Osage County, Kansas
Shrink-swell clay limits houses without basements on 77% of Osage County's mapped land, a higher share than 99% of US counties and the 9th highest of 105 Kansas counties. A shallow water table limits basements on 69%.
None of the county is in drought on the October 13, 2026 Drought Monitor map. FEMA's flood data list 2 flood losses here since 2016. 61% of homes were built before 1980, against 50% nationally; the median home dates from 1974.
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 Osage County
| Expansive clay (limits slab homes) | 77.5% |
| High water table (limits basements) | 68.7% |
| Septic fields very limited | 96.7% |
| Clay swell (LEP, by area) | 7.1% |
| High-swell land (LEP 6%+) | 76.0% |
| Mapped soil | 460,608 acres |
How we count · survey areas KS139 (2025-08-26)
What the numbers mean here
Clay swell averages a linear extensibility of 7.1% by land area here, and 76% of the land reaches USDA's high class (6% or more). Clay like that swells when wet and shrinks when dry, under 77% of the mapped land.
On 69% of Osage 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: 38.96 in, 1.60 in above the 1991-2020 average year of 37.36 in.
USDA rates 97% 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. No part of the county was in drought in the last 52 weeks.
| 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
2 flood losses since 2016, $35,633 paid. The worst year was 2024, with 1.
| Year | Flood losses |
|---|---|
| 2016 | 0 |
| 2017 | 0 |
| 2018 | 0 |
| 2019 | 1 |
| 2020 | 0 |
| 2021 | 0 |
| 2022 | 0 |
| 2023 | 0 |
| 2024 | 1 |
| 2025 | 0 |
| 2026 to date | 0 |
Rain
| Average year, 1991-2020 | 37.36 in |
| 12 months to August 2026 | 38.96 in (+1.60) |
| 2025 | 33.99 in (-3.37) |
| Wettest year since 1895 | 1951: 58.10 in |
| Driest year since 1895 | 1936: 20.51 in |
| Days with 1 inch or more, normal at POMONA LAKE (8 mi away) | 10.9 |
Homes
| Housing units | 7,337 |
| Median year built | 1974 |
| Built before 1980 | 61% |
| Built 2000 or later | 14% |
| Owner-occupied | 82% |
| Median value, owner-occupied | $156,800 |
| Single-family detached | 84% |
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 |
|---|---|---|---|
| Franklin County, KS | 24 mi | 75% | 70% |
| Shawnee County, KS | 27 mi | 65% | 59% |
| Lyon County, KS | 28 mi | 80% | 53% |
| Douglas County, KS | 28 mi | 56% | 51% |
| Coffey County, KS | 29 mi | 77% | 76% |
| Wabaunsee County, KS | 34 mi | 73% | 27% |
| Anderson County, KS | 38 mi | 80% | 72% |
| Jefferson County, KS | 44 mi | 59% | 54% |
Sources: USDA SSURGO (August 26, 2025) · US Drought Monitor (October 13, 2026) · FEMA NFIP v3 (September 9, 2026) · NOAA (August 2026) · Census ACS 2020-2024. Methods · Data status