Woodbury County, Iowa
A shallow water table limits basements on 25% of Woodbury County's mapped land. Shrink-swell clay limits houses without basements on 16%.
None of the county is in drought on the October 13, 2026 Drought Monitor map. FEMA's flood data list 45 flood losses here since 2016, 67% of them in buildings with basements. 74% of homes were built before 1980, against 50% nationally; the median home dates from 1959.
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 Woodbury County
| Expansive clay (limits slab homes) | 16.1% |
| High water table (limits basements) | 25.3% |
| Septic fields very limited | 52.9% |
| Clay swell (LEP, by area) | 4.1% |
| High-swell land (LEP 6%+) | 15.8% |
| Urban land, not rated | 1.3% |
| Mapped soil | 561,500 acres |
| Soil series | Share here | Series nationally: high water table |
|---|---|---|
| Ida | 25% | n/a |
| Monona | 19% | n/a |
| Napier | 10% | n/a |
| Judson | 5% | n/a |
| Luton | 4% | n/a |
| Rawles | 4% | n/a |
How we count · survey areas IA193 (2025-09-09)
What the numbers mean here
Clay swell averages a linear extensibility of 4.1% by land area here, and 16% 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.
On 25% of Woodbury 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: 23.07 in, 7.27 in below the 1991-2020 average year of 30.34 in.
USDA rates 53% 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 28 of the last 52 weeks; the most was 100% of its area, in 5 weeks, most recently on the September 1, 2026 map.
| Category, October 13, 2026 | Share of county |
|---|---|
| D0 abnormally dry or worse | 0.6% |
| D1 moderate drought or worse | 0% |
| D2 severe or worse | 0% |
| D3 extreme or worse | 0% |
| D4 exceptional | 0% |
Flood losses since 2016
45 flood losses since 2016, $986,887 paid. The worst year was 2024, with 21. Foundations of the buildings, where recorded: 67% basements, 21% slabs, 9% crawl spaces, 3% elevated. Median water depth outside the building: 18 in.
| Year | Flood losses |
|---|---|
| 2016 | 1 |
| 2017 | 0 |
| 2018 | 1 |
| 2019 | 21 |
| 2020 | 0 |
| 2021 | 0 |
| 2022 | 0 |
| 2023 | 1 |
| 2024 | 21 |
| 2025 | 0 |
| 2026 to date | 0 |
Rain
| Average year, 1991-2020 | 30.34 in |
| 12 months to August 2026 | 23.07 in (-7.27) |
| 2025 | 30.93 in (+0.59) |
| Wettest year since 1895 | 1903: 41.11 in |
| Driest year since 1895 | 1976: 15.28 in |
| Days with 1 inch or more, normal at SIOUX CITY GATEWAY AP (17 mi away) | 7.3 |
Homes
| Housing units | 43,388 |
| Median year built | 1959 |
| Built before 1980 | 74% |
| Built 2000 or later | 12% |
| Owner-occupied | 68% |
| Median value, owner-occupied | $183,200 |
| Single-family detached | 72% |
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 |
|---|---|---|---|
| Monona County, IA | 24 mi | 30% | 46% |
| Plymouth County, IA | 25 mi | 8% | 27% |
| Dakota County, NE | 26 mi | 13% | 22% |
| Ida County, IA | 28 mi | 23% | 27% |
| Thurston County, NE | 30 mi | 4% | 14% |
| Cherokee County, IA | 32 mi | 27% | 36% |
| Burt County, NE | 40 mi | 32% | 30% |
| Dixon County, NE | 41 mi | 2% | 9% |
Sources: USDA SSURGO (September 9, 2025) · US Drought Monitor (October 13, 2026) · FEMA NFIP v3 (September 9, 2026) · NOAA (August 2026) · Census ACS 2020-2024. Methods · Data status