Lyon County, Kansas
Shrink-swell clay limits houses without basements on 80% of Lyon County's mapped land, a higher share than 99% of US counties and the 5th highest of 105 Kansas counties. A shallow water table limits basements on 53%.
None of the county is in drought on the October 13, 2026 Drought Monitor map. FEMA's flood data list 9 flood losses here since 2016. 69% of homes were built before 1980, against 50% nationally; the median home dates from 1970.
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 Lyon County
| Expansive clay (limits slab homes) | 79.7% |
| High water table (limits basements) | 53.4% |
| Septic fields very limited | 99.3% |
| Clay swell (LEP, by area) | 8.0% |
| High-swell land (LEP 6%+) | 75.9% |
| Mapped soil | 547,559 acres |
| Soil series | Share here | Series nationally: expansive clay |
|---|---|---|
| Kenoma | 24% | over 99% |
| Clime | 9% | n/a |
| Martin | 8% | n/a |
| Ivan | 8% | n/a |
| Ladysmith | 8% | n/a |
| Labette | 6% | n/a |
How we count · survey areas KS111 (2025-08-26)
What the numbers mean here
Clay swell averages a linear extensibility of 8.0% by land area here, and 76% of the land reaches USDA's high class (6% or more). Clay like that swells when wet and shrinks when dry, under 80% of the mapped land.
On 53% of Lyon 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: 35.78 in, 0.61 in below the 1991-2020 average year of 36.39 in.
USDA rates 99% 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 1 of the last 52 weeks; the most was 30.3% of its area, on the September 8, 2026 map.
| Category, October 13, 2026 | Share of county |
|---|---|
| D0 abnormally dry or worse | 16.7% |
| D1 moderate drought or worse | 0% |
| D2 severe or worse | 0% |
| D3 extreme or worse | 0% |
| D4 exceptional | 0% |
Flood losses since 2016
9 flood losses since 2016, $110,908 paid. The worst year was 2019, with 5.
| Year | Flood losses |
|---|---|
| 2016 | 0 |
| 2017 | 0 |
| 2018 | 0 |
| 2019 | 5 |
| 2020 | 0 |
| 2021 | 0 |
| 2022 | 0 |
| 2023 | 1 |
| 2024 | 2 |
| 2025 | 1 |
| 2026 to date | 0 |
Rain
| Average year, 1991-2020 | 36.39 in |
| 12 months to August 2026 | 35.78 in (-0.61) |
| 2025 | 32.67 in (-3.72) |
| Wettest year since 1895 | 1951: 56.70 in |
| Driest year since 1895 | 1936: 18.85 in |
| Days with 1 inch or more, normal at EMPORIA 3 NW (4 mi away) | 10.7 |
Homes
| Housing units | 15,027 |
| Median year built | 1970 |
| Built before 1980 | 69% |
| Built 2000 or later | 13% |
| Owner-occupied | 58% |
| Median value, owner-occupied | $150,600 |
| Single-family detached | 61% |
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 |
|---|---|---|---|
| Chase County, KS | 26 mi | 71% | 10% |
| Coffey County, KS | 28 mi | 77% | 76% |
| Osage County, KS | 28 mi | 77% | 69% |
| Morris County, KS | 31 mi | 82% | 10% |
| Wabaunsee County, KS | 35 mi | 73% | 27% |
| Greenwood County, KS | 40 mi | 78% | 39% |
| Woodson County, KS | 45 mi | 73% | 72% |
| Shawnee County, KS | 46 mi | 65% | 59% |
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