Buying a Home in a Flood Zone in Snohomish or King County (2026)

Short answer: Before you make an offer on a house near a river, creek or the shoreline, look the address up on FEMA’s flood map. If the building sits in a Special Flood Hazard Area (an A or V zone) and you’re using a typical mortgage, your lender will require flood insurance, and your homeowners policy won’t cover flooding. Get a flood insurance quote during your inspection period, ask the seller about past flooding and their current policy, and check whether their policy can be transferred to you.

How to look up a property’s flood zone

FEMA’s official flood maps are called Flood Insurance Rate Maps (FIRMs). Lenders use them to decide whether flood insurance is required, and insurers use them to help set rates.

• Anywhere: enter the address on the FEMA Flood Map Service Center. Snohomish County points buyers there and notes you can print a small map of the property, called a "FIRMette."
• Snohomish County: the county adopted updated digital FIRMs for its unincorporated areas in June 2020. Planning and Development Services (425-388-3311) can help with flood map questions. The county says it gives basic flood map information but doesn’t decide whether flood insurance is required for a specific property. That’s the lender’s call.
• King County: enter the address or parcel number in King County iMap and turn on the "Flooding info" and "FEMA 100 year floodplain" layers. The King County Flood Control District also has its own flood risk map. King County iMap layers also show floodways, the 500-year floodplain, areas with reduced risk because of a levee, and channel migration hazard zones.

Snohomish County describes the Special Flood Hazard Area, sometimes called the 100-year floodplain, as land with a 1 percent or greater chance of flooding in any year. The CFPB, citing FEMA, puts it another way: at least a one-in-four chance of flooding over a 30-year mortgage.

When flood insurance is required

Based on: Snohomish County "About the Mandatory Purchase of Flood Insurance" handout (updated May 2018); King County floodplain maps page; FEMA’s NFIP Q&A for real estate professionals (August 2025); CFPB. Ask your lender what it will require on your specific loan.

The coverage a lender requires has to equal the loan amount, not counting the land, or the NFIP maximum, whichever is less. FloodSmart lists NFIP homeowner limits of $250,000 for the building and $100,000 for contents. FEMA’s guide for real estate professionals notes that almost one-third of NFIP claims from 2014 to 2024 came from outside current high-risk areas.

Homeowners insurance doesn’t cover flooding

The Washington Office of the Insurance Commissioner says a typical home insurance policy specifically excludes flood damage. Under RCW 48.27.030, insurers have to tell you that in writing when the policy is issued and again at each renewal. Flood coverage comes from the National Flood Insurance Program (NFIP) through an agent, or from a private insurer. The Commissioner notes that standard NFIP homeowner coverage doesn’t extend to detached buildings and their contents, and that excess flood coverage is available if you need more.

Timing your policy around closing

FloodSmart says an NFIP policy normally takes effect 30 days after purchase, with four exceptions. The one that matters most for buyers: there’s no wait when you buy flood insurance in connection with making, increasing, extending or renewing a mortgage. FEMA’s real estate guide adds that a seller can transfer their NFIP policy to the new owner, whether or not there’s a mortgage. The Insurance Commissioner notes that coverage from a surplus line insurer usually starts right away.

Get a quote early. Premiums depend on the property’s flood risk and features like elevation and rebuilding cost. The CFPB warns that the seller’s premium can be lower than what you’ll pay. FEMA’s guide also says lenders’ flood requirements are worth understanding before you buy, so they don’t hold up closing. Our closing process article covers how the rest of the timeline fits together.

Questions to ask before you’re committed

• What does the seller disclosure say? The Environmental section of the Washington form asks about past flooding, standing water or drainage problems, material damage from floods, and whether there are shorelines, wetlands, floodplains or critical areas on the property. RCW 64.06.020 currently has two versions on the Legislature’s site: one marked effective until January 1, 2027, and one effective January 1, 2027. The questions quoted here appear in both. If your purchase runs across the new year, check which form the seller used.
• Is there an Elevation Certificate? FEMA says it can lower a flood insurance premium. Snohomish County and King County keep elevation certificates for some properties in the Special Flood Hazard Area.
• Has the map been amended? If a property was mapped into the zone even though it sits at or above the base flood elevation, the owner can ask FEMA for a Letter of Map Amendment or a Letter of Map Revision Based on Fill. Ask whether one exists or whether one was ever denied.
• What’s the flood and insurance history? The CFPB suggests asking about past damage and how it was repaired, current coverage and cost, and whether the homeowner policy was nonrenewed in the past five years.
• What can you change later? King County’s floodplain rules require new or substantially improved homes in its unincorporated floodplains to be elevated 3 feet above the 100-year flood elevation. Ask the local permit office before planning a remodel or addition.

Use your contingencies to make room for the insurance quote and any extra inspection, and have your inspector look closely at the foundation, crawlspace and drainage. See what a standard home inspection covers for what a general inspection includes.

FAQ

How do I check if a house is in a flood zone in Snohomish or King County?

Enter the address on FEMA’s Flood Map Service Center at msc.fema.gov, which shows the official Flood Insurance Rate Map and lets you print a small map called a FIRMette. In King County, you can also use King County iMap with the Flooding info and FEMA 100-year floodplain layers turned on. In Snohomish County, Planning and Development Services (425-388-3311) can help with flood map questions.

Is flood insurance required if the house is in a flood zone?

If the building is in a Special Flood Hazard Area, meaning an A or V zone on the FEMA map, and you’re getting a federally backed or federally regulated mortgage, the lender has to require flood insurance. Snohomish County’s handout notes the requirement doesn’t apply when only part of the lot is in the zone and the building itself isn’t. Lenders can also require flood insurance outside those zones.

Does homeowners insurance cover flooding in Washington?

Usually not. The Washington Office of the Insurance Commissioner says a typical home insurance policy specifically excludes flood damage, and state law requires insurers to tell policyholders when their homeowner policy doesn’t cover flood. Flood coverage is a separate policy from the National Flood Insurance Program or a private insurer.

Is there a waiting period for flood insurance when buying a house?

An NFIP policy normally starts 30 days after purchase. FloodSmart lists exceptions, including no waiting period when you buy flood insurance in connection with making, increasing, extending or renewing a mortgage. FEMA’s real estate guide also says a seller can transfer their policy to the new owner.

How much flood coverage can I get through the NFIP?

FloodSmart says NFIP homeowner policies cover up to $250,000 for the building and up to $100,000 for contents. The Washington Insurance Commissioner notes that detached buildings and their contents aren’t covered under the standard homeowner policy, and that you can buy excess flood coverage if you need more.

Talk it through with a local agent

Peter Kim and Odigo Real Estate Club can help you check flood maps, line up insurance quotes and set contingency deadlines before you’re committed on a house near the water, with 25+ years combined experience, 593+ closings, and 122 five-star Zillow reviews. See our home buying services.

Odigo Real Estate Club · REAL Brokerage, WA #112064 · 16108 Ash Way, Suite 201, Lynnwood, WA 98087 · (425) 409-3823 · Mon–Sat 9 AM–6 PM, closed Sunday

Sources

• FEMA, Flood Map Service Center (official Flood Insurance Rate Maps by address), https://msc.fema.gov/portal/home , accessed Nov 2, 2026.
• FEMA FloodSmart, Buy a Policy (NFIP homeowner limits; 30-day waiting period and exceptions), https://www.floodsmart.gov/get-insured/buy-a-policy , accessed Nov 2, 2026.
• FEMA National Flood Insurance Program, Questions & Answers: Flood Insurance for Real Estate Professionals (F-435, August 2025) (lenders outside SFHAs; claims outside high-risk areas; no wait at loan closing; seller policy transfer; Elevation Certificates; LOMA), https://agents.floodsmart.gov/sites/default/files/media/document/2025-09/questions-answers-real-estate-professionals-brochure-08-2025.pdf , accessed Nov 2, 2026.
• Snohomish County Surface Water Management, Know Your Flood Risk (FEMA map lookup, FIRMette, PDS contact, SFHA definition, LOMA and LOMR-F), https://www.snohomishcountywa.gov/968/Know-Your-Flood-Risk , accessed Nov 2, 2026.
• Snohomish County, DFIRM Floodplain Maps (updated digital FIRMs adopted June 2020), https://www.snohomishcountywa.gov/893/DFIRM-Floodplain-Maps , accessed Nov 2, 2026.
• Snohomish County, About the Mandatory Purchase of Flood Insurance (updated May 2018) (SFHA = A or V zone; building vs. lot; coverage amount; lender discretion outside SFHAs), https://snohomishcountywa.gov/DocumentCenter/View/6363 , accessed Nov 2, 2026.
• Snohomish County, Notice to Realtors, Lending Institutions, and Insurance Agents (updated 2021) (DFIRMs for unincorporated county; elevation certificates; county does not determine insurance requirement), https://www.snohomishcountywa.gov/DocumentCenter/View/6364 , accessed Nov 2, 2026.
• King County, King County floodplain maps (iMap layers; federal flood insurance requirement; elevation certificates; floodplain development standards), https://kingcounty.gov/en/dept/dnrp/nature-recreation/environment-ecology-conservation/flood-services/flood-hazards/floodplain-maps , accessed Nov 2, 2026.
• King County Flood Control District, Flood Risk Map (address lookup for flood risk areas), https://kingcountyfloodcontrol.org/be-flood-ready/floodplain-map/ , accessed Nov 2, 2026.
• Washington State Office of the Insurance Commissioner, Flood insurance (homeowner policies exclude flood; NFIP limits; detached buildings; when coverage starts), https://www.insurance.wa.gov/insurance-resources/natural-disasters/disaster-preparedness/flood-insurance , accessed Nov 2, 2026.
• Washington State Legislature, RCW 48.27.030 (insurer notice that a homeowner policy does not cover flood), https://app.leg.wa.gov/RCW/default.aspx?cite=48.27.030 , accessed Nov 2, 2026.
• Consumer Financial Protection Bureau, What questions should I ask about flood and disaster risk when buying a house? (SFHA odds over 30 years; seller’s premium vs. new owner; disaster assistance; nonrenewals), https://www.consumerfinance.gov/ask-cfpb/what-questions-should-i-ask-about-flood-and-disaster-risk-when-buying-a-house-en-2147/ , accessed Nov 2, 2026.
• Washington State Legislature, RCW 64.06.020 (seller disclosure statement form, Environmental section; version effective until Jan 1, 2027 and version effective Jan 1, 2027), https://app.leg.wa.gov/RCW/default.aspx?cite=64.06.020 , accessed Nov 2, 2026.

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