Malheur County, OR zoning map, flood zone and property lines by address
Free, no account. Or open the Oregon map and tap a lot.
Towns in Malheur County: Ontario, Nyssa, Vale.
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 has 44 FIRM panels covering Malheur County, the newest effective April 2022; no coastal V zones are mapped in it.
The official panel and any Letter of Map Amendment are at FEMA's Map Service Center. An elevation certificate for a Malheur 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 Oregon county parcel layers (each county publishes its own), so a Malheur lot shows the same lines the county assessor draws. Malheur County covers about 6,328,132 acres of land and 26,936 acres of water.
Mapped lines are approximate. The Malheur County assessor keeps the parcel record (Malheur County website); a licensed surveyor sets the true corners.
Zoning
Malheur County zones its unincorporated land, and Ontario, Nyssa, Vale each zone the land inside their 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 Oregon's county land use planning law (Oregon Revised Statutes Chapter 215), local governments can allow an accessory dwelling unit on a lot with a house. Whether a Malheur 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. Malheur County is soil survey area OR641, Malheur County, Oregon, Northeastern Part, last updated September 2026, on Web Soil Survey.
A new or changed septic system in Malheur County needs a permit from the Malheur County onsite septic program office (run by the county or by Oregon DEQ, under DEQ onsite rules).
Setbacks
Setbacks in Malheur 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 Ontario, Nyssa, Vale for land inside their limits.
Hazards that apply
- Wetlands and wildfire. ParcelSheet shows the National Wetlands Inventory near a Malheur lot and the Forest Service wildfire hazard rating at it.
Questions
Is my house in a flood zone in Malheur County?
Type the address in the box above and ParcelSheet reads FEMA's flood zone at the lot's center. FEMA has 44 flood map panels covering Malheur County, the newest effective April 2022. A lender or insurer uses the official FIRM panel; FEMA's Map Service Center has it.
How do I find property lines in Malheur County?
Open the Oregon map, type the address, and the parcel outline from the Malheur 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 Malheur County?
Zoning in Malheur County is set by the county for unincorporated land and by each city (such as Ontario, Nyssa) 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 Malheur County?
Under Oregon's county land use planning law (Oregon Revised Statutes Chapter 215), counties and cities can allow an accessory dwelling unit, and each sets its own rules. In Malheur 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 Malheur County?
Yes. A new or changed septic system in Malheur County needs a permit from the Malheur County onsite septic program office (run by the county or by Oregon DEQ, under DEQ onsite rules). ParcelSheet shows the USDA soil survey's septic rating at the lot, from survey area OR641 (Malheur County, Oregon, Northeastern Part).
What can I build on 5 acres in Malheur County?
Zoning in Malheur County is set by the county for unincorporated land and each city inside its own limits (such as Ontario, Nyssa). 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 Malheur County website.
What are the residential setbacks in Malheur County (2026)?
Setbacks in Malheur 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 Malheur County website.
Next to Malheur County: Baker County, Grant County, Harney County.
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