Fulton County, Illinois
A shallow water table limits basements on 38% of Fulton County's mapped land, a higher share than 56% of US counties. Shrink-swell clay limits houses without basements on 24%.
None of the county is in drought on the October 13, 2026 Drought Monitor map. FEMA's flood data list 4 flood losses here since 2016. 79% of homes were built before 1980, against 50% nationally; the median home dates from 1960.
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 Fulton County
| Expansive clay (limits slab homes) | 24.3% |
| High water table (limits basements) | 37.5% |
| Septic fields very limited | 59.6% |
| Clay swell (LEP, by area) | 4.3% |
| High-swell land (LEP 6%+) | 18.4% |
| Mapped soil | 565,000 acres |
How we count · survey areas IL057 (2025-08-31)
What the numbers mean here
Clay swell averages a linear extensibility of 4.3% by land area here, and 18% of the land reaches USDA's high class (6% or more). Clay like that swells when wet and shrinks when dry, under 24% of the mapped land.
On 38% of Fulton 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: 40.52 in, 1.56 in above the 1991-2020 average year of 38.96 in.
USDA rates 60% 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 24 of the last 52 weeks; the most was 100% of its area, in 21 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
4 flood losses since 2016, $87,233 paid. The worst year was 2019, with 3.
| Year | Flood losses |
|---|---|
| 2016 | 0 |
| 2017 | 0 |
| 2018 | 0 |
| 2019 | 3 |
| 2020 | 1 |
| 2021 | 0 |
| 2022 | 0 |
| 2023 | 0 |
| 2024 | 0 |
| 2025 | 0 |
| 2026 to date | 0 |
Rain
| Average year, 1991-2020 | 38.96 in |
| 12 months to August 2026 | 40.52 in (+1.56) |
| 2025 | 26.43 in (-12.53) |
| Wettest year since 1895 | 2009: 58.06 in |
| Driest year since 1895 | 1901: 20.74 in |
| Days with 1 inch or more, normal at HAVANA (13 mi away) | 11.1 |
Homes
| Housing units | 15,848 |
| Median year built | 1960 |
| Built before 1980 | 79% |
| Built 2000 or later | 10% |
| Owner-occupied | 77% |
| Median value, owner-occupied | $107,200 |
| Single-family detached | 86% |
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 |
|---|---|---|---|
| Mason County, IL | 22 mi | 3% | 42% |
| McDonough County, IL | 25 mi | 63% | 70% |
| Schuyler County, IL | 30 mi | 31% | 46% |
| Peoria County, IL | 32 mi | 29% | 37% |
| Knox County, IL | 32 mi | 41% | 41% |
| Cass County, IL | 34 mi | 13% | 45% |
| Warren County, IL | 34 mi | 35% | 54% |
| Tazewell County, IL | 36 mi | 33% | 53% |
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