Wapello County, Iowa
A shallow water table limits basements on 85% of Wapello County's mapped land, a higher share than 92% of US counties. Shrink-swell clay limits houses without basements on 70%.
None of the county is in drought on the October 13, 2026 Drought Monitor map. FEMA's flood data list 7 flood losses here since 2016. 76% of homes were built before 1980, against 50% nationally; the median home dates from 1958.
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 Wapello County
| Expansive clay (limits slab homes) | 70.3% |
| High water table (limits basements) | 84.8% |
| Septic fields very limited | 97.5% |
| Clay swell (LEP, by area) | 6.3% |
| High-swell land (LEP 6%+) | 64.1% |
| Mapped soil | 278,800 acres |
| Soil series | Share here | Series nationally: high water table |
|---|---|---|
| Lindley | 8% | n/a |
| Weller | 7% | n/a |
| Pershing | 7% | n/a |
| Otley | 6% | n/a |
| Nodaway | 5% | n/a |
| Keswick | 5% | n/a |
How we count · survey areas IA179 (2025-09-09)
What the numbers mean here
Clay swell averages a linear extensibility of 6.3% by land area here, and 64% of the land reaches USDA's high class (6% or more). Clay like that swells when wet and shrinks when dry, under 70% of the mapped land.
On 85% of Wapello 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: 28.94 in, 8.29 in below the 1991-2020 average year of 37.23 in.
USDA rates 97% 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 19 of the last 52 weeks; the most was 100% of its area, in 6 weeks, most recently on the March 31, 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
7 flood losses since 2016, $87,965 paid. The worst year was 2019, with 5.
| Year | Flood losses |
|---|---|
| 2016 | 0 |
| 2017 | 0 |
| 2018 | 0 |
| 2019 | 5 |
| 2020 | 0 |
| 2021 | 1 |
| 2022 | 0 |
| 2023 | 0 |
| 2024 | 1 |
| 2025 | 0 |
| 2026 to date | 0 |
Rain
| Average year, 1991-2020 | 37.23 in |
| 12 months to August 2026 | 28.94 in (-8.29) |
| 2025 | 28.18 in (-9.05) |
| Wettest year since 1895 | 2010: 53.57 in |
| Driest year since 1895 | 1910: 20.15 in |
| Days with 1 inch or more, normal at OTTUMWA INDUSTRIAL AP (6 mi away) | 9.3 |
Homes
| Housing units | 15,730 |
| Median year built | 1958 |
| Built before 1980 | 76% |
| Built 2000 or later | 9% |
| Owner-occupied | 68% |
| Median value, owner-occupied | $125,100 |
| Single-family detached | 77% |
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 |
|---|---|---|---|
| Davis County, IA | 20 mi | 74% | 80% |
| Jefferson County, IA | 23 mi | 71% | 87% |
| Mahaska County, IA | 24 mi | 71% | 88% |
| Monroe County, IA | 24 mi | 72% | 77% |
| Keokuk County, IA | 24 mi | 71% | 87% |
| Van Buren County, IA | 31 mi | 70% | 82% |
| Appanoose County, IA | 31 mi | 69% | 78% |
| Schuyler County, MO | 39 mi | 72% | 84% |
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