From December 8 to 11, 2025, an atmospheric river dropped 15 inches or more of rain in 72 hours at many Cascade and Olympic sites, prompting a statewide emergency and sandbagging in Renton's Maplewood. River-valley homes flood first, and flood damage needs a separate policy from standard homeowners coverage.
Key takeaways
- From December 8 to 11, 2025, many Cascade and Olympic sites received 15 inches or more of rain in 72 hours, and the governor declared a statewide emergency.
- In King County, Duvall closed NE 124th Street, and residents of Renton's Maplewood neighborhood sandbagged as the Cedar River rose; we found no sourced gauge crest figures, so none is printed.
- River valleys and low ground near the Cedar, Sammamish and creek systems flood first, while hillsides face slope and drainage problems in the same storm.
- Flood is not covered by a standard homeowners policy; it needs a separate NFIP or private policy, and a sewer-backup endorsement does not cover flood.
- Floodwater is Category 3: carpet and pad come out, drywall is cut back and the structure is dried and disinfected, and mold can start within a day or two in a damp climate.
What happened in the December 2025 atmospheric river?
From December 8 to 11, 2025, an atmospheric river brought record river levels to Washington. Many Cascade and Olympic sites received 15 inches or more of rain in 72 hours, the governor declared a statewide emergency, Duvall closed NE 124th Street and residents of Renton's Maplewood sandbagged as the Cedar River rose.
An atmospheric river is a long, narrow band of moist air that moves in from the Pacific and can deliver days of heavy rain. In winter, they fall on mountains where snow levels, soil moisture and river capacity decide how much of the water ends up in valleys.
The details we can source come from news reports by OPB and the Associated Press and by the Kent Reporter. They describe a statewide emergency declaration by the governor, rainfall of 15 inches or more in 72 hours at many Cascade and Olympic sites, a road closure at NE 124th Street in Duvall and sandbagging in Maplewood in Renton.
What we cannot source is how high King County rivers crested. Gauge figures were not found, so we do not print any. If you need them, the National Weather Service and the county's flood warning pages are the places to look.
How is an atmospheric river different from ordinary Seattle rain?
Ordinary Seattle rain is steady and light, spread over a long wet season. An atmospheric river concentrates days of heavy rain into one event, falling on mountains and feeding rivers that run through valleys where people live. The difference is rate, not just total, and rate is what overwhelms drains and banks.
For scale, Sea-Tac's 1991 to 2020 normal is reported at about 39.34 inches a year, with November near 6.57 inches, December 6.07 and January 5.78, according to secondary weather summaries; we did not open the National Weather Service page. The rainy season, roughly October to March, brings about three quarters of the year's rain. Compare that with the 15 inches or more that fell in 72 hours at many mountain sites in December 2025. The places are different, so this is a comparison of scale, not a Seattle rainfall figure.
Ordinary winter rain wets basements slowly through the ground. An atmospheric river adds rivers to the list: water rising from outside rather than seeping from beneath. Both can happen in the same house in the same week, and they are handled and insured differently.
The National Weather Service Seattle office issues flood watches and warnings. If you live near a river or creek, sign up for alerts and read them as instructions, not as news.
Which parts of the Puget Sound area flood first?
River valleys and low ground flood first: the Cedar River valley in Renton, the Sammamish River corridor through Redmond, Kenmore and Bothell, and creeks such as Swamp Creek and North Creek. Slopes and bluffs face a different danger, drainage and landslides, in the same storm.
The notes behind this site describe mapped flood zones in Renton's valley floor, on low ground near the Sammamish River and Bear Creek in Redmond, near the lake and the Sammamish River and along Swamp Creek and Little Swamp Creek in Kenmore, and along North Creek, Swamp Creek and the river in Bothell. Bellevue's Mercer Slough and Kelsey Creek have mapped flood-prone stretches. Our area pages for Renton, Kenmore and Bothell give the local detail.
Hillside neighborhoods sit in a different risk. The same rain that fills a valley saturates slopes, and Seattle maps 8.4 percent of its land as slide-prone. Read the guide on wet winters, slopes and landslide risk in Seattle for what that means.
Kitsap and island communities have their own exposure: storm surge and wind-driven rain on the shoreline, power outages that stop wells and sump pumps and ferry-dependent access. They are separate from the river valleys, and the ferry matters for crews.
| Setting | How water arrives | Examples in our service area |
|---|---|---|
| River valley floor | River rises and overtops banks; storm drains back up | Renton (Cedar River), Kenmore, Bothell, Redmond |
| Creek-side low ground | Creeks overflow into yards and lower floors | Swamp Creek, North Creek, Bear Creek, Kelsey Creek |
| Hillside and bluff | Saturated soil, runoff and slope movement | Seattle hillsides, Edmonds, Seahurst, Mercer Island |
| Shoreline | Storm surge and wind-driven rain | Kitsap shoreline towns, Rich Passage, Liberty Bay |
| Older urban core | Combined sewers surge and push water back to low fixtures | Parts of Seattle |
Is flood damage covered by my homeowners policy?
Usually not. Flood is typically excluded from standard homeowners coverage and needs a separate NFIP or private flood policy. A sewer or drain backup endorsement does not cover flood. The Insurance Commissioner's emergency order after the December 2025 storm did not change policy coverage, and it is no longer active.
The flood program is run by FEMA through the National Flood Insurance Program, and private insurers also sell flood policies. These policies commonly have a waiting period before they take effect, so buying after the forecast is usually too late.
We could not source a Washington Insurance Commissioner page about flood claims, so the rest is the general pattern. Standard policies cover sudden pipe failures but typically exclude ground-water seepage and flood. Sewer backup is usually an endorsement, and that endorsement does not cover flood.
The commissioner's emergency order ran from December 15, 2025 to February 12, 2026, according to a news report, and it did not change what policies cover. Do not read it as a promise of payment. Check FEMA's flood pages and ask your agent which cause of loss applies to you.
What does a flood cleanup involve?
Floodwater is Category 3, so carpet and pad come out, drywall is cut back above the water line, hard surfaces are cleaned and disinfected, and the structure is dried. Silt and contamination mean materials are removed rather than dried in place. Mold can begin within a day or two, so speed matters.
Start with safety. Do not enter flooded areas with live outlets, do not wade through floodwater unless you must and wear boots and gloves. Stay away from water that may carry sewage or fuel. If utilities are on in the flooded area, call a professional to shut them off safely.
Then the work. Crews pump, remove and discard saturated porous materials, scrub silt from hard surfaces and disinfect. They cut drywall and insulation above the water line, open wall bases and set dehumidifiers and air movers. Read flood damage cleanup for the full sequence.
Be patient with the dry-out. In a cool, wet winter, drying is slow. Readings, not appearances, decide when equipment leaves. The EPA advises drying water-damaged materials within 24 to 48 hours to prevent mold.
How should I prepare before the next one?
Know your flood zone, buy flood coverage early, photograph your belongings, move valuables above the floor and know where your shutoffs are. Clear gutters and drains, test sump pumps and keep a plan for outages. Preparation costs little next to a flooded floor.
Start with paperwork. Look up your address on the flood maps and ask your agent about a flood policy. Waiting periods mean that a policy bought the day of a storm will not help. Photograph or video each room, including the contents, and store copies somewhere safe.
Then the house. Raise valuables off basement floors and keep important papers upstairs. Clear gutters, downspouts and storm drains near your property. Test the sump pump and consider a battery backup, because atmospheric rivers come with high winds and power loss.
Finally, plan to leave if you have to. Low ground near a river can become unsafe fast. Ready.gov has checklists for flood readiness. If water has already entered, do not wait for it to recede; call a crew. See storm damage restoration for what to document.
What paperwork should I keep after a flood?
Keep photographs and video of the damage before cleanup, a list of damaged items with approximate value, moisture readings and equipment logs from the drying crew, receipts for emergency steps and a record of every call to your insurer. Together they let an adjuster see the loss as it was.
Start while the water is still visible. Photograph the high-water line on each wall and the standing water on floors. Take wide shots of each room, then close shots of damaged belongings. Do the same for the outside of the house, including any drainage that failed.
Make a list as you discard things. Write what it was, roughly when you bought it and what it cost. Keep one or two samples of materials, such as a piece of carpet or pad, if the adjuster wants to see them. Do not throw out large items without telling the insurer.
Ask your restoration crew for the moisture log, the equipment list and the dates. These are objective and they are what an adjuster uses to judge whether the drying was reasonable. Finally, write down the name and date of every conversation with an insurer or a government office, because flood programs can involve several.
How long does it take for a flooded house to dry out?
It depends on the material, the water and the season, and readings decide, not the calendar. In a cool, humid Puget Sound winter drying is slow, and a flooded finished basement can need equipment running for days. Expect the technician to return to take readings until the framing is dry.
No honest number applies to every house. A garage with a concrete floor dries quickly. A basement with finished walls, insulation and carpet holds water for much longer. The technician tracks progress with a moisture meter and compares it with a dry reference.
Common causes of delay are re-wetting from rain, equipment turned off early, closed-up areas that cannot be reached and walls with trapped moisture that were not opened. Keep equipment on, keep doors closed and report any new water at once.
After drying, rebuilding is a separate job. Permits, drywall, flooring and paint come after the structure reads dry, not before.
Frequently asked questions
How much rain fell in the December 2025 atmospheric river?
Many Cascade and Olympic sites received 15 inches or more in 72 hours, according to OPB and AP reports, and the governor declared a statewide emergency. We did not find sourced King County gauge crests, so we do not print river heights.
Do I need flood insurance if I am not next to a river?
Possibly. Low ground, creeks and storm drains can flood a house away from the main river. Check flood maps for your address and ask your agent. A standard homeowners policy typically excludes flood, and flood policies often have a waiting period.
Does my sewer-backup endorsement cover flood?
No. A backup endorsement does not cover flood. Flood coverage comes from the NFIP or a private flood policy. If both causes were involved in your loss, ask your agent in writing how each is treated.
Is the Insurance Commissioner's emergency order still in effect?
No. It ran from December 15, 2025 to February 12, 2026, according to a news report, and it did not change what policies cover.
Should I throw out everything the floodwater touched?
Porous items such as carpet, pad, mattresses and upholstered furniture usually go, because floodwater is Category 3. Hard items can often be cleaned and disinfected. Photograph before discarding, and ask your insurer what it needs to see.
Sources
- FEMA – Flood insurance (NFIP)
- Ready.gov – Floods
- National Weather Service – Flood safety
- U.S. EPA – A Brief Guide to Mold, Moisture, and Your Home
This guide is general information for King County homeowners, not a substitute for an on-site inspection. Prices are estimates. See our disclaimer.