Blog · October 14, 2026 · Washington
San Juan County Flood Zone Map in Washington
How to check if a property in San Juan County sits in a FEMA flood zone, and what the answer means for a buyer near Friday Harbor.
Main page: San Juan County, WA GIS & Parcel Viewer (official map link, San Juan County facts and neighboring maps).
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Is that lot in Roche Harbor in a flood zone? The San Juan County flood zone map answer comes from FEMA, and it is free to look up. For any tract in San Juan County, Washington, the answer affects insurance, permits and resale.
We'll cover finding a San Juan County address on FEMA's map, what Zone A, AE and X mean, how the county viewer fits in, and what to do if the map looks wrong.
Look up the San Juan County flood zone map step by step
FEMA's official flood maps for San Juan County are free at the FEMA Flood Map Service Center. Search returns the effective FIRM panel for the spot in San Juan County, plus any pending changes FEMA has posted. If the PDF panel for San Juan County is hard to read, the National Flood Hazard Layer viewer is easier to use, so you can see if the shading reaches a house near Roche Harbor. Switch to the Washington Current Parcels layer in ArcGIS Map Viewer and find the same piece of ground near Roche Harbor. Match the San Juan County lines and acreage to the FEMA view, since flood maps don't draw property lines in detail.
Step one: the free San Juan County viewer
For San Juan County, the free public parcel layer is state-run: open the Washington Current Parcels layer in ArcGIS Map Viewer and pan to Argyle. Use the search box for an address in Roche Harbor or a parcel number, or simply zoom in and click a piece of ground near Argyle. Bookmark our San Juan County page too; it tracks the official Washington link if it moves and lists the maps around Roche Harbor.
High, moderate and minimal risk in San Juan County
On the FIRM covering San Juan County, zones that start with A or V are Special Flood Hazard Areas, meaning FEMA estimates a 1-percent annual chance of flooding. Where a San Juan County tract shows Zone AE, there's a base flood elevation to compare a building against; in Zone A there is not one. Land near Roche Harbor in shaded X (Zone B on older maps) is moderate risk, between the 1-percent and 0.2-percent annual chance lines. Clear, unshaded X near Friday Harbor is outside the 500-year floodplain.
Unmapped creeks in San Juan County
A low spot on a San Juan County tract outside any mapped zone can still flood; FEMA says moderate- and low-risk areas still carry risk.
A short buyer checklist for Friday Harbor
For a house near Roche Harbor, ask the seller for any elevation certificate on file and the current flood insurance declarations page. An agent working in San Juan County can quote flood coverage once you know the zone for the lot near Roche Harbor.
What a flood zone means for a San Juan County buyer
Lenders watch the zone closely on San Juan County properties. If a barn or house outside Friday Harbor falls inside an A or V zone and secures a loan from a federally regulated or insured lender, federal rules call for flood insurance, as long as San Juan County or the town participates in the NFIP. In Zone X near Friday Harbor, coverage is optional, although a lender in Washington can still ask for it. When a county homesite is on a rise inside a mapped zone, FEMA's LOMA process allows a review; a surveyor near Roche Harbor can supply the elevation data. New construction in a San Juan County Special Flood Hazard Area commonly requires a permit and an elevation check, so call the county or the town office in Friday Harbor before work starts.
Questions about the San Juan County flood zone map
Does the San Juan County parcel map show flood zones?
Check the layer list in the Washington Current Parcels layer in ArcGIS Map Viewer; if San Juan County includes a floodplain layer, confirm the zone on FEMA's map anyway.
Is flood insurance required for a Zone X lot in Roche Harbor?
Not under federal rules; Zone X in San Juan County is outside the Special Flood Hazard Area, although a lender can still require coverage.
What does 100-year flood mean for San Juan County land?
No, ground around Roche Harbor mapped that way has a 1-percent chance of flooding every year, not a once-a-century schedule.
Is my Roche Harbor address in a flood zone?
Look it up at FEMA's Flood Map Service Center, then match the parcel lines in the Washington Current Parcels layer in ArcGIS Map Viewer; for land near Friday Harbor, a zone starting with A or V is high risk.
Is Zone AE near Friday Harbor high risk?
Yes, a piece of ground near Friday Harbor in Zone AE is high risk: a 1-percent-annual-chance floodplain where FEMA lists a base flood elevation.
What if FEMA's map is wrong about my house near Friday Harbor?
An owner near Friday Harbor can request a Letter of Map Amendment from FEMA with elevation data, most commonly from a professional surveyor.
Open the official San Juan County, WA parcel map San Juan County in the Platbookmapper directory
Not a survey. County GIS and tax parcel maps are assessment and planning layers. They are not a substitute for a recorded plat, deed, or licensed survey, especially for fences, setbacks, or boundary disputes.