Gallatin County, Illinois
A shallow water table limits basements on 67% of Gallatin County's mapped land, a higher share than 79% of US counties. Shrink-swell clay limits houses without basements on 31%.
None of the county is in drought on the October 13, 2026 Drought Monitor map. FEMA's flood data list 1 flood losses here since 2016. 72% of homes were built before 1980, against 50% nationally; the median home dates from 1969.
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 Gallatin County
| Expansive clay (limits slab homes) | 30.8% |
| High water table (limits basements) | 67.2% |
| Septic fields very limited | 86.8% |
| Clay swell (LEP, by area) | 4.3% |
| High-swell land (LEP 6%+) | 20.1% |
| Mapped soil | 209,985 acres |
| Soil series | Share here | Series nationally: high water table |
|---|---|---|
| Reesville | 8% | n/a |
| Patton | 7% | n/a |
| Alford | 6% | n/a |
| Hosmer | 6% | over 99% |
| Karnak | 5% | n/a |
| Uniontown | 4% | n/a |
How we count · survey areas IL059 (2025-08-31)
What the numbers mean here
Clay swell averages a linear extensibility of 4.3% by land area here, and 20% of the land reaches USDA's high class (6% or more). Clay like that swells when wet and shrinks when dry, under 31% of the mapped land.
On 67% of Gallatin 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: 35.07 in, 12.27 in below the 1991-2020 average year of 47.34 in.
USDA rates 87% 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 14 of the last 52 weeks; the most was 100% of its area, in 2 weeks, most recently on the April 21, 2026 map.
| Category, October 13, 2026 | Share of county |
|---|---|
| D0 abnormally dry or worse | 100% |
| D1 moderate drought or worse | 0% |
| D2 severe or worse | 0% |
| D3 extreme or worse | 0% |
| D4 exceptional | 0% |
Flood losses since 2016
1 flood losses since 2016, $0 paid. The worst year was 2026, with 1.
| Year | Flood losses |
|---|---|
| 2016 | 0 |
| 2017 | 0 |
| 2018 | 0 |
| 2019 | 0 |
| 2020 | 0 |
| 2021 | 0 |
| 2022 | 0 |
| 2023 | 0 |
| 2024 | 0 |
| 2025 | 0 |
| 2026 to date | 1 |
Rain
| Average year, 1991-2020 | 47.34 in |
| 12 months to August 2026 | 35.07 in (-12.27) |
| 2025 | 41.91 in (-5.43) |
| Wettest year since 1895 | 2011: 69.00 in |
| Driest year since 1895 | 1963: 27.45 in |
| Days with 1 inch or more, normal at JT MYERS LOCKS & DAM (13 mi away) | 14.1 |
Homes
| Housing units | 2,505 |
| Median year built | 1969 |
| Built before 1980 | 72% |
| Built 2000 or later | 9% |
| Owner-occupied | 77% |
| Median value, owner-occupied | $82,900 |
| Single-family detached | 73% |
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 |
|---|---|---|---|
| Union County, KY | 17 mi | 4% | 53% |
| Saline County, IL | 17 mi | 20% | 86% |
| Hardin County, IL | 17 mi | 1% | 41% |
| White County, IL | 22 mi | 12% | 75% |
| Posey County, IN | 27 mi | 4% | 54% |
| Hamilton County, IL | 27 mi | 23% | 95% |
| Crittenden County, KY | 29 mi | 1% | 54% |
| Pope County, IL | 30 mi | 2% | 67% |
Sources: USDA SSURGO (August 31, 2025) · US Drought Monitor (October 13, 2026) · FEMA NFIP v3 (September 9, 2026) · NOAA (August 2026) · Census ACS 2020-2024. Methods · Data status