Pottawatomie County, Kansas
Shrink-swell clay limits houses without basements on 71% of Pottawatomie County's mapped land, a higher share than 97% of US counties. A shallow water table limits basements on 35%.
None of the county is in drought on the October 13, 2026 Drought Monitor map. FEMA's flood data list 8 flood losses here since 2016. 43% 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 Pottawatomie County
| Expansive clay (limits slab homes) | 71.2% |
| High water table (limits basements) | 35.3% |
| Septic fields very limited | 96.4% |
| Clay swell (LEP, by area) | 6.4% |
| High-swell land (LEP 6%+) | 61.4% |
| Mapped soil | 551,366 acres |
| Soil series | Share here | Series nationally: expansive clay |
|---|---|---|
| Clime | 16% | n/a |
| Pawnee | 11% | n/a |
| Tully | 10% | n/a |
| Kennebec | 7% | n/a |
| Benfield | 7% | n/a |
| Wymore | 7% | 100% |
How we count · survey areas KS149 (2025-08-26)
What the numbers mean here
Clay swell averages a linear extensibility of 6.4% by land area here, and 61% of the land reaches USDA's high class (6% or more). Clay like that swells when wet and shrinks when dry, under 71% of the mapped land.
On 35% of Pottawatomie 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: 39.09 in, 4.94 in above the 1991-2020 average year of 34.15 in.
USDA rates 96% 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. Part of the county was in drought in 12 of the last 52 weeks; the most was 53% of its area, on the October 14, 2025 map.
| 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
8 flood losses since 2016, $82,253 paid. The worst year was 2019, with 6.
| Year | Flood losses |
|---|---|
| 2016 | 2 |
| 2017 | 0 |
| 2018 | 0 |
| 2019 | 6 |
| 2020 | 0 |
| 2021 | 0 |
| 2022 | 0 |
| 2023 | 0 |
| 2024 | 0 |
| 2025 | 0 |
| 2026 to date | 0 |
Rain
| Average year, 1991-2020 | 34.15 in |
| 12 months to August 2026 | 39.09 in (+4.94) |
| 2025 | 31.25 in (-2.90) |
| Wettest year since 1895 | 1973: 54.32 in |
| Driest year since 1895 | 1966: 20.25 in |
| Days with 1 inch or more, normal at WAMEGO 4 W (12 mi away) | 9.4 |
Homes
| Housing units | 10,214 |
| Median year built | 1987 |
| Built before 1980 | 43% |
| Built 2000 or later | 35% |
| Owner-occupied | 82% |
| Median value, owner-occupied | $245,900 |
| Single-family detached | 79% |
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 |
|---|---|---|---|
| Riley County, KS | 22 mi | 76% | 22% |
| Jackson County, KS | 29 mi | 76% | 73% |
| Marshall County, KS | 29 mi | 72% | 73% |
| Wabaunsee County, KS | 30 mi | 73% | 27% |
| Nemaha County, KS | 33 mi | 75% | 70% |
| Geary County, KS | 35 mi | 71% | 6% |
| Shawnee County, KS | 39 mi | 65% | 59% |
| Clay County, KS | 44 mi | 67% | 2% |
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