Clinton County, Iowa
A shallow water table limits basements on 44% of Clinton County's mapped land, a higher share than 62% of US counties. Shrink-swell clay limits houses without basements on 15%.
None of the county is in drought on the October 13, 2026 Drought Monitor map. FEMA's flood data list 31 flood losses here since 2016, 67% of them in buildings with basements. 77% of homes were built before 1980, against 50% nationally; the median home dates from 1957.
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 Clinton County
| Expansive clay (limits slab homes) | 14.7% |
| High water table (limits basements) | 44.4% |
| Septic fields very limited | 95.8% |
| Clay swell (LEP, by area) | 3.9% |
| High-swell land (LEP 6%+) | 7.0% |
| Mapped soil | 454,100 acres |
How we count · survey areas IA045 (2025-09-09)
What the numbers mean here
On 44% of Clinton 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: 33.52 in, 4.26 in below the 1991-2020 average year of 37.78 in.
USDA rates 96% 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 20 of the last 52 weeks; the most was 100% of its area, in 5 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
31 flood losses since 2016, $304,478 paid. The worst year was 2019, with 11. Foundations of the buildings, where recorded: 67% basements, 24% slabs, 10% elevated.
| Year | Flood losses |
|---|---|
| 2016 | 1 |
| 2017 | 10 |
| 2018 | 1 |
| 2019 | 11 |
| 2020 | 0 |
| 2021 | 1 |
| 2022 | 1 |
| 2023 | 5 |
| 2024 | 1 |
| 2025 | 0 |
| 2026 to date | 0 |
Rain
| Average year, 1991-2020 | 37.78 in |
| 12 months to August 2026 | 33.52 in (-4.26) |
| 2025 | 32.60 in (-5.18) |
| Wettest year since 1895 | 1973: 50.62 in |
| Driest year since 1895 | 1988: 20.73 in |
| Days with 1 inch or more, normal at DE WITT (6 mi away) | 9.4 |
Homes
| Housing units | 21,581 |
| Median year built | 1957 |
| Built before 1980 | 77% |
| Built 2000 or later | 12% |
| Owner-occupied | 75% |
| Median value, owner-occupied | $160,600 |
| Single-family detached | 78% |
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 |
|---|---|---|---|
| Scott County, IA | 18 mi | 36% | 41% |
| Jackson County, IA | 19 mi | 1% | 18% |
| Rock Island County, IL | 30 mi | 6% | 32% |
| Cedar County, IA | 32 mi | 39% | 43% |
| Carroll County, IL | 34 mi | 13% | 17% |
| Whiteside County, IL | 34 mi | 2% | 40% |
| Jones County, IA | 34 mi | 12% | 38% |
| Jo Daviess County, IL | 36 mi | 17% | 20% |
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