Carroll County, Missouri
A shallow water table limits basements on 88% of Carroll County's mapped land, a higher share than 94% of US counties and the 10th highest of 115 Missouri counties. Shrink-swell clay limits houses without basements on 72%.
None of the county is in drought on the October 13, 2026 Drought Monitor map. FEMA's flood data list 40 flood losses here since 2016. 77% of homes were built before 1980, against 50% nationally; the median home dates from 1961.
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 Carroll County
| Expansive clay (limits slab homes) | 72.0% |
| High water table (limits basements) | 87.6% |
| Septic fields very limited | 95.7% |
| Clay swell (LEP, by area) | 6.7% |
| High-swell land (LEP 6%+) | 66.5% |
| Mapped soil | 448,992 acres |
| Soil series | Share here | Series nationally: high water table |
|---|---|---|
| Lagonda | 17% | n/a |
| Greenton | 8% | n/a |
| Armster | 8% | n/a |
| Bremer | 6% | n/a |
| Nodaway | 6% | n/a |
| Gosport | 6% | n/a |
How we count · survey areas MO033 (2025-09-02)
What the numbers mean here
Clay swell averages a linear extensibility of 6.7% by land area here, and 67% of the land reaches USDA's high class (6% or more). Clay like that swells when wet and shrinks when dry, under 72% of the mapped land.
On 88% of Carroll 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: 35.49 in, 4.78 in below the 1991-2020 average year of 40.27 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 6 of the last 52 weeks; the most was 67.4% of its area, in 4 weeks, most recently on the November 18, 2025 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
40 flood losses since 2016, $1.1 million paid. The worst year was 2019, with 29.
| Year | Flood losses |
|---|---|
| 2016 | 5 |
| 2017 | 0 |
| 2018 | 0 |
| 2019 | 29 |
| 2020 | 1 |
| 2021 | 4 |
| 2022 | 0 |
| 2023 | 1 |
| 2024 | 0 |
| 2025 | 0 |
| 2026 to date | 0 |
Rain
| Average year, 1991-2020 | 40.27 in |
| 12 months to August 2026 | 35.49 in (-4.78) |
| 2025 | 34.19 in (-6.08) |
| Wettest year since 1895 | 1998: 58.75 in |
| Driest year since 1895 | 1956: 21.30 in |
| Days with 1 inch or more, normal at CARROLLTON (5 mi away) | 11.1 |
Homes
| Housing units | 4,381 |
| Median year built | 1961 |
| Built before 1980 | 77% |
| Built 2000 or later | 9% |
| Owner-occupied | 72% |
| Median value, owner-occupied | $117,500 |
| 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 |
|---|---|---|---|
| Livingston County, MO | 24 mi | 76% | 98% |
| Saline County, MO | 26 mi | 44% | 69% |
| Ray County, MO | 28 mi | 71% | 84% |
| Chariton County, MO | 29 mi | 66% | 88% |
| Lafayette County, MO | 30 mi | 25% | 64% |
| Caldwell County, MO | 30 mi | 79% | 96% |
| Linn County, MO | 37 mi | 83% | 99% |
| Daviess County, MO | 45 mi | 79% | 87% |
Sources: USDA SSURGO (September 2, 2025) · US Drought Monitor (October 13, 2026) · FEMA NFIP v3 (September 9, 2026) · NOAA (August 2026) · Census ACS 2020-2024. Methods · Data status