Delaware County, Oklahoma
A shallow water table limits basements on 23% of Delaware County's mapped land. Shrink-swell clay limits houses without basements on 5%.
100% of the county is in drought on the October 13, 2026 Drought Monitor map. FEMA's flood data list 37 flood losses here since 2016. 36% of homes were built before 1980, against 50% nationally; the median home dates from 1987.
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 Delaware County
| Expansive clay (limits slab homes) | 4.8% |
| High water table (limits basements) | 22.9% |
| Septic fields very limited | 66.8% |
| Clay swell (LEP, by area) | 2.4% |
| High-swell land (LEP 6%+) | 5.6% |
| Mapped soil | 506,880 acres |
| Soil series | Share here | Series nationally: high water table |
|---|---|---|
| Clarksville | 36% | 0% |
| Britwater | 8% | n/a |
| Doniphan | 7% | n/a |
| Razort | 6% | n/a |
| Eldorado | 6% | n/a |
| Tonti | 4% | n/a |
How we count · survey areas OK041 (2025-08-29)
What the numbers mean here
On 23% of Delaware 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: 41.05 in, 5.89 in below the 1991-2020 average year of 46.94 in.
USDA rates 67% 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 33 of the last 52 weeks; the most was 100% of its area, in 26 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 | 94.4% |
| D4 exceptional | 0% |
Flood losses since 2016
37 flood losses since 2016, $892,434 paid. The worst year was 2019, with 29. Median water depth outside the building: 16 in.
| Year | Flood losses |
|---|---|
| 2016 | 0 |
| 2017 | 7 |
| 2018 | 0 |
| 2019 | 29 |
| 2020 | 0 |
| 2021 | 0 |
| 2022 | 0 |
| 2023 | 0 |
| 2024 | 0 |
| 2025 | 1 |
| 2026 to date | 0 |
Rain
| Average year, 1991-2020 | 46.94 in |
| 12 months to August 2026 | 41.05 in (-5.89) |
| 2025 | 50.97 in (+4.03) |
| Wettest year since 1895 | 2019: 79.06 in |
| Driest year since 1895 | 1963: 20.79 in |
| Days with 1 inch or more, normal at SPAVINAW (14 mi away) | 14.7 |
Homes
| Housing units | 24,396 |
| Median year built | 1987 |
| Built before 1980 | 36% |
| Built 2000 or later | 28% |
| Owner-occupied | 77% |
| Median value, owner-occupied | $175,300 |
| Single-family detached | 66% |
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 |
|---|---|---|---|
| Mayes County, OK | 25 mi | 31% | 44% |
| McDonald County, MO | 30 mi | 2% | 29% |
| Ottawa County, OK | 31 mi | 31% | 51% |
| Benton County, AR | 31 mi | 3% | 47% |
| Craig County, OK | 34 mi | 53% | 58% |
| Adair County, OK | 35 mi | 14% | 21% |
| Cherokee County, OK | 35 mi | 16% | 20% |
| Washington County, AR | 44 mi | 20% | 24% |
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