DeKalb County, Missouri
A shallow water table limits basements on 83% of DeKalb County's mapped land, a higher share than 91% of US counties. Shrink-swell clay limits houses without basements on 78%.
None of the county is in drought on the October 13, 2026 Drought Monitor map. FEMA's flood data list no flood losses here since 2016. 48% of homes were built before 1980, against 50% nationally; the median home dates from 1982.
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 DeKalb County
| Expansive clay (limits slab homes) | 78.3% |
| High water table (limits basements) | 83.3% |
| Septic fields very limited | 99.3% |
| Clay swell (LEP, by area) | 7.6% |
| High-swell land (LEP 6%+) | 66.8% |
| Mapped soil | 272,064 acres |
| Soil series | Share here | Series nationally: high water table |
|---|---|---|
| Lamoni | 26% | n/a |
| Zook | 17% | n/a |
| Lagonda | 12% | n/a |
| Shelby | 11% | n/a |
| Grundy | 9% | n/a |
| Sharpsburg | 3% | 93% |
How we count · survey areas MO063 (2025-09-02)
What the numbers mean here
Clay swell averages a linear extensibility of 7.6% 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 78% of the mapped land.
On 83% of DeKalb 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: 36.84 in, 2.18 in below the 1991-2020 average year of 39.02 in.
USDA rates 99% 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 7 of the last 52 weeks; the most was 72% of its area, in 4 weeks, most recently on the October 14, 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
FEMA's flood data list no flood losses in DeKalb County since 2016.
Rain
| Average year, 1991-2020 | 39.02 in |
| 12 months to August 2026 | 36.84 in (-2.18) |
| 2025 | 33.40 in (-5.62) |
| Wettest year since 1895 | 1993: 57.20 in |
| Driest year since 1895 | 1988: 19.58 in |
| Days with 1 inch or more, normal at AMITY 4 NE (2 mi away) | 11.2 |
Homes
| Housing units | 4,270 |
| Median year built | 1982 |
| Built before 1980 | 48% |
| Built 2000 or later | 23% |
| Owner-occupied | 71% |
| Median value, owner-occupied | $169,200 |
| Single-family detached | 72% |
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 |
|---|---|---|---|
| Clinton County, MO | 20 mi | 78% | 77% |
| Gentry County, MO | 22 mi | 68% | 71% |
| Andrew County, MO | 22 mi | 48% | 58% |
| Daviess County, MO | 24 mi | 79% | 87% |
| Buchanan County, MO | 27 mi | 28% | 40% |
| Caldwell County, MO | 28 mi | 79% | 96% |
| Harrison County, MO | 38 mi | 66% | 68% |
| Doniphan County, KS | 40 mi | 27% | 15% |
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