Ottawa County, Oklahoma
A shallow water table limits basements on 51% of Ottawa County's mapped land, a higher share than 68% of US counties and the 6th highest of 77 Oklahoma counties. Shrink-swell clay limits houses without basements on 31%.
100% of the county is in drought on the October 13, 2026 Drought Monitor map. FEMA's flood data list 73 flood losses here since 2016, 9% of them in buildings with basements. 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 Ottawa County
| Expansive clay (limits slab homes) | 31.2% |
| High water table (limits basements) | 51.4% |
| Septic fields very limited | 87.2% |
| Clay swell (LEP, by area) | 4.6% |
| High-swell land (LEP 6%+) | 37.6% |
| Mapped soil | 309,600 acres |
| Soil series | Share here | Series nationally: high water table |
|---|---|---|
| Clarksville | 22% | 0% |
| Dennis | 13% | 100% |
| Taloka | 13% | n/a |
| Parsons | 10% | n/a |
| Osage | 4% | n/a |
| Bates | 3% | n/a |
How we count · survey areas OK115 (2025-08-29)
What the numbers mean here
Clay swell averages a linear extensibility of 4.6% by land area here, and 38% of the land reaches USDA's high class (6% or more). Clay like that swells when wet and shrinks when dry, under 31% of the mapped land.
Clay shrinks as it dries: 100% of the county is in drought on the latest map, and 31% of Ottawa County's mapped land has shrink-swell clay.
On 51% of Ottawa 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: 39.04 in, 6.88 in below the 1991-2020 average year of 45.92 in.
USDA rates 87% 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 31 of the last 52 weeks; the most was 100% of its area, in 25 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 | 100% |
| D3 extreme or worse | 57.5% |
| D4 exceptional | 0% |
Flood losses since 2016
73 flood losses since 2016, $3.6 million paid. The worst year was 2019, with 64. Foundations of the buildings, where recorded: 9% basements, 67% slabs, 17% crawl spaces, 7% elevated. Median water depth outside the building: 16 in.
| Year | Flood losses |
|---|---|
| 2016 | 1 |
| 2017 | 5 |
| 2018 | 0 |
| 2019 | 64 |
| 2020 | 0 |
| 2021 | 0 |
| 2022 | 0 |
| 2023 | 0 |
| 2024 | 0 |
| 2025 | 1 |
| 2026 to date | 2 |
Rain
| Average year, 1991-2020 | 45.92 in |
| 12 months to August 2026 | 39.04 in (-6.88) |
| 2025 | 43.75 in (-2.17) |
| Wettest year since 1895 | 2019: 75.96 in |
| Driest year since 1895 | 1963: 20.28 in |
| Days with 1 inch or more, normal at COLUMBUS (24 mi away) | 14.2 |
Homes
| Housing units | 13,701 |
| Median year built | 1974 |
| Built before 1980 | 61% |
| Built 2000 or later | 17% |
| Owner-occupied | 68% |
| Median value, owner-occupied | $123,300 |
| 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 |
|---|---|---|---|
| Craig County, OK | 23 mi | 53% | 58% |
| Cherokee County, KS | 23 mi | 52% | 80% |
| Newton County, MO | 26 mi | 6% | 65% |
| McDonald County, MO | 29 mi | 2% | 29% |
| Delaware County, OK | 31 mi | 5% | 23% |
| Jasper County, MO | 36 mi | 35% | 48% |
| Labette County, KS | 37 mi | 75% | 72% |
| Mayes County, OK | 44 mi | 31% | 44% |
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