The short answer
Quick answer: parts of Bothell, WA flood, mostly low spots along North Creek and near the Sammamish River during heavy winter rain. The city's hazard plan lists December 2007 as its most recent significant flood. Flooding in the region is most common from October through April. This guide is for Bothell homeowners checking their risk.
Bothell has a documented flood history, but the city's own pages name few places. The specific streets below come from news reports of real events, not from a risk map, so use them as examples of where water has collected, and check your own address on the official flood maps.
When does Bothell flood?
King County says flooding and high water are most common from October through April, during heavy rainfall or rapid snowmelt, and that its rivers have flooded in every month except August.
| When | What was reported in Bothell |
|---|---|
| Dec. 1 to 17, 2007 | The city's hazard plan lists this as the most recent significant flood, with some homes and a business park evacuated. |
| Dec. 12, 2010 | During a storm, the Sammamish Slough overflowed into the amphitheater at the Park at Bothell Landing (just under three feet of water), North Creek spread past its banks near 228th Street SE, and clogged drains flooded roads. |
| Jan. 21, 2016 | Persistent heavy rain caused a manhole overflow on King County's North Creek Interceptor sewer line, near 208th Street SE and 14th Drive SE. |
| Feb. 6, 2020 | The city kept 240th Street SE at 35th Avenue SE closed because of flooding, closed the eastbound lane of 120th Avenue NE between NE 195th Street and North Creek Parkway N, and the National Weather Service flood watch for Bothell continued through Feb. 7. |
| Dec. 2025 | King County describes extensive flooding across the region. We found no source describing Bothell-specific damage. |
Sources: King County: Flood Warning System; King County Regional Hazard Mitigation Plan: City of Bothell annex (2025); Bothell-Kenmore Reporter: Flooding in Bothell, from the streets to the slough (Dec. 13, 2010); Bothell Reporter: Heavy rains cause manhole overflow in Bothell (2016); Bothell-Kenmore Reporter: Flood watch for Bothell, Kenmore (Feb. 6, 2020); King County: Flood recovery.
Where flooding has been reported in Bothell
These are places a news report or official notice named during a real flood. They are examples, not a complete list and not a risk map.
| Place | What was reported | Year |
|---|---|---|
| 120th Avenue NE, north of NE 195th Street | Completely covered with water and closed, with traffic detoured to North Creek Parkway. Closed again in part in 2020. | 2010, 2020 |
| North Creek Business Park and North Creek Parkway | A hotel parking lot held about three inches of water, and water rose to curb level along 120th Avenue NE. | 2010 |
| 228th Street SE at the North Creek bridge, just east of Fitzgerald Road | Water covered the road until a city crew pumped a clogged storm drain. North Creek spread into a large field nearby. | 2010 |
| 35th Avenue SE and 240th Street SE | Flooded intersection in 2010, and closed because of flooding in 2020. | 2010, 2020 |
| Park at Bothell Landing | Amphitheater filled with just under three feet of water overflowing from the slough. | 2010 |
| 39th Avenue SE, just east of Bothell | Snohomish County Public Works crews cleared clogged drains after backed-up water ran down the road. | 2010 |
Sources: Bothell-Kenmore Reporter: Flooding in Bothell, from the streets to the slough (Dec. 13, 2010); Bothell-Kenmore Reporter: Flood watch for Bothell, Kenmore (Feb. 6, 2020).
How water gets into Bothell streets and homes
The reported causes fall into four groups: creeks and the river spilling over, clogged storm drains, sewer lines overloaded by rain, and groundwater and stormwater leaking into sewer pipes.
| How | What the sources say |
|---|---|
| Creek or river overflow | In 2010, North Creek spread past its banks near 228th Street SE and the Sammamish Slough overflowed at Bothell Landing. |
| Clogged storm drains | In 2010, drains on 228th Street SE and 39th Avenue SE backed up and flooded the road. The city says leaves covering storm drains cause localized flooding and asks residents to rake drains clear. |
| Sewer line overflow | In January 2016, heavy rain caused a manhole overflow on a King County sewer line that serves the Bothell area. |
| Rain in the sewer pipes | King County says groundwater and stormwater enter sewer pipes through cracks, joint failures, faulty connections, roof downspouts, foundation drains, storm drain cross-connections and holes in manhole covers. It estimates this extra water makes up 75 percent of peak winter sewer flows countywide and contributes to overflows into homes. |
King County adds that most of this extra water comes from aging infrastructure, particularly side sewers on private property. If sewage is already in your home, see sewage cleanup in Bothell and who pays for a sewer backup in Bothell.
Sources: Bothell-Kenmore Reporter: Flooding in Bothell, from the streets to the slough (Dec. 13, 2010); City of Bothell: Flood prevention; Bothell Reporter: Heavy rains cause manhole overflow in Bothell (2016); King County: Infiltration and Inflow Control Program.
What the city's hazard plan says
The City of Bothell's 2025 hazard plan annex names North Creek as its flood waterway, says minor flooding happens fairly often in low spots along North Creek, and lists December 2007 as the most recent significant flood.
- About 6.10 percent of the city's land is in FEMA Special Flood Hazard Areas.
- About 3.39 percent is in Zone X, which the plan describes as protected by a levee.
- The plan reports no repetitive-loss properties in Bothell.
A caution about the levee. A Snohomish County fact sheet says the North Creek levee in Bothell is not accredited, and that areas behind it keep their current flood designation for now and will be re-mapped later. The fact sheet shows no year, and the two documents describe the same area differently. Ask the city or Snohomish County for the current status of your address before you rely on levee protection.
Sources: King County Regional Hazard Mitigation Plan: City of Bothell annex (2025); Snohomish County: North Creek levee fact sheet (Bothell).
King County side or Snohomish County side?
Bothell sits in both counties, with roughly 60 percent of its population in the King County part and 40 percent in the Snohomish County part, according to the city's hazard plan and the state's population estimates.
That matters because each county, and the city, handle flood information, permits and some services separately. The FEMA Flood Map Service Center covers both sides, and the city can tell you which county serves your address. Look up your address on the FEMA Flood Map Service Center. Flood insurance is a separate policy, and coverage usually starts 30 days after purchase, so don't wait for a storm. See WA Office of the Insurance Commissioner: Flood insurance.
Sources: King County Regional Hazard Mitigation Plan: City of Bothell annex (2025); WA Office of Financial Management: April 1 population estimates; WA Office of the Insurance Commissioner: Flood insurance.
Alerts: what covers Bothell and what doesn't
King County's free Flood Alerts cover major rivers only: the Cedar, Green, Tolt, White, Issaquah Creek, South Fork Skykomish and the Snoqualmie basin. The Sammamish River and North Creek are not on that list.
- Also sign up for ALERT King County and your local jurisdiction's alerts, by phone, text and email, as King County suggests.
- NOAA Weather Radio and USGS WaterAlert are other options King County recommends.
- The King County Flood Warning Center (206-296-8200) is staffed around the clock, with live representatives during flood events. Call 911 in a flood emergency.
- For minor street or drainage flooding, call City of Bothell Public Works at 425-488-0118, option 1.
- Follow flood watches and warnings from the National Weather Service Seattle/Tacoma.
Sources: King County: Flood Warning System; City of Bothell: Rain and flooding; National Weather Service Seattle/Tacoma.
If water is already in your home
Start with the safety steps and claim checklist on our flood cleanup in Bothell page. For indoor leaks and burst pipes, see water damage restoration in Bothell. For what insurance usually covers, see water damage insurance in Washington.
Questions about flooding in Bothell
Is Bothell, WA in a flood zone?
Parts of it are. The City of Bothell's hazard plan says about 6.10 percent of the city's land is in FEMA Special Flood Hazard Areas, and it names North Creek as its flood waterway. Whether your home is in one depends on your address, so look it up on the FEMA Flood Map Service Center or ask the city.
When does Bothell flood?
King County says flooding and high water are most common from October through April, during heavy rainfall or rapid snowmelt, and its rivers have flooded in every month except August. Bothell's best-documented floods, in December 2007 and December 2010, both fell inside that window.
Does North Creek flood in Bothell?
In low spots, yes. The city's hazard plan says minor flooding happens fairly often in low spots along North Creek. In December 2010 the Bothell Reporter photographed the creek spreading past its banks into a large field near 228th Street SE, while a city crew pumped a clogged drain nearby.
Will I get a flood alert for the Sammamish River or North Creek?
Not from King County's free Flood Alerts, which cover major rivers like the Cedar, Green, Tolt and White, not the Sammamish River or North Creek. King County suggests also signing up for ALERT King County, NOAA Weather Radio and your local jurisdiction's alerts by phone, text and email.
Why does my sewer back up when it rains?
Rain can overload sewers as well as streets. King County says groundwater and stormwater leak into sewer pipes through cracks, faulty connections, downspouts, foundation drains and manhole covers, and that this extra water contributes to overflows into homes. It adds that most of it comes from aging side sewers on private property.
Which flood map applies to my Bothell address?
Bothell sits in both King County and Snohomish County, so your address matters. Roughly 60 percent of the city's population lives in the King County part and 40 percent in the Snohomish County part. The FEMA Flood Map Service Center covers both, and the city can confirm your side.