Harrison County, Iowa
A shallow water table limits basements on 30% of Harrison County's mapped land. Shrink-swell clay limits houses without basements on 17%.
None of the county is in drought on the October 13, 2026 Drought Monitor map. FEMA's flood data list 23 flood losses here since 2016. 72% of homes were built before 1980, against 50% nationally; the median home dates from 1954.
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 Harrison County
| Expansive clay (limits slab homes) | 17.2% |
| High water table (limits basements) | 30.4% |
| Septic fields very limited | 55.6% |
| Clay swell (LEP, by area) | 3.9% |
| High-swell land (LEP 6%+) | 17.1% |
| Mapped soil | 448,500 acres |
| Soil series | Share here | Series nationally: high water table |
|---|---|---|
| Monona | 26% | n/a |
| Napier | 17% | n/a |
| Ida | 17% | n/a |
| Luton | 7% | n/a |
| Albaton | 4% | n/a |
| Kennebec | 3% | n/a |
How we count · survey areas IA085 (2025-09-08)
What the numbers mean here
Clay swell averages a linear extensibility of 3.9% by land area here, and 17% of the land reaches USDA's high class (6% or more). Clay like that swells when wet and shrinks when dry, under 17% of the mapped land.
On 30% of Harrison 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: 26.29 in, 6.27 in below the 1991-2020 average year of 32.56 in.
USDA rates 56% 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 15 of the last 52 weeks; the most was 100% 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
23 flood losses since 2016, $904,611 paid. The worst year was 2019, with 21.
| Year | Flood losses |
|---|---|
| 2016 | 0 |
| 2017 | 0 |
| 2018 | 1 |
| 2019 | 21 |
| 2020 | 0 |
| 2021 | 0 |
| 2022 | 0 |
| 2023 | 0 |
| 2024 | 1 |
| 2025 | 0 |
| 2026 to date | 0 |
Rain
| Average year, 1991-2020 | 32.56 in |
| 12 months to August 2026 | 26.29 in (-6.27) |
| 2025 | 34.58 in (+2.02) |
| Wettest year since 1895 | 2015: 43.70 in |
| Driest year since 1895 | 1936: 16.35 in |
| Days with 1 inch or more, normal at LOGAN (4 mi away) | 8.2 |
Homes
| Housing units | 6,698 |
| Median year built | 1954 |
| Built before 1980 | 72% |
| Built 2000 or later | 14% |
| Owner-occupied | 77% |
| Median value, owner-occupied | $176,000 |
| Single-family detached | 85% |
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 |
|---|---|---|---|
| Washington County, NE | 23 mi | 20% | 16% |
| Monona County, IA | 26 mi | 30% | 46% |
| Shelby County, IA | 27 mi | 21% | 21% |
| Pottawattamie County, IA | 28 mi | 14% | 25% |
| Burt County, NE | 29 mi | 32% | 30% |
| Douglas County, NE | 32 mi | 3% | 19% |
| Crawford County, IA | 33 mi | 12% | 15% |
| Sarpy County, NE | 42 mi | 7% | 15% |
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