Thomas County, KS zoning map, flood zone and property lines by address
Free, no account. Or open the Kansas map and tap a lot.
Towns in Thomas County: Colby.
Property lines
The parcel outline, parcel number and mapped size come from the Kansas county parcel layers (each county publishes its own), so a Thomas lot shows the same lines the county appraiser draws. Thomas County covers about 687,799 acres of land and 71 acres of water.
Mapped lines are approximate. The Thomas County appraiser keeps the parcel record (Thomas County website); a licensed surveyor sets the true corners.
Zoning
Thomas County zones its unincorporated land, and Colby zones the land inside its limits. ParcelSheet shows the use the county appraiser lists for the lot and links the county planning and zoning office for the district, the uses it allows and the lot size it needs.
ADU and guest houses
Under Kansas's planning and zoning law for cities and counties (Kansas Statutes 12-741 and following), local governments can allow an accessory dwelling unit on a lot with a house. Whether a Thomas lot can add one depends on its district; the county planning and 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. Thomas County is soil survey area KS193, Thomas County, Kansas, last updated August 2026, on Web Soil Survey.
A new or changed septic system in Thomas County needs a permit from the Thomas County sanitarian (under the county sanitary code and Kansas Department of Health and Environment standards).
Setbacks
Setbacks in Thomas 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 Colby for land inside its limits.
Hazards that apply
- Wetlands and wildfire. ParcelSheet shows the National Wetlands Inventory near a Thomas lot and the Forest Service wildfire hazard rating at it.
Questions
How do I find property lines in Thomas County?
Open the Kansas map, type the address, and the parcel outline from the Thomas County appraiser 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 Thomas County?
Zoning in Thomas County is set by the county for unincorporated land and by each city (such as Colby) inside its own limits. ParcelSheet shows the use code the county appraiser lists and links the office that sets the zoning; the planning office has the final word.
Can I build an ADU in Thomas County?
Under Kansas's planning and zoning law for cities and counties (Kansas Statutes 12-741 and following), counties and cities can allow an accessory dwelling unit, and each sets its own rules. In Thomas 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 Thomas County?
Yes. A new or changed septic system in Thomas County needs a permit from the Thomas County sanitarian (under the county sanitary code and Kansas Department of Health and Environment standards). ParcelSheet shows the USDA soil survey's septic rating at the lot, from survey area KS193 (Thomas County, Kansas).
What can I build on 5 acres in Thomas County?
Zoning in Thomas County is set by the county for unincorporated land and each city inside its own limits (such as Colby). 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 Thomas County website.
What are the residential setbacks in Thomas County (2026)?
Setbacks in Thomas 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 Thomas County website.
Next to Thomas County: Gove County, Logan County, Rawlins County, Sheridan County, Sherman County.
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