Atchison County, Kansas
Shrink-swell clay limits houses without basements on 73% of Atchison County's mapped land, a higher share than 98% of US counties. A shallow water table limits basements on 62%.
None of the county is in drought on the October 13, 2026 Drought Monitor map. FEMA's flood data list no flood losses here since 2016. 72% of homes were built before 1980, against 50% nationally; the median home dates from 1968.
Data as of October 13, 2026 · sources
expansive clay: shrink-swell limits slab homes
high water table: limits basements
in drought, October 13, 2026
of homes built before 1980
Soil under Atchison County
| Expansive clay (limits slab homes) | 73.2% |
| High water table (limits basements) | 62.5% |
| Septic fields very limited | 95.1% |
| Clay swell (LEP, by area) | 6.9% |
| High-swell land (LEP 6%+) | 60.9% |
| Mapped soil | 278,400 acres |
| Soil series | Share here | Series nationally: expansive clay |
|---|---|---|
| Pawnee | 15% | n/a |
| Shelby | 14% | n/a |
| Wymore | 11% | 100% |
| Sharpsburg | 7% | 98% |
| Kennebec | 6% | n/a |
| Armster | 6% | n/a |
How we count · survey areas KS005 (2025-08-27)
What the numbers mean here
Clay swell averages a linear extensibility of 6.9% by land area here, and 61% of the land reaches USDA's high class (6% or more). Clay like that swells when wet and shrinks when dry, under 73% of the mapped land.
On 62% of Atchison County's mapped land, soil stays saturated within about 6 feet of the surface for part of the year, which is basement depth.
Rain over the 12 months to August 2026: 33.84 in, 2.91 in below the 1991-2020 average year of 36.75 in.
USDA rates 95% of the land very limited for septic absorption fields.
Drought
0% of the county is in drought (D1 or worse) on the October 13, 2026 map. Part of the county was in drought in 12 of the last 52 weeks; the most was 22.3% of its area, in 4 weeks, most recently on the November 18, 2025 map.
| Category, October 13, 2026 | Share of county |
|---|---|
| D0 abnormally dry or worse | 0% |
| D1 moderate drought or worse | 0% |
| D2 severe or worse | 0% |
| D3 extreme or worse | 0% |
| D4 exceptional | 0% |
Flood losses since 2016
FEMA's flood data list no flood losses in Atchison County since 2016.
Rain
| Average year, 1991-2020 | 36.75 in |
| 12 months to August 2026 | 33.84 in (-2.91) |
| 2025 | 31.70 in (-5.05) |
| Wettest year since 1895 | 1973: 59.38 in |
| Driest year since 1895 | 1988: 18.03 in |
| Days with 1 inch or more, normal at ATCHISON (11 mi away) | 9.9 |
Homes
| Housing units | 6,817 |
| Median year built | 1968 |
| Built before 1980 | 72% |
| Built 2000 or later | 10% |
| Owner-occupied | 72% |
| Median value, owner-occupied | $145,700 |
| Single-family detached | 81% |
What repairs cost
Published ranges from cost guides, not quotes. More sources, and where they disagree.
Nearby counties
| Place | Distance | Expansive clay | High water table |
|---|---|---|---|
| Doniphan County, KS | 20 mi | 27% | 15% |
| Jefferson County, KS | 21 mi | 59% | 54% |
| Brown County, KS | 24 mi | 77% | 60% |
| Jackson County, KS | 27 mi | 76% | 73% |
| Leavenworth County, KS | 28 mi | 63% | 52% |
| Buchanan County, MO | 28 mi | 28% | 40% |
| Platte County, MO | 31 mi | 30% | 57% |
| Holt County, MO | 39 mi | 30% | 41% |
Sources: USDA SSURGO (August 27, 2025) · US Drought Monitor (October 13, 2026) · FEMA NFIP v3 (September 9, 2026) · NOAA (August 2026) · Census ACS 2020-2024. Methods · Data status