Knox County, Nebraska
Shrink-swell clay limits houses without basements on 16% of Knox County's mapped land, a higher share than 65% of US counties. A shallow water table limits basements on 6%.
80.1% of the county is in drought on the October 13, 2026 Drought Monitor map. FEMA's flood data list 12 flood losses here since 2016. 69% of homes were built before 1980, against 50% nationally; the median home dates from 1967.
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 Knox County
| Expansive clay (limits slab homes) | 16.2% |
| High water table (limits basements) | 6.5% |
| Septic fields very limited | 77.3% |
| Clay swell (LEP, by area) | 4.0% |
| High-swell land (LEP 6%+) | 14.2% |
| Mapped soil | 728,679 acres |
| Soil series | Share here | Series nationally: expansive clay |
|---|---|---|
| Crofton | 15% | n/a |
| Thurman | 9% | n/a |
| Moody | 7% | 2% |
| Nora | 7% | n/a |
| Bazile | 7% | n/a |
| Alcester | 5% | n/a |
How we count · survey areas NE107 (2025-09-08)
What the numbers mean here
Clay swell averages a linear extensibility of 4.0% by land area here, and 14% of the land reaches USDA's high class (6% or more). Clay like that swells when wet and shrinks when dry, under 16% of the mapped land.
Clay shrinks as it dries: 80.1% of the county is in drought on the latest map, and 16% of Knox County's mapped land has shrink-swell clay.
Rain over the 12 months to August 2026: 16.44 in, 10.93 in below the 1991-2020 average year of 27.37 in.
USDA rates 77% of the land very limited for septic absorption fields.
Drought
80.1% of the county is in drought (D1 or worse) on the October 13, 2026 map. Part of the county was in drought in 52 of the last 52 weeks; the most was 100% of its area, in 44 weeks, most recently on the September 1, 2026 map.
| Category, October 13, 2026 | Share of county |
|---|---|
| D0 abnormally dry or worse | 100% |
| D1 moderate drought or worse | 80.1% |
| D2 severe or worse | 0% |
| D3 extreme or worse | 0% |
| D4 exceptional | 0% |
Flood losses since 2016
12 flood losses since 2016, $160,637 paid. The worst year was 2019, with 10.
| Year | Flood losses |
|---|---|
| 2016 | 0 |
| 2017 | 0 |
| 2018 | 1 |
| 2019 | 10 |
| 2020 | 0 |
| 2021 | 0 |
| 2022 | 0 |
| 2023 | 0 |
| 2024 | 1 |
| 2025 | 0 |
| 2026 to date | 0 |
Rain
| Average year, 1991-2020 | 27.37 in |
| 12 months to August 2026 | 16.44 in (-10.93) |
| 2025 | 27.35 in (-0.02) |
| Wettest year since 1895 | 1944: 35.83 in |
| Driest year since 1895 | 2012: 13.04 in |
| Days with 1 inch or more, normal at BLOOMFIELD (13 mi away) | 6.6 |
Homes
| Housing units | 4,521 |
| Median year built | 1967 |
| Built before 1980 | 69% |
| Built 2000 or later | 13% |
| Owner-occupied | 78% |
| Median value, owner-occupied | $127,700 |
| Single-family detached | 85% |
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 |
|---|---|---|---|
| Bon Homme County, SD | 24 mi | 27% | 26% |
| Pierce County, NE | 29 mi | 2% | 17% |
| Antelope County, NE | 32 mi | 1% | 8% |
| Cedar County, NE | 32 mi | 2% | 7% |
| Yankton County, SD | 36 mi | 21% | 30% |
| Holt County, NE | 47 mi | 2% | 41% |
| Boyd County, NE | 48 mi | 52% | 13% |
| Wayne County, NE | 49 mi | 6% | 11% |
Sources: USDA SSURGO (September 8, 2025) · US Drought Monitor (October 13, 2026) · FEMA NFIP v3 (September 9, 2026) · NOAA (August 2026) · Census ACS 2020-2024. Methods · Data status