Sioux County, ND zoning map, flood zone and property lines by address
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Towns in Sioux County: Fort Yates.
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 Sioux County has 44 FIRM panels, the newest effective May 2004; 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 Sioux 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 North Dakota GIS Hub parcel layer (from each county), so a Sioux lot shows the same lines the county director of tax equalization draws. Sioux County covers about 700,193 acres of land and 21,856 acres of water.
Mapped lines are approximate. The Sioux County director of tax equalization keeps the parcel record; a licensed surveyor sets the true corners.
Zoning
In North Dakota zoning is set by the county, the township or the city, depending on where the lot is: in Sioux County, Fort Yates zones the land inside its limits. ParcelSheet shows the use code on the lot's parcel record and the municipality it sits in; the county, township or city zoning office has the district, the uses it allows and the lot size it needs. The Sioux County website lists the county's municipalities.
ADU and guest houses
Under North Dakota's zoning laws (N.D. Cent. Code chapters 11-33 for counties and 40-47 for cities), the county, the township or the city, depending on where the lot is can allow an accessory dwelling unit on a lot with a house. Whether a Sioux lot can add one depends on its district; the county, township or city zoning office 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. Sioux County is soil survey area ND085, Sioux County, North Dakota, last updated September 2026, on Web Soil Survey.
A new or changed septic system in Sioux County needs a permit from the Sioux County local public health unit (installers are licensed by the ND Department of Environmental Quality).
Setbacks
Setbacks in Sioux County come from the zoning district: the front, side and rear distances a house must keep. ParcelSheet does not draw setback lines; the county, township or city zoning office gives them for the lot's district, and Fort Yates for land inside its limits.
Hazards that apply
- Wetlands and wildfire. ParcelSheet shows the National Wetlands Inventory near a Sioux lot and the Forest Service wildfire hazard rating at it.
Questions
Is my house in a flood zone in Sioux 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 Sioux County has 44 panels, the newest effective May 2004. A lender or insurer uses the official FIRM panel; FEMA's Map Service Center has it.
How do I find property lines in Sioux County?
Open the North Dakota map, type the address, and the parcel outline from the Sioux County director of tax equalization 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 Sioux County?
Zoning in Sioux County is set by the county, the township or the city, depending on where the lot is (such as Fort Yates). ParcelSheet shows the use code on the parcel record and names the municipality; the county, township or city zoning office has the final word.
Can I build an ADU in Sioux County?
Under North Dakota's zoning laws (N.D. Cent. Code chapters 11-33 for counties and 40-47 for cities), the county, the township or the city, depending on where the lot is can allow an accessory dwelling unit, and each sets its own rules. In Sioux County ask the county, township or city 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 Sioux County?
Yes. A new or changed septic system in Sioux County needs a permit from the Sioux County local public health unit (installers are licensed by the ND Department of Environmental Quality). ParcelSheet shows the USDA soil survey's septic rating at the lot, from survey area ND085 (Sioux County, North Dakota).
What can I build on 5 acres in Sioux County?
Zoning in Sioux County is set by the county, the township or the city, depending on where the lot is (such as Fort Yates). 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 county, township or city zoning office has the district and its rules.
What are the residential setbacks in Sioux County (2026)?
Setbacks in Sioux County come from the zoning code of the municipality the lot sits in: 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 county, township or city zoning office gives them for the district.
Next to Sioux County: Adams County, Emmons County, Grant County, Morton County.
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