Polk County, Nebraska
Shrink-swell clay limits houses without basements on 57% of Polk County's mapped land, a higher share than 93% of US counties. A shallow water table limits basements on 18%.
None of the county is in drought on the October 13, 2026 Drought Monitor map. FEMA's flood data list 2 flood losses here since 2016. 77% of homes were built before 1980, against 50% nationally; the median home dates from 1960.
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 Polk County
| Expansive clay (limits slab homes) | 57.2% |
| High water table (limits basements) | 17.9% |
| Septic fields very limited | 84.9% |
| Clay swell (LEP, by area) | 5.6% |
| High-swell land (LEP 6%+) | 57.2% |
| Mapped soil | 280,979 acres |
How we count · survey areas NE143 (2025-09-08)
What the numbers mean here
Clay swell averages a linear extensibility of 5.6% by land area here, and 57% of the land reaches USDA's high class (6% or more). Clay like that swells when wet and shrinks when dry, under 57% of the mapped land.
On 18% of Polk 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: 22.97 in, 5.54 in below the 1991-2020 average year of 28.51 in.
USDA rates 85% 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 38 of the last 52 weeks; the most was 100% of its area, in 13 weeks, most recently on the May 26, 2026 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
2 flood losses since 2016, $20,000 paid. The worst year was 2020, with 1.
| Year | Flood losses |
|---|---|
| 2016 | 0 |
| 2017 | 0 |
| 2018 | 0 |
| 2019 | 1 |
| 2020 | 1 |
| 2021 | 0 |
| 2022 | 0 |
| 2023 | 0 |
| 2024 | 0 |
| 2025 | 0 |
| 2026 to date | 0 |
Rain
| Average year, 1991-2020 | 28.51 in |
| 12 months to August 2026 | 22.97 in (-5.54) |
| 2025 | 25.35 in (-3.16) |
| Wettest year since 1895 | 1903: 41.40 in |
| Driest year since 1895 | 1936: 13.66 in |
| Days with 1 inch or more, normal at OSCEOLA (1 mi away) | 6.7 |
Homes
| Housing units | 2,531 |
| Median year built | 1960 |
| Built before 1980 | 77% |
| Built 2000 or later | 10% |
| Owner-occupied | 79% |
| Median value, owner-occupied | $189,900 |
| Single-family detached | 87% |
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 |
|---|---|---|---|
| York County, NE | 22 mi | 83% | 12% |
| Butler County, NE | 23 mi | 57% | 21% |
| Merrick County, NE | 24 mi | 3% | 53% |
| Nance County, NE | 26 mi | 6% | 14% |
| Platte County, NE | 27 mi | 11% | 13% |
| Seward County, NE | 31 mi | 63% | 19% |
| Hamilton County, NE | 32 mi | 78% | 11% |
| Colfax County, NE | 37 mi | 10% | 20% |
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