Osage County, Missouri
A shallow water table limits basements on 70% of Osage County's mapped land, a higher share than 82% of US counties. Shrink-swell clay limits houses without basements on 29%.
19.3% of the county is in drought on the October 13, 2026 Drought Monitor map, up from 0% a week earlier. FEMA's flood data list 25 flood losses here since 2016. 48% of homes were built before 1980, against 50% nationally; the median home dates from 1982.
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) | 29.2% |
| High water table (limits basements) | 70.2% |
| Septic fields very limited | 96.9% |
| Clay swell (LEP, by area) | 6.0% |
| High-swell land (LEP 6%+) | 36.7% |
| Mapped soil | 391,002 acres |
| Soil series | Share here | Series nationally: high water table |
|---|---|---|
| Gatewood | 23% | n/a |
| Wrengart | 13% | n/a |
| Rueter | 7% | n/a |
| Gravois | 7% | n/a |
| Menfro | 6% | 0% |
| Plato | 5% | n/a |
How we count · survey areas MO151 (2025-09-02)
What the numbers mean here
Clay swell averages a linear extensibility of 6.0% by land area here, and 37% of the land reaches USDA's high class (6% or more). Clay like that swells when wet and shrinks when dry, under 29% of the mapped land.
Clay shrinks as it dries: 19.3% of the county is in drought on the latest map, and 29% of Osage County's mapped land has shrink-swell clay.
On 70% 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: 41.13 in, 2.12 in below the 1991-2020 average year of 43.25 in.
USDA rates 97% of the land very limited for septic absorption fields.
Drought
19.3% of the county is in drought (D1 or worse) on the October 13, 2026 map. Part of the county was in drought in 21 of the last 52 weeks; the most was 100% of its area, in 6 weeks, most recently on the February 10, 2026 map.
| Category, October 13, 2026 | Share of county |
|---|---|
| D0 abnormally dry or worse | 100% |
| D1 moderate drought or worse | 19.3% |
| D2 severe or worse | 0% |
| D3 extreme or worse | 0% |
| D4 exceptional | 0% |
Flood losses since 2016
25 flood losses since 2016, $795,510 paid. The worst year was 2017, with 17.
| Year | Flood losses |
|---|---|
| 2016 | 0 |
| 2017 | 17 |
| 2018 | 0 |
| 2019 | 6 |
| 2020 | 0 |
| 2021 | 0 |
| 2022 | 1 |
| 2023 | 0 |
| 2024 | 0 |
| 2025 | 1 |
| 2026 to date | 0 |
Rain
| Average year, 1991-2020 | 43.25 in |
| 12 months to August 2026 | 41.13 in (-2.12) |
| 2025 | 35.16 in (-8.09) |
| Wettest year since 1895 | 1993: 68.22 in |
| Driest year since 1895 | 1901: 22.75 in |
| Days with 1 inch or more, normal at FREEDOM (9 mi away) | 12.9 |
Homes
| Housing units | 6,501 |
| Median year built | 1982 |
| Built before 1980 | 48% |
| Built 2000 or later | 28% |
| Owner-occupied | 79% |
| Median value, owner-occupied | $223,300 |
| Single-family detached | 80% |
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 |
|---|---|---|---|
| Gasconade County, MO | 19 mi | 37% | 76% |
| Maries County, MO | 21 mi | 29% | 70% |
| Cole County, MO | 23 mi | 14% | 69% |
| Callaway County, MO | 26 mi | 54% | 63% |
| Miller County, MO | 35 mi | 23% | 44% |
| Montgomery County, MO | 39 mi | 67% | 76% |
| Moniteau County, MO | 41 mi | 23% | 80% |
| Phelps County, MO | 42 mi | 15% | 53% |
Sources: USDA SSURGO (September 2, 2025) · US Drought Monitor (October 13, 2026) · FEMA NFIP v3 (September 9, 2026) · NOAA (August 2026) · Census ACS 2020-2024. Methods · Data status