning-System).
Remember that even at full wail, the sirens are intended to alert people outdoors. To help alert people in other, indoor settings, people should sign up for their local/regional alert systems.
Who do I contact if I have questions?
If you are a reporter or news media representative with questions about the exercise, please contact Eric Johnson, Public Affairs Officer, via email or 253-344-6269. If you are a member of the public with questions about the exercise, please email our Emergency Manager Kirstin Hofmann.
Additional media contacts for specific locations/topics:
For City of Sumner: Carmen Palmer, [email protected]
For USGS (more info about lahars and eruptions): Holly Weiss-Racine, [email protected]
