Island County, WA zoning map, flood zone and property lines by address
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Towns in Island County: Oak Harbor, Camano, Freeland.
Flood zone by address
ParcelSheet reads FEMA's National Flood Hazard Layer at the lot: the zone, whether it is a high risk area where lenders ask for flood insurance, and the base flood elevation where FEMA lists one. FEMA's countywide study for Island County has 54 FIRM panels, the newest effective March 2017; coastal V zones, where waves add to the flood, are mapped along its shore.
The official panel and any Letter of Map Amendment are at FEMA's Map Service Center. An elevation certificate for an Island house comes from a licensed surveyor and is often on file with the county or city building office.
Property lines
The parcel outline, parcel number and mapped size come from the Washington Technology Solutions (WaTech), statewide parcels from the counties, so an Island lot shows the same lines the county assessor draws. Island County covers about 133,567 acres of land and 197,521 acres of water.
Mapped lines are approximate. The Island County assessor keeps the parcel record (Island County website); a licensed surveyor sets the true corners.
Zoning
Island County zones its unincorporated land, and Oak Harbor zones the land inside its limits. ParcelSheet shows the use the county assessor lists for the lot and links the county planning department for the district, the uses it allows and the lot size it needs.
ADU and guest houses
Under Washington's Planning Enabling Act and Growth Management Act (Revised Code of Washington Chapters 36.70 and 36.70A), local governments can allow an accessory dwelling unit on a lot with a house. Whether an Island lot can add one depends on its district; the county planning department has the rule. ParcelSheet shows the mapped lot size and the ground's slope, the first two things the question turns on.
Septic and soil
ParcelSheet reads the USDA soil survey at the lot: the soil's name, its septic absorption rating and whether it is prime farmland. Island County is soil survey area WA029, Island County, Washington, last updated September 2026, on Web Soil Survey.
A new or changed septic system in Island County needs a permit from the Island County health department (local health jurisdiction, under Washington State Department of Health on site sewage rules).
Setbacks
Setbacks in Island County come from the zoning district: the front, side and rear distances a house must keep. ParcelSheet does not draw setback lines; the county zoning office gives them for the lot's district, and Oak Harbor for land inside its limits.
Hazards that apply
- Storm surge. Island County has coastal V zones on its FEMA map, so storm surge reaches its shore. The county's evacuation zones are on its emergency management site; ParcelSheet shows the FEMA zone and the 3 ft sea level rise map at the lot.
- Wetlands and wildfire. ParcelSheet shows the National Wetlands Inventory near an Island lot and the Forest Service wildfire hazard rating at it.
Questions
Is my house in a flood zone in Island County?
Type the address in the box above and ParcelSheet reads FEMA's flood zone at the lot's center. FEMA's countywide flood map for Island County has 54 panels, the newest effective March 2017. A lender or insurer uses the official FIRM panel; FEMA's Map Service Center has it.
How do I find property lines in Island County?
Open the Washington map, type the address, and the parcel outline from the Island County assessor shows on the map with its parcel number and mapped size. Mapped lines are approximate; only a licensed surveyor sets the true corners.
What is my property zoned in Island County?
Zoning in Island County is set by the county for unincorporated land and by each city (such as Oak Harbor) inside its own limits. ParcelSheet shows the use code the county assessor lists and links the office that sets the zoning; the planning office has the final word.
Can I build an ADU in Island County?
Under Washington's Planning Enabling Act and Growth Management Act (Revised Code of Washington Chapters 36.70 and 36.70A), counties and cities can allow an accessory dwelling unit, and each sets its own rules. In Island County ask the zoning office for the lot's district first; ParcelSheet shows the lot size as mapped so you can see the room you have.
Do I need a septic permit in Island County?
Yes. A new or changed septic system in Island County needs a permit from the Island County health department (local health jurisdiction, under Washington State Department of Health on site sewage rules). ParcelSheet shows the USDA soil survey's septic rating at the lot, from survey area WA029 (Island County, Washington).
What can I build on 5 acres in Island County?
Zoning in Island County is set by the county for unincorporated land and each city inside its own limits (such as Oak Harbor). The zoning district decides the uses, how many homes and the smallest lot it allows on 5 acres. ParcelSheet shows the lot size as mapped and the use code on the parcel record; the planning office has the district and its rules. See the Island County website.
What are the residential setbacks in Island County (2026)?
Setbacks in Island County come from the zoning code of the county, or of the city when the lot is inside city limits: the front, side and rear distances depend on the lot's district. ParcelSheet does not draw setback lines or give a number it did not read; the zoning office gives them for the district. See the Island County website.
Next to Island County: Jefferson County, Kitsap County, San Juan County, Skagit County, Snohomish County.
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