Pottawattamie County, Iowa
A shallow water table limits basements on 25% of Pottawattamie County's mapped land. Shrink-swell clay limits houses without basements on 14%.
None of the county is in drought on the October 13, 2026 Drought Monitor map. FEMA's flood data list 89 flood losses here since 2016, 52% of them in buildings with basements. 66% 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 Pottawattamie County
| Expansive clay (limits slab homes) | 14.3% |
| High water table (limits basements) | 25.3% |
| Septic fields very limited | 69.9% |
| Clay swell (LEP, by area) | 4.1% |
| High-swell land (LEP 6%+) | 8.3% |
| Mapped soil | 613,800 acres |
| Soil series | Share here | Series nationally: high water table |
|---|---|---|
| Monona | 16% | n/a |
| Marshall | 12% | 0% |
| Ida | 11% | n/a |
| Exira | 10% | n/a |
| Napier | 9% | n/a |
| Judson | 7% | n/a |
How we count · survey areas IA155 (2025-09-09)
What the numbers mean here
On 25% of Pottawattamie 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: 27.72 in, 6.81 in below the 1991-2020 average year of 34.53 in.
USDA rates 70% 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 8 of the last 52 weeks; the most was 71.4% of its area, in 2 weeks, most recently on the August 4, 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
89 flood losses since 2016, $2.6 million paid. The worst year was 2019, with 56. Foundations of the buildings, where recorded: 52% basements, 27% slabs, 8% crawl spaces, 13% elevated. Median water depth outside the building: 12 in.
| Year | Flood losses |
|---|---|
| 2016 | 4 |
| 2017 | 1 |
| 2018 | 7 |
| 2019 | 56 |
| 2020 | 2 |
| 2021 | 1 |
| 2022 | 0 |
| 2023 | 1 |
| 2024 | 16 |
| 2025 | 1 |
| 2026 to date | 0 |
Rain
| Average year, 1991-2020 | 34.53 in |
| 12 months to August 2026 | 27.72 in (-6.81) |
| 2025 | 29.23 in (-5.30) |
| Wettest year since 1895 | 1993: 47.80 in |
| Driest year since 1895 | 1988: 20.15 in |
| Days with 1 inch or more, normal at OAKLAND (9 mi away) | 9.5 |
Homes
| Housing units | 40,083 |
| Median year built | 1967 |
| Built before 1980 | 66% |
| Built 2000 or later | 18% |
| Owner-occupied | 70% |
| Median value, owner-occupied | $195,700 |
| Single-family detached | 76% |
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 |
|---|---|---|---|
| Mills County, IA | 21 mi | 16% | 28% |
| Shelby County, IA | 26 mi | 21% | 21% |
| Harrison County, IA | 28 mi | 17% | 30% |
| Montgomery County, IA | 30 mi | 36% | 40% |
| Cass County, IA | 32 mi | 49% | 46% |
| Douglas County, NE | 32 mi | 3% | 19% |
| Sarpy County, NE | 33 mi | 7% | 15% |
| Washington County, NE | 38 mi | 20% | 16% |
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