Osage County, Oklahoma
Shrink-swell clay limits houses without basements on 41% of Osage County's mapped land, a higher share than 87% of US counties. A shallow water table limits basements on 40%.
100% of the county is in drought on the October 13, 2026 Drought Monitor map. FEMA's flood data list 16 flood losses here since 2016. 50% of homes were built before 1980, against 50% nationally; the median home dates from 1980.
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) | 40.9% |
| High water table (limits basements) | 40.4% |
| Septic fields very limited | 80.6% |
| Clay swell (LEP, by area) | 5.9% |
| High-swell land (LEP 6%+) | 40.6% |
| Mapped soil | 1,474,509 acres |
| Soil series | Share here | Series nationally: expansive clay |
|---|---|---|
| Bigheart | 10% | n/a |
| Niotaze | 9% | n/a |
| Steedman | 8% | n/a |
| Lucien | 5% | n/a |
| Verdigris | 5% | n/a |
| Shidler | 5% | n/a |
How we count · survey areas OK113 (2025-08-29)
What the numbers mean here
Clay swell averages a linear extensibility of 5.9% by land area here, and 41% of the land reaches USDA's high class (6% or more). Clay like that swells when wet and shrinks when dry, under 41% of the mapped land.
Clay shrinks as it dries: 100% of the county is in drought on the latest map, and 41% of Osage County's mapped land has shrink-swell clay.
On 40% 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: 36.69 in, 3.29 in below the 1991-2020 average year of 39.98 in.
USDA rates 81% of the land very limited for septic absorption fields.
Drought
100% of the county is in drought (D1 or worse) on the October 13, 2026 map. Part of the county was in drought in 38 of the last 52 weeks; the most was 100% of its area, in 17 weeks, most recently on the October 13, 2026 map.
| Category, October 13, 2026 | Share of county |
|---|---|
| D0 abnormally dry or worse | 100% |
| D1 moderate drought or worse | 100% |
| D2 severe or worse | 3.9% |
| D3 extreme or worse | 0% |
| D4 exceptional | 0% |
Flood losses since 2016
16 flood losses since 2016, $470,334 paid. The worst year was 2019, with 12.
| Year | Flood losses |
|---|---|
| 2016 | 1 |
| 2017 | 1 |
| 2018 | 0 |
| 2019 | 12 |
| 2020 | 0 |
| 2021 | 1 |
| 2022 | 0 |
| 2023 | 0 |
| 2024 | 0 |
| 2025 | 1 |
| 2026 to date | 0 |
Rain
| Average year, 1991-2020 | 39.98 in |
| 12 months to August 2026 | 36.69 in (-3.29) |
| 2025 | 50.00 in (+10.02) |
| Wettest year since 1895 | 2019: 56.05 in |
| Driest year since 1895 | 1910: 19.31 in |
| Days with 1 inch or more, normal at RALSTON (20 mi away) | 11.7 |
Homes
| Housing units | 19,886 |
| Median year built | 1980 |
| Built before 1980 | 50% |
| Built 2000 or later | 26% |
| Owner-occupied | 78% |
| Median value, owner-occupied | $182,100 |
| Single-family detached | 77% |
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 |
|---|---|---|---|
| Pawnee County, OK | 27 mi | 33% | 22% |
| Washington County, OK | 28 mi | 52% | 55% |
| Chautauqua County, KS | 38 mi | 67% | 51% |
| Kay County, OK | 43 mi | 59% | 19% |
| Tulsa County, OK | 43 mi | 47% | 52% |
| Nowata County, OK | 45 mi | 48% | 49% |
| Rogers County, OK | 48 mi | 38% | 42% |
| Cowley County, KS | 48 mi | 59% | 12% |
Sources: USDA SSURGO (August 29, 2025) · US Drought Monitor (October 13, 2026) · FEMA NFIP v3 (September 9, 2026) · NOAA (August 2026) · Census ACS 2020-2024. Methods · Data status