Clay County, Iowa
A shallow water table limits basements on 77% of Clay County's mapped land, a higher share than 87% of US counties. Shrink-swell clay limits houses without basements on 32%.
None of the county is in drought on the October 13, 2026 Drought Monitor map. FEMA's flood data list 64 flood losses here since 2016, 56% of them in buildings with basements. 70% 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 Clay County
| Expansive clay (limits slab homes) | 31.7% |
| High water table (limits basements) | 77.3% |
| Septic fields very limited | 94.5% |
| Clay swell (LEP, by area) | 4.9% |
| High-swell land (LEP 6%+) | 28.0% |
| Mapped soil | 366,400 acres |
| Soil series | Share here | Series nationally: high water table |
|---|---|---|
| McCreath | 13% | n/a |
| Gillett Grove | 10% | n/a |
| Clarion | 8% | 61% |
| Everly | 5% | n/a |
| Wadena | 5% | n/a |
| Ransom | 4% | n/a |
How we count · survey areas IA041 (2025-09-08)
What the numbers mean here
Clay swell averages a linear extensibility of 4.9% by land area here, and 28% of the land reaches USDA's high class (6% or more). Clay like that swells when wet and shrinks when dry, under 32% of the mapped land.
On 77% of Clay 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: 22.19 in, 8.81 in below the 1991-2020 average year of 31.00 in.
USDA rates 94% 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 22 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% |
| D1 moderate drought or worse | 0% |
| D2 severe or worse | 0% |
| D3 extreme or worse | 0% |
| D4 exceptional | 0% |
Flood losses since 2016
64 flood losses since 2016, $5.5 million paid. The worst year was 2024, with 59. Foundations of the buildings, where recorded: 56% basements, 29% slabs, 8% crawl spaces, 7% elevated. Median water depth outside the building: 51 in.
| Year | Flood losses |
|---|---|
| 2016 | 0 |
| 2017 | 0 |
| 2018 | 5 |
| 2019 | 0 |
| 2020 | 0 |
| 2021 | 0 |
| 2022 | 0 |
| 2023 | 0 |
| 2024 | 59 |
| 2025 | 0 |
| 2026 to date | 0 |
Rain
| Average year, 1991-2020 | 31.00 in |
| 12 months to August 2026 | 22.19 in (-8.81) |
| 2025 | 30.64 in (-0.36) |
| Wettest year since 1895 | 2018: 43.06 in |
| Driest year since 1895 | 1958: 14.32 in |
| Days with 1 inch or more, normal at SPENCER 1 N (6 mi away) | 7 |
Homes
| Housing units | 8,157 |
| Median year built | 1967 |
| Built before 1980 | 70% |
| Built 2000 or later | 17% |
| Owner-occupied | 73% |
| Median value, owner-occupied | $178,600 |
| Single-family detached | 74% |
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 |
|---|---|---|---|
| Dickinson County, IA | 21 mi | 10% | 75% |
| Buena Vista County, IA | 23 mi | 22% | 83% |
| O'Brien County, IA | 24 mi | 47% | 64% |
| Palo Alto County, IA | 24 mi | 10% | 85% |
| Emmet County, IA | 32 mi | 10% | 84% |
| Osceola County, IA | 32 mi | 21% | 76% |
| Pocahontas County, IA | 34 mi | 13% | 93% |
| Cherokee County, IA | 34 mi | 27% | 36% |
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